{"example_id": "rules_00000", "split": "rules", "task_type": "legal_moves", "fen": "1k1r3r/1p3pp1/3ppb2/1qn2P1P/3NP1Q1/pPP5/P1B5/1K1R3R b - -", "prompt": "FEN: 1k1r3r/1p3pp1/3ppb2/1qn2P1P/3NP1Q1/pPP5/P1B5/1K1R3R b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b5a4 b5a5 b5a6 b5b3 b5b4 b5b6 b5c4 b5c6 b5d3 b5d7 b5e2 b5e8 b5f1 b7b6 b8a7 b8a8 b8c7 b8c8 c5a4 c5a6 c5b3 c5d3 c5d7 c5e4 d6d5 d8c8 d8d7 d8e8 d8f8 d8g8 e6e5 e6f5 f6d4 f6e5 f6e7 f6g5 f6h4 g7g5 g7g6 h8e8 h8f8 h8g8 h8h5 h8h6 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00001", "split": "rules", "task_type": "side_piece_inventory", "fen": "1Rb1q1kr/5p2/3Q4/3p4/2pb4/p7/P1B2PP1/5NK1 w - -", "prompt": "FEN: 1Rb1q1kr/5p2/3Q4/3p4/2pb4/p7/P1B2PP1/5NK1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: f1 white knight; g1 white king; a2 white pawn; c2 white bishop; f2 white pawn; g2 white pawn; d6 white queen; b8 white rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "f1", "piece": "white knight"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "c2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "d6", "piece": "white queen"}, {"square": "b8", "piece": "white rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "f1", "piece": "white knight"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "c2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "d6", "piece": "white queen"}, {"square": "b8", "piece": "white rook"}]}}
{"example_id": "rules_00002", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1q2rk1/2p1pp1p/b5p1/p2Pb1Nn/P7/1PB5/5PPP/R2Q2K1 w - - 0 21", "prompt": "FEN: r1q2rk1/2p1pp1p/b5p1/p2Pb1Nn/P7/1PB5/5PPP/R2Q2K1 w - - 0 21\nWhat legal moves does the piece on g5 have?", "gold_answer": "g5e4 g5e6 g5f3 g5f7 g5h3 g5h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "g5", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "g5", "piece": "knight"}}
{"example_id": "rules_00003", "split": "rules", "task_type": "check_detection", "fen": "rnbq1rk1/pp3ppp/2p1pn2/3p4/1bPP4/1P2PN2/P1QN1PPP/R1B1KB1R b KQ -", "prompt": "FEN: rnbq1rk1/pp3ppp/2p1pn2/3p4/1bPP4/1P2PN2/P1QN1PPP/R1B1KB1R b KQ -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00004", "split": "rules", "task_type": "captures", "fen": "4r1k1/4qpp1/rp5p/p1pRp3/P1P5/1PQ4P/2P3P1/5RK1 b - - 2 34", "prompt": "FEN: 4r1k1/4qpp1/rp5p/p1pRp3/P1P5/1PQ4P/2P3P1/5RK1 b - - 2 34\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00005", "split": "rules", "task_type": "special_rules", "fen": "r1bqkb1r/p6p/2n1pp2/1p1p3P/2pP3p/1PP1PN2/P1QN1P1P/R3KB1R b KQkq -", "prompt": "Given FEN: r1bqkb1r/p6p/2n1pp2/1p1p3P/2pP3p/1PP1PN2/P1QN1P1P/R3KB1R b KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00006", "split": "rules", "task_type": "legality_check", "fen": "8/2r2pkp/pp2p1p1/1B2P3/2P5/6P1/3R1PKP/r7 w - - 0 31", "prompt": "FEN: 8/2r2pkp/pp2p1p1/1B2P3/2P5/6P1/3R1PKP/r7 w - - 0 31\nIs the move f2f4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f2f4", "_legality_check_reason_label": "legal", "move": "f2f4", "legality_reason_label": "legal"}}
{"example_id": "rules_00007", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rn3rk1/pp3pp1/3qp2p/3n4/2N5/8/PP1N1PPP/R2Q1RK1 b - - 5 15", "prompt": "FEN: rn3rk1/pp3pp1/3qp2p/3n4/2N5/8/PP1N1PPP/R2Q1RK1 b - - 5 15\nList pseudo-legal moves from d5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d5: d5b4 d5b6 d5c3 d5c7 d5e3 d5e7 d5f4 d5f6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_00008", "split": "rules", "task_type": "piece_legal_filter", "fen": "1r4k1/6p1/7p/rN2p3/4P3/2NP1P2/PPPK2PP/1R5R b - - 8 27", "prompt": "FEN: 1r4k1/6p1/7p/rN2p3/4P3/2NP1P2/PPPK2PP/1R5R b - - 8 27\nFor the piece on a5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a5: a5a2 a5a3 a5a4 a5a6 a5a7 a5a8 a5b5.\nLegal: a5a2 a5a3 a5a4 a5a6 a5a7 a5a8 a5b5.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_00009", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bq1rk1/pp1nbppp/2n1p3/3pP3/3P4/1P3N2/PB2BPPP/RN1QK2R w KQ -", "prompt": "FEN: r1bq1rk1/pp1nbppp/2n1p3/3pP3/3P4/1P3N2/PB2BPPP/RN1QK2R w KQ -\nFor move a2a3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a2a3.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a2a3", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a2a3", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00010", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1r1q1rk1/Q4ppp/8/4p1b1/Nn1p2nP/1B1P1P2/PPP1K1P1/R6R w - - 0 16", "prompt": "FEN: 1r1q1rk1/Q4ppp/8/4p1b1/Nn1p2nP/1B1P1P2/PPP1K1P1/R6R w - - 0 16\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; e2 white king; g2 white pawn; b3 white bishop; d3 white pawn; f3 white pawn; a4 white knight; h4 white pawn; a7 white queen.\nMoves by piece:\na1 white rook: a1b1 a1c1 a1d1 a1e1 a1f1 a1g1\nh1 white rook: h1b1 h1c1 h1d1 h1e1 h1f1 h1g1 h1h2 h1h3\na2 white pawn: a2a3\nb2 white pawn: no legal moves\nc2 white pawn: c2c3 c2c4\ne2 white king: e2d1 e2e1 e2f1\ng2 white pawn: g2g3\nb3 white bishop: b3c4 b3d5 b3e6 b3f7\nd3 white pawn: no legal moves\nf3 white pawn: f3f4 f3g4\na4 white knight: a4b6 a4c3 a4c5\nh4 white pawn: h4g5 h4h5\na7 white queen: a7a5 a7a6 a7a8 a7b6 a7b7 a7b8 a7c5 a7c7 a7d4 a7d7 a7e7 a7f7\nAll legal moves: a1b1 a1c1 a1d1 a1e1 a1f1 a1g1 a2a3 a4b6 a4c3 a4c5 a7a5 a7a6 a7a8 a7b6 a7b7 a7b8 a7c5 a7c7 a7d4 a7d7 a7e7 a7f7 b3c4 b3d5 b3e6 b3f7 c2c3 c2c4 e2d1 e2e1 e2f1 f3f4 f3g4 g2g3 h1b1 h1c1 h1d1 h1e1 h1f1 h1g1 h1h2 h1h3 h4g5 h4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1", "a1c1", "a1d1", "a1e1", "a1f1", "a1g1"], "h1": ["h1b1", "h1c1", "h1d1", "h1e1", "h1f1", "h1g1", "h1h2", "h1h3"], "a2": ["a2a3"], "b2": [], "c2": ["c2c3", "c2c4"], "e2": ["e2d1", "e2e1", "e2f1"], "g2": ["g2g3"], "b3": ["b3c4", "b3d5", "b3e6", "b3f7"], "d3": [], "f3": ["f3f4", "f3g4"], "a4": ["a4b6", "a4c3", "a4c5"], "h4": ["h4g5", "h4h5"], "a7": ["a7a5", "a7a6", "a7a8", "a7b6", "a7b7", "a7b8", "a7c5", "a7c7", "a7d4", "a7d7", "a7e7", "a7f7"]}, "_legal_moves_by_piece_moves": "a1b1 a1c1 a1d1 a1e1 a1f1 a1g1 a2a3 a4b6 a4c3 a4c5 a7a5 a7a6 a7a8 a7b6 a7b7 a7b8 a7c5 a7c7 a7d4 a7d7 a7e7 a7f7 b3c4 b3d5 b3e6 b3f7 c2c3 c2c4 e2d1 e2e1 e2f1 f3f4 f3g4 g2g3 h1b1 h1c1 h1d1 h1e1 h1f1 h1g1 h1h2 h1h3 h4g5 h4h5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1", "a1c1", "a1d1", "a1e1", "a1f1", "a1g1"], "h1": ["h1b1", "h1c1", "h1d1", "h1e1", "h1f1", "h1g1", "h1h2", "h1h3"], "a2": ["a2a3"], "b2": [], "c2": ["c2c3", "c2c4"], "e2": ["e2d1", "e2e1", "e2f1"], "g2": ["g2g3"], "b3": ["b3c4", "b3d5", "b3e6", "b3f7"], "d3": [], "f3": ["f3f4", "f3g4"], "a4": ["a4b6", "a4c3", "a4c5"], "h4": ["h4g5", "h4h5"], "a7": ["a7a5", "a7a6", "a7a8", "a7b6", "a7b7", "a7b8", "a7c5", "a7c7", "a7d4", "a7d7", "a7e7", "a7f7"]}, "legal_moves": "a1b1 a1c1 a1d1 a1e1 a1f1 a1g1 a2a3 a4b6 a4c3 a4c5 a7a5 a7a6 a7a8 a7b6 a7b7 a7b8 a7c5 a7c7 a7d4 a7d7 a7e7 a7f7 b3c4 b3d5 b3e6 b3f7 c2c3 c2c4 e2d1 e2e1 e2f1 f3f4 f3g4 g2g3 h1b1 h1c1 h1d1 h1e1 h1f1 h1g1 h1h2 h1h3 h4g5 h4h5"}}
{"example_id": "rules_00011", "split": "rules", "task_type": "ray_walk", "fen": "r2r2k1/6p1/1R1p3p/p1pP2P1/P1P2p2/2q1pP1P/4Q3/5NK1 w - - 0 27", "prompt": "FEN: r2r2k1/6p1/1R1p3p/p1pP2P1/P1P2p2/2q1pP1P/4Q3/5NK1 w - - 0 27\nWalk each ray for the slider on e2: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e2 white queen.\nRay N: e3 black pawn: capture (stop, included).\nRay NE: f3 white pawn: own piece (stop, excluded).\nRay E: f2 empty; g2 empty; h2 empty; edge.\nRay SE: f1 white knight: own piece (stop, excluded).\nRay S: e1 empty; edge.\nRay SW: d1 empty; edge.\nRay W: d2 empty; c2 empty; b2 empty; a2 empty; edge.\nRay NW: d3 empty; c4 white pawn: own piece (stop, excluded).\nMoves from rays: e2a2 e2b2 e2c2 e2d1 e2d2 e2d3 e2e1 e2e3 e2f2 e2g2 e2h2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "e2", "diagnostic": true, "hard_gate": false, "source_square": "e2"}}
{"example_id": "rules_00012", "split": "rules", "task_type": "legal_moves", "fen": "1r4k1/3b1pb1/p5p1/3P2N1/5Ppq/4B1N1/3Q2PP/2R3K1 b - -", "prompt": "FEN: 1r4k1/3b1pb1/p5p1/3P2N1/5Ppq/4B1N1/3Q2PP/2R3K1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 b8a8 b8b1 b8b2 b8b3 b8b4 b8b5 b8b6 b8b7 b8c8 b8d8 b8e8 b8f8 d7a4 d7b5 d7c6 d7c8 d7e6 d7e8 d7f5 f7f5 f7f6 g7a1 g7b2 g7c3 g7d4 g7e5 g7f6 g7f8 g7h6 g7h8 g8f8 g8h8 h4g3 h4g5 h4h2 h4h3 h4h5 h4h6 h4h7 h4h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00013", "split": "rules", "task_type": "legal_moves", "fen": "r1bk3r/ppp2ppp/1bp5/8/3Np3/2PB4/PP4PP/RNB1K1R1 b Q -", "prompt": "FEN: r1bk3r/ppp2ppp/1bp5/8/3Np3/2PB4/PP4PP/RNB1K1R1 b Q -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b6a5 b6c5 b6d4 c6c5 c8d7 c8e6 c8f5 c8g4 c8h3 d8d7 d8e7 d8e8 e4d3 e4e3 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00014", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2qr1k1/pb3pp1/7p/2ppb2N/5Q2/2PB4/PP3PPP/R4RK1 w - -", "prompt": "FEN: r2qr1k1/pb3pp1/7p/2ppb2N/5Q2/2PB4/PP3PPP/R4RK1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white pawn; d3 white bishop; f4 white queen; h5 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "f4", "piece": "white queen"}, {"square": "h5", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "f4", "piece": "white queen"}, {"square": "h5", "piece": "white knight"}]}}
{"example_id": "rules_00015", "split": "rules", "task_type": "piece_legal_moves", "fen": "R7/2q2k2/8/8/p6P/5P2/P5PK/8 w - - 6 42", "prompt": "FEN: R7/2q2k2/8/8/p6P/5P2/P5PK/8 w - - 6 42\nWhat legal moves does the piece on h2 have?", "gold_answer": "h2g1 h2h1 h2h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h2", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "h2", "piece": "king"}}
{"example_id": "rules_00016", "split": "rules", "task_type": "check_detection", "fen": "rn1q1rk1/pbp2ppp/1p1b1n2/3p4/3P4/P1NBPN2/1P3PPP/R1BQ1RK1 w - -", "prompt": "FEN: rn1q1rk1/pbp2ppp/1p1b1n2/3p4/3P4/P1NBPN2/1P3PPP/R1BQ1RK1 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00017", "split": "rules", "task_type": "captures", "fen": "r2qr1k1/3n1pbp/p2p1np1/2pPp3/2B1P3/1P3N2/PBQ2PPP/R4RK1 w - e6 0 15", "prompt": "FEN: r2qr1k1/3n1pbp/p2p1np1/2pPp3/2B1P3/1P3N2/PBQ2PPP/R4RK1 w - e6 0 15\nList all capture moves available.", "gold_answer": "b2e5 c4a6 d5e6 f3e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00018", "split": "rules", "task_type": "special_rules", "fen": "1k6/p2K4/P1N5/8/6p1/8/8/8 b - -", "prompt": "Given FEN: 1k6/p2K4/P1N5/8/6p1/8/8/8 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00019", "split": "rules", "task_type": "legality_check", "fen": "R7/5kp1/2r2p1p/4p3/4P3/7P/2p2PP1/5K2 w - - 4 37", "prompt": "FEN: R7/5kp1/2r2p1p/4p3/4P3/7P/2p2PP1/5K2 w - - 4 37\nIs the move a8d8 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "a8d8", "_legality_check_reason_label": "legal", "move": "a8d8", "legality_reason_label": "legal"}}
{"example_id": "rules_00020", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/8/6p1/3k1p1p/KP3P1P/6P1/8/8 w - - 1 48", "prompt": "FEN: 8/8/6p1/3k1p1p/KP3P1P/6P1/8/8 w - - 1 48\nList pseudo-legal moves from g3.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g3: g3g4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g3", "diagnostic": true, "hard_gate": false, "source_square": "g3"}}
{"example_id": "rules_00021", "split": "rules", "task_type": "piece_legal_filter", "fen": "2r1r1k1/1b1nbpp1/pp2pn1p/8/2q5/P1P1PPPP/RB1QK1BR/1N4N1 w - - 0 19", "prompt": "FEN: 2r1r1k1/1b1nbpp1/pp2pn1p/8/2q5/P1P1PPPP/RB1QK1BR/1N4N1 w - - 0 19\nFor the piece on a2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a2: a2a1.\nLegal: none.\nRejected: a2a1 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a2", "diagnostic": true, "hard_gate": false, "source_square": "a2"}}
{"example_id": "rules_00022", "split": "rules", "task_type": "king_safety_filter", "fen": "8/8/8/2K5/5p2/8/3k4/4R3 w - -", "prompt": "FEN: 8/8/8/2K5/5p2/8/3k4/4R3 w - -\nFor move c5b4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c5b4.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "c5b4", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "c5b4", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00023", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/8/p1p5/4k1p1/PP3pP1/4pK2/2Rr4/8 w - - 3 40", "prompt": "FEN: 8/8/p1p5/4k1p1/PP3pP1/4pK2/2Rr4/8 w - - 3 40\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c2 white rook; f3 white king; a4 white pawn; b4 white pawn; g4 white pawn.\nMoves by piece:\nc2 white rook: c2a2 c2b2 c2c1 c2c3 c2c4 c2c5 c2c6 c2d2\nf3 white king: no legal moves\na4 white pawn: a4a5\nb4 white pawn: b4b5\ng4 white pawn: no legal moves\nAll legal moves: a4a5 b4b5 c2a2 c2b2 c2c1 c2c3 c2c4 c2c5 c2c6 c2d2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c2": ["c2a2", "c2b2", "c2c1", "c2c3", "c2c4", "c2c5", "c2c6", "c2d2"], "f3": [], "a4": ["a4a5"], "b4": ["b4b5"], "g4": []}, "_legal_moves_by_piece_moves": "a4a5 b4b5 c2a2 c2b2 c2c1 c2c3 c2c4 c2c5 c2c6 c2d2", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c2": ["c2a2", "c2b2", "c2c1", "c2c3", "c2c4", "c2c5", "c2c6", "c2d2"], "f3": [], "a4": ["a4a5"], "b4": ["b4b5"], "g4": []}, "legal_moves": "a4a5 b4b5 c2a2 c2b2 c2c1 c2c3 c2c4 c2c5 c2c6 c2d2"}}
{"example_id": "rules_00024", "split": "rules", "task_type": "ray_walk", "fen": "r1b1q1k1/pp4p1/1bp1p2p/2n1Bp2/2PN4/1PQ3P1/P3PPBP/R5K1 b - - 6 22", "prompt": "FEN: r1b1q1k1/pp4p1/1bp1p2p/2n1Bp2/2PN4/1PQ3P1/P3PPBP/R5K1 b - - 6 22\nWalk each ray for the slider on b6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b6 black bishop.\nRay NE: c7 empty; d8 empty; edge.\nRay SE: c5 black knight: own piece (stop, excluded).\nRay SW: a5 empty; edge.\nRay NW: a7 black pawn: own piece (stop, excluded).\nMoves from rays: b6a5 b6c7 b6d8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "b6", "diagnostic": true, "hard_gate": false, "source_square": "b6"}}
{"example_id": "rules_00025", "split": "rules", "task_type": "legal_moves", "fen": "rnbqkb1r/1pp2ppp/p3pn2/8/2BP4/4PN2/PP3PPP/RNBQK2R b KQkq -", "prompt": "FEN: rnbqkb1r/1pp2ppp/p3pn2/8/2BP4/4PN2/PP3PPP/RNBQK2R b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 b7b5 b7b6 b8c6 b8d7 c7c5 c7c6 c8d7 d8d4 d8d5 d8d6 d8d7 d8e7 e6e5 e8d7 e8e7 f6d5 f6d7 f6e4 f6g4 f6g8 f6h5 f8a3 f8b4 f8c5 f8d6 f8e7 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00026", "split": "rules", "task_type": "legal_moves", "fen": "rn6/3b4/p1p1p3/1p2k3/8/1PP1Q3/P2K4/b4R2 b - - 6 26", "prompt": "FEN: rn6/3b4/p1p1p3/1p2k3/8/1PP1Q3/P2K4/b4R2 b - - 6 26\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: e5d5 e5d6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00027", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/5p2/6k1/6p1/4Q3/7P/7K/8 b - -", "prompt": "FEN: 8/5p2/6k1/6p1/4Q3/7P/7K/8 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: g5 black pawn; g6 black king; f7 black pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "g5", "piece": "black pawn"}, {"square": "g6", "piece": "black king"}, {"square": "f7", "piece": "black pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "g5", "piece": "black pawn"}, {"square": "g6", "piece": "black king"}, {"square": "f7", "piece": "black pawn"}]}}
{"example_id": "rules_00028", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b2kn1/p1p4r/1pN4p/3P1p2/2P4B/5RP1/P1P4P/4R1K1 b - - 1 25", "prompt": "FEN: r1b2kn1/p1p4r/1pN4p/3P1p2/2P4B/5RP1/P1P4P/4R1K1 b - - 1 25\nWhat legal moves does the piece on b6 have?", "gold_answer": "b6b5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b6", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "b6", "piece": "pawn"}}
{"example_id": "rules_00029", "split": "rules", "task_type": "check_detection", "fen": "3b4/5p2/4p3/3p1k1p/3P1Pp1/2PK2P1/6RP/6Br w - - 4 43", "prompt": "FEN: 3b4/5p2/4p3/3p1k1p/3P1Pp1/2PK2P1/6RP/6Br w - - 4 43\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00030", "split": "rules", "task_type": "captures", "fen": "1r2k2r/p1qb1ppp/3b1n2/3p4/8/2N1PB2/PP3PPP/R1BQK2R w KQk -", "prompt": "FEN: 1r2k2r/p1qb1ppp/3b1n2/3p4/8/2N1PB2/PP3PPP/R1BQK2R w KQk -\nList all capture moves available.", "gold_answer": "c3d5 d1d5 f3d5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00031", "split": "rules", "task_type": "special_rules", "fen": "r1bqkb1r/pp3ppp/2n1pn2/1Bpp4/4P3/2PP3N/PP3PPP/RNBQK2R b KQkq - 1 8", "prompt": "Given FEN: r1bqkb1r/pp3ppp/2n1pn2/1Bpp4/4P3/2PP3N/PP3PPP/RNBQK2R b KQkq - 1 8\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00032", "split": "rules", "task_type": "legality_check", "fen": "rn1qk2r/p1pbbpp1/1p5p/1BPp4/Q2P1B2/2P2N2/P4PPP/R4RK1 w kq -", "prompt": "FEN: rn1qk2r/p1pbbpp1/1p5p/1BPp4/Q2P1B2/2P2N2/P4PPP/R4RK1 w kq -\nIs the move c3g2 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "c3g2", "_legality_check_reason_label": "own_piece_destination", "move": "c3g2", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_00033", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "3r4/p3k2p/6p1/3B4/8/P2P4/2PN1PPP/b5K1 w - - 2 23", "prompt": "FEN: 3r4/p3k2p/6p1/3B4/8/P2P4/2PN1PPP/b5K1 w - - 2 23\nList pseudo-legal moves from g1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g1: g1f1 g1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g1", "diagnostic": true, "hard_gate": false, "source_square": "g1"}}
{"example_id": "rules_00034", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1bqk1nr/pp3pbp/2npp1p1/2p3N1/2B1P3/2NP4/PPP2PPP/R1BQK2R w KQkq -", "prompt": "FEN: r1bqk1nr/pp3pbp/2npp1p1/2p3N1/2B1P3/2NP4/PPP2PPP/R1BQK2R w KQkq -\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1.\nLegal: a1b1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00035", "split": "rules", "task_type": "king_safety_filter", "fen": "8/6p1/1R2P3/8/5Pkp/1P4P1/r6P/3R1BK1 w - - 0 35", "prompt": "FEN: 8/6p1/1R2P3/8/5Pkp/1P4P1/r6P/3R1BK1 w - - 0 35\nFor move g1f2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: g1f2.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "g1f2", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "g1f2", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00036", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1nk3nr/1pprq3/p3p2b/2N1Pp1p/P1BB1Pp1/2P3P1/1P2Q2P/R3R1K1 b - - 1 23", "prompt": "FEN: 1nk3nr/1pprq3/p3p2b/2N1Pp1p/P1BB1Pp1/2P3P1/1P2Q2P/R3R1K1 b - - 1 23\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: g4 black pawn; f5 black pawn; h5 black pawn; a6 black pawn; e6 black pawn; h6 black bishop; b7 black pawn; c7 black pawn; d7 black rook; e7 black queen; b8 black knight; c8 black king; g8 black knight; h8 black rook.\nMoves by piece:\ng4 black pawn: no legal moves\nf5 black pawn: no legal moves\nh5 black pawn: h5h4\na6 black pawn: a6a5\ne6 black pawn: no legal moves\nh6 black bishop: h6f4 h6f8 h6g5 h6g7\nb7 black pawn: b7b5 b7b6\nc7 black pawn: c7c6\nd7 black rook: d7d4 d7d5 d7d6 d7d8\ne7 black queen: e7c5 e7d6 e7d8 e7e8 e7f6 e7f7 e7f8 e7g5 e7g7 e7h4 e7h7\nb8 black knight: b8c6\nc8 black king: c8d8\ng8 black knight: g8f6\nh8 black rook: h8h7\nAll legal moves: a6a5 b7b5 b7b6 b8c6 c7c6 c8d8 d7d4 d7d5 d7d6 d7d8 e7c5 e7d6 e7d8 e7e8 e7f6 e7f7 e7f8 e7g5 e7g7 e7h4 e7h7 g8f6 h5h4 h6f4 h6f8 h6g5 h6g7 h8h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"g4": [], "f5": [], "h5": ["h5h4"], "a6": ["a6a5"], "e6": [], "h6": ["h6f4", "h6f8", "h6g5", "h6g7"], "b7": ["b7b5", "b7b6"], "c7": ["c7c6"], "d7": ["d7d4", "d7d5", "d7d6", "d7d8"], "e7": ["e7c5", "e7d6", "e7d8", "e7e8", "e7f6", "e7f7", "e7f8", "e7g5", "e7g7", "e7h4", "e7h7"], "b8": ["b8c6"], "c8": ["c8d8"], "g8": ["g8f6"], "h8": ["h8h7"]}, "_legal_moves_by_piece_moves": "a6a5 b7b5 b7b6 b8c6 c7c6 c8d8 d7d4 d7d5 d7d6 d7d8 e7c5 e7d6 e7d8 e7e8 e7f6 e7f7 e7f8 e7g5 e7g7 e7h4 e7h7 g8f6 h5h4 h6f4 h6f8 h6g5 h6g7 h8h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"g4": [], "f5": [], "h5": ["h5h4"], "a6": ["a6a5"], "e6": [], "h6": ["h6f4", "h6f8", "h6g5", "h6g7"], "b7": ["b7b5", "b7b6"], "c7": ["c7c6"], "d7": ["d7d4", "d7d5", "d7d6", "d7d8"], "e7": ["e7c5", "e7d6", "e7d8", "e7e8", "e7f6", "e7f7", "e7f8", "e7g5", "e7g7", "e7h4", "e7h7"], "b8": ["b8c6"], "c8": ["c8d8"], "g8": ["g8f6"], "h8": ["h8h7"]}, "legal_moves": "a6a5 b7b5 b7b6 b8c6 c7c6 c8d8 d7d4 d7d5 d7d6 d7d8 e7c5 e7d6 e7d8 e7e8 e7f6 e7f7 e7f8 e7g5 e7g7 e7h4 e7h7 g8f6 h5h4 h6f4 h6f8 h6g5 h6g7 h8h7"}}
{"example_id": "rules_00037", "split": "rules", "task_type": "ray_walk", "fen": "3b4/8/1BK5/1P6/8/3k4/8/8 b - -", "prompt": "FEN: 3b4/8/1BK5/1P6/8/3k4/8/8 b - -\nWalk each ray for the slider on d8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d8 black bishop.\nRay NE: edge.\nRay SE: e7 empty; f6 empty; g5 empty; h4 empty; edge.\nRay SW: c7 empty; b6 white bishop: capture (stop, included).\nRay NW: edge.\nMoves from rays: d8b6 d8c7 d8e7 d8f6 d8g5 d8h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "d8", "diagnostic": true, "hard_gate": false, "source_square": "d8"}}
{"example_id": "rules_00038", "split": "rules", "task_type": "legal_moves", "fen": "r1bq1rk1/1pp2ppp/p1nbpn2/8/1PBP4/P3PN2/1B3PPP/RN1QK2R w KQ - 3 9", "prompt": "FEN: r1bq1rk1/1pp2ppp/p1nbpn2/8/1PBP4/P3PN2/1B3PPP/RN1QK2R w KQ - 3 9\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a3a4 b1c3 b1d2 b2c1 b2c3 b4b5 c4a2 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 d1a4 d1b3 d1c1 d1c2 d1d2 d1d3 d1e2 d4d5 e1d2 e1e2 e1f1 e1g1 e3e4 f3d2 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00039", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/1b2bp1p/p3p3/1p3p2/3P4/2P2NP1/P3QPBP/3R1RK1 w - -", "prompt": "FEN: r2q1rk1/1b2bp1p/p3p3/1p3p2/3P4/2P2NP1/P3QPBP/3R1RK1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 c3c4 d1a1 d1b1 d1c1 d1d2 d1d3 d1e1 d4d5 e2b2 e2b5 e2c2 e2c4 e2d2 e2d3 e2e1 e2e3 e2e4 e2e5 e2e6 f1e1 f3d2 f3e1 f3e5 f3g5 f3h4 g1h1 g2h1 g2h3 g3g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00040", "split": "rules", "task_type": "side_piece_inventory", "fen": "4r3/pbkp3p/1p6/2b2pN1/5P2/2Q3P1/1P1B3P/RN1K1r2 w - - 4 30", "prompt": "FEN: 4r3/pbkp3p/1p6/2b2pN1/5P2/2Q3P1/1P1B3P/RN1K1r2 w - - 4 30\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; d1 white king; b2 white pawn; d2 white bishop; h2 white pawn; c3 white queen; g3 white pawn; f4 white pawn; g5 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "d1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white queen"}, {"square": "g3", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "g5", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "d1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white queen"}, {"square": "g3", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "g5", "piece": "white knight"}]}}
{"example_id": "rules_00041", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/p1k1b3/1p6/3pq3/3p4/1P1Q4/P1P4P/5RK1 w - - 2 32", "prompt": "FEN: 8/p1k1b3/1p6/3pq3/3p4/1P1Q4/P1P4P/5RK1 w - - 2 32\nWhat legal moves does the piece on b3 have?", "gold_answer": "b3b4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b3", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "b3", "piece": "pawn"}}
{"example_id": "rules_00042", "split": "rules", "task_type": "check_detection", "fen": "1r5r/2p1kp1p/3b1p2/p1pPp3/1P4P1/P1PP1P1P/8/1R3RK1 b - - 0 19", "prompt": "FEN: 1r5r/2p1kp1p/3b1p2/p1pPp3/1P4P1/P1PP1P1P/8/1R3RK1 b - - 0 19\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00043", "split": "rules", "task_type": "captures", "fen": "2kr1b1r/pp3pp1/2ppqn1p/4p3/4P3/B1NP3Q/P2K1PPP/1R4NR w - - 1 14", "prompt": "FEN: 2kr1b1r/pp3pp1/2ppqn1p/4p3/4P3/B1NP3Q/P2K1PPP/1R4NR w - - 1 14\nList all capture moves available.", "gold_answer": "a3d6 b1b7 h3e6 h3h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00044", "split": "rules", "task_type": "special_rules", "fen": "r2q1k2/pp2r1pp/3p4/3P3Q/3Pn3/8/4NPPP/R1R3K1 w - - 11 25", "prompt": "Given FEN: r2q1k2/pp2r1pp/3p4/3P3Q/3Pn3/8/4NPPP/R1R3K1 w - - 11 25\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00045", "split": "rules", "task_type": "legality_check", "fen": "r1b2rk1/pp2q1b1/2pp1npp/8/2PPN3/2N2PP1/PPQ1B3/2KR3R b - - 0 18", "prompt": "FEN: r1b2rk1/pp2q1b1/2pp1npp/8/2PPN3/2N2PP1/PPQ1B3/2KR3R b - - 0 18\nIs the move e7c7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "e7c7", "_legality_check_reason_label": "legal", "move": "e7c7", "legality_reason_label": "legal"}}
{"example_id": "rules_00046", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/N7/5k2/8/1p3R2/8/PPP1K2P/8 b - - 1 40", "prompt": "FEN: 8/N7/5k2/8/1p3R2/8/PPP1K2P/8 b - - 1 40\nList pseudo-legal moves from b4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b4: b4b3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_00047", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/6p1/5p1k/4p3/6RP/r4PK1/8/8 b - - 2 46", "prompt": "FEN: 8/6p1/5p1k/4p3/6RP/r4PK1/8/8 b - - 2 46\nFor the piece on h6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from h6: h6g5 h6g6 h6h5 h6h7.\nLegal: h6h5 h6h7.\nRejected: h6g5 king_would_be_in_check; h6g6 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "h6", "diagnostic": true, "hard_gate": false, "source_square": "h6"}}
{"example_id": "rules_00048", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbqk2r/3pnpbp/p3p1p1/1pp5/4P3/PB1P1N2/1PP2PPP/RNBQK2R w KQkq - 3 8", "prompt": "FEN: rnbqk2r/3pnpbp/p3p1p1/1pp5/4P3/PB1P1N2/1PP2PPP/RNBQK2R w KQkq - 3 8\nFor move a1a2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1a2.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1a2", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1a2", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00049", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/pp3p2/2p2n1k/P5pp/2P2K2/8/8/8 w - - 0 42", "prompt": "FEN: 8/pp3p2/2p2n1k/P5pp/2P2K2/8/8/8 w - - 0 42\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c4 white pawn; f4 white king; a5 white pawn.\nMoves by piece:\nc4 white pawn: no legal moves\nf4 white king: f4e3 f4e5 f4f3 f4f5 f4g3\na5 white pawn: no legal moves\nAll legal moves: f4e3 f4e5 f4f3 f4f5 f4g3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c4": [], "f4": ["f4e3", "f4e5", "f4f3", "f4f5", "f4g3"], "a5": []}, "_legal_moves_by_piece_moves": "f4e3 f4e5 f4f3 f4f5 f4g3", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c4": [], "f4": ["f4e3", "f4e5", "f4f3", "f4f5", "f4g3"], "a5": []}, "legal_moves": "f4e3 f4e5 f4f3 f4f5 f4g3"}}
{"example_id": "rules_00050", "split": "rules", "task_type": "ray_walk", "fen": "8/pp1R2p1/4pk1p/2r5/4P3/7P/P4P2/7K w - - 4 37", "prompt": "FEN: 8/pp1R2p1/4pk1p/2r5/4P3/7P/P4P2/7K w - - 4 37\nWalk each ray for the slider on d7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d7 white rook.\nRay N: d8 empty; edge.\nRay E: e7 empty; f7 empty; g7 black pawn: capture (stop, included).\nRay S: d6 empty; d5 empty; d4 empty; d3 empty; d2 empty; d1 empty; edge.\nRay W: c7 empty; b7 black pawn: capture (stop, included).\nMoves from rays: d7b7 d7c7 d7d1 d7d2 d7d3 d7d4 d7d5 d7d6 d7d8 d7e7 d7f7 d7g7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "d7", "diagnostic": true, "hard_gate": false, "source_square": "d7"}}
{"example_id": "rules_00051", "split": "rules", "task_type": "legal_moves", "fen": "r3kb1r/pp3ppp/2N1pn2/8/3P2b1/2P5/P4PPP/R1BQ1RK1 w - -", "prompt": "FEN: r3kb1r/pp3ppp/2N1pn2/8/3P2b1/2P5/P4PPP/R1BQ1RK1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a2a3 a2a4 c1a3 c1b2 c1d2 c1e3 c1f4 c1g5 c1h6 c3c4 c6a5 c6a7 c6b4 c6b8 c6d8 c6e5 c6e7 d1a4 d1b3 d1c2 d1d2 d1d3 d1e1 d1e2 d1f3 d1g4 d4d5 f1e1 f2f3 f2f4 g1h1 g2g3 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00052", "split": "rules", "task_type": "legal_moves", "fen": "8/1bp1k3/5p2/pK3r2/3pp3/P7/1PP5/2R5 w - - 0 41", "prompt": "FEN: 8/1bp1k3/5p2/pK3r2/3pp3/P7/1PP5/2R5 w - - 0 41\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b5a4 b5c4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00053", "split": "rules", "task_type": "side_piece_inventory", "fen": "5b1k/q3n2p/2Q3p1/2P4r/8/1N5P/P5P1/6K1 w - - 1 35", "prompt": "FEN: 5b1k/q3n2p/2Q3p1/2P4r/8/1N5P/P5P1/6K1 w - - 1 35\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: g1 white king; a2 white pawn; g2 white pawn; b3 white knight; h3 white pawn; c5 white pawn; c6 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "b3", "piece": "white knight"}, {"square": "h3", "piece": "white pawn"}, {"square": "c5", "piece": "white pawn"}, {"square": "c6", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "b3", "piece": "white knight"}, {"square": "h3", "piece": "white pawn"}, {"square": "c5", "piece": "white pawn"}, {"square": "c6", "piece": "white queen"}]}}
{"example_id": "rules_00054", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/8/7Q/8/1kr3p1/8/6PP/4K3 b - - 0 54", "prompt": "FEN: 8/8/7Q/8/1kr3p1/8/6PP/4K3 b - - 0 54\nWhat legal moves does the piece on b4 have?", "gold_answer": "b4a3 b4a4 b4a5 b4b3 b4b5 b4c3 b4c5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b4", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "b4", "piece": "king"}}
{"example_id": "rules_00055", "split": "rules", "task_type": "check_detection", "fen": "8/8/3k4/5K2/3N4/8/6B1/8 b - -", "prompt": "FEN: 8/8/3k4/5K2/3N4/8/6B1/8 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00056", "split": "rules", "task_type": "captures", "fen": "rn1qk2r/pbppn1pp/1p2pp2/4P3/8/2BP1N2/PPP1BPPP/R2QK2R b KQkq - 0 8", "prompt": "FEN: rn1qk2r/pbppn1pp/1p2pp2/4P3/8/2BP1N2/PPP1BPPP/R2QK2R b KQkq - 0 8\nList all capture moves available.", "gold_answer": "b7f3 f6e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00057", "split": "rules", "task_type": "special_rules", "fen": "4rk2/ppp1r2p/6p1/1B3b2/1Q6/2N2N2/PPP2PPP/4RRK1 w - - 3 20", "prompt": "Given FEN: 4rk2/ppp1r2p/6p1/1B3b2/1Q6/2N2N2/PPP2PPP/4RRK1 w - - 3 20\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00058", "split": "rules", "task_type": "legality_check", "fen": "r3r1k1/pp1q1pp1/5B1p/3p4/3P2N1/P5R1/1P2bPPP/3Q2K1 w - -", "prompt": "FEN: r3r1k1/pp1q1pp1/5B1p/3p4/3P2N1/P5R1/1P2bPPP/3Q2K1 w - -\nIs the move d1c2 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "d1c2", "_legality_check_reason_label": "legal", "move": "d1c2", "legality_reason_label": "legal"}}
{"example_id": "rules_00059", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnbqkb1r/pp1p1ppp/2p1pn2/8/2PPP3/2N5/PP3PPP/R1BQKBNR b KQkq - 0 4", "prompt": "FEN: rnbqkb1r/pp1p1ppp/2p1pn2/8/2PPP3/2N5/PP3PPP/R1BQKBNR b KQkq - 0 4\nList pseudo-legal moves from c6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c6: c6c5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_00060", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/1p1r4/1B4k1/2p2RR1/2P1P3/3P3P/PP4P1/6K1 b - - 5 37", "prompt": "FEN: 8/1p1r4/1B4k1/2p2RR1/2P1P3/3P3P/PP4P1/6K1 b - - 5 37\nFor the piece on g6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g6: g6f5 g6f6 g6f7 g6g5 g6g7 g6h5 g6h6 g6h7.\nLegal: g6h6 g6h7.\nRejected: g6f5 does_not_resolve_check; g6f6 does_not_resolve_check; g6f7 does_not_resolve_check; g6g5 does_not_resolve_check; g6g7 does_not_resolve_check; g6h5 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g6", "diagnostic": true, "hard_gate": false, "source_square": "g6"}}
{"example_id": "rules_00061", "split": "rules", "task_type": "king_safety_filter", "fen": "r1r3k1/1b1nbp1p/pq2p1p1/1p1n4/3N4/P1BQP3/1P2NPPP/1BR2RK1 w - -", "prompt": "FEN: r1r3k1/1b1nbp1p/pq2p1p1/1p1n4/3N4/P1BQP3/1P2NPPP/1BR2RK1 w - -\nFor move a3a4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a3a4.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a3a4", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a3a4", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00062", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/5k1p/6pP/2B1K3/pP3P2/3b4/8/8 w - -", "prompt": "FEN: 8/5k1p/6pP/2B1K3/pP3P2/3b4/8/8 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: b4 white pawn; f4 white pawn; c5 white bishop; e5 white king; h6 white pawn.\nMoves by piece:\nb4 white pawn: b4b5\nf4 white pawn: f4f5\nc5 white bishop: c5a7 c5b6 c5d4 c5d6 c5e3 c5e7 c5f2 c5f8 c5g1\ne5 white king: e5d4 e5d5 e5d6\nh6 white pawn: no legal moves\nAll legal moves: b4b5 c5a7 c5b6 c5d4 c5d6 c5e3 c5e7 c5f2 c5f8 c5g1 e5d4 e5d5 e5d6 f4f5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b4": ["b4b5"], "f4": ["f4f5"], "c5": ["c5a7", "c5b6", "c5d4", "c5d6", "c5e3", "c5e7", "c5f2", "c5f8", "c5g1"], "e5": ["e5d4", "e5d5", "e5d6"], "h6": []}, "_legal_moves_by_piece_moves": "b4b5 c5a7 c5b6 c5d4 c5d6 c5e3 c5e7 c5f2 c5f8 c5g1 e5d4 e5d5 e5d6 f4f5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b4": ["b4b5"], "f4": ["f4f5"], "c5": ["c5a7", "c5b6", "c5d4", "c5d6", "c5e3", "c5e7", "c5f2", "c5f8", "c5g1"], "e5": ["e5d4", "e5d5", "e5d6"], "h6": []}, "legal_moves": "b4b5 c5a7 c5b6 c5d4 c5d6 c5e3 c5e7 c5f2 c5f8 c5g1 e5d4 e5d5 e5d6 f4f5"}}
{"example_id": "rules_00063", "split": "rules", "task_type": "ray_walk", "fen": "1r1q1rk1/1p3pp1/5n1p/BPbbN3/2N5/3P3P/R4PP1/3QR1K1 b - -", "prompt": "FEN: 1r1q1rk1/1p3pp1/5n1p/BPbbN3/2N5/3P3P/R4PP1/3QR1K1 b - -\nWalk each ray for the slider on c5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c5 black bishop.\nRay NE: d6 empty; e7 empty; f8 black rook: own piece (stop, excluded).\nRay SE: d4 empty; e3 empty; f2 white pawn: capture (stop, included).\nRay SW: b4 empty; a3 empty; edge.\nRay NW: b6 empty; a7 empty; edge.\nMoves from rays: c5a3 c5a7 c5b4 c5b6 c5d4 c5d6 c5e3 c5e7 c5f2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_00064", "split": "rules", "task_type": "legal_moves", "fen": "rn1qk1nr/ppp2ppp/3b4/3p4/3P2b1/2PB1N2/PP3PPP/RNBQK2R b KQkq -", "prompt": "FEN: rn1qk1nr/ppp2ppp/3b4/3p4/3P2b1/2PB1N2/PP3PPP/RNBQK2R b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c7c5 c7c6 d6a3 d6b4 d6c5 d6e5 d6e7 d6f4 d6f8 d6g3 d6h2 d8c8 d8d7 d8e7 d8f6 d8g5 d8h4 e8d7 e8e7 e8f8 f7f5 f7f6 g4c8 g4d7 g4e6 g4f3 g4f5 g4h3 g4h5 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00065", "split": "rules", "task_type": "legal_moves", "fen": "r2qr1k1/pp2ppbp/2n3p1/3p4/3P4/2Q1PB2/PP3PPP/R1B2RK1 b - - 0 13", "prompt": "FEN: r2qr1k1/pp2ppbp/2n3p1/3p4/3P4/2Q1PB2/PP3PPP/R1B2RK1 b - - 0 13\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 a8c8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 d8a5 d8b6 d8b8 d8c7 d8c8 d8d6 d8d7 e7e5 e7e6 e8f8 f7f5 f7f6 g6g5 g7d4 g7e5 g7f6 g7f8 g7h6 g7h8 g8f8 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00066", "split": "rules", "task_type": "side_piece_inventory", "fen": "r5q1/3bbr1k/2n1p2p/p2pPpp1/1ppP1P2/2P1QN1P/PP1B2PN/R4RK1 w - - 0 25", "prompt": "FEN: r5q1/3bbr1k/2n1p2p/p2pPpp1/1ppP1P2/2P1QN1P/PP1B2PN/R4RK1 w - - 0 25\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; d2 white bishop; g2 white pawn; h2 white knight; c3 white pawn; e3 white queen; f3 white knight; h3 white pawn; d4 white pawn; f4 white pawn; e5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white knight"}, {"square": "c3", "piece": "white pawn"}, {"square": "e3", "piece": "white queen"}, {"square": "f3", "piece": "white knight"}, {"square": "h3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white knight"}, {"square": "c3", "piece": "white pawn"}, {"square": "e3", "piece": "white queen"}, {"square": "f3", "piece": "white knight"}, {"square": "h3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}]}}
{"example_id": "rules_00067", "split": "rules", "task_type": "piece_legal_moves", "fen": "r2qkbnr/1b1ppppp/p7/nppB4/4P3/1PN2N2/P1PP1PPP/R1BQ1RK1 b kq - 0 7", "prompt": "FEN: r2qkbnr/1b1ppppp/p7/nppB4/4P3/1PN2N2/P1PP1PPP/R1BQ1RK1 b kq - 0 7\nWhat legal moves does the piece on a6 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a6", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a6", "piece": "pawn"}}
{"example_id": "rules_00068", "split": "rules", "task_type": "check_detection", "fen": "rn2r1k1/ppp2ppp/8/5b2/2PPnp1q/2PB4/P1QN2PP/R1B1R1K1 w - -", "prompt": "FEN: rn2r1k1/ppp2ppp/8/5b2/2PPnp1q/2PB4/P1QN2PP/R1B1R1K1 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00069", "split": "rules", "task_type": "captures", "fen": "1r6/1p1b1k1p/3P2p1/2p1Bp2/RbP1pP2/6P1/4BP1P/6K1 w - - 0 26", "prompt": "FEN: 1r6/1p1b1k1p/3P2p1/2p1Bp2/RbP1pP2/6P1/4BP1P/6K1 w - - 0 26\nList all capture moves available.", "gold_answer": "a4b4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00070", "split": "rules", "task_type": "special_rules", "fen": "2r1kb1r/p1q2p1p/Q3pnp1/2p4b/2Pp4/BP4R1/P2P1PBP/RN2K3 w Qk - 0 16", "prompt": "Given FEN: 2r1kb1r/p1q2p1p/Q3pnp1/2p4b/2Pp4/BP4R1/P2P1PBP/RN2K3 w Qk - 0 16\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00071", "split": "rules", "task_type": "legality_check", "fen": "r1q2rk1/p2n1ppp/bp1Npn2/2p5/2PP4/1P3NP1/P1Q2PBP/R2R2K1 b - -", "prompt": "FEN: r1q2rk1/p2n1ppp/bp1Npn2/2p5/2PP4/1P3NP1/P1Q2PBP/R2R2K1 b - -\nIs the move c8e8 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "c8e8", "_legality_check_reason_label": "legal", "move": "c8e8", "legality_reason_label": "legal"}}
{"example_id": "rules_00072", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2qkb1r/pp4pp/3p4/2pnppQ1/8/P2PB1PP/1PPR1PB1/2K4R w kq - 0 17", "prompt": "FEN: r2qkb1r/pp4pp/3p4/2pnppQ1/8/P2PB1PP/1PPR1PB1/2K4R w kq - 0 17\nList pseudo-legal moves from c1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c1: c1b1 c1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_00073", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn4Q1/p2kr2p/2p2pBB/2P1p3/Np6/1P3N2/P4PPP/2KR4 b - - 0 24", "prompt": "FEN: rn4Q1/p2kr2p/2p2pBB/2P1p3/Np6/1P3N2/P4PPP/2KR4 b - - 0 24\nFor the piece on e5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e5: e5e4.\nLegal: none.\nRejected: e5e4 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "e5", "diagnostic": true, "hard_gate": false, "source_square": "e5"}}
{"example_id": "rules_00074", "split": "rules", "task_type": "king_safety_filter", "fen": "R7/P5k1/1r6/4K3/8/8/8/8 b - -", "prompt": "FEN: R7/P5k1/1r6/4K3/8/8/8/8 b - -\nFor move g7f6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: g7f6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "g7f6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "g7f6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00075", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnbqkbnr/pppp1p1p/4p1p1/8/2PP4/2N5/PP2PPPP/R1BQKBNR b KQkq - 1 3", "prompt": "FEN: rnbqkbnr/pppp1p1p/4p1p1/8/2PP4/2N5/PP2PPPP/R1BQKBNR b KQkq - 1 3\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e6 black pawn; g6 black pawn; a7 black pawn; b7 black pawn; c7 black pawn; d7 black pawn; f7 black pawn; h7 black pawn; a8 black rook; b8 black knight; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\ne6 black pawn: e6e5\ng6 black pawn: g6g5\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nc7 black pawn: c7c5 c7c6\nd7 black pawn: d7d5 d7d6\nf7 black pawn: f7f5 f7f6\nh7 black pawn: h7h5 h7h6\na8 black rook: no legal moves\nb8 black knight: b8a6 b8c6\nc8 black bishop: no legal moves\nd8 black queen: d8e7 d8f6 d8g5 d8h4\ne8 black king: e8e7\nf8 black bishop: f8a3 f8b4 f8c5 f8d6 f8e7 f8g7 f8h6\ng8 black knight: g8e7 g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 c7c5 c7c6 d7d5 d7d6 d8e7 d8f6 d8g5 d8h4 e6e5 e8e7 f7f5 f7f6 f8a3 f8b4 f8c5 f8d6 f8e7 f8g7 f8h6 g6g5 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e6": ["e6e5"], "g6": ["g6g5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7c5", "c7c6"], "d7": ["d7d5", "d7d6"], "f7": ["f7f5", "f7f6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8c6"], "c8": [], "d8": ["d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8e7"], "f8": ["f8a3", "f8b4", "f8c5", "f8d6", "f8e7", "f8g7", "f8h6"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 c7c5 c7c6 d7d5 d7d6 d8e7 d8f6 d8g5 d8h4 e6e5 e8e7 f7f5 f7f6 f8a3 f8b4 f8c5 f8d6 f8e7 f8g7 f8h6 g6g5 g8e7 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e6": ["e6e5"], "g6": ["g6g5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7c5", "c7c6"], "d7": ["d7d5", "d7d6"], "f7": ["f7f5", "f7f6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8c6"], "c8": [], "d8": ["d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8e7"], "f8": ["f8a3", "f8b4", "f8c5", "f8d6", "f8e7", "f8g7", "f8h6"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "legal_moves": "a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 c7c5 c7c6 d7d5 d7d6 d8e7 d8f6 d8g5 d8h4 e6e5 e8e7 f7f5 f7f6 f8a3 f8b4 f8c5 f8d6 f8e7 f8g7 f8h6 g6g5 g8e7 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_00076", "split": "rules", "task_type": "ray_walk", "fen": "rnbqk1nr/ppppp1bp/5pp1/8/1P6/4PN2/PBPP1PPP/RN1QKB1R b KQkq - 0 4", "prompt": "FEN: rnbqk1nr/ppppp1bp/5pp1/8/1P6/4PN2/PBPP1PPP/RN1QKB1R b KQkq - 0 4\nWalk each ray for the slider on g7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: g7 black bishop.\nRay NE: h8 black rook: own piece (stop, excluded).\nRay SE: h6 empty; edge.\nRay SW: f6 black pawn: own piece (stop, excluded).\nRay NW: f8 empty; edge.\nMoves from rays: g7f8 g7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "g7", "diagnostic": true, "hard_gate": false, "source_square": "g7"}}
{"example_id": "rules_00077", "split": "rules", "task_type": "legal_filter_trace", "fen": "1r6/5kpp/5p2/3Pp3/1P4P1/P1K1R2P/8/8 b - - 2 31", "prompt": "FEN: 1r6/5kpp/5p2/3Pp3/1P4P1/P1K1R2P/8/8 b - - 2 31\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e5 black pawn; f6 black pawn; f7 black king; g7 black pawn; h7 black pawn; b8 black rook.\nFilter by piece:\ne5 black pawn: pseudo-legal e5e4 | rejected none | legal e5e4\nf6 black pawn: pseudo-legal f6f5 | rejected none | legal f6f5\nf7 black king: pseudo-legal f7e6 f7e7 f7e8 f7f8 f7g6 f7g8 | rejected f7e6 king_would_be_in_check | legal f7e7 f7e8 f7f8 f7g6 f7g8\ng7 black pawn: pseudo-legal g7g5 g7g6 | rejected none | legal g7g5 g7g6\nh7 black pawn: pseudo-legal h7h5 h7h6 | rejected none | legal h7h5 h7h6\nb8 black rook: pseudo-legal b8a8 b8b4 b8b5 b8b6 b8b7 b8c8 b8d8 b8e8 b8f8 b8g8 b8h8 | rejected none | legal b8a8 b8b4 b8b5 b8b6 b8b7 b8c8 b8d8 b8e8 b8f8 b8g8 b8h8\nAll legal moves: b8a8 b8b4 b8b5 b8b6 b8b7 b8c8 b8d8 b8e8 b8f8 b8g8 b8h8 e5e4 f6f5 f7e7 f7e8 f7f8 f7g6 f7g8 g7g5 g7g6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00078", "split": "rules", "task_type": "legal_moves", "fen": "rn1qkb1r/ppp1pppp/5n2/8/2pP2b1/2N1PN2/PP3PPP/R1BQKB1R b KQkq - 2 5", "prompt": "FEN: rn1qkb1r/ppp1pppp/5n2/8/2pP2b1/2N1PN2/PP3PPP/R1BQKB1R b KQkq - 2 5\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c7c5 c7c6 d8c8 d8d4 d8d5 d8d6 d8d7 e7e5 e7e6 e8d7 f6d5 f6d7 f6e4 f6g8 f6h5 g4c8 g4d7 g4e6 g4f3 g4f5 g4h3 g4h5 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00079", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1b2rk1/2p2ppp/pq6/1p2Nn2/3P4/1N4BP/PPP2PP1/R2QR1K1 b - - 0 19", "prompt": "FEN: r1b2rk1/2p2ppp/pq6/1p2Nn2/3P4/1N4BP/PPP2PP1/R2QR1K1 b - - 0 19\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: b5 black pawn; f5 black knight; a6 black pawn; b6 black queen; c7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "b5", "piece": "black pawn"}, {"square": "f5", "piece": "black knight"}, {"square": "a6", "piece": "black pawn"}, {"square": "b6", "piece": "black queen"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "b5", "piece": "black pawn"}, {"square": "f5", "piece": "black knight"}, {"square": "a6", "piece": "black pawn"}, {"square": "b6", "piece": "black queen"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_00080", "split": "rules", "task_type": "piece_legal_moves", "fen": "rn1q1rk1/pp1b2pp/2p1pn2/4Np2/3P4/3BPN2/PPQ2PPP/R3K2R w KQ - 2 11", "prompt": "FEN: rn1q1rk1/pp1b2pp/2p1pn2/4Np2/3P4/3BPN2/PPQ2PPP/R3K2R w KQ - 2 11\nWhat legal moves does the piece on c2 have?", "gold_answer": "c2a4 c2b1 c2b3 c2c1 c2c3 c2c4 c2c5 c2c6 c2d1 c2d2 c2e2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c2", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "c2", "piece": "queen"}}
{"example_id": "rules_00081", "split": "rules", "task_type": "check_detection", "fen": "r1bqk2r/pp3ppp/2pb1n2/4n3/3Q1B2/5N2/PP2PPPP/RN2KB1R b KQkq -", "prompt": "FEN: r1bqk2r/pp3ppp/2pb1n2/4n3/3Q1B2/5N2/PP2PPPP/RN2KB1R b KQkq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00082", "split": "rules", "task_type": "captures", "fen": "rn1qkb1r/ppp1pp1p/3p1np1/6B1/3P4/2N2P1P/PPP2PP1/R2QKB1R b KQkq - 0 6", "prompt": "FEN: rn1qkb1r/ppp1pp1p/3p1np1/6B1/3P4/2N2P1P/PPP2PP1/R2QKB1R b KQkq - 0 6\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00083", "split": "rules", "task_type": "special_rules", "fen": "1r3k2/4b1p1/7p/8/p2PPPb1/P1B2Bq1/3Q2P1/4R1K1 w - - 1 41", "prompt": "Given FEN: 1r3k2/4b1p1/7p/8/p2PPPb1/P1B2Bq1/3Q2P1/4R1K1 w - - 1 41\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00084", "split": "rules", "task_type": "legality_check", "fen": "r1b1k2r/3p1pp1/p1n5/1p2p3/3bP3/2N1BR2/PPP1K1P1/R2B4 w kq - 0 20", "prompt": "FEN: r1b1k2r/3p1pp1/p1n5/1p2p3/3bP3/2N1BR2/PPP1K1P1/R2B4 w kq - 0 20\nIs the move a2f3 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "a2f3", "_legality_check_reason_label": "own_piece_destination", "move": "a2f3", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_00085", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1b1kb1r/pppp1ppp/2n2q2/8/2Bpn3/1QP2N2/PP3PPP/RNB2RK1 b kq -", "prompt": "FEN: r1b1kb1r/pppp1ppp/2n2q2/8/2Bpn3/1QP2N2/PP3PPP/RNB2RK1 b kq -\nList pseudo-legal moves from d4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d4: d4c3 d4d3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_00086", "split": "rules", "task_type": "piece_legal_filter", "fen": "r3k2r/pppbqppp/1bn2n2/8/1P1pN3/PNPB2PP/1B3P2/R2Q1RK1 b kq - 1 18", "prompt": "FEN: r3k2r/pppbqppp/1bn2n2/8/1P1pN3/PNPB2PP/1B3P2/R2Q1RK1 b kq - 1 18\nFor the piece on d4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d4: d4c3.\nLegal: d4c3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_00087", "split": "rules", "task_type": "king_safety_filter", "fen": "r2qk2r/pb1n1p2/1p4pb/3p3p/2pP2n1/2N1PNBP/PPB1QPP1/2R2RK1 b kq - 0 15", "prompt": "FEN: r2qk2r/pb1n1p2/1p4pb/3p3p/2pP2n1/2N1PNBP/PPB1QPP1/2R2RK1 b kq - 0 15\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00088", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "4k3/8/3p4/1pp5/1p2PpP1/qP1P4/2P2Q2/1K6 w - - 0 41", "prompt": "FEN: 4k3/8/3p4/1pp5/1p2PpP1/qP1P4/2P2Q2/1K6 w - - 0 41\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: b1 white king; c2 white pawn; f2 white queen; b3 white pawn; d3 white pawn; e4 white pawn; g4 white pawn.\nMoves by piece:\nb1 white king: no legal moves\nc2 white pawn: c2c3 c2c4\nf2 white queen: f2c5 f2d2 f2d4 f2e1 f2e2 f2e3 f2f1 f2f3 f2f4 f2g1 f2g2 f2g3 f2h2 f2h4\nb3 white pawn: no legal moves\nd3 white pawn: d3d4\ne4 white pawn: e4e5\ng4 white pawn: g4g5\nAll legal moves: c2c3 c2c4 d3d4 e4e5 f2c5 f2d2 f2d4 f2e1 f2e2 f2e3 f2f1 f2f3 f2f4 f2g1 f2g2 f2g3 f2h2 f2h4 g4g5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b1": [], "c2": ["c2c3", "c2c4"], "f2": ["f2c5", "f2d2", "f2d4", "f2e1", "f2e2", "f2e3", "f2f1", "f2f3", "f2f4", "f2g1", "f2g2", "f2g3", "f2h2", "f2h4"], "b3": [], "d3": ["d3d4"], "e4": ["e4e5"], "g4": ["g4g5"]}, "_legal_moves_by_piece_moves": "c2c3 c2c4 d3d4 e4e5 f2c5 f2d2 f2d4 f2e1 f2e2 f2e3 f2f1 f2f3 f2f4 f2g1 f2g2 f2g3 f2h2 f2h4 g4g5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b1": [], "c2": ["c2c3", "c2c4"], "f2": ["f2c5", "f2d2", "f2d4", "f2e1", "f2e2", "f2e3", "f2f1", "f2f3", "f2f4", "f2g1", "f2g2", "f2g3", "f2h2", "f2h4"], "b3": [], "d3": ["d3d4"], "e4": ["e4e5"], "g4": ["g4g5"]}, "legal_moves": "c2c3 c2c4 d3d4 e4e5 f2c5 f2d2 f2d4 f2e1 f2e2 f2e3 f2f1 f2f3 f2f4 f2g1 f2g2 f2g3 f2h2 f2h4 g4g5"}}
{"example_id": "rules_00089", "split": "rules", "task_type": "ray_walk", "fen": "3r2k1/p3r1bp/2p3p1/3p4/4p3/2P3B1/PP2RPPP/4R1K1 b - - 1 22", "prompt": "FEN: 3r2k1/p3r1bp/2p3p1/3p4/4p3/2P3B1/PP2RPPP/4R1K1 b - - 1 22\nWalk each ray for the slider on e7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e7 black rook.\nRay N: e8 empty; edge.\nRay E: f7 empty; g7 black bishop: own piece (stop, excluded).\nRay S: e6 empty; e5 empty; e4 black pawn: own piece (stop, excluded).\nRay W: d7 empty; c7 empty; b7 empty; a7 black pawn: own piece (stop, excluded).\nMoves from rays: e7b7 e7c7 e7d7 e7e5 e7e6 e7e8 e7f7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "e7", "diagnostic": true, "hard_gate": false, "source_square": "e7"}}
{"example_id": "rules_00090", "split": "rules", "task_type": "legal_moves", "fen": "rn1qk2r/pp1bb1pp/2p2p1B/8/2BP4/5N2/PPP2PPP/RN1Q1RK1 b kq - 0 10", "prompt": "FEN: rn1qk2r/pp1bb1pp/2p2p1B/8/2BP4/5N2/PPP2PPP/RN1Q1RK1 b kq - 0 10\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 c6c5 d7c8 d7e6 d7f5 d7g4 d7h3 d8a5 d8b6 d8c7 d8c8 e7a3 e7b4 e7c5 e7d6 e7f8 e8f8 f6f5 g7g5 g7g6 g7h6 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00091", "split": "rules", "task_type": "legal_moves", "fen": "4qrk1/rb2bppp/pN1p2n1/B1p5/3pP3/1P3N2/1PP2PPP/R2QR1K1 w - -", "prompt": "FEN: 4qrk1/rb2bppp/pN1p2n1/B1p5/3pP3/1P3N2/1PP2PPP/R2QR1K1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 a1a4 a1b1 a1c1 a5b4 a5c3 a5d2 b3b4 b6a4 b6a8 b6c4 b6c8 b6d5 b6d7 c2c3 c2c4 d1b1 d1c1 d1d2 d1d3 d1d4 d1e2 e1e2 e1e3 e1f1 e4e5 f3d2 f3d4 f3e5 f3g5 f3h4 g1f1 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00092", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqkb1r/ppp2ppp/2n5/4p3/4N3/2N5/PPPP1PPP/R1BQK2R w KQkq -", "prompt": "FEN: r1bqkb1r/ppp2ppp/2n5/4p3/4N3/2N5/PPPP1PPP/R1BQK2R w KQkq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; e1 white king; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; d2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white knight; e4 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "e4", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "e4", "piece": "white knight"}]}}
{"example_id": "rules_00093", "split": "rules", "task_type": "piece_legal_moves", "fen": "4r3/4n2p/3R2p1/1pN2p2/3B1k2/1P4P1/P4P1P/6K1 b - - 0 29", "prompt": "FEN: 4r3/4n2p/3R2p1/1pN2p2/3B1k2/1P4P1/P4P1P/6K1 b - - 0 29\nWhat legal moves does the piece on e8 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "e8", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "e8", "piece": "rook"}}
{"example_id": "rules_00094", "split": "rules", "task_type": "check_detection", "fen": "8/8/8/2k5/8/3BK3/1Q6/8 b - -", "prompt": "FEN: 8/8/8/2k5/8/3BK3/1Q6/8 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00095", "split": "rules", "task_type": "captures", "fen": "r4rk1/pp1bqpp1/2p4p/8/2BPp3/4P3/PP3PPP/R2Q1RK1 b - - 3 14", "prompt": "FEN: r4rk1/pp1bqpp1/2p4p/8/2BPp3/4P3/PP3PPP/R2Q1RK1 b - - 3 14\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00096", "split": "rules", "task_type": "special_rules", "fen": "6rk/p3Q1pp/1p6/n3Bp2/3P2q1/P2BPbP1/5P1P/5RK1 w - - 1 28", "prompt": "Given FEN: 6rk/p3Q1pp/1p6/n3Bp2/3P2q1/P2BPbP1/5P1P/5RK1 w - - 1 28\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00097", "split": "rules", "task_type": "legality_check", "fen": "r5k1/p6p/8/5p2/2R1p3/2P1P3/1r3P2/4K2R w K -", "prompt": "FEN: r5k1/p6p/8/5p2/2R1p3/2P1P3/1r3P2/4K2R w K -\nIs the move c4c5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "c4c5", "_legality_check_reason_label": "legal", "move": "c4c5", "legality_reason_label": "legal"}}
{"example_id": "rules_00098", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r4rk1/pp2bpp1/2pp3p/4n3/4P1q1/1PN4R/PBQ3PP/5R1K b - -", "prompt": "FEN: r4rk1/pp2bpp1/2pp3p/4n3/4P1q1/1PN4R/PBQ3PP/5R1K b - -\nList pseudo-legal moves from g4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g4: g4c8 g4d1 g4d7 g4e2 g4e4 g4e6 g4f3 g4f4 g4f5 g4g2 g4g3 g4g5 g4g6 g4h3 g4h4 g4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g4", "diagnostic": true, "hard_gate": false, "source_square": "g4"}}
{"example_id": "rules_00099", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnbq1rk1/ppp1bppp/4p2n/3p4/3PPP2/3B1NP1/PPP4P/RNBQ1RK1 w - - 0 8", "prompt": "FEN: rnbq1rk1/ppp1bppp/4p2n/3p4/3PPP2/3B1NP1/PPP4P/RNBQ1RK1 w - - 0 8\nFor the piece on b1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b1: b1a3 b1c3 b1d2.\nLegal: b1a3 b1c3 b1d2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_00100", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bq2k1/ppp2Bpp/2np1n2/8/4r3/2B1QN2/PPP2PPP/2KR3R b - -", "prompt": "FEN: r1bq2k1/ppp2Bpp/2np1n2/8/4r3/2B1QN2/PPP2PPP/2KR3R b - -\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_00101", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "4Q3/6p1/3bp2p/3p4/3P3k/3R4/5PP1/2q3K1 w - - 1 41", "prompt": "FEN: 4Q3/6p1/3bp2p/3p4/3P3k/3R4/5PP1/2q3K1 w - - 1 41\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: g1 white king; f2 white pawn; g2 white pawn; d3 white rook; d4 white pawn; e8 white queen.\nMoves by piece:\ng1 white king: no legal moves\nf2 white pawn: no legal moves\ng2 white pawn: no legal moves\nd3 white rook: d3d1\nd4 white pawn: no legal moves\ne8 white queen: no legal moves\nAll legal moves: d3d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"g1": [], "f2": [], "g2": [], "d3": ["d3d1"], "d4": [], "e8": []}, "_legal_moves_by_piece_moves": "d3d1", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"g1": [], "f2": [], "g2": [], "d3": ["d3d1"], "d4": [], "e8": []}, "legal_moves": "d3d1"}}
{"example_id": "rules_00102", "split": "rules", "task_type": "legal_moves", "fen": "8/1R2k3/2Q5/8/1P3Pp1/N3N1K1/6P1/8 b - - 14 60", "prompt": "FEN: 8/1R2k3/2Q5/8/1P3Pp1/N3N1K1/6P1/8 b - - 14 60\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: e7d8 e7f8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": ""}}
{"example_id": "rules_00103", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/p4pp1/1b3n1p/2p5/3P1P2/3B1QN1/PP4PP/5R1K b - - 0 20", "prompt": "FEN: r2q1rk1/p4pp1/1b3n1p/2p5/3P1P2/3B1QN1/PP4PP/5R1K b - - 0 20\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 a8c8 b6a5 b6c7 c5c4 c5d4 d8b8 d8c7 d8c8 d8d4 d8d5 d8d6 d8d7 d8e7 d8e8 f6d5 f6d7 f6e4 f6e8 f6g4 f6h5 f6h7 f8e8 g7g5 g7g6 g8h8 h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00104", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/pp3ppp/2nbpn2/3p4/3P2b1/PP1B1N2/1BPN1PPP/R2QK2R w KQ -", "prompt": "FEN: r2q1rk1/pp3ppp/2nbpn2/3p4/3P2b1/PP1B1N2/1BPN1PPP/R2QK2R w KQ -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1b1 a1c1 a3a4 b2c1 b2c3 b3b4 c2c3 c2c4 d1b1 d1c1 d1e2 d2b1 d2c4 d2e4 d2f1 d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 d3g6 d3h7 e1e2 e1f1 e1g1 f3e5 f3g1 f3g5 f3h4 g2g3 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00105", "split": "rules", "task_type": "side_piece_inventory", "fen": "1k5r/1qb4p/4Q1p1/p1Pp1p2/R2P1P2/6N1/1P4PP/2B3K1 w - - 1 32", "prompt": "FEN: 1k5r/1qb4p/4Q1p1/p1Pp1p2/R2P1P2/6N1/1P4PP/2B3K1 w - - 1 32\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: c1 white bishop; g1 white king; b2 white pawn; g2 white pawn; h2 white pawn; g3 white knight; a4 white rook; d4 white pawn; f4 white pawn; c5 white pawn; e6 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "c1", "piece": "white bishop"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "g3", "piece": "white knight"}, {"square": "a4", "piece": "white rook"}, {"square": "d4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "c5", "piece": "white pawn"}, {"square": "e6", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "c1", "piece": "white bishop"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "g3", "piece": "white knight"}, {"square": "a4", "piece": "white rook"}, {"square": "d4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "c5", "piece": "white pawn"}, {"square": "e6", "piece": "white queen"}]}}
{"example_id": "rules_00106", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnbq1rk1/ppp1bpp1/4p2p/4P1n1/2BP4/2N2N2/PPQ2PPP/R1B2RK1 w - - 7 10", "prompt": "FEN: rnbq1rk1/ppp1bpp1/4p2p/4P1n1/2BP4/2N2N2/PPQ2PPP/R1B2RK1 w - - 7 10\nWhat legal moves does the piece on c2 have?", "gold_answer": "c2a4 c2b1 c2b3 c2d1 c2d2 c2d3 c2e2 c2e4 c2f5 c2g6 c2h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c2", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "c2", "piece": "queen"}}
{"example_id": "rules_00107", "split": "rules", "task_type": "check_detection", "fen": "rnbqkbnr/pp4pp/5p2/1B1pp3/3P4/5N2/PPP2PPP/RNBQK2R b KQkq - 1 6", "prompt": "FEN: rnbqkbnr/pp4pp/5p2/1B1pp3/3P4/5N2/PPP2PPP/RNBQK2R b KQkq - 1 6\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00108", "split": "rules", "task_type": "captures", "fen": "rn1q1rk1/ppp1bb1p/6p1/5p2/3P4/2P2N1P/PP2Q1P1/RNB2RK1 w - - 0 14", "prompt": "FEN: rn1q1rk1/ppp1bb1p/6p1/5p2/3P4/2P2N1P/PP2Q1P1/RNB2RK1 w - - 0 14\nList all capture moves available.", "gold_answer": "e2e7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00109", "split": "rules", "task_type": "special_rules", "fen": "r1bqkb1r/ppp1pppp/5n2/4n3/8/2N5/PPP2PPP/R1BQKBNR w KQkq -", "prompt": "Given FEN: r1bqkb1r/ppp1pppp/5n2/4n3/8/2N5/PPP2PPP/R1BQKBNR w KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00110", "split": "rules", "task_type": "legality_check", "fen": "r1bqkbnr/ppp2ppp/2n1p3/8/2BP4/P3P3/1P3PPP/RNBQK1NR b KQkq - 0 5", "prompt": "FEN: r1bqkbnr/ppp2ppp/2n1p3/8/2BP4/P3P3/1P3PPP/RNBQK1NR b KQkq - 0 5\nIs the move c6a5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c6a5", "_legality_check_reason_label": "legal", "move": "c6a5", "legality_reason_label": "legal"}}
{"example_id": "rules_00111", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1bqk2r/pppp1ppp/2n2n2/6B1/2P5/2N5/PP2PKPP/R2Q1BNR b kq - 0 7", "prompt": "FEN: r1bqk2r/pppp1ppp/2n2n2/6B1/2P5/2N5/PP2PKPP/R2Q1BNR b kq - 0 7\nList pseudo-legal moves from c6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c6: c6a5 c6b4 c6b8 c6d4 c6e5 c6e7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_00112", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnbqk2r/ppp2ppp/4pn2/3p4/3P1B2/P1b2N2/1PP1PPPP/R2QKB1R w KQkq -", "prompt": "FEN: rnbqk2r/ppp2ppp/4pn2/3p4/3P1B2/P1b2N2/1PP1PPPP/R2QKB1R w KQkq -\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1a2 a1b1 a1c1.\nLegal: none.\nRejected: a1a2 does_not_resolve_check; a1b1 does_not_resolve_check; a1c1 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00113", "split": "rules", "task_type": "king_safety_filter", "fen": "r6k/2p1P1p1/p4p1p/1p6/1q6/7P/P4PP1/3RR1K1 w - - 0 28", "prompt": "FEN: r6k/2p1P1p1/p4p1p/1p6/1q6/7P/P4PP1/3RR1K1 w - - 0 28\nFor move a2a3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a2a3.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a2a3", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a2a3", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00114", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2r1r2k/3R2pp/p7/1p6/2n1N1Q1/P5PP/1q3R1K/8 b - -", "prompt": "FEN: 2r1r2k/3R2pp/p7/1p6/2n1N1Q1/P5PP/1q3R1K/8 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b2 black queen; c4 black knight; b5 black pawn; a6 black pawn; g7 black pawn; h7 black pawn; c8 black rook; e8 black rook; h8 black king.\nMoves by piece:\nb2 black queen: b2a1 b2a2 b2a3 b2b1 b2b3 b2b4 b2c1 b2c2 b2c3 b2d2 b2d4 b2e2 b2e5 b2f2 b2f6\nc4 black knight: c4a3 c4a5 c4b6 c4d2 c4d6 c4e3 c4e5\nb5 black pawn: b5b4\na6 black pawn: a6a5\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\nc8 black rook: c8a8 c8b8 c8c5 c8c6 c8c7 c8d8\ne8 black rook: e8d8 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8\nh8 black king: h8g8\nAll legal moves: a6a5 b2a1 b2a2 b2a3 b2b1 b2b3 b2b4 b2c1 b2c2 b2c3 b2d2 b2d4 b2e2 b2e5 b2f2 b2f6 b5b4 c4a3 c4a5 c4b6 c4d2 c4d6 c4e3 c4e5 c8a8 c8b8 c8c5 c8c6 c8c7 c8d8 e8d8 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b2": ["b2a1", "b2a2", "b2a3", "b2b1", "b2b3", "b2b4", "b2c1", "b2c2", "b2c3", "b2d2", "b2d4", "b2e2", "b2e5", "b2f2", "b2f6"], "c4": ["c4a3", "c4a5", "c4b6", "c4d2", "c4d6", "c4e3", "c4e5"], "b5": ["b5b4"], "a6": ["a6a5"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8a8", "c8b8", "c8c5", "c8c6", "c8c7", "c8d8"], "e8": ["e8d8", "e8e4", "e8e5", "e8e6", "e8e7", "e8f8", "e8g8"], "h8": ["h8g8"]}, "_legal_moves_by_piece_moves": "a6a5 b2a1 b2a2 b2a3 b2b1 b2b3 b2b4 b2c1 b2c2 b2c3 b2d2 b2d4 b2e2 b2e5 b2f2 b2f6 b5b4 c4a3 c4a5 c4b6 c4d2 c4d6 c4e3 c4e5 c8a8 c8b8 c8c5 c8c6 c8c7 c8d8 e8d8 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 g7g5 g7g6 h7h5 h7h6 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b2": ["b2a1", "b2a2", "b2a3", "b2b1", "b2b3", "b2b4", "b2c1", "b2c2", "b2c3", "b2d2", "b2d4", "b2e2", "b2e5", "b2f2", "b2f6"], "c4": ["c4a3", "c4a5", "c4b6", "c4d2", "c4d6", "c4e3", "c4e5"], "b5": ["b5b4"], "a6": ["a6a5"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8a8", "c8b8", "c8c5", "c8c6", "c8c7", "c8d8"], "e8": ["e8d8", "e8e4", "e8e5", "e8e6", "e8e7", "e8f8", "e8g8"], "h8": ["h8g8"]}, "legal_moves": "a6a5 b2a1 b2a2 b2a3 b2b1 b2b3 b2b4 b2c1 b2c2 b2c3 b2d2 b2d4 b2e2 b2e5 b2f2 b2f6 b5b4 c4a3 c4a5 c4b6 c4d2 c4d6 c4e3 c4e5 c8a8 c8b8 c8c5 c8c6 c8c7 c8d8 e8d8 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 g7g5 g7g6 h7h5 h7h6 h8g8"}}
{"example_id": "rules_00115", "split": "rules", "task_type": "ray_walk", "fen": "r1b2rk1/2pqbppp/p1n2n2/1p1p4/3P4/1BP2N1P/PP3PP1/RNBQR1K1 b - - 0 11", "prompt": "FEN: r1b2rk1/2pqbppp/p1n2n2/1p1p4/3P4/1BP2N1P/PP3PP1/RNBQR1K1 b - - 0 11\nWalk each ray for the slider on d7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d7 black queen.\nRay N: d8 empty; edge.\nRay NE: e8 empty; edge.\nRay E: e7 black bishop: own piece (stop, excluded).\nRay SE: e6 empty; f5 empty; g4 empty; h3 white pawn: capture (stop, included).\nRay S: d6 empty; d5 black pawn: own piece (stop, excluded).\nRay SW: c6 black knight: own piece (stop, excluded).\nRay W: c7 black pawn: own piece (stop, excluded).\nRay NW: c8 black bishop: own piece (stop, excluded).\nMoves from rays: d7d6 d7d8 d7e6 d7e8 d7f5 d7g4 d7h3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "d7", "diagnostic": true, "hard_gate": false, "source_square": "d7"}}
{"example_id": "rules_00116", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/8/8/6p1/pr4k1/6R1/6K1/8 b - -", "prompt": "FEN: 8/8/8/6p1/pr4k1/6R1/6K1/8 b - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a4 black pawn; b4 black rook; g4 black king; g5 black pawn.\nFilter by piece:\na4 black pawn: pseudo-legal a4a3 | rejected a4a3 does_not_resolve_check | legal none\nb4 black rook: pseudo-legal b4b1 b4b2 b4b3 b4b5 b4b6 b4b7 b4b8 b4c4 b4d4 b4e4 b4f4 | rejected b4b1 does_not_resolve_check; b4b2 does_not_resolve_check; b4b3 does_not_resolve_check; b4b5 does_not_resolve_check; b4b6 does_not_resolve_check; b4b7 does_not_resolve_check; b4b8 does_not_resolve_check; b4c4 does_not_resolve_check; b4d4 does_not_resolve_check; b4e4 does_not_resolve_check; b4f4 does_not_resolve_check | legal none\ng4 black king: pseudo-legal g4f3 g4f4 g4f5 g4g3 g4h3 g4h4 g4h5 | rejected g4f3 does_not_resolve_check; g4g3 does_not_resolve_check; g4h3 does_not_resolve_check | legal g4f4 g4f5 g4h4 g4h5\ng5 black pawn: pseudo-legal none | rejected none | legal none\nAll legal moves: g4f4 g4f5 g4h4 g4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00117", "split": "rules", "task_type": "legal_moves", "fen": "rn1qkb1r/ppp2ppp/4pn2/3p4/2PP2b1/4PN1P/PP3PP1/RNBQKB1R b KQkq - 0 5", "prompt": "FEN: rn1qkb1r/ppp2ppp/4pn2/3p4/2PP2b1/4PN1P/PP3PP1/RNBQKB1R b KQkq - 0 5\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c7c5 c7c6 d5c4 d8c8 d8d6 d8d7 d8e7 e6e5 e8d7 e8e7 f6d7 f6e4 f6g8 f6h5 f8a3 f8b4 f8c5 f8d6 f8e7 g4f3 g4f5 g4h3 g4h5 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00118", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2qkbnr/pp4p1/4Pp1p/3Pp3/2N5/2P1BN2/PP3PPP/R2QK2R b KQkq - 0 12", "prompt": "FEN: r2qkbnr/pp4p1/4Pp1p/3Pp3/2N5/2P1BN2/PP3PPP/R2QK2R b KQkq - 0 12\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: e5 black pawn; f6 black pawn; h6 black pawn; a7 black pawn; b7 black pawn; g7 black pawn; a8 black rook; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00119", "split": "rules", "task_type": "piece_legal_moves", "fen": "k1K5/p7/P3N3/8/8/8/6p1/8 w - -", "prompt": "FEN: k1K5/p7/P3N3/8/8/8/6p1/8 w - -\nWhat legal moves does the piece on a6 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "a6", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a6", "piece": "pawn"}}
{"example_id": "rules_00120", "split": "rules", "task_type": "check_detection", "fen": "r6r/p2npk2/1p1p1p2/PRpP2p1/2P1P3/2P3BP/6P1/R5K1 b - - 0 28", "prompt": "FEN: r6r/p2npk2/1p1p1p2/PRpP2p1/2P1P3/2P3BP/6P1/R5K1 b - - 0 28\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00121", "split": "rules", "task_type": "captures", "fen": "r1bq1rk1/pp1n1pp1/4pn1p/b2p4/2PP3B/P1N2N2/1P2BPPP/R2Q1RK1 b - - 0 11", "prompt": "FEN: r1bq1rk1/pp1n1pp1/4pn1p/b2p4/2PP3B/P1N2N2/1P2BPPP/R2Q1RK1 b - - 0 11\nList all capture moves available.", "gold_answer": "a5c3 d5c4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00122", "split": "rules", "task_type": "special_rules", "fen": "r3kb1r/pp2npp1/1qn1p2p/3pP3/3P3B/1P3B2/P4PPP/RN1Q1RK1 b kq -", "prompt": "Given FEN: r3kb1r/pp2npp1/1qn1p2p/3pP3/3P3B/1P3B2/P4PPP/RN1Q1RK1 b kq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: queenside.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00123", "split": "rules", "task_type": "legality_check", "fen": "2k2r2/1pp3pp/4p3/r7/pn2P3/5N2/PPPR1PPP/2KR4 w - -", "prompt": "FEN: 2k2r2/1pp3pp/4p3/r7/pn2P3/5N2/PPPR1PPP/2KR4 w - -\nIs the move d2d8 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "d2d8", "_legality_check_reason_label": "legal", "move": "d2d8", "legality_reason_label": "legal"}}
{"example_id": "rules_00124", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5rk1/1b5p/p7/2pp1pp1/8/3RP3/P4PPP/4K2R w K - 0 29", "prompt": "FEN: 5rk1/1b5p/p7/2pp1pp1/8/3RP3/P4PPP/4K2R w K - 0 29\nList pseudo-legal moves from e1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e1: e1d1 e1d2 e1e2 e1f1 e1g1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e1", "diagnostic": true, "hard_gate": false, "source_square": "e1"}}
{"example_id": "rules_00125", "split": "rules", "task_type": "piece_legal_filter", "fen": "r3r1k1/pppq1pbp/4bnp1/8/1BP1P3/4P3/P1Q1B1PP/RN2K1NR b KQ - 0 15", "prompt": "FEN: r3r1k1/pppq1pbp/4bnp1/8/1BP1P3/4P3/P1Q1B1PP/RN2K1NR b KQ - 0 15\nFor the piece on g8, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g8: g8f8 g8h8.\nLegal: g8h8.\nRejected: g8f8 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g8", "diagnostic": true, "hard_gate": false, "source_square": "g8"}}
{"example_id": "rules_00126", "split": "rules", "task_type": "king_safety_filter", "fen": "r6r/2K2kpp/p4p2/1p1P4/5P2/2N5/PP6/R7 b - -", "prompt": "FEN: r6r/2K2kpp/p4p2/1p1P4/5P2/2N5/PP6/R7 b - -\nFor move f7e6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: f7e6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "f7e6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "f7e6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00127", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r3k3/pp1q1pp1/2pPp3/7r/3P1n2/P4QP1/1P5P/2R2RK1 w q - 0 23", "prompt": "FEN: r3k3/pp1q1pp1/2pPp3/7r/3P1n2/P4QP1/1P5P/2R2RK1 w q - 0 23\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c1 white rook; f1 white rook; g1 white king; b2 white pawn; h2 white pawn; a3 white pawn; f3 white queen; g3 white pawn; d4 white pawn; d6 white pawn.\nMoves by piece:\nc1 white rook: c1a1 c1b1 c1c2 c1c3 c1c4 c1c5 c1c6 c1d1 c1e1\nf1 white rook: f1d1 f1e1 f1f2\ng1 white king: g1f2 g1h1\nb2 white pawn: b2b3 b2b4\nh2 white pawn: h2h3 h2h4\na3 white pawn: a3a4\nf3 white queen: f3b3 f3c3 f3c6 f3d1 f3d3 f3d5 f3e2 f3e3 f3e4 f3f2 f3f4 f3g2 f3g4 f3h1 f3h5\ng3 white pawn: g3f4 g3g4\nd4 white pawn: d4d5\nd6 white pawn: no legal moves\nAll legal moves: a3a4 b2b3 b2b4 c1a1 c1b1 c1c2 c1c3 c1c4 c1c5 c1c6 c1d1 c1e1 d4d5 f1d1 f1e1 f1f2 f3b3 f3c3 f3c6 f3d1 f3d3 f3d5 f3e2 f3e3 f3e4 f3f2 f3f4 f3g2 f3g4 f3h1 f3h5 g1f2 g1h1 g3f4 g3g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c1": ["c1a1", "c1b1", "c1c2", "c1c3", "c1c4", "c1c5", "c1c6", "c1d1", "c1e1"], "f1": ["f1d1", "f1e1", "f1f2"], "g1": ["g1f2", "g1h1"], "b2": ["b2b3", "b2b4"], "h2": ["h2h3", "h2h4"], "a3": ["a3a4"], "f3": ["f3b3", "f3c3", "f3c6", "f3d1", "f3d3", "f3d5", "f3e2", "f3e3", "f3e4", "f3f2", "f3f4", "f3g2", "f3g4", "f3h1", "f3h5"], "g3": ["g3f4", "g3g4"], "d4": ["d4d5"], "d6": []}, "_legal_moves_by_piece_moves": "a3a4 b2b3 b2b4 c1a1 c1b1 c1c2 c1c3 c1c4 c1c5 c1c6 c1d1 c1e1 d4d5 f1d1 f1e1 f1f2 f3b3 f3c3 f3c6 f3d1 f3d3 f3d5 f3e2 f3e3 f3e4 f3f2 f3f4 f3g2 f3g4 f3h1 f3h5 g1f2 g1h1 g3f4 g3g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c1": ["c1a1", "c1b1", "c1c2", "c1c3", "c1c4", "c1c5", "c1c6", "c1d1", "c1e1"], "f1": ["f1d1", "f1e1", "f1f2"], "g1": ["g1f2", "g1h1"], "b2": ["b2b3", "b2b4"], "h2": ["h2h3", "h2h4"], "a3": ["a3a4"], "f3": ["f3b3", "f3c3", "f3c6", "f3d1", "f3d3", "f3d5", "f3e2", "f3e3", "f3e4", "f3f2", "f3f4", "f3g2", "f3g4", "f3h1", "f3h5"], "g3": ["g3f4", "g3g4"], "d4": ["d4d5"], "d6": []}, "legal_moves": "a3a4 b2b3 b2b4 c1a1 c1b1 c1c2 c1c3 c1c4 c1c5 c1c6 c1d1 c1e1 d4d5 f1d1 f1e1 f1f2 f3b3 f3c3 f3c6 f3d1 f3d3 f3d5 f3e2 f3e3 f3e4 f3f2 f3f4 f3g2 f3g4 f3h1 f3h5 g1f2 g1h1 g3f4 g3g4 h2h3 h2h4"}}
{"example_id": "rules_00128", "split": "rules", "task_type": "ray_walk", "fen": "r3kbnr/pb1nq1pp/1ppppp2/8/8/1P2P1P1/PBPPQPBP/RN2K1NR w KQkq - 0 9", "prompt": "FEN: r3kbnr/pb1nq1pp/1ppppp2/8/8/1P2P1P1/PBPPQPBP/RN2K1NR w KQkq - 0 9\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 white knight: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: none", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00129", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/8/8/2K5/7Q/3k4/8/8 w - -", "prompt": "FEN: 8/8/8/2K5/7Q/3k4/8/8 w - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: h4 white queen; c5 white king.\nFilter by piece:\nh4 white queen: pseudo-legal h4a4 h4b4 h4c4 h4d4 h4d8 h4e1 h4e4 h4e7 h4f2 h4f4 h4f6 h4g3 h4g4 h4g5 h4h1 h4h2 h4h3 h4h5 h4h6 h4h7 h4h8 | rejected none | legal h4a4 h4b4 h4c4 h4d4 h4d8 h4e1 h4e4 h4e7 h4f2 h4f4 h4f6 h4g3 h4g4 h4g5 h4h1 h4h2 h4h3 h4h5 h4h6 h4h7 h4h8\nc5 white king: pseudo-legal c5b4 c5b5 c5b6 c5c4 c5c6 c5d4 c5d5 c5d6 | rejected c5c4 king_would_be_in_check; c5d4 king_would_be_in_check | legal c5b4 c5b5 c5b6 c5c6 c5d5 c5d6\nAll legal moves: c5b4 c5b5 c5b6 c5c6 c5d5 c5d6 h4a4 h4b4 h4c4 h4d4 h4d8 h4e1 h4e4 h4e7 h4f2 h4f4 h4f6 h4g3 h4g4 h4g5 h4h1 h4h2 h4h3 h4h5 h4h6 h4h7 h4h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00130", "split": "rules", "task_type": "legal_moves", "fen": "5rk1/pp1r2bq/n4p1p/2pPp2B/2P1P1QN/P7/1P4PP/2R2RK1 b - - 1 24", "prompt": "FEN: 5rk1/pp1r2bq/n4p1p/2pPp2B/2P1P1QN/P7/1P4PP/2R2RK1 b - - 1 24\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6b4 a6b8 a6c7 b7b5 b7b6 d7c7 d7d5 d7d6 d7d8 d7e7 d7f7 f6f5 f8a8 f8b8 f8c8 f8d8 f8e8 f8f7 g8h8 h7e4 h7f5 h7g6 h7h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00131", "split": "rules", "task_type": "side_piece_inventory", "fen": "r3k2r/ppp2ppp/3b4/3N4/4n3/1P2Pn2/PBPP2P1/R2Q1R1K b kq -", "prompt": "FEN: r3k2r/ppp2ppp/3b4/3N4/4n3/1P2Pn2/PBPP2P1/R2Q1R1K b kq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: f3 black knight; e4 black knight; d6 black bishop; a7 black pawn; b7 black pawn; c7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; e8 black king; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "f3", "piece": "black knight"}, {"square": "e4", "piece": "black knight"}, {"square": "d6", "piece": "black bishop"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "f3", "piece": "black knight"}, {"square": "e4", "piece": "black knight"}, {"square": "d6", "piece": "black bishop"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00132", "split": "rules", "task_type": "piece_legal_moves", "fen": "4r1k1/5ppp/4p3/8/1n2P1N1/3n3P/1P3PP1/R2R2K1 w - - 3 30", "prompt": "FEN: 4r1k1/5ppp/4p3/8/1n2P1N1/3n3P/1P3PP1/R2R2K1 w - - 3 30\nWhat legal moves does the piece on f2 have?", "gold_answer": "f2f3 f2f4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f2", "piece": "pawn"}}
{"example_id": "rules_00133", "split": "rules", "task_type": "check_detection", "fen": "r1b1k2r/ppp2pp1/2Bq1n1p/2p1p3/4P3/3P1N2/PPP2PPP/R1BQK2R b KQkq -", "prompt": "FEN: r1b1k2r/ppp2pp1/2Bq1n1p/2p1p3/4P3/3P1N2/PPP2PPP/R1BQK2R b KQkq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00134", "split": "rules", "task_type": "captures", "fen": "3qrbk1/1b3p2/r4npp/2p2N2/pn2P3/4R2P/1P1N1PP1/1BBQR1K1 w - -", "prompt": "FEN: 3qrbk1/1b3p2/r4npp/2p2N2/pn2P3/4R2P/1P1N1PP1/1BBQR1K1 w - -\nList all capture moves available.", "gold_answer": "d1a4 f5h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00135", "split": "rules", "task_type": "special_rules", "fen": "8/8/4ppk1/3p2p1/3Pn1P1/4R2P/r7/5KN1 b - -", "prompt": "Given FEN: 8/8/4ppk1/3p2p1/3Pn1P1/4R2P/r7/5KN1 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00136", "split": "rules", "task_type": "legality_check", "fen": "1R6/3b4/3pk1p1/4n3/1P1KP2P/8/8/8 w - - 3 59", "prompt": "FEN: 1R6/3b4/3pk1p1/4n3/1P1KP2P/8/8/8 w - - 3 59\nIs the move d4b4 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "d4b4", "_legality_check_reason_label": "own_piece_destination", "move": "d4b4", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_00137", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/2k2ppp/2p5/7r/2q2PK1/pp6/8/8 w - - 0 37", "prompt": "FEN: 8/2k2ppp/2p5/7r/2q2PK1/pp6/8/8 w - - 0 37\nList pseudo-legal moves from f4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from f4: f4f5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "f4", "diagnostic": true, "hard_gate": false, "source_square": "f4"}}
{"example_id": "rules_00138", "split": "rules", "task_type": "piece_legal_filter", "fen": "3nk3/5p1p/6p1/1P2K3/5B2/6P1/5P1P/8 w - -", "prompt": "FEN: 3nk3/5p1p/6p1/1P2K3/5B2/6P1/5P1P/8 w - -\nFor the piece on e5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e5: e5d4 e5d5 e5d6 e5e4 e5e6 e5f5 e5f6.\nLegal: e5d4 e5d5 e5d6 e5e4 e5f6.\nRejected: e5e6 king_would_be_in_check; e5f5 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "e5", "diagnostic": true, "hard_gate": false, "source_square": "e5"}}
{"example_id": "rules_00139", "split": "rules", "task_type": "king_safety_filter", "fen": "6k1/8/p1p4p/P1p5/2P5/1P1Pq3/8/3K4 w - - 2 53", "prompt": "FEN: 6k1/8/p1p4p/P1p5/2P5/1P1Pq3/8/3K4 w - - 2 53\nFor move d1c1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: d1c1.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "d1c1", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "d1c1", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00140", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "4r2k/5Q1p/6p1/p4p1q/P2n1P2/3B2P1/6KP/8 b - -", "prompt": "FEN: 4r2k/5Q1p/6p1/p4p1q/P2n1P2/3B2P1/6KP/8 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d4 black knight; a5 black pawn; f5 black pawn; h5 black queen; g6 black pawn; h7 black pawn; e8 black rook; h8 black king.\nMoves by piece:\nd4 black knight: d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3\na5 black pawn: no legal moves\nf5 black pawn: no legal moves\nh5 black queen: h5d1 h5e2 h5f3 h5g4 h5g5 h5h2 h5h3 h5h4 h5h6\ng6 black pawn: g6g5\nh7 black pawn: h7h6\ne8 black rook: e8a8 e8b8 e8c8 e8d8 e8e1 e8e2 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8\nh8 black king: no legal moves\nAll legal moves: d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3 e8a8 e8b8 e8c8 e8d8 e8e1 e8e2 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 g6g5 h5d1 h5e2 h5f3 h5g4 h5g5 h5h2 h5h3 h5h4 h5h6 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d4": ["d4b3", "d4b5", "d4c2", "d4c6", "d4e2", "d4e6", "d4f3"], "a5": [], "f5": [], "h5": ["h5d1", "h5e2", "h5f3", "h5g4", "h5g5", "h5h2", "h5h3", "h5h4", "h5h6"], "g6": ["g6g5"], "h7": ["h7h6"], "e8": ["e8a8", "e8b8", "e8c8", "e8d8", "e8e1", "e8e2", "e8e3", "e8e4", "e8e5", "e8e6", "e8e7", "e8f8", "e8g8"], "h8": []}, "_legal_moves_by_piece_moves": "d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3 e8a8 e8b8 e8c8 e8d8 e8e1 e8e2 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 g6g5 h5d1 h5e2 h5f3 h5g4 h5g5 h5h2 h5h3 h5h4 h5h6 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d4": ["d4b3", "d4b5", "d4c2", "d4c6", "d4e2", "d4e6", "d4f3"], "a5": [], "f5": [], "h5": ["h5d1", "h5e2", "h5f3", "h5g4", "h5g5", "h5h2", "h5h3", "h5h4", "h5h6"], "g6": ["g6g5"], "h7": ["h7h6"], "e8": ["e8a8", "e8b8", "e8c8", "e8d8", "e8e1", "e8e2", "e8e3", "e8e4", "e8e5", "e8e6", "e8e7", "e8f8", "e8g8"], "h8": []}, "legal_moves": "d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3 e8a8 e8b8 e8c8 e8d8 e8e1 e8e2 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 g6g5 h5d1 h5e2 h5f3 h5g4 h5g5 h5h2 h5h3 h5h4 h5h6 h7h6"}}
{"example_id": "rules_00141", "split": "rules", "task_type": "ray_walk", "fen": "2rq1rk1/3b1ppp/p2Q1n2/1p2p3/2P1P3/1PN5/P1B2PPP/R4RK1 w - -", "prompt": "FEN: 2rq1rk1/3b1ppp/p2Q1n2/1p2p3/2P1P3/1PN5/P1B2PPP/R4RK1 w - -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 empty; e1 empty; f1 white rook: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1 a1d1 a1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00142", "split": "rules", "task_type": "legal_filter_trace", "fen": "3r3k/8/2B4p/1P2p1p1/1r1bP3/5N2/5PPP/3R2K1 w - - 2 33", "prompt": "FEN: 3r3k/8/2B4p/1P2p1p1/1r1bP3/5N2/5PPP/3R2K1 w - - 2 33\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: d1 white rook; g1 white king; f2 white pawn; g2 white pawn; h2 white pawn; f3 white knight; e4 white pawn; b5 white pawn; c6 white bishop.\nFilter by piece:\nd1 white rook: pseudo-legal d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1e1 d1f1 | rejected none | legal d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1e1 d1f1\ng1 white king: pseudo-legal g1f1 g1h1 | rejected none | legal g1f1 g1h1\nf2 white pawn: pseudo-legal none | rejected none | legal none\ng2 white pawn: pseudo-legal g2g3 g2g4 | rejected none | legal g2g3 g2g4\nh2 white pawn: pseudo-legal h2h3 h2h4 | rejected none | legal h2h3 h2h4\nf3 white knight: pseudo-legal f3d2 f3d4 f3e1 f3e5 f3g5 f3h4 | rejected none | legal f3d2 f3d4 f3e1 f3e5 f3g5 f3h4\ne4 white pawn: pseudo-legal none | rejected none | legal none\nb5 white pawn: pseudo-legal b5b6 | rejected none | legal b5b6\nc6 white bishop: pseudo-legal c6a8 c6b7 c6d5 c6d7 c6e8 | rejected none | legal c6a8 c6b7 c6d5 c6d7 c6e8\nAll legal moves: b5b6 c6a8 c6b7 c6d5 c6d7 c6e8 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1e1 d1f1 f3d2 f3d4 f3e1 f3e5 f3g5 f3h4 g1f1 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00143", "split": "rules", "task_type": "legal_moves", "fen": "2kr3r/Rpp3pp/4p3/4P1P1/2P5/4P2b/1q3R2/4Q1K1 b - - 1 28", "prompt": "FEN: 2kr3r/Rpp3pp/4p3/4P1P1/2P5/4P2b/1q3R2/4Q1K1 b - - 1 28\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b2a1 b2a2 b2a3 b2b1 b2b3 b2b4 b2b5 b2b6 b2c1 b2c2 b2c3 b2d2 b2d4 b2e2 b2e5 b2f2 b7b5 b7b6 c7c5 c7c6 c8b8 c8d7 d8d1 d8d2 d8d3 d8d4 d8d5 d8d6 d8d7 d8e8 d8f8 d8g8 g7g6 h3f1 h3f5 h3g2 h3g4 h7h5 h7h6 h8e8 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00144", "split": "rules", "task_type": "side_piece_inventory", "fen": "r4rk1/2p2ppp/p1n2q2/1pb1p3/4P1b1/1BP2N2/PP1N1PPP/R2Q1RK1 b - - 2 12", "prompt": "FEN: r4rk1/2p2ppp/p1n2q2/1pb1p3/4P1b1/1BP2N2/PP1N1PPP/R2Q1RK1 b - - 2 12\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: g4 black bishop; b5 black pawn; c5 black bishop; e5 black pawn; a6 black pawn; c6 black knight; f6 black queen; c7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "g4", "piece": "black bishop"}, {"square": "b5", "piece": "black pawn"}, {"square": "c5", "piece": "black bishop"}, {"square": "e5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "f6", "piece": "black queen"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "g4", "piece": "black bishop"}, {"square": "b5", "piece": "black pawn"}, {"square": "c5", "piece": "black bishop"}, {"square": "e5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "f6", "piece": "black queen"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_00145", "split": "rules", "task_type": "piece_legal_moves", "fen": "r4rk1/ppp2ppp/2Bq4/2b5/3p2b1/2P2N2/PP3PPP/RNBQ1RK1 b - - 0 11", "prompt": "FEN: r4rk1/ppp2ppp/2Bq4/2b5/3p2b1/2P2N2/PP3PPP/RNBQ1RK1 b - - 0 11\nWhat legal moves does the piece on a8 have?", "gold_answer": "a8b8 a8c8 a8d8 a8e8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a8", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "a8", "piece": "rook"}}
{"example_id": "rules_00146", "split": "rules", "task_type": "check_detection", "fen": "rnbqk2r/ppp2pp1/3p1n1p/2b1p1B1/2B1P3/2NP4/PPP2PPP/R2QK1NR w KQkq - 0 6", "prompt": "FEN: rnbqk2r/ppp2pp1/3p1n1p/2b1p1B1/2B1P3/2NP4/PPP2PPP/R2QK1NR w KQkq - 0 6\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00147", "split": "rules", "task_type": "captures", "fen": "r5k1/p5bp/1p2q1p1/1P3p2/P1rPp3/3RP1P1/5PBP/RQ4K1 b - - 0 25", "prompt": "FEN: r5k1/p5bp/1p2q1p1/1P3p2/P1rPp3/3RP1P1/5PBP/RQ4K1 b - - 0 25\nList all capture moves available.", "gold_answer": "c4a4 c4d4 e4d3 g7d4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00148", "split": "rules", "task_type": "special_rules", "fen": "1r5r/4k3/4p2p/p1p1P1p1/2Pp1p2/PP6/1R3PPP/4R1K1 w - - 0 25", "prompt": "Given FEN: 1r5r/4k3/4p2p/p1p1P1p1/2Pp1p2/PP6/1R3PPP/4R1K1 w - - 0 25\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00149", "split": "rules", "task_type": "legality_check", "fen": "8/8/6k1/4p1pp/3r1p2/4NP1P/5KP1/8 b - - 1 45", "prompt": "FEN: 8/8/6k1/4p1pp/3r1p2/4NP1P/5KP1/8 b - - 1 45\nIs the move g6g7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g6g7", "_legality_check_reason_label": "legal", "move": "g6g7", "legality_reason_label": "legal"}}
{"example_id": "rules_00150", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r5k1/pb2bppp/1pq1p3/2p5/4PB2/2P4P/PPB1QPP1/3r1RK1 w - - 0 18", "prompt": "FEN: r5k1/pb2bppp/1pq1p3/2p5/4PB2/2P4P/PPB1QPP1/3r1RK1 w - - 0 18\nList pseudo-legal moves from f1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from f1: f1d1 f1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "f1", "diagnostic": true, "hard_gate": false, "source_square": "f1"}}
{"example_id": "rules_00151", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1bq1rk1/3nppbp/3p1np1/pp6/2P1P3/1B1P1N1P/1P3PP1/RNBQ1RK1 b - - 0 11", "prompt": "FEN: r1bq1rk1/3nppbp/3p1np1/pp6/2P1P3/1B1P1N1P/1P3PP1/RNBQ1RK1 b - - 0 11\nFor the piece on a5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a5: a5a4.\nLegal: a5a4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_00152", "split": "rules", "task_type": "king_safety_filter", "fen": "2rqr1k1/pb1n1pb1/8/2p1p1p1/2P1P3/1P1P1NP1/PBB5/R2Q1RK1 b - - 0 22", "prompt": "FEN: 2rqr1k1/pb1n1pb1/8/2p1p1p1/2P1P3/1P1P1NP1/PBB5/R2Q1RK1 b - - 0 22\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00153", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2r2rk1/qp1b1ppp/p3p3/2bpnP2/3N2P1/2P5/P1P2BBP/1R1Q1R1K b - - 1 21", "prompt": "FEN: 2r2rk1/qp1b1ppp/p3p3/2bpnP2/3N2P1/2P5/P1P2BBP/1R1Q1R1K b - - 1 21\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black bishop; d5 black pawn; e5 black knight; a6 black pawn; e6 black pawn; a7 black queen; b7 black pawn; d7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; c8 black rook; f8 black rook; g8 black king.\nMoves by piece:\nc5 black bishop: c5a3 c5b4 c5b6 c5d4 c5d6 c5e7\nd5 black pawn: no legal moves\ne5 black knight: e5c4 e5c6 e5d3 e5f3 e5g4 e5g6\na6 black pawn: a6a5\ne6 black pawn: e6f5\na7 black queen: a7a8 a7b6 a7b8\nb7 black pawn: b7b5 b7b6\nd7 black bishop: d7a4 d7b5 d7c6 d7e8\nf7 black pawn: f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\nc8 black rook: c8a8 c8b8 c8c6 c8c7 c8d8 c8e8\nf8 black rook: f8d8 f8e8\ng8 black king: g8h8\nAll legal moves: a6a5 a7a8 a7b6 a7b8 b7b5 b7b6 c5a3 c5b4 c5b6 c5d4 c5d6 c5e7 c8a8 c8b8 c8c6 c8c7 c8d8 c8e8 d7a4 d7b5 d7c6 d7e8 e5c4 e5c6 e5d3 e5f3 e5g4 e5g6 e6f5 f7f6 f8d8 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": ["c5a3", "c5b4", "c5b6", "c5d4", "c5d6", "c5e7"], "d5": [], "e5": ["e5c4", "e5c6", "e5d3", "e5f3", "e5g4", "e5g6"], "a6": ["a6a5"], "e6": ["e6f5"], "a7": ["a7a8", "a7b6", "a7b8"], "b7": ["b7b5", "b7b6"], "d7": ["d7a4", "d7b5", "d7c6", "d7e8"], "f7": ["f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8a8", "c8b8", "c8c6", "c8c7", "c8d8", "c8e8"], "f8": ["f8d8", "f8e8"], "g8": ["g8h8"]}, "_legal_moves_by_piece_moves": "a6a5 a7a8 a7b6 a7b8 b7b5 b7b6 c5a3 c5b4 c5b6 c5d4 c5d6 c5e7 c8a8 c8b8 c8c6 c8c7 c8d8 c8e8 d7a4 d7b5 d7c6 d7e8 e5c4 e5c6 e5d3 e5f3 e5g4 e5g6 e6f5 f7f6 f8d8 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": ["c5a3", "c5b4", "c5b6", "c5d4", "c5d6", "c5e7"], "d5": [], "e5": ["e5c4", "e5c6", "e5d3", "e5f3", "e5g4", "e5g6"], "a6": ["a6a5"], "e6": ["e6f5"], "a7": ["a7a8", "a7b6", "a7b8"], "b7": ["b7b5", "b7b6"], "d7": ["d7a4", "d7b5", "d7c6", "d7e8"], "f7": ["f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8a8", "c8b8", "c8c6", "c8c7", "c8d8", "c8e8"], "f8": ["f8d8", "f8e8"], "g8": ["g8h8"]}, "legal_moves": "a6a5 a7a8 a7b6 a7b8 b7b5 b7b6 c5a3 c5b4 c5b6 c5d4 c5d6 c5e7 c8a8 c8b8 c8c6 c8c7 c8d8 c8e8 d7a4 d7b5 d7c6 d7e8 e5c4 e5c6 e5d3 e5f3 e5g4 e5g6 e6f5 f7f6 f8d8 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6"}}
{"example_id": "rules_00154", "split": "rules", "task_type": "ray_walk", "fen": "r2q1rk1/4b1p1/3p3p/2p1pb2/1nP3P1/1BNPQN1P/1P3P2/2KR3R b - - 0 20", "prompt": "FEN: r2q1rk1/4b1p1/3p3p/2p1pb2/1nP3P1/1BNPQN1P/1P3P2/2KR3R b - - 0 20\nWalk each ray for the slider on f5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: f5 black bishop.\nRay NE: g6 empty; h7 empty; edge.\nRay SE: g4 white pawn: capture (stop, included).\nRay SW: e4 empty; d3 white pawn: capture (stop, included).\nRay NW: e6 empty; d7 empty; c8 empty; edge.\nMoves from rays: f5c8 f5d3 f5d7 f5e4 f5e6 f5g4 f5g6 f5h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "f5", "diagnostic": true, "hard_gate": false, "source_square": "f5"}}
{"example_id": "rules_00155", "split": "rules", "task_type": "legal_moves", "fen": "3rr1k1/pp1B2b1/2p2qp1/2np3p/1P1P3P/P2R1PB1/2N2K2/3QR3 b - - 0 31", "prompt": "FEN: 3rr1k1/pp1B2b1/2p2qp1/2np3p/1P1P3P/P2R1PB1/2N2K2/3QR3 b - - 0 31\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 c5a4 c5a6 c5b3 c5d3 c5d7 c5e4 c5e6 d8a8 d8b8 d8c8 d8d7 e8e1 e8e2 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 f6d4 f6d6 f6e5 f6e6 f6e7 f6f3 f6f4 f6f5 f6f7 f6f8 f6g5 f6h4 g6g5 g7f8 g7h6 g7h8 g8f7 g8f8 g8h7 g8h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00156", "split": "rules", "task_type": "legal_moves", "fen": "8/8/3K4/R7/3k4/8/8/8 b - -", "prompt": "FEN: 8/8/3K4/R7/3k4/8/8/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: d4c3 d4c4 d4d3 d4e3 d4e4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00157", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/2R3p1/7p/8/5P2/r1p4P/2k3P1/5K2 b - -", "prompt": "FEN: 8/2R3p1/7p/8/5P2/r1p4P/2k3P1/5K2 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c2 black king; a3 black rook; c3 black pawn; h6 black pawn; g7 black pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c2", "piece": "black king"}, {"square": "a3", "piece": "black rook"}, {"square": "c3", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c2", "piece": "black king"}, {"square": "a3", "piece": "black rook"}, {"square": "c3", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}]}}
{"example_id": "rules_00158", "split": "rules", "task_type": "piece_legal_moves", "fen": "1r3rk1/p4pp1/7p/2Q3n1/2P5/4P1PP/2PN4/1N2K2b b - -", "prompt": "FEN: 1r3rk1/p4pp1/7p/2Q3n1/2P5/4P1PP/2PN4/1N2K2b b - -\nWhat legal moves does the piece on a7 have?", "gold_answer": "a7a5 a7a6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "a7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a7", "piece": "pawn"}}
{"example_id": "rules_00159", "split": "rules", "task_type": "check_detection", "fen": "r4Bk1/1p3ppp/pn2qn2/3p4/3Pp3/P3P1P1/1P2QPBP/R4RK1 b - - 0 17", "prompt": "FEN: r4Bk1/1p3ppp/pn2qn2/3p4/3Pp3/P3P1P1/1P2QPBP/R4RK1 b - - 0 17\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00160", "split": "rules", "task_type": "captures", "fen": "4R3/pR3pk1/1pq3pp/8/8/P4NP1/1P3PP1/6K1 w - -", "prompt": "FEN: 4R3/pR3pk1/1pq3pp/8/8/P4NP1/1P3PP1/6K1 w - -\nList all capture moves available.", "gold_answer": "b7a7 b7b6 b7f7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00161", "split": "rules", "task_type": "special_rules", "fen": "8/5p2/4pk2/3r2p1/8/6PK/R6P/8 w - -", "prompt": "Given FEN: 8/5p2/4pk2/3r2p1/8/6PK/R6P/8 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00162", "split": "rules", "task_type": "legality_check", "fen": "r4rk1/1pq1bppp/3p4/pP1Pp3/2P5/5Q2/1B1P1PPP/R4RK1 w - - 1 16", "prompt": "FEN: r4rk1/1pq1bppp/3p4/pP1Pp3/2P5/5Q2/1B1P1PPP/R4RK1 w - - 1 16\nIs the move a8a5 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "a8a5", "_legality_check_reason_label": "wrong_side_piece", "move": "a8a5", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_00163", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r6r/3b2k1/n1p1p1p1/3qPpNp/ppPP3P/3Q2P1/P1B2P2/1K1R3R b - - 0 22", "prompt": "FEN: r6r/3b2k1/n1p1p1p1/3qPpNp/ppPP3P/3Q2P1/P1B2P2/1K1R3R b - - 0 22\nList pseudo-legal moves from a4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a4: a4a3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a4", "diagnostic": true, "hard_gate": false, "source_square": "a4"}}
{"example_id": "rules_00164", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnbqk1nr/pppp1pp1/3b3p/4p3/2B1P3/3P4/PPP2PPP/RNBQK1NR w KQkq - 0 4", "prompt": "FEN: rnbqk1nr/pppp1pp1/3b3p/4p3/2B1P3/3P4/PPP2PPP/RNBQK1NR w KQkq - 0 4\nFor the piece on b1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b1: b1a3 b1c3 b1d2.\nLegal: b1a3 b1c3 b1d2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_00165", "split": "rules", "task_type": "king_safety_filter", "fen": "8/1kp2p2/7r/p3p3/Pp1pPqpQ/1P6/2P3P1/1K1R4 w - - 2 37", "prompt": "FEN: 8/1kp2p2/7r/p3p3/Pp1pPqpQ/1P6/2P3P1/1K1R4 w - - 2 37\nFor move b1c1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: b1c1.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "b1c1", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "b1c1", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00166", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/8/8/3K4/8/4k3/8/5R2 b - -", "prompt": "FEN: 8/8/8/3K4/8/4k3/8/5R2 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e3 black king.\nMoves by piece:\ne3 black king: e3d2 e3d3 e3e2\nAll legal moves: e3d2 e3d3 e3e2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e3": ["e3d2", "e3d3", "e3e2"]}, "_legal_moves_by_piece_moves": "e3d2 e3d3 e3e2", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e3": ["e3d2", "e3d3", "e3e2"]}, "legal_moves": "e3d2 e3d3 e3e2"}}
{"example_id": "rules_00167", "split": "rules", "task_type": "ray_walk", "fen": "8/4n1P1/5n2/4pb2/1k6/4P2p/B4K2/8 w - - 0 51", "prompt": "FEN: 8/4n1P1/5n2/4pb2/1k6/4P2p/B4K2/8 w - - 0 51\nWalk each ray for the slider on a2: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a2 white bishop.\nRay NE: b3 empty; c4 empty; d5 empty; e6 empty; f7 empty; g8 empty; edge.\nRay SE: b1 empty; edge.\nRay SW: edge.\nRay NW: edge.\nMoves from rays: a2b1 a2b3 a2c4 a2d5 a2e6 a2f7 a2g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a2", "diagnostic": true, "hard_gate": false, "source_square": "a2"}}
{"example_id": "rules_00168", "split": "rules", "task_type": "legal_moves", "fen": "4rrk1/2pn2p1/1p1n3p/pPbPpp2/P1P1P3/2N2RPq/2BBQ2P/4R2K w - -", "prompt": "FEN: 4rrk1/2pn2p1/1p1n3p/pPbPpp2/P1P1P3/2N2RPq/2BBQ2P/4R2K w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: c2b1 c2b3 c2d1 c2d3 c3a2 c3b1 c3d1 d2c1 d2e3 d2f4 d2g5 d2h6 e1a1 e1b1 e1c1 e1d1 e1f1 e1g1 e2d1 e2d3 e2e3 e2f1 e2f2 e2g2 e4f5 f3d3 f3e3 f3f1 f3f2 f3f4 f3f5 g3g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00169", "split": "rules", "task_type": "legal_moves", "fen": "8/p4rk1/1p5p/6p1/1P1pNB2/P2P1qP1/7P/4RBK1 w - - 0 31", "prompt": "FEN: 8/p4rk1/1p5p/6p1/1P1pNB2/P2P1qP1/7P/4RBK1 w - - 0 31\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 b4b5 e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e4c3 e4c5 e4d2 e4d6 e4f2 e4f6 e4g5 f1e2 f1g2 f1h3 f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g5 g3g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00170", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1b1qrk1/5ppp/p3p3/1pp5/3nRB2/2NP2PB/PPP2P1P/2K4R w - -", "prompt": "FEN: r1b1qrk1/5ppp/p3p3/1pp5/3nRB2/2NP2PB/PPP2P1P/2K4R w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: c1 white king; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; h2 white pawn; c3 white knight; d3 white pawn; g3 white pawn; h3 white bishop; e4 white rook; f4 white bishop.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "c1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "h3", "piece": "white bishop"}, {"square": "e4", "piece": "white rook"}, {"square": "f4", "piece": "white bishop"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "c1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "h3", "piece": "white bishop"}, {"square": "e4", "piece": "white rook"}, {"square": "f4", "piece": "white bishop"}]}}
{"example_id": "rules_00171", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnb1kbnr/2qp1ppp/p3p3/1p6/3NP3/P1N2P2/1PP3PP/R1BQKB1R b KQkq -", "prompt": "FEN: rnb1kbnr/2qp1ppp/p3p3/1p6/3NP3/P1N2P2/1PP3PP/R1BQKB1R b KQkq -\nWhat legal moves does the piece on e8 have?", "gold_answer": "e8d8 e8e7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "e8", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "e8", "piece": "king"}}
{"example_id": "rules_00172", "split": "rules", "task_type": "check_detection", "fen": "B7/6p1/8/7p/8/2k5/K5P1/8 w - -", "prompt": "FEN: B7/6p1/8/7p/8/2k5/K5P1/8 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00173", "split": "rules", "task_type": "captures", "fen": "3r3r/2p1k1pp/2q1b3/pp2R3/8/P1N2N2/1PP1QPPP/R5K1 b - - 3 19", "prompt": "FEN: 3r3r/2p1k1pp/2q1b3/pp2R3/8/P1N2N2/1PP1QPPP/R5K1 b - - 3 19\nList all capture moves available.", "gold_answer": "c6c3 c6f3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00174", "split": "rules", "task_type": "special_rules", "fen": "r1bq1rk1/1p2Bp1p/p1n1p1p1/2npP3/5Q1P/2N2N2/PPP2PP1/2KR1B1R b - -", "prompt": "Given FEN: r1bq1rk1/1p2Bp1p/p1n1p1p1/2npP3/5Q1P/2N2N2/PPP2PP1/2KR1B1R b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00175", "split": "rules", "task_type": "legality_check", "fen": "rkn3q1/pp3R2/2p3BQ/4P3/3P4/2P5/P5PP/R6K w - - 7 28", "prompt": "FEN: rkn3q1/pp3R2/2p3BQ/4P3/3P4/2P5/P5PP/R6K w - - 7 28\nIs the move f7g4 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f7g4", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "f7g4", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_00176", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "7k/1R6/8/6KP/8/8/2b5/8 w - -", "prompt": "FEN: 7k/1R6/8/6KP/8/8/2b5/8 w - -\nList pseudo-legal moves from g5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g5: g5f4 g5f5 g5f6 g5g4 g5g6 g5h4 g5h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g5", "diagnostic": true, "hard_gate": false, "source_square": "g5"}}
{"example_id": "rules_00177", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2qk2r/pb1pbpp1/1pn1pn1p/2p5/2B1P3/P1NP1N1P/1PP2PP1/R1BQ1RK1 w kq - 1 9", "prompt": "FEN: r2qk2r/pb1pbpp1/1pn1pn1p/2p5/2B1P3/P1NP1N1P/1PP2PP1/R1BQ1RK1 w kq - 1 9\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1a2 a1b1.\nLegal: a1a2 a1b1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00178", "split": "rules", "task_type": "king_safety_filter", "fen": "r5k1/2r3p1/b3n2p/5p2/1p3P1P/3N1PR1/3K1P2/6R1 w - - 0 32", "prompt": "FEN: r5k1/2r3p1/b3n2p/5p2/1p3P1P/3N1PR1/3K1P2/6R1 w - - 0 32\nFor move d2c1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: d2c1.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "d2c1", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "d2c1", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00179", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r4rk1/ppp2p1p/4p1p1/3p4/3P4/2BBPP1n/PPP4P/R4RK1 w - - 0 17", "prompt": "FEN: r4rk1/ppp2p1p/4p1p1/3p4/3P4/2BBPP1n/PPP4P/R4RK1 w - - 0 17\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; c2 white pawn; h2 white pawn; c3 white bishop; d3 white bishop; e3 white pawn; f3 white pawn; d4 white pawn.\nMoves by piece:\na1 white rook: no legal moves\nf1 white rook: no legal moves\ng1 white king: g1g2 g1h1\na2 white pawn: no legal moves\nb2 white pawn: no legal moves\nc2 white pawn: no legal moves\nh2 white pawn: no legal moves\nc3 white bishop: no legal moves\nd3 white bishop: no legal moves\ne3 white pawn: no legal moves\nf3 white pawn: no legal moves\nd4 white pawn: no legal moves\nAll legal moves: g1g2 g1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "f1": [], "g1": ["g1g2", "g1h1"], "a2": [], "b2": [], "c2": [], "h2": [], "c3": [], "d3": [], "e3": [], "f3": [], "d4": []}, "_legal_moves_by_piece_moves": "g1g2 g1h1", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "f1": [], "g1": ["g1g2", "g1h1"], "a2": [], "b2": [], "c2": [], "h2": [], "c3": [], "d3": [], "e3": [], "f3": [], "d4": []}, "legal_moves": "g1g2 g1h1"}}
{"example_id": "rules_00180", "split": "rules", "task_type": "ray_walk", "fen": "rn1qkb1r/pp1b1p2/4p2p/1Bp3p1/3Pp2P/6B1/PPP2PP1/R2QK1NR w KQkq -", "prompt": "FEN: rn1qkb1r/pp1b1p2/4p2p/1Bp3p1/3Pp2P/6B1/PPP2PP1/R2QK1NR w KQkq -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 white queen: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00181", "split": "rules", "task_type": "legal_moves", "fen": "r1bqk2r/pp2ppb1/2np1np1/7p/3NP3/2N1B2P/PPP1BPP1/R2Q1RK1 b kq -", "prompt": "FEN: r1bqk2r/pp2ppb1/2np1np1/7p/3NP3/2N1B2P/PPP1BPP1/R2Q1RK1 b kq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 c8d7 c8e6 c8f5 c8g4 c8h3 d6d5 d8a5 d8b6 d8c7 d8d7 e7e5 e7e6 e8d7 e8f8 e8g8 f6d5 f6d7 f6e4 f6g4 f6g8 f6h7 g6g5 g7f8 g7h6 h5h4 h8f8 h8g8 h8h6 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00182", "split": "rules", "task_type": "legal_moves", "fen": "r1bqkbnr/2p1p1pp/p1p2p2/3p4/5P2/1P2PN2/P1PP2PP/RNBQK2R b KQkq - 0 6", "prompt": "FEN: r1bqkbnr/2p1p1pp/p1p2p2/3p4/5P2/1P2PN2/P1PP2PP/RNBQK2R b KQkq - 0 6\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 a8b8 c6c5 c8b7 c8d7 c8e6 c8f5 c8g4 c8h3 d5d4 d8d6 d8d7 e7e5 e7e6 e8d7 e8f7 f6f5 g7g5 g7g6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00183", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/8/6k1/6P1/6K1/8/8/8 w - -", "prompt": "FEN: 8/8/6k1/6P1/6K1/8/8/8 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: g4 white king; g5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "g4", "piece": "white king"}, {"square": "g5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "g4", "piece": "white king"}, {"square": "g5", "piece": "white pawn"}]}}
{"example_id": "rules_00184", "split": "rules", "task_type": "piece_legal_moves", "fen": "3b4/p4k2/1p4pp/2pN1p2/P4P2/1nPK2P1/5B1P/8 b - - 1 38", "prompt": "FEN: 3b4/p4k2/1p4pp/2pN1p2/P4P2/1nPK2P1/5B1P/8 b - - 1 38\nWhat legal moves does the piece on c5 have?", "gold_answer": "c5c4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c5", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "c5", "piece": "pawn"}}
{"example_id": "rules_00185", "split": "rules", "task_type": "check_detection", "fen": "1k3rB1/pb1n2p1/1p5p/3pP3/1P1P4/P5P1/7P/R1BQ2K1 b - - 0 27", "prompt": "FEN: 1k3rB1/pb1n2p1/1p5p/3pP3/1P1P4/P5P1/7P/R1BQ2K1 b - - 0 27\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00186", "split": "rules", "task_type": "captures", "fen": "r3r1k1/2qn1ppp/2pb1p2/p7/1p1P3P/P4Q2/1PPB1PP1/2KR1B1R w - -", "prompt": "FEN: r3r1k1/2qn1ppp/2pb1p2/p7/1p1P3P/P4Q2/1PPB1PP1/2KR1B1R w - -\nList all capture moves available.", "gold_answer": "a3b4 d2b4 f3c6 f3f6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00187", "split": "rules", "task_type": "special_rules", "fen": "r1b4r/1pq1k1pp/pb3n2/2pBp3/2P1P3/B1N5/P4PPP/1R1Q1RK1 b - -", "prompt": "Given FEN: r1b4r/1pq1k1pp/pb3n2/2pBp3/2P1P3/B1N5/P4PPP/1R1Q1RK1 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00188", "split": "rules", "task_type": "legality_check", "fen": "6k1/8/6Np/r7/2rbR3/6BP/5PPK/8 w - - 2 41", "prompt": "FEN: 6k1/8/6Np/r7/2rbR3/6BP/5PPK/8 w - - 2 41\nIs the move g3b8 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g3b8", "_legality_check_reason_label": "legal", "move": "g3b8", "legality_reason_label": "legal"}}
{"example_id": "rules_00189", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnb1k1nr/p1pp1ppp/4p3/4P3/3P4/3Q4/1PPb1PPP/RN2K1NR w KQkq - 0 9", "prompt": "FEN: rnb1k1nr/p1pp1ppp/4p3/4P3/3P4/3Q4/1PPb1PPP/RN2K1NR w KQkq - 0 9\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1a2 a1a3 a1a4 a1a5 a1a6 a1a7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00190", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/8/2B5/3n1p1p/3k3P/4r3/6RK/8 w - - 0 50", "prompt": "FEN: 8/8/2B5/3n1p1p/3k3P/4r3/6RK/8 w - - 0 50\nFor the piece on h2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from h2: h2g1 h2g3 h2h1 h2h3.\nLegal: h2g1 h2h1.\nRejected: h2g3 king_would_be_in_check; h2h3 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "h2", "diagnostic": true, "hard_gate": false, "source_square": "h2"}}
{"example_id": "rules_00191", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bq1rk1/pp2ppb1/1n4pp/4P3/3P1n1B/P2B1N2/1P4PP/RN1Q1RK1 w - - 2 16", "prompt": "FEN: r1bq1rk1/pp2ppb1/1n4pp/4P3/3P1n1B/P2B1N2/1P4PP/RN1Q1RK1 w - - 2 16\nFor move a1a2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1a2.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1a2", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1a2", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00192", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r3r1k1/ppp2ppp/5q2/n2B4/3P4/P1P1R2P/2P2PP1/R2Q2K1 b - - 0 20", "prompt": "FEN: r3r1k1/ppp2ppp/5q2/n2B4/3P4/P1P1R2P/2P2PP1/R2Q2K1 b - - 0 20\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a5 black knight; f6 black queen; a7 black pawn; b7 black pawn; c7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; e8 black rook; g8 black king.\nMoves by piece:\na5 black knight: a5b3 a5c4 a5c6\nf6 black queen: f6a6 f6b6 f6c6 f6d4 f6d6 f6d8 f6e5 f6e6 f6e7 f6f2 f6f3 f6f4 f6f5 f6g5 f6g6 f6h4 f6h6\na7 black pawn: a7a6\nb7 black pawn: b7b5 b7b6\nc7 black pawn: c7c5 c7c6\nf7 black pawn: no legal moves\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8 a8c8 a8d8\ne8 black rook: e8b8 e8c8 e8d8 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8\ng8 black king: g8f8 g8h8\nAll legal moves: a5b3 a5c4 a5c6 a7a6 a8b8 a8c8 a8d8 b7b5 b7b6 c7c5 c7c6 e8b8 e8c8 e8d8 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 f6a6 f6b6 f6c6 f6d4 f6d6 f6d8 f6e5 f6e6 f6e7 f6f2 f6f3 f6f4 f6f5 f6g5 f6g6 f6h4 f6h6 g7g5 g7g6 g8f8 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a5": ["a5b3", "a5c4", "a5c6"], "f6": ["f6a6", "f6b6", "f6c6", "f6d4", "f6d6", "f6d8", "f6e5", "f6e6", "f6e7", "f6f2", "f6f3", "f6f4", "f6f5", "f6g5", "f6g6", "f6h4", "f6h6"], "a7": ["a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7c5", "c7c6"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8", "a8c8", "a8d8"], "e8": ["e8b8", "e8c8", "e8d8", "e8e3", "e8e4", "e8e5", "e8e6", "e8e7", "e8f8"], "g8": ["g8f8", "g8h8"]}, "_legal_moves_by_piece_moves": "a5b3 a5c4 a5c6 a7a6 a8b8 a8c8 a8d8 b7b5 b7b6 c7c5 c7c6 e8b8 e8c8 e8d8 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 f6a6 f6b6 f6c6 f6d4 f6d6 f6d8 f6e5 f6e6 f6e7 f6f2 f6f3 f6f4 f6f5 f6g5 f6g6 f6h4 f6h6 g7g5 g7g6 g8f8 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a5": ["a5b3", "a5c4", "a5c6"], "f6": ["f6a6", "f6b6", "f6c6", "f6d4", "f6d6", "f6d8", "f6e5", "f6e6", "f6e7", "f6f2", "f6f3", "f6f4", "f6f5", "f6g5", "f6g6", "f6h4", "f6h6"], "a7": ["a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7c5", "c7c6"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8", "a8c8", "a8d8"], "e8": ["e8b8", "e8c8", "e8d8", "e8e3", "e8e4", "e8e5", "e8e6", "e8e7", "e8f8"], "g8": ["g8f8", "g8h8"]}, "legal_moves": "a5b3 a5c4 a5c6 a7a6 a8b8 a8c8 a8d8 b7b5 b7b6 c7c5 c7c6 e8b8 e8c8 e8d8 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 f6a6 f6b6 f6c6 f6d4 f6d6 f6d8 f6e5 f6e6 f6e7 f6f2 f6f3 f6f4 f6f5 f6g5 f6g6 f6h4 f6h6 g7g5 g7g6 g8f8 g8h8 h7h5 h7h6"}}
{"example_id": "rules_00193", "split": "rules", "task_type": "ray_walk", "fen": "r2qkb2/1p1n2p1/p1p2ppr/2Ppp2n/3P3B/2N1P3/PPQ2PPP/R3KB1R b KQq -", "prompt": "FEN: r2qkb2/1p1n2p1/p1p2ppr/2Ppp2n/3P3B/2N1P3/PPQ2PPP/R3KB1R b KQq -\nWalk each ray for the slider on h6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: h6 black rook.\nRay N: h7 empty; h8 empty; edge.\nRay E: edge.\nRay S: h5 black knight: own piece (stop, excluded).\nRay W: g6 black pawn: own piece (stop, excluded).\nMoves from rays: h6h7 h6h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "h6", "diagnostic": true, "hard_gate": false, "source_square": "h6"}}
{"example_id": "rules_00194", "split": "rules", "task_type": "legal_moves", "fen": "r2qk2r/pp1b1ppp/n1pNp3/3pQ2n/3P4/P3P3/1PP2PPP/R3KBNR b KQkq - 1 10", "prompt": "FEN: r2qk2r/pp1b1ppp/n1pNp3/3pQ2n/3P4/P3P3/1PP2PPP/R3KBNR b KQkq - 1 10\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: e8e7 e8f8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00195", "split": "rules", "task_type": "legal_moves", "fen": "5k2/3b2b1/2p1p2p/1pPpP2N/1P1P2K1/7P/3B2P1/8 b - - 9 34", "prompt": "FEN: 5k2/3b2b1/2p1p2p/1pPpP2N/1P1P2K1/7P/3B2P1/8 b - - 9 34\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: d7c8 d7e8 f8e7 f8e8 f8f7 f8g8 g7e5 g7f6 g7h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00196", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/8/8/8/R7/8/1r5p/5K1k b - -", "prompt": "FEN: 8/8/8/8/R7/8/1r5p/5K1k b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: h1 black king; b2 black rook; h2 black pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "h1", "piece": "black king"}, {"square": "b2", "piece": "black rook"}, {"square": "h2", "piece": "black pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "h1", "piece": "black king"}, {"square": "b2", "piece": "black rook"}, {"square": "h2", "piece": "black pawn"}]}}
{"example_id": "rules_00197", "split": "rules", "task_type": "piece_legal_moves", "fen": "6k1/p6p/4RKp1/2r5/1r6/8/P6P/8 b - - 0 34", "prompt": "FEN: 6k1/p6p/4RKp1/2r5/1r6/8/P6P/8 b - - 0 34\nWhat legal moves does the piece on a7 have?", "gold_answer": "a7a5 a7a6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a7", "piece": "pawn"}}
{"example_id": "rules_00198", "split": "rules", "task_type": "check_detection", "fen": "8/4R3/6p1/3K1p2/8/4k3/8/8 b - -", "prompt": "FEN: 8/4R3/6p1/3K1p2/8/4k3/8/8 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00199", "split": "rules", "task_type": "captures", "fen": "8/8/6P1/3kBP2/5bK1/8/8/8 b - -", "prompt": "FEN: 8/8/6P1/3kBP2/5bK1/8/8/8 b - -\nList all capture moves available.", "gold_answer": "d5e5 f4e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00200", "split": "rules", "task_type": "special_rules", "fen": "8/p7/1p5p/2p3k1/2P1B3/n2PK1P1/7P/8 b - - 1 34", "prompt": "Given FEN: 8/p7/1p5p/2p3k1/2P1B3/n2PK1P1/7P/8 b - - 1 34\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00201", "split": "rules", "task_type": "legality_check", "fen": "6k1/5p2/P3Q1p1/8/8/8/5K2/8 b - - 0 60", "prompt": "FEN: 6k1/5p2/P3Q1p1/8/8/8/5K2/8 b - - 0 60\nIs the move a8g3 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "a8g3", "_legality_check_reason_label": "empty_source", "move": "a8g3", "legality_reason_label": "empty_source"}}
{"example_id": "rules_00202", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/5pk1/1R6/pP6/P5P1/6b1/5r1r/R3K3 w - - 7 41", "prompt": "FEN: 8/5pk1/1R6/pP6/P5P1/6b1/5r1r/R3K3 w - - 7 41\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1a2 a1a3 a1b1 a1c1 a1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00203", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/1k6/P2r1p1p/1K4pP/6P1/4RP2/8/8 b - -", "prompt": "FEN: 8/1k6/P2r1p1p/1K4pP/6P1/4RP2/8/8 b - -\nFor the piece on d6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d6: d6a6 d6b6 d6c6 d6d1 d6d2 d6d3 d6d4 d6d5 d6d7 d6d8 d6e6.\nLegal: d6a6.\nRejected: d6b6 does_not_resolve_check; d6c6 does_not_resolve_check; d6d1 does_not_resolve_check; d6d2 does_not_resolve_check; d6d3 does_not_resolve_check; d6d4 does_not_resolve_check; d6d5 does_not_resolve_check; d6d7 does_not_resolve_check; d6d8 does_not_resolve_check; d6e6 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "d6", "diagnostic": true, "hard_gate": false, "source_square": "d6"}}
{"example_id": "rules_00204", "split": "rules", "task_type": "king_safety_filter", "fen": "5rk1/6pp/8/2p1Qp2/2P5/3qP3/1P4PP/4K2R w K - 0 29", "prompt": "FEN: 5rk1/6pp/8/2p1Qp2/2P5/3qP3/1P4PP/4K2R w K - 0 29\nFor move e1d1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e1d1.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e1d1", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e1d1", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00205", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnb1k1nr/1pp2pp1/1b1p1q1p/Pp2p3/2B1P3/2P2N2/3P1PPP/RNBQK2R w KQkq - 0 9", "prompt": "FEN: rnb1k1nr/1pp2pp1/1b1p1q1p/Pp2p3/2B1P3/2P2N2/3P1PPP/RNBQK2R w KQkq - 0 9\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; d1 white queen; e1 white king; h1 white rook; d2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white pawn; f3 white knight; c4 white bishop; e4 white pawn; a5 white pawn.\nMoves by piece:\na1 white rook: a1a2 a1a3 a1a4\nb1 white knight: b1a3\nc1 white bishop: c1a3 c1b2\nd1 white queen: d1a4 d1b3 d1c2 d1e2\ne1 white king: e1e2 e1f1 e1g1\nh1 white rook: h1f1 h1g1\nd2 white pawn: d2d3 d2d4\nf2 white pawn: no legal moves\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nc3 white pawn: no legal moves\nf3 white knight: f3d4 f3e5 f3g1 f3g5 f3h4\nc4 white bishop: c4a2 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7\ne4 white pawn: no legal moves\na5 white pawn: a5a6 a5b6\nAll legal moves: a1a2 a1a3 a1a4 a5a6 a5b6 b1a3 c1a3 c1b2 c4a2 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 d1a4 d1b3 d1c2 d1e2 d2d3 d2d4 e1e2 e1f1 e1g1 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1a2", "a1a3", "a1a4"], "b1": ["b1a3"], "c1": ["c1a3", "c1b2"], "d1": ["d1a4", "d1b3", "d1c2", "d1e2"], "e1": ["e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1"], "d2": ["d2d3", "d2d4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c3": [], "f3": ["f3d4", "f3e5", "f3g1", "f3g5", "f3h4"], "c4": ["c4a2", "c4b3", "c4b5", "c4d3", "c4d5", "c4e2", "c4e6", "c4f1", "c4f7"], "e4": [], "a5": ["a5a6", "a5b6"]}, "_legal_moves_by_piece_moves": "a1a2 a1a3 a1a4 a5a6 a5b6 b1a3 c1a3 c1b2 c4a2 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 d1a4 d1b3 d1c2 d1e2 d2d3 d2d4 e1e2 e1f1 e1g1 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1a2", "a1a3", "a1a4"], "b1": ["b1a3"], "c1": ["c1a3", "c1b2"], "d1": ["d1a4", "d1b3", "d1c2", "d1e2"], "e1": ["e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1"], "d2": ["d2d3", "d2d4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c3": [], "f3": ["f3d4", "f3e5", "f3g1", "f3g5", "f3h4"], "c4": ["c4a2", "c4b3", "c4b5", "c4d3", "c4d5", "c4e2", "c4e6", "c4f1", "c4f7"], "e4": [], "a5": ["a5a6", "a5b6"]}, "legal_moves": "a1a2 a1a3 a1a4 a5a6 a5b6 b1a3 c1a3 c1b2 c4a2 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 d1a4 d1b3 d1c2 d1e2 d2d3 d2d4 e1e2 e1f1 e1g1 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4"}}
{"example_id": "rules_00206", "split": "rules", "task_type": "ray_walk", "fen": "4br1k/6p1/p7/3BP2p/P1N5/1P4Q1/7K/5q2 w - - 8 45", "prompt": "FEN: 4br1k/6p1/p7/3BP2p/P1N5/1P4Q1/7K/5q2 w - - 8 45\nWalk each ray for the slider on g3: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: g3 white queen.\nRay N: g4 empty; g5 empty; g6 empty; g7 black pawn: capture (stop, included).\nRay NE: h4 empty; edge.\nRay E: h3 empty; edge.\nRay SE: h2 white king: own piece (stop, excluded).\nRay S: g2 empty; g1 empty; edge.\nRay SW: f2 empty; e1 empty; edge.\nRay W: f3 empty; e3 empty; d3 empty; c3 empty; b3 white pawn: own piece (stop, excluded).\nRay NW: f4 empty; e5 white pawn: own piece (stop, excluded).\nMoves from rays: g3c3 g3d3 g3e1 g3e3 g3f2 g3f3 g3f4 g3g1 g3g2 g3g4 g3g5 g3g6 g3g7 g3h3 g3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "g3", "diagnostic": true, "hard_gate": false, "source_square": "g3"}}
{"example_id": "rules_00207", "split": "rules", "task_type": "legal_moves", "fen": "r4r2/4qpbk/2p3pp/4Pp2/p1pP3R/P1P5/3B1QPP/2R3K1 w - - 2 27", "prompt": "FEN: r4r2/4qpbk/2p3pp/4Pp2/p1pP3R/P1P5/3B1QPP/2R3K1 w - - 2 27\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: c1a1 c1b1 c1c2 c1d1 c1e1 c1f1 d2e1 d2e3 d2f4 d2g5 d2h6 d4d5 e5e6 f2e1 f2e2 f2e3 f2f1 f2f3 f2f4 f2f5 f2g3 g1f1 g1h1 g2g3 g2g4 h2h3 h4e4 h4f4 h4g4 h4h3 h4h5 h4h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00208", "split": "rules", "task_type": "legal_moves", "fen": "8/8/8/8/8/R3k3/8/6KR b - -", "prompt": "FEN: 8/8/8/8/8/R3k3/8/6KR b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: e3d2 e3d4 e3e2 e3e4 e3f4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00209", "split": "rules", "task_type": "side_piece_inventory", "fen": "2r1k2r/p1q2pp1/2p1pbp1/3p4/3P4/2NQ4/PPP2PPP/R4RK1 w k - 2 16", "prompt": "FEN: 2r1k2r/p1q2pp1/2p1pbp1/3p4/3P4/2NQ4/PPP2PPP/R4RK1 w k - 2 16\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white knight; d3 white queen; d4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d3", "piece": "white queen"}, {"square": "d4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d3", "piece": "white queen"}, {"square": "d4", "piece": "white pawn"}]}}
{"example_id": "rules_00210", "split": "rules", "task_type": "piece_legal_moves", "fen": "2r5/8/8/p2R4/k2P1n2/B7/1P1N1PP1/1K6 w - - 0 41", "prompt": "FEN: 2r5/8/8/p2R4/k2P1n2/B7/1P1N1PP1/1K6 w - - 0 41\nWhat legal moves does the piece on a3 have?", "gold_answer": "a3b4 a3c5 a3d6 a3e7 a3f8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a3", "_piece_legal_moves_piece": "bishop", "diagnostic": true, "hard_gate": false, "source_square": "a3", "piece": "bishop"}}
{"example_id": "rules_00211", "split": "rules", "task_type": "check_detection", "fen": "r1b2rk1/pp1nbpp1/4pn1p/q7/2pP3B/2NB1N2/PPQ2PPP/3RK2R w K -", "prompt": "FEN: r1b2rk1/pp1nbpp1/4pn1p/q7/2pP3B/2NB1N2/PPQ2PPP/3RK2R w K -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00212", "split": "rules", "task_type": "captures", "fen": "r1bqk2r/1pp2pp1/p1np1n1p/2b1p3/4P3/P1NP1N2/1PP1BPPP/R1BQ1RK1 w kq - 0 8", "prompt": "FEN: r1bqk2r/1pp2pp1/p1np1n1p/2b1p3/4P3/P1NP1N2/1PP1BPPP/R1BQ1RK1 w kq - 0 8\nList all capture moves available.", "gold_answer": "c1h6 f3e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00213", "split": "rules", "task_type": "special_rules", "fen": "r2qk1r1/pnppn3/1p2p2b/1P2Np1Q/3P1P2/2P3Pp/PBN4P/R4RK1 b q - 5 21", "prompt": "Given FEN: r2qk1r1/pnppn3/1p2p2b/1P2Np1Q/3P1P2/2P3Pp/PBN4P/R4RK1 b q - 5 21\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00214", "split": "rules", "task_type": "legality_check", "fen": "r1bk1b1r/ppp1qppp/2p5/8/4n3/3N4/PPPP1PPP/RNBQ1RK1 w - - 3 8", "prompt": "FEN: r1bk1b1r/ppp1qppp/2p5/8/4n3/3N4/PPPP1PPP/RNBQ1RK1 w - - 3 8\nIs the move c2c3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c2c3", "_legality_check_reason_label": "legal", "move": "c2c3", "legality_reason_label": "legal"}}
{"example_id": "rules_00215", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5kr1/pR3ppp/5n2/5r2/3p4/1P6/2PP1PPP/R1B3K1 w - - 0 21", "prompt": "FEN: 5kr1/pR3ppp/5n2/5r2/3p4/1P6/2PP1PPP/R1B3K1 w - - 0 21\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1a2 a1a3 a1a4 a1a5 a1a6 a1a7 a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00216", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/8/4b2R/4k3/8/P5K1/8/8 w - - 0 46", "prompt": "FEN: 8/8/4b2R/4k3/8/P5K1/8/8 w - - 0 46\nFor the piece on g3, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g3: g3f2 g3f3 g3f4 g3g2 g3g4 g3h2 g3h3 g3h4.\nLegal: g3f2 g3f3 g3g2 g3h2 g3h4.\nRejected: g3f4 king_would_be_in_check; g3g4 king_would_be_in_check; g3h3 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g3", "diagnostic": true, "hard_gate": false, "source_square": "g3"}}
{"example_id": "rules_00217", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bqkbnr/1p1ppppp/p1n5/8/4P3/2Q5/PPP2PPP/RNB1KBNR w KQkq -", "prompt": "FEN: r1bqkbnr/1p1ppppp/p1n5/8/4P3/2Q5/PPP2PPP/RNB1KBNR w KQkq -\nFor move a2a3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a2a3.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a2a3", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a2a3", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00218", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rn1k1bnr/ppp3pp/4bp2/4p3/4P3/4BN2/PPP2PPP/RN2KB1R w KQ -", "prompt": "FEN: rn1k1bnr/ppp3pp/4bp2/4p3/4P3/4BN2/PPP2PPP/RN2KB1R w KQ -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; e1 white king; f1 white bishop; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; e3 white bishop; f3 white knight; e4 white pawn.\nMoves by piece:\na1 white rook: no legal moves\nb1 white knight: b1a3 b1c3 b1d2\ne1 white king: e1d1 e1d2 e1e2\nf1 white bishop: f1a6 f1b5 f1c4 f1d3 f1e2\nh1 white rook: h1g1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: c2c3 c2c4\nf2 white pawn: no legal moves\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\ne3 white bishop: e3a7 e3b6 e3c1 e3c5 e3d2 e3d4 e3f4 e3g5 e3h6\nf3 white knight: f3d2 f3d4 f3e5 f3g1 f3g5 f3h4\ne4 white pawn: no legal moves\nAll legal moves: a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c2c3 c2c4 e1d1 e1d2 e1e2 e3a7 e3b6 e3c1 e3c5 e3d2 e3d4 e3f4 e3g5 e3h6 f1a6 f1b5 f1c4 f1d3 f1e2 f3d2 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1g1 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "b1": ["b1a3", "b1c3", "b1d2"], "e1": ["e1d1", "e1d2", "e1e2"], "f1": ["f1a6", "f1b5", "f1c4", "f1d3", "f1e2"], "h1": ["h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "e3": ["e3a7", "e3b6", "e3c1", "e3c5", "e3d2", "e3d4", "e3f4", "e3g5", "e3h6"], "f3": ["f3d2", "f3d4", "f3e5", "f3g1", "f3g5", "f3h4"], "e4": []}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c2c3 c2c4 e1d1 e1d2 e1e2 e3a7 e3b6 e3c1 e3c5 e3d2 e3d4 e3f4 e3g5 e3h6 f1a6 f1b5 f1c4 f1d3 f1e2 f3d2 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1g1 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "b1": ["b1a3", "b1c3", "b1d2"], "e1": ["e1d1", "e1d2", "e1e2"], "f1": ["f1a6", "f1b5", "f1c4", "f1d3", "f1e2"], "h1": ["h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "e3": ["e3a7", "e3b6", "e3c1", "e3c5", "e3d2", "e3d4", "e3f4", "e3g5", "e3h6"], "f3": ["f3d2", "f3d4", "f3e5", "f3g1", "f3g5", "f3h4"], "e4": []}, "legal_moves": "a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c2c3 c2c4 e1d1 e1d2 e1e2 e3a7 e3b6 e3c1 e3c5 e3d2 e3d4 e3f4 e3g5 e3h6 f1a6 f1b5 f1c4 f1d3 f1e2 f3d2 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1g1 h2h3 h2h4"}}
{"example_id": "rules_00219", "split": "rules", "task_type": "ray_walk", "fen": "r1bqk1nr/ppp2ppp/2np4/8/3NP3/2P5/P1P2PPP/R1BQKB1R w KQkq -", "prompt": "FEN: r1bqk1nr/ppp2ppp/2np4/8/3NP3/2P5/P1P2PPP/R1BQKB1R w KQkq -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 white bishop: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00220", "split": "rules", "task_type": "legal_filter_trace", "fen": "6k1/5p1p/4p1p1/8/1p4P1/pr3P1P/4K3/R7 b - - 0 41", "prompt": "FEN: 6k1/5p1p/4p1p1/8/1p4P1/pr3P1P/4K3/R7 b - - 0 41\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a3 black pawn; b3 black rook; b4 black pawn; e6 black pawn; g6 black pawn; f7 black pawn; h7 black pawn; g8 black king.\nFilter by piece:\na3 black pawn: pseudo-legal a3a2 | rejected none | legal a3a2\nb3 black rook: pseudo-legal b3b1 b3b2 b3c3 b3d3 b3e3 b3f3 | rejected none | legal b3b1 b3b2 b3c3 b3d3 b3e3 b3f3\nb4 black pawn: pseudo-legal none | rejected none | legal none\ne6 black pawn: pseudo-legal e6e5 | rejected none | legal e6e5\ng6 black pawn: pseudo-legal g6g5 | rejected none | legal g6g5\nf7 black pawn: pseudo-legal f7f5 f7f6 | rejected none | legal f7f5 f7f6\nh7 black pawn: pseudo-legal h7h5 h7h6 | rejected none | legal h7h5 h7h6\ng8 black king: pseudo-legal g8f8 g8g7 g8h8 | rejected none | legal g8f8 g8g7 g8h8\nAll legal moves: a3a2 b3b1 b3b2 b3c3 b3d3 b3e3 b3f3 e6e5 f7f5 f7f6 g6g5 g8f8 g8g7 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00221", "split": "rules", "task_type": "legal_moves", "fen": "r1bqkb1r/1ppp1ppp/p1n5/2n1p3/8/1B3N2/PPPP1PPP/RNBQR1K1 b kq -", "prompt": "FEN: r1bqkb1r/1ppp1ppp/p1n5/2n1p3/8/1B3N2/PPPP1PPP/RNBQR1K1 b kq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 a8b8 b7b5 b7b6 c5a4 c5b3 c5d3 c5e4 c5e6 c6a5 c6a7 c6b4 c6b8 c6d4 c6e7 d7d5 d7d6 d8e7 d8f6 d8g5 d8h4 e5e4 e8e7 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00222", "split": "rules", "task_type": "side_piece_inventory", "fen": "2k5/6pp/p7/b3p3/P1p1P3/2NR1Pn1/1P1K2PP/2Q3q1 b - -", "prompt": "FEN: 2k5/6pp/p7/b3p3/P1p1P3/2NR1Pn1/1P1K2PP/2Q3q1 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: g1 black queen; g3 black knight; c4 black pawn; a5 black bishop; e5 black pawn; a6 black pawn; g7 black pawn; h7 black pawn; c8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "g1", "piece": "black queen"}, {"square": "g3", "piece": "black knight"}, {"square": "c4", "piece": "black pawn"}, {"square": "a5", "piece": "black bishop"}, {"square": "e5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "c8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "g1", "piece": "black queen"}, {"square": "g3", "piece": "black knight"}, {"square": "c4", "piece": "black pawn"}, {"square": "a5", "piece": "black bishop"}, {"square": "e5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "c8", "piece": "black king"}]}}
{"example_id": "rules_00223", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/8/8/8/8/8/K1N1pk2/8 w - -", "prompt": "FEN: 8/8/8/8/8/8/K1N1pk2/8 w - -\nWhat legal moves does the piece on a2 have?", "gold_answer": "a2a1 a2a3 a2b1 a2b2 a2b3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "a2", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "a2", "piece": "king"}}
{"example_id": "rules_00224", "split": "rules", "task_type": "check_detection", "fen": "rnbqkb1r/1p3ppp/p2p1n2/2p1p3/2P1P3/3P4/PPN2PPP/R1BQKBNR w KQkq - 1 6", "prompt": "FEN: rnbqkb1r/1p3ppp/p2p1n2/2p1p3/2P1P3/3P4/PPN2PPP/R1BQKBNR w KQkq - 1 6\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00225", "split": "rules", "task_type": "captures", "fen": "r1bqk2r/pppp1ppp/2n5/1B2P3/1b1Pn3/5N2/PP3PPP/RNBQ1K1R b kq -", "prompt": "FEN: r1bqk2r/pppp1ppp/2n5/1B2P3/1b1Pn3/5N2/PP3PPP/RNBQ1K1R b kq -\nList all capture moves available.", "gold_answer": "c6d4 c6e5 e4f2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00226", "split": "rules", "task_type": "special_rules", "fen": "1nr2rk1/pn3ppp/1p1p4/3Pp3/1P2P1P1/P3B1P1/5PB1/2R2RK1 b - -", "prompt": "Given FEN: 1nr2rk1/pn3ppp/1p1p4/3Pp3/1P2P1P1/P3B1P1/5PB1/2R2RK1 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00227", "split": "rules", "task_type": "legality_check", "fen": "r3k1nr/4q1p1/pRpbp2p/4B3/P1pP4/2P4P/1RQ1NPP1/6K1 b kq - 2 24", "prompt": "FEN: r3k1nr/4q1p1/pRpbp2p/4B3/P1pP4/2P4P/1RQ1NPP1/6K1 b kq - 2 24\nIs the move e7c7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "e7c7", "_legality_check_reason_label": "legal", "move": "e7c7", "legality_reason_label": "legal"}}
{"example_id": "rules_00228", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "1r4k1/Q4p1p/2Bb2p1/4p3/7q/3p2Nb/PP3PRP/1R3K2 w - - 0 28", "prompt": "FEN: 1r4k1/Q4p1p/2Bb2p1/4p3/7q/3p2Nb/PP3PRP/1R3K2 w - - 0 28\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a1 b1c1 b1d1 b1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_00229", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1b1k2r/bpp2ppp/p1np3n/4p1N1/PPB1P3/1QPP4/5qPP/RNBK3R b kq - 1 10", "prompt": "FEN: r1b1k2r/bpp2ppp/p1np3n/4p1N1/PPB1P3/1QPP4/5qPP/RNBK3R b kq - 1 10\nFor the piece on f2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f2: f2a2 f2b2 f2b6 f2c2 f2c5 f2d2 f2d4 f2e1 f2e2 f2e3 f2f1 f2f3 f2f4 f2f5 f2f6 f2g1 f2g2 f2g3 f2h4.\nLegal: f2a2 f2b2 f2b6 f2c2 f2c5 f2d2 f2d4 f2e1 f2e2 f2e3 f2f1 f2f3 f2f4 f2f5 f2f6 f2g1 f2g2 f2g3 f2h4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "f2", "diagnostic": true, "hard_gate": false, "source_square": "f2"}}
{"example_id": "rules_00230", "split": "rules", "task_type": "king_safety_filter", "fen": "1nb5/r3b2p/2p3pk/1p1p4/p4r2/P2P1PNP/BPP2P2/2KR3R w - - 1 22", "prompt": "FEN: 1nb5/r3b2p/2p3pk/1p1p4/p4r2/P2P1PNP/BPP2P2/2KR3R w - - 1 22\nFor move a2b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a2b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a2b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a2b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00231", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "3NR3/5pk1/6pn/7p/R1B4P/2r3P1/2n2P1K/3r4 b - -", "prompt": "FEN: 3NR3/5pk1/6pn/7p/R1B4P/2r3P1/2n2P1K/3r4 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d1 black rook; c2 black knight; c3 black rook; h5 black pawn; g6 black pawn; h6 black knight; f7 black pawn; g7 black king.\nMoves by piece:\nd1 black rook: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 d1g1 d1h1\nc2 black knight: c2a1 c2a3 c2b4 c2d4 c2e1 c2e3\nc3 black rook: c3a3 c3b3 c3c4 c3d3 c3e3 c3f3 c3g3\nh5 black pawn: no legal moves\ng6 black pawn: g6g5\nh6 black knight: h6f5 h6g4 h6g8\nf7 black pawn: f7f5 f7f6\ng7 black king: g7f6 g7h7\nAll legal moves: c2a1 c2a3 c2b4 c2d4 c2e1 c2e3 c3a3 c3b3 c3c4 c3d3 c3e3 c3f3 c3g3 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 d1g1 d1h1 f7f5 f7f6 g6g5 g7f6 g7h7 h6f5 h6g4 h6g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d1": ["d1a1", "d1b1", "d1c1", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1d7", "d1d8", "d1e1", "d1f1", "d1g1", "d1h1"], "c2": ["c2a1", "c2a3", "c2b4", "c2d4", "c2e1", "c2e3"], "c3": ["c3a3", "c3b3", "c3c4", "c3d3", "c3e3", "c3f3", "c3g3"], "h5": [], "g6": ["g6g5"], "h6": ["h6f5", "h6g4", "h6g8"], "f7": ["f7f5", "f7f6"], "g7": ["g7f6", "g7h7"]}, "_legal_moves_by_piece_moves": "c2a1 c2a3 c2b4 c2d4 c2e1 c2e3 c3a3 c3b3 c3c4 c3d3 c3e3 c3f3 c3g3 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 d1g1 d1h1 f7f5 f7f6 g6g5 g7f6 g7h7 h6f5 h6g4 h6g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d1": ["d1a1", "d1b1", "d1c1", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1d7", "d1d8", "d1e1", "d1f1", "d1g1", "d1h1"], "c2": ["c2a1", "c2a3", "c2b4", "c2d4", "c2e1", "c2e3"], "c3": ["c3a3", "c3b3", "c3c4", "c3d3", "c3e3", "c3f3", "c3g3"], "h5": [], "g6": ["g6g5"], "h6": ["h6f5", "h6g4", "h6g8"], "f7": ["f7f5", "f7f6"], "g7": ["g7f6", "g7h7"]}, "legal_moves": "c2a1 c2a3 c2b4 c2d4 c2e1 c2e3 c3a3 c3b3 c3c4 c3d3 c3e3 c3f3 c3g3 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 d1g1 d1h1 f7f5 f7f6 g6g5 g7f6 g7h7 h6f5 h6g4 h6g8"}}
{"example_id": "rules_00232", "split": "rules", "task_type": "ray_walk", "fen": "r4rk1/1p2q1p1/p2p1pBp/3P1P2/2PpP3/1P2b2P/P5P1/R2Q1R1K b - - 0 22", "prompt": "FEN: r4rk1/1p2q1p1/p2p1pBp/3P1P2/2PpP3/1P2b2P/P5P1/R2Q1R1K b - - 0 22\nWalk each ray for the slider on e3: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e3 black bishop.\nRay NE: f4 empty; g5 empty; h6 black pawn: own piece (stop, excluded).\nRay SE: f2 empty; g1 empty; edge.\nRay SW: d2 empty; c1 empty; edge.\nRay NW: d4 black pawn: own piece (stop, excluded).\nMoves from rays: e3c1 e3d2 e3f2 e3f4 e3g1 e3g5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "e3", "diagnostic": true, "hard_gate": false, "source_square": "e3"}}
{"example_id": "rules_00233", "split": "rules", "task_type": "legal_moves", "fen": "1Q1q2k1/p3bppp/4p3/3r4/8/6P1/P3PP1P/1R3RK1 b - -", "prompt": "FEN: 1Q1q2k1/p3bppp/4p3/3r4/8/6P1/P3PP1P/1R3RK1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 d5a5 d5b5 d5c5 d5d1 d5d2 d5d3 d5d4 d5d6 d5d7 d5e5 d5f5 d5g5 d5h5 d8b8 d8c8 d8e8 d8f8 e6e5 e7a3 e7b4 e7c5 e7d6 e7f6 e7f8 e7g5 e7h4 f7f5 f7f6 g7g5 g7g6 g8f8 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00234", "split": "rules", "task_type": "legal_moves", "fen": "r4qk1/1bp2p1p/1p1n1P2/1p1ppBP1/1P2P3/2PP4/PB5P/R2Q1RK1 w - - 2 26", "prompt": "FEN: r4qk1/1bp2p1p/1p1n1P2/1p1ppBP1/1P2P3/2PP4/PB5P/R2Q1RK1 w - - 2 26\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a2a3 a2a4 b2a3 b2c1 c3c4 d1a4 d1b1 d1b3 d1c1 d1c2 d1d2 d1e1 d1e2 d1f3 d1g4 d1h5 d3d4 e4d5 f1e1 f1f2 f1f3 f1f4 f5c8 f5d7 f5e6 f5g4 f5g6 f5h3 f5h7 g1f2 g1g2 g1h1 g5g6 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00235", "split": "rules", "task_type": "side_piece_inventory", "fen": "rn1qk2r/pp1bnpbp/6p1/1BPp4/8/2P2N2/PP2QPPP/RNB1K2R b KQkq -", "prompt": "FEN: rn1qk2r/pp1bnpbp/6p1/1BPp4/8/2P2N2/PP2QPPP/RNB1K2R b KQkq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; g6 black pawn; a7 black pawn; b7 black pawn; d7 black bishop; e7 black knight; f7 black pawn; g7 black bishop; h7 black pawn; a8 black rook; b8 black knight; d8 black queen; e8 black king; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "d5", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black bishop"}, {"square": "e7", "piece": "black knight"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black bishop"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "d5", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black bishop"}, {"square": "e7", "piece": "black knight"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black bishop"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00236", "split": "rules", "task_type": "piece_legal_moves", "fen": "3r3r/kbRP1pnp/1p2pNp1/pP6/P7/4N3/4BPPP/2R3K1 w - - 5 29", "prompt": "FEN: 3r3r/kbRP1pnp/1p2pNp1/pP6/P7/4N3/4BPPP/2R3K1 w - - 5 29\nWhat legal moves does the piece on e3 have?", "gold_answer": "e3c2 e3c4 e3d1 e3d5 e3f1 e3f5 e3g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "e3", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "e3", "piece": "knight"}}
{"example_id": "rules_00237", "split": "rules", "task_type": "check_detection", "fen": "rn1qkbnr/ppp1pppp/8/3p4/2PP4/5P2/PP2PP1P/RNBQKB1R b KQkq - 0 4", "prompt": "FEN: rn1qkbnr/ppp1pppp/8/3p4/2PP4/5P2/PP2PP1P/RNBQKB1R b KQkq - 0 4\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00238", "split": "rules", "task_type": "captures", "fen": "r3k1nr/p2bq3/n1ppp1pp/5p2/1P3P2/1P2P1P1/PRNPQ1BP/4K1NR w Kkq - 1 15", "prompt": "FEN: r3k1nr/p2bq3/n1ppp1pp/5p2/1P3P2/1P2P1P1/PRNPQ1BP/4K1NR w Kkq - 1 15\nList all capture moves available.", "gold_answer": "e2a6 g2c6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00239", "split": "rules", "task_type": "special_rules", "fen": "r1bqk2r/1pp2pp1/pbnp1n1p/4p3/PPB1P3/2PP1N2/5PPP/RNBQ1RK1 w kq - 0 9", "prompt": "Given FEN: r1bqk2r/1pp2pp1/pbnp1n1p/4p3/PPB1P3/2PP1N2/5PPP/RNBQ1RK1 w kq - 0 9\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00240", "split": "rules", "task_type": "legality_check", "fen": "r1b2rk1/3nnppp/4p3/qp1p4/2pP4/2P2N2/P1BN1PPP/R2QR1K1 w - - 0 16", "prompt": "FEN: r1b2rk1/3nnppp/4p3/qp1p4/2pP4/2P2N2/P1BN1PPP/R2QR1K1 w - - 0 16\nIs the move b5h7 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b5h7", "_legality_check_reason_label": "wrong_side_piece", "move": "b5h7", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_00241", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/1K2k1p1/7p/pB2np2/1p5P/1P6/P7/8 b - - 1 56", "prompt": "FEN: 8/1K2k1p1/7p/pB2np2/1p5P/1P6/P7/8 b - - 1 56\nList pseudo-legal moves from a5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a5: a5a4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_00242", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/8/1K6/3k4/2B5/5R2/8/8 b - -", "prompt": "FEN: 8/8/1K6/3k4/2B5/5R2/8/8 b - -\nFor the piece on d5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d5: d5c4 d5c5 d5c6 d5d4 d5d6 d5e4 d5e5 d5e6.\nLegal: d5c4 d5d4 d5d6 d5e4 d5e5.\nRejected: d5c5 does_not_resolve_check; d5c6 does_not_resolve_check; d5e6 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_00243", "split": "rules", "task_type": "king_safety_filter", "fen": "8/8/1k6/2NK4/3Q4/8/8/8 w - -", "prompt": "FEN: 8/8/1k6/2NK4/3Q4/8/8/8 w - -\nFor move d5c6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: d5c6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "d5c6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "d5c6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00244", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/7p/p1k3p1/P1p1p3/4P3/1P5P/5KP1/8 w - -", "prompt": "FEN: 8/7p/p1k3p1/P1p1p3/4P3/1P5P/5KP1/8 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: f2 white king; g2 white pawn; b3 white pawn; h3 white pawn; e4 white pawn; a5 white pawn.\nMoves by piece:\nf2 white king: f2e1 f2e2 f2e3 f2f1 f2f3 f2g1 f2g3\ng2 white pawn: g2g3 g2g4\nb3 white pawn: b3b4\nh3 white pawn: h3h4\ne4 white pawn: no legal moves\na5 white pawn: no legal moves\nAll legal moves: b3b4 f2e1 f2e2 f2e3 f2f1 f2f3 f2g1 f2g3 g2g3 g2g4 h3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"f2": ["f2e1", "f2e2", "f2e3", "f2f1", "f2f3", "f2g1", "f2g3"], "g2": ["g2g3", "g2g4"], "b3": ["b3b4"], "h3": ["h3h4"], "e4": [], "a5": []}, "_legal_moves_by_piece_moves": "b3b4 f2e1 f2e2 f2e3 f2f1 f2f3 f2g1 f2g3 g2g3 g2g4 h3h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"f2": ["f2e1", "f2e2", "f2e3", "f2f1", "f2f3", "f2g1", "f2g3"], "g2": ["g2g3", "g2g4"], "b3": ["b3b4"], "h3": ["h3h4"], "e4": [], "a5": []}, "legal_moves": "b3b4 f2e1 f2e2 f2e3 f2f1 f2f3 f2g1 f2g3 g2g3 g2g4 h3h4"}}
{"example_id": "rules_00245", "split": "rules", "task_type": "ray_walk", "fen": "r4rk1/pp3ppp/1q2p3/4Rn2/6Q1/2N5/PPP2PPP/R5K1 w - - 1 18", "prompt": "FEN: r4rk1/pp3ppp/1q2p3/4Rn2/6Q1/2N5/PPP2PPP/R5K1 w - - 1 18\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 empty; e1 empty; f1 empty; g1 white king: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1 a1d1 a1e1 a1f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00246", "split": "rules", "task_type": "legal_moves", "fen": "rn1qkbnr/pbp1p3/1p1p1p2/6pp/2PP4/2NBPN2/PP1B1PPP/R2QK2R b KQkq - 1 7", "prompt": "FEN: rn1qkbnr/pbp1p3/1p1p1p2/6pp/2PP4/2NBPN2/PP1B1PPP/R2QK2R b KQkq - 1 7\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6b5 b7a6 b7c6 b7c8 b7d5 b7e4 b7f3 b8a6 b8c6 b8d7 c7c5 c7c6 d6d5 d8c8 d8d7 e7e5 e7e6 e8d7 e8f7 f6f5 f8g7 f8h6 g5g4 g8h6 h5h4 h8h6 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00247", "split": "rules", "task_type": "legal_moves", "fen": "r2qkb1r/pp1bpppp/2np1n2/1Bp5/4P3/2P2N1P/PP1P1PP1/RNBQ1RK1 b kq -", "prompt": "FEN: r2qkb1r/pp1bpppp/2np1n2/1Bp5/4P3/2P2N1P/PP1P1PP1/RNBQ1RK1 b kq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 a8c8 b7b6 c5c4 c6a5 c6b4 c6b8 c6d4 c6e5 d6d5 d7c8 d7e6 d7f5 d7g4 d7h3 d8a5 d8b6 d8b8 d8c7 d8c8 e7e5 e7e6 f6d5 f6e4 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00248", "split": "rules", "task_type": "side_piece_inventory", "fen": "3rk2r/pp3ppp/2n2n2/2b2b2/8/2N2P2/PP1BP1PP/R1K2BNR b k -", "prompt": "FEN: 3rk2r/pp3ppp/2n2n2/2b2b2/8/2N2P2/PP1BP1PP/R1K2BNR b k -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c5 black bishop; f5 black bishop; c6 black knight; f6 black knight; a7 black pawn; b7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; d8 black rook; e8 black king; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c5", "piece": "black bishop"}, {"square": "f5", "piece": "black bishop"}, {"square": "c6", "piece": "black knight"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "d8", "piece": "black rook"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c5", "piece": "black bishop"}, {"square": "f5", "piece": "black bishop"}, {"square": "c6", "piece": "black knight"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "d8", "piece": "black rook"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00249", "split": "rules", "task_type": "piece_legal_moves", "fen": "2k2r1r/pp4p1/2p2p2/P1n5/3p4/5Q2/1P3KBB/R4R2 b - - 0 27", "prompt": "FEN: 2k2r1r/pp4p1/2p2p2/P1n5/3p4/5Q2/1P3KBB/R4R2 b - - 0 27\nWhat legal moves does the piece on c8 have?", "gold_answer": "c8d7 c8d8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c8", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "c8", "piece": "king"}}
{"example_id": "rules_00250", "split": "rules", "task_type": "check_detection", "fen": "rnbqk2r/pppp2pp/3bp3/5p2/3PN3/4BN2/PPPQPPPP/R3KB1R b KQkq - 0 6", "prompt": "FEN: rnbqk2r/pppp2pp/3bp3/5p2/3PN3/4BN2/PPPQPPPP/R3KB1R b KQkq - 0 6\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00251", "split": "rules", "task_type": "captures", "fen": "3R4/6Bk/5p2/1p2p3/1P2n2p/7P/6PK/2r5 b - -", "prompt": "FEN: 3R4/6Bk/5p2/1p2p3/1P2n2p/7P/6PK/2r5 b - -\nList all capture moves available.", "gold_answer": "h7g7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00252", "split": "rules", "task_type": "special_rules", "fen": "rnbqk1nr/pp2bppp/2p1p3/8/4P3/2N3P1/PP1P1PBP/R1BQK1NR w KQkq - 2 7", "prompt": "Given FEN: rnbqk1nr/pp2bppp/2p1p3/8/4P3/2N3P1/PP1P1PBP/R1BQK1NR w KQkq - 2 7\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00253", "split": "rules", "task_type": "legality_check", "fen": "8/5p1p/4k1p1/p1p5/1b1rKPPP/1P6/3p4/3R4 w - - 3 35", "prompt": "FEN: 8/5p1p/4k1p1/p1p5/1b1rKPPP/1P6/3p4/3R4 w - - 3 35\nIs the move c4d4 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c4d4", "_legality_check_reason_label": "empty_source", "move": "c4d4", "legality_reason_label": "empty_source"}}
{"example_id": "rules_00254", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r4rk1/3q1p2/p1n1b1p1/1p1nP1Bp/1p2N2Q/3B1N2/P1P4P/R4RK1 b - - 1 19", "prompt": "FEN: r4rk1/3q1p2/p1n1b1p1/1p1nP1Bp/1p2N2Q/3B1N2/P1P4P/R4RK1 b - - 1 19\nList pseudo-legal moves from b4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b4: b4b3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_00255", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/2R5/8/4K3/8/4k3/8/8 w - -", "prompt": "FEN: 8/2R5/8/4K3/8/4k3/8/8 w - -\nFor the piece on e5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e5: e5d4 e5d5 e5d6 e5e4 e5e6 e5f4 e5f5 e5f6.\nLegal: e5d5 e5d6 e5e6 e5f5 e5f6.\nRejected: e5d4 king_would_be_in_check; e5e4 king_would_be_in_check; e5f4 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "e5", "diagnostic": true, "hard_gate": false, "source_square": "e5"}}
{"example_id": "rules_00256", "split": "rules", "task_type": "king_safety_filter", "fen": "2r2k2/3p2pp/p7/1p1pN3/5n2/2P2P2/PP1P1K1P/1R6 w - - 0 27", "prompt": "FEN: 2r2k2/3p2pp/p7/1p1pN3/5n2/2P2P2/PP1P1K1P/1R6 w - - 0 27\nFor move f2e2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: f2e2.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "f2e2", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "f2e2", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00257", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rn1qkbnr/pbp2ppp/1p1pp3/1N6/3P1B2/5P2/PPP1P1PP/R2QKBNR b KQkq - 0 5", "prompt": "FEN: rn1qkbnr/pbp2ppp/1p1pp3/1N6/3P1B2/5P2/PPP1P1PP/R2QKBNR b KQkq - 0 5\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b6 black pawn; d6 black pawn; e6 black pawn; a7 black pawn; b7 black bishop; c7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\nb6 black pawn: no legal moves\nd6 black pawn: d6d5\ne6 black pawn: e6e5\na7 black pawn: a7a5 a7a6\nb7 black bishop: b7a6 b7c6 b7c8 b7d5 b7e4 b7f3\nc7 black pawn: c7c5 c7c6\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: no legal moves\nb8 black knight: b8a6 b8c6 b8d7\nd8 black queen: d8c8 d8d7 d8e7 d8f6 d8g5 d8h4\ne8 black king: e8d7 e8e7\nf8 black bishop: f8e7\ng8 black knight: g8e7 g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a7a5 a7a6 b7a6 b7c6 b7c8 b7d5 b7e4 b7f3 b8a6 b8c6 b8d7 c7c5 c7c6 d6d5 d8c8 d8d7 d8e7 d8f6 d8g5 d8h4 e6e5 e8d7 e8e7 f7f5 f7f6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b6": [], "d6": ["d6d5"], "e6": ["e6e5"], "a7": ["a7a5", "a7a6"], "b7": ["b7a6", "b7c6", "b7c8", "b7d5", "b7e4", "b7f3"], "c7": ["c7c5", "c7c6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8c6", "b8d7"], "d8": ["d8c8", "d8d7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8d7", "e8e7"], "f8": ["f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7a6 b7c6 b7c8 b7d5 b7e4 b7f3 b8a6 b8c6 b8d7 c7c5 c7c6 d6d5 d8c8 d8d7 d8e7 d8f6 d8g5 d8h4 e6e5 e8d7 e8e7 f7f5 f7f6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b6": [], "d6": ["d6d5"], "e6": ["e6e5"], "a7": ["a7a5", "a7a6"], "b7": ["b7a6", "b7c6", "b7c8", "b7d5", "b7e4", "b7f3"], "c7": ["c7c5", "c7c6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8c6", "b8d7"], "d8": ["d8c8", "d8d7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8d7", "e8e7"], "f8": ["f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "legal_moves": "a7a5 a7a6 b7a6 b7c6 b7c8 b7d5 b7e4 b7f3 b8a6 b8c6 b8d7 c7c5 c7c6 d6d5 d8c8 d8d7 d8e7 d8f6 d8g5 d8h4 e6e5 e8d7 e8e7 f7f5 f7f6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_00258", "split": "rules", "task_type": "ray_walk", "fen": "r1bqk2r/1pppbppp/p1n5/4p2P/2B1Pn2/2N2N2/PPPP1PP1/R1BQK2R w KQkq -", "prompt": "FEN: r1bqk2r/1pppbppp/p1n5/4p2P/2B1Pn2/2N2N2/PPPP1PP1/R1BQK2R w KQkq -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 white bishop: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00259", "split": "rules", "task_type": "legal_moves", "fen": "rnbq1rk1/pp2bppp/4pn2/2pP4/8/1P2PN2/PBQP1PPP/RN2KB1R b KQ -", "prompt": "FEN: rnbq1rk1/pp2bppp/4pn2/2pP4/8/1P2PN2/PBQP1PPP/RN2KB1R b KQ -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c5c4 c8d7 d8a5 d8b6 d8c7 d8d5 d8d6 d8d7 d8e8 e6d5 e6e5 e7d6 f6d5 f6d7 f6e4 f6e8 f6g4 f6h5 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00260", "split": "rules", "task_type": "legal_moves", "fen": "r1b1kb1r/1pp2ppp/p2p1n2/8/3Pq3/4BN2/PPP2PPP/R2QKB1R b KQkq - 1 9", "prompt": "FEN: r1b1kb1r/1pp2ppp/p2p1n2/8/3Pq3/4BN2/PPP2PPP/R2QKB1R b KQkq - 1 9\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 a8b8 b7b5 b7b6 c7c5 c7c6 c8d7 c8e6 c8f5 c8g4 c8h3 d6d5 e4c2 e4c6 e4d3 e4d4 e4d5 e4e3 e4e5 e4e6 e4e7 e4f3 e4f4 e4f5 e4g4 e4g6 e4h4 e8d7 e8d8 e8e7 f6d5 f6d7 f6g4 f6g8 f6h5 f8e7 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00261", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqk2r/p3ppbp/p1p2np1/3p4/3P1B2/2N1P3/PPP2PPP/R2QK1NR w KQkq -", "prompt": "FEN: r1bqk2r/p3ppbp/p1p2np1/3p4/3P1B2/2N1P3/PPP2PPP/R2QK1NR w KQkq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white queen; e1 white king; g1 white knight; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white knight; e3 white pawn; d4 white pawn; f4 white bishop.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "e3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "f4", "piece": "white bishop"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "e3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "f4", "piece": "white bishop"}]}}
{"example_id": "rules_00262", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b1k2r/ppp1qppp/2np1n2/6B1/3pP3/5N2/PPP2PPP/R2QKB1R w KQkq -", "prompt": "FEN: r1b1k2r/ppp1qppp/2np1n2/6B1/3pP3/5N2/PPP2PPP/R2QKB1R w KQkq -\nWhat legal moves does the piece on e1 have?", "gold_answer": "e1d2 e1e2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "e1", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "e1", "piece": "king"}}
{"example_id": "rules_00263", "split": "rules", "task_type": "check_detection", "fen": "2r2rk1/p5Pp/8/2p5/3pRp2/8/PPP2P1P/4R1K1 b - - 0 24", "prompt": "FEN: 2r2rk1/p5Pp/8/2p5/3pRp2/8/PPP2P1P/4R1K1 b - - 0 24\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00264", "split": "rules", "task_type": "captures", "fen": "rnb1kb1r/pp2pppp/1qp5/3p4/2PPnB2/2N5/PPQ1PPPP/R3KBNR b KQkq -", "prompt": "FEN: rnb1kb1r/pp2pppp/1qp5/3p4/2PPnB2/2N5/PPQ1PPPP/R3KBNR b KQkq -\nList all capture moves available.", "gold_answer": "b6b2 b6d4 d5c4 e4c3 e4f2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00265", "split": "rules", "task_type": "special_rules", "fen": "8/pp2kb2/3pr3/2pR2pp/2P1p3/P3K2P/1P6/5R2 w - - 2 30", "prompt": "Given FEN: 8/pp2kb2/3pr3/2pR2pp/2P1p3/P3K2P/1P6/5R2 w - - 2 30\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00266", "split": "rules", "task_type": "legality_check", "fen": "2k4r/ppp2pp1/2n4p/8/8/1NPrb3/PP1N2PP/R2R1K2 b - - 1 20", "prompt": "FEN: 2k4r/ppp2pp1/2n4p/8/8/1NPrb3/PP1N2PP/R2R1K2 b - - 1 20\nIs the move f7f5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f7f5", "_legality_check_reason_label": "legal", "move": "f7f5", "legality_reason_label": "legal"}}
{"example_id": "rules_00267", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5k2/1r5p/1p3R2/3r4/8/1P3P2/1K5P/8 b - - 3 34", "prompt": "FEN: 5k2/1r5p/1p3R2/3r4/8/1P3P2/1K5P/8 b - - 3 34\nList pseudo-legal moves from d5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d5: d5a5 d5b5 d5c5 d5d1 d5d2 d5d3 d5d4 d5d6 d5d7 d5d8 d5e5 d5f5 d5g5 d5h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_00268", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1b1k2r/ppqppp2/2n2np1/4P2p/5P2/PN1B4/2PB2PP/R2Q1RK1 b kq - 0 14", "prompt": "FEN: r1b1k2r/ppqppp2/2n2np1/4P2p/5P2/PN1B4/2PB2PP/R2Q1RK1 b kq - 0 14\nFor the piece on h5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from h5: h5h4.\nLegal: h5h4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "h5", "diagnostic": true, "hard_gate": false, "source_square": "h5"}}
{"example_id": "rules_00269", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bqkb1r/pp3ppp/2n2n2/4p3/N2p4/1B1P4/PPP2PPP/R1BQK1NR w KQkq - 1 8", "prompt": "FEN: r1bqkb1r/pp3ppp/2n2n2/4p3/N2p4/1B1P4/PPP2PPP/R1BQK1NR w KQkq - 1 8\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00270", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "7k/8/2r5/2N2rp1/1p4R1/P3P2P/2R2P1K/8 w - - 0 42", "prompt": "FEN: 7k/8/2r5/2N2rp1/1p4R1/P3P2P/2R2P1K/8 w - - 0 42\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c2 white rook; f2 white pawn; h2 white king; a3 white pawn; e3 white pawn; h3 white pawn; g4 white rook; c5 white knight.\nMoves by piece:\nc2 white rook: c2a2 c2b2 c2c1 c2c3 c2c4 c2d2 c2e2\nf2 white pawn: f2f3 f2f4\nh2 white king: h2g1 h2g2 h2g3 h2h1\na3 white pawn: a3a4 a3b4\ne3 white pawn: e3e4\nh3 white pawn: h3h4\ng4 white rook: g4b4 g4c4 g4d4 g4e4 g4f4 g4g1 g4g2 g4g3 g4g5 g4h4\nc5 white knight: c5a4 c5a6 c5b3 c5b7 c5d3 c5d7 c5e4 c5e6\nAll legal moves: a3a4 a3b4 c2a2 c2b2 c2c1 c2c3 c2c4 c2d2 c2e2 c5a4 c5a6 c5b3 c5b7 c5d3 c5d7 c5e4 c5e6 e3e4 f2f3 f2f4 g4b4 g4c4 g4d4 g4e4 g4f4 g4g1 g4g2 g4g3 g4g5 g4h4 h2g1 h2g2 h2g3 h2h1 h3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c2": ["c2a2", "c2b2", "c2c1", "c2c3", "c2c4", "c2d2", "c2e2"], "f2": ["f2f3", "f2f4"], "h2": ["h2g1", "h2g2", "h2g3", "h2h1"], "a3": ["a3a4", "a3b4"], "e3": ["e3e4"], "h3": ["h3h4"], "g4": ["g4b4", "g4c4", "g4d4", "g4e4", "g4f4", "g4g1", "g4g2", "g4g3", "g4g5", "g4h4"], "c5": ["c5a4", "c5a6", "c5b3", "c5b7", "c5d3", "c5d7", "c5e4", "c5e6"]}, "_legal_moves_by_piece_moves": "a3a4 a3b4 c2a2 c2b2 c2c1 c2c3 c2c4 c2d2 c2e2 c5a4 c5a6 c5b3 c5b7 c5d3 c5d7 c5e4 c5e6 e3e4 f2f3 f2f4 g4b4 g4c4 g4d4 g4e4 g4f4 g4g1 g4g2 g4g3 g4g5 g4h4 h2g1 h2g2 h2g3 h2h1 h3h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c2": ["c2a2", "c2b2", "c2c1", "c2c3", "c2c4", "c2d2", "c2e2"], "f2": ["f2f3", "f2f4"], "h2": ["h2g1", "h2g2", "h2g3", "h2h1"], "a3": ["a3a4", "a3b4"], "e3": ["e3e4"], "h3": ["h3h4"], "g4": ["g4b4", "g4c4", "g4d4", "g4e4", "g4f4", "g4g1", "g4g2", "g4g3", "g4g5", "g4h4"], "c5": ["c5a4", "c5a6", "c5b3", "c5b7", "c5d3", "c5d7", "c5e4", "c5e6"]}, "legal_moves": "a3a4 a3b4 c2a2 c2b2 c2c1 c2c3 c2c4 c2d2 c2e2 c5a4 c5a6 c5b3 c5b7 c5d3 c5d7 c5e4 c5e6 e3e4 f2f3 f2f4 g4b4 g4c4 g4d4 g4e4 g4f4 g4g1 g4g2 g4g3 g4g5 g4h4 h2g1 h2g2 h2g3 h2h1 h3h4"}}
{"example_id": "rules_00271", "split": "rules", "task_type": "ray_walk", "fen": "5nk1/1p3n1p/1q4p1/2p1p3/rbP1P1NP/2B3P1/1Q3P2/3R2K1 w - -", "prompt": "FEN: 5nk1/1p3n1p/1q4p1/2p1p3/rbP1P1NP/2B3P1/1Q3P2/3R2K1 w - -\nWalk each ray for the slider on d1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d1 white rook.\nRay N: d2 empty; d3 empty; d4 empty; d5 empty; d6 empty; d7 empty; d8 empty; edge.\nRay E: e1 empty; f1 empty; g1 white king: own piece (stop, excluded).\nRay S: edge.\nRay W: c1 empty; b1 empty; a1 empty; edge.\nMoves from rays: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_00272", "split": "rules", "task_type": "legal_moves", "fen": "5r1k/q5Bp/p3Q3/1p6/1P6/P2P2P1/5P1P/3n1RK1 b - - 0 26", "prompt": "FEN: 5r1k/q5Bp/p3Q3/1p6/1P6/P2P2P1/5P1P/3n1RK1 b - - 0 26\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7g7 h8g7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00273", "split": "rules", "task_type": "legal_moves", "fen": "8/8/5pp1/3p1k2/p5bP/2B1K3/6P1/8 b - -", "prompt": "FEN: 8/8/5pp1/3p1k2/p5bP/2B1K3/6P1/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a4a3 d5d4 f5e6 g4d1 g4e2 g4f3 g4h3 g4h5 g6g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00274", "split": "rules", "task_type": "side_piece_inventory", "fen": "rn2k2r/pp3pp1/3qpnp1/2pp4/3P4/3Q2P1/PPP1PPBP/RN3RK1 b kq -", "prompt": "FEN: rn2k2r/pp3pp1/3qpnp1/2pp4/3P4/3Q2P1/PPP1PPBP/RN3RK1 b kq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c5 black pawn; d5 black pawn; d6 black queen; e6 black pawn; f6 black knight; g6 black pawn; a7 black pawn; b7 black pawn; f7 black pawn; g7 black pawn; a8 black rook; b8 black knight; e8 black king; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c5", "piece": "black pawn"}, {"square": "d5", "piece": "black pawn"}, {"square": "d6", "piece": "black queen"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c5", "piece": "black pawn"}, {"square": "d5", "piece": "black pawn"}, {"square": "d6", "piece": "black queen"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00275", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnbk3N/pppq2pp/3p4/4p2B/4P2b/6P1/PPPP1K1P/RNBQ3R b - - 0 10", "prompt": "FEN: rnbk3N/pppq2pp/3p4/4p2B/4P2b/6P1/PPPP1K1P/RNBQ3R b - - 0 10\nWhat legal moves does the piece on b7 have?", "gold_answer": "b7b5 b7b6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "b7", "piece": "pawn"}}
{"example_id": "rules_00276", "split": "rules", "task_type": "check_detection", "fen": "r1bqk1nr/ppp2ppp/3b4/3pn3/8/1P2PN2/P1PP2PP/RNBQKB1R w KQkq -", "prompt": "FEN: r1bqk1nr/ppp2ppp/3b4/3pn3/8/1P2PN2/P1PP2PP/RNBQKB1R w KQkq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00277", "split": "rules", "task_type": "captures", "fen": "8/4k3/p4p1p/1b6/2n1NPPP/1BP2K2/8/8 w - -", "prompt": "FEN: 8/4k3/p4p1p/1b6/2n1NPPP/1BP2K2/8/8 w - -\nList all capture moves available.", "gold_answer": "b3c4 e4f6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00278", "split": "rules", "task_type": "special_rules", "fen": "2rq1rk1/pp2bppp/2n1pn2/2pp3b/3PP3/2P1BN1P/PPBN1PP1/RQ3RK1 b - -", "prompt": "Given FEN: 2rq1rk1/pp2bppp/2n1pn2/2pp3b/3PP3/2P1BN1P/PPBN1PP1/RQ3RK1 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00279", "split": "rules", "task_type": "legality_check", "fen": "rn1qkb1r/pp2pp1p/2p2p2/5b2/3P4/2P5/PP3PPP/R1BQKBNR w KQkq -", "prompt": "FEN: rn1qkb1r/pp2pp1p/2p2p2/5b2/3P4/2P5/PP3PPP/R1BQKBNR w KQkq -\nIs the move d1b3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "d1b3", "_legality_check_reason_label": "legal", "move": "d1b3", "legality_reason_label": "legal"}}
{"example_id": "rules_00280", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "3rr1k1/1p3p1p/p5p1/3q1n2/3P1Q2/P3B3/1P3PPP/3RR1K1 b - -", "prompt": "FEN: 3rr1k1/1p3p1p/p5p1/3q1n2/3P1Q2/P3B3/1P3PPP/3RR1K1 b - -\nList pseudo-legal moves from d5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d5: d5a2 d5a5 d5b3 d5b5 d5c4 d5c5 d5c6 d5d4 d5d6 d5d7 d5e4 d5e5 d5e6 d5f3 d5g2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_00281", "split": "rules", "task_type": "piece_legal_filter", "fen": "2R5/4k1pp/4P3/p4P2/rb6/6P1/6PK/8 w - -", "prompt": "FEN: 2R5/4k1pp/4P3/p4P2/rb6/6P1/6PK/8 w - -\nFor the piece on h2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from h2: h2g1 h2h1 h2h3.\nLegal: h2g1 h2h1 h2h3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "h2", "diagnostic": true, "hard_gate": false, "source_square": "h2"}}
{"example_id": "rules_00282", "split": "rules", "task_type": "king_safety_filter", "fen": "5rk1/3qnpp1/7p/b2p1bP1/2pP1B2/p1P2Q2/P1B2PP1/1R3NK1 w - -", "prompt": "FEN: 5rk1/3qnpp1/7p/b2p1bP1/2pP1B2/p1P2Q2/P1B2PP1/1R3NK1 w - -\nFor move b1a1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: b1a1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "b1a1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "b1a1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00283", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2kr1bnr/pbq2ppp/1pn5/2pNp3/1P1pP3/P2B1N2/1BPP1PPP/R2Q1RK1 b - - 1 10", "prompt": "FEN: 2kr1bnr/pbq2ppp/1pn5/2pNp3/1P1pP3/P2B1N2/1BPP1PPP/R2Q1RK1 b - - 1 10\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d4 black pawn; c5 black pawn; e5 black pawn; b6 black pawn; c6 black knight; a7 black pawn; b7 black bishop; c7 black queen; f7 black pawn; g7 black pawn; h7 black pawn; c8 black king; d8 black rook; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\nd4 black pawn: no legal moves\nc5 black pawn: c5b4 c5c4\ne5 black pawn: no legal moves\nb6 black pawn: b6b5\nc6 black knight: c6a5 c6b4 c6b8 c6e7\na7 black pawn: a7a5 a7a6\nb7 black bishop: b7a6 b7a8\nc7 black queen: c7b8 c7d6 c7d7 c7e7\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\nc8 black king: c8b8 c8d7\nd8 black rook: d8d5 d8d6 d8d7 d8e8\nf8 black bishop: f8d6 f8e7\ng8 black knight: g8e7 g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a7a5 a7a6 b6b5 b7a6 b7a8 c5b4 c5c4 c6a5 c6b4 c6b8 c6e7 c7b8 c7d6 c7d7 c7e7 c8b8 c8d7 d8d5 d8d6 d8d7 d8e8 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d4": [], "c5": ["c5b4", "c5c4"], "e5": [], "b6": ["b6b5"], "c6": ["c6a5", "c6b4", "c6b8", "c6e7"], "a7": ["a7a5", "a7a6"], "b7": ["b7a6", "b7a8"], "c7": ["c7b8", "c7d6", "c7d7", "c7e7"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8b8", "c8d7"], "d8": ["d8d5", "d8d6", "d8d7", "d8e8"], "f8": ["f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b6b5 b7a6 b7a8 c5b4 c5c4 c6a5 c6b4 c6b8 c6e7 c7b8 c7d6 c7d7 c7e7 c8b8 c8d7 d8d5 d8d6 d8d7 d8e8 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d4": [], "c5": ["c5b4", "c5c4"], "e5": [], "b6": ["b6b5"], "c6": ["c6a5", "c6b4", "c6b8", "c6e7"], "a7": ["a7a5", "a7a6"], "b7": ["b7a6", "b7a8"], "c7": ["c7b8", "c7d6", "c7d7", "c7e7"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8b8", "c8d7"], "d8": ["d8d5", "d8d6", "d8d7", "d8e8"], "f8": ["f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "legal_moves": "a7a5 a7a6 b6b5 b7a6 b7a8 c5b4 c5c4 c6a5 c6b4 c6b8 c6e7 c7b8 c7d6 c7d7 c7e7 c8b8 c8d7 d8d5 d8d6 d8d7 d8e8 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_00284", "split": "rules", "task_type": "ray_walk", "fen": "2r2rk1/1p3ppp/p2qp3/3p1b2/3P4/1Q6/PP2NPPP/2R2RK1 w - - 0 18", "prompt": "FEN: 2r2rk1/1p3ppp/p2qp3/3p1b2/3P4/1Q6/PP2NPPP/2R2RK1 w - - 0 18\nWalk each ray for the slider on c1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c1 white rook.\nRay N: c2 empty; c3 empty; c4 empty; c5 empty; c6 empty; c7 empty; c8 black rook: capture (stop, included).\nRay E: d1 empty; e1 empty; f1 white rook: own piece (stop, excluded).\nRay S: edge.\nRay W: b1 empty; a1 empty; edge.\nMoves from rays: c1a1 c1b1 c1c2 c1c3 c1c4 c1c5 c1c6 c1c7 c1c8 c1d1 c1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_00285", "split": "rules", "task_type": "legal_moves", "fen": "2r3k1/1bq4p/p1p3p1/2P4n/P3p3/7P/1Q3PP1/3R1BK1 w - -", "prompt": "FEN: 2r3k1/1bq4p/p1p3p1/2P4n/P3p3/7P/1Q3PP1/3R1BK1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a4a5 b2a1 b2a2 b2a3 b2b1 b2b3 b2b4 b2b5 b2b6 b2b7 b2c1 b2c2 b2c3 b2d2 b2d4 b2e2 b2e5 b2f6 b2g7 b2h8 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 f1a6 f1b5 f1c4 f1d3 f1e2 f2f3 f2f4 g1h1 g2g3 g2g4 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00286", "split": "rules", "task_type": "legal_moves", "fen": "5r1k/1p4p1/p1p4p/P2p4/1P3P2/2P2Q1P/2q3P1/3RB1K1 w - - 4 30", "prompt": "FEN: 5r1k/1p4p1/p1p4p/P2p4/1P3P2/2P2Q1P/2q3P1/3RB1K1 w - - 4 30\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b4b5 c3c4 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 e1d2 e1f2 e1g3 e1h4 f3d3 f3d5 f3e2 f3e3 f3e4 f3f1 f3f2 f3g3 f3g4 f3h5 f4f5 g1f1 g1h1 g1h2 g2g3 g2g4 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00287", "split": "rules", "task_type": "side_piece_inventory", "fen": "r4r2/ppp1p1kp/2n1q1pn/5P2/5P2/2NBB2P/PPP1Q3/2KR3R b - - 0 18", "prompt": "FEN: r4r2/ppp1p1kp/2n1q1pn/5P2/5P2/2NBB2P/PPP1Q3/2KR3R b - - 0 18\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c6 black knight; e6 black queen; g6 black pawn; h6 black knight; a7 black pawn; b7 black pawn; c7 black pawn; e7 black pawn; g7 black king; h7 black pawn; a8 black rook; f8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c6", "piece": "black knight"}, {"square": "e6", "piece": "black queen"}, {"square": "g6", "piece": "black pawn"}, {"square": "h6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "e7", "piece": "black pawn"}, {"square": "g7", "piece": "black king"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "f8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c6", "piece": "black knight"}, {"square": "e6", "piece": "black queen"}, {"square": "g6", "piece": "black pawn"}, {"square": "h6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "e7", "piece": "black pawn"}, {"square": "g7", "piece": "black king"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "f8", "piece": "black rook"}]}}
{"example_id": "rules_00288", "split": "rules", "task_type": "piece_legal_moves", "fen": "2r4r/1b2kpbp/p3p3/3p1p2/B7/P1p5/R1R2PPP/1N3K2 b - - 3 23", "prompt": "FEN: 2r4r/1b2kpbp/p3p3/3p1p2/B7/P1p5/R1R2PPP/1N3K2 b - - 3 23\nWhat legal moves does the piece on d5 have?", "gold_answer": "d5d4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "d5", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "d5", "piece": "pawn"}}
{"example_id": "rules_00289", "split": "rules", "task_type": "check_detection", "fen": "r2k1r2/pppb2p1/4p1B1/4P3/3Q2Pq/P1B5/2P2P1P/1R2K2R w K - 1 18", "prompt": "FEN: r2k1r2/pppb2p1/4p1B1/4P3/3Q2Pq/P1B5/2P2P1P/1R2K2R w K - 1 18\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00290", "split": "rules", "task_type": "captures", "fen": "2r2b1r/p2k1npn/2pP1p2/2N4p/8/2P3P1/PP4BP/2KRR3 b - -", "prompt": "FEN: 2r2b1r/p2k1npn/2pP1p2/2N4p/8/2P3P1/PP4BP/2KRR3 b - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00291", "split": "rules", "task_type": "special_rules", "fen": "r3kbr1/pp1nq1pp/2p5/4pbN1/8/3P4/PPP2PPP/RNBQ1RK1 w q - 2 10", "prompt": "Given FEN: r3kbr1/pp1nq1pp/2p5/4pbN1/8/3P4/PPP2PPP/RNBQ1RK1 w q - 2 10\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00292", "split": "rules", "task_type": "legality_check", "fen": "rnbq1rk1/pppp1ppp/4pn2/8/2PP4/5N2/PP1NPPPP/R2QKB1R w KQ - 1 6", "prompt": "FEN: rnbq1rk1/pppp1ppp/4pn2/8/2PP4/5N2/PP1NPPPP/R2QKB1R w KQ - 1 6\nIs the move h8h3 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "h8h3", "_legality_check_reason_label": "empty_source", "move": "h8h3", "legality_reason_label": "empty_source"}}
{"example_id": "rules_00293", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnbqkbnr/ppp2ppp/8/3p4/2P1p3/4P3/PP1P1PPP/RNBQKBNR b KQkq - 1 4", "prompt": "FEN: rnbqkbnr/ppp2ppp/8/3p4/2P1p3/4P3/PP1P1PPP/RNBQKBNR b KQkq - 1 4\nList pseudo-legal moves from d5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d5: d5c4 d5d4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_00294", "split": "rules", "task_type": "piece_legal_filter", "fen": "1kn1r2r/nppq4/1P4p1/3p1pPp/Q2P1P2/2P1B3/3N1KP1/RR6 b - - 0 22", "prompt": "FEN: 1kn1r2r/nppq4/1P4p1/3p1pPp/Q2P1P2/2P1B3/3N1KP1/RR6 b - - 0 22\nFor the piece on h5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from h5: h5h4.\nLegal: h5h4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "h5", "diagnostic": true, "hard_gate": false, "source_square": "h5"}}
{"example_id": "rules_00295", "split": "rules", "task_type": "king_safety_filter", "fen": "4B3/4n1k1/pp1N1p1p/1P2p3/P7/7P/2b2PP1/6K1 b - - 0 33", "prompt": "FEN: 4B3/4n1k1/pp1N1p1p/1P2p3/P7/7P/2b2PP1/6K1 b - - 0 33\nFor move g7f7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: g7f7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "g7f7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "g7f7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00296", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/pp6/3pkpp1/1P4b1/P1K3P1/8/8/B7 b - - 0 41", "prompt": "FEN: 8/pp6/3pkpp1/1P4b1/P1K3P1/8/8/B7 b - - 0 41\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: g5 black bishop; d6 black pawn; e6 black king; f6 black pawn; g6 black pawn; a7 black pawn; b7 black pawn.\nMoves by piece:\ng5 black bishop: g5c1 g5d2 g5e3 g5f4 g5h4 g5h6\nd6 black pawn: d6d5\ne6 black king: e6d7 e6e7 e6f7\nf6 black pawn: f6f5\ng6 black pawn: no legal moves\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b6\nAll legal moves: a7a5 a7a6 b7b6 d6d5 e6d7 e6e7 e6f7 f6f5 g5c1 g5d2 g5e3 g5f4 g5h4 g5h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"g5": ["g5c1", "g5d2", "g5e3", "g5f4", "g5h4", "g5h6"], "d6": ["d6d5"], "e6": ["e6d7", "e6e7", "e6f7"], "f6": ["f6f5"], "g6": [], "a7": ["a7a5", "a7a6"], "b7": ["b7b6"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7b6 d6d5 e6d7 e6e7 e6f7 f6f5 g5c1 g5d2 g5e3 g5f4 g5h4 g5h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"g5": ["g5c1", "g5d2", "g5e3", "g5f4", "g5h4", "g5h6"], "d6": ["d6d5"], "e6": ["e6d7", "e6e7", "e6f7"], "f6": ["f6f5"], "g6": [], "a7": ["a7a5", "a7a6"], "b7": ["b7b6"]}, "legal_moves": "a7a5 a7a6 b7b6 d6d5 e6d7 e6e7 e6f7 f6f5 g5c1 g5d2 g5e3 g5f4 g5h4 g5h6"}}
{"example_id": "rules_00297", "split": "rules", "task_type": "ray_walk", "fen": "r3k1nr/p2p2b1/1p2p1P1/2p1p1p1/6B1/3P4/PPP5/RN1K2nb b kq - 1 19", "prompt": "FEN: r3k1nr/p2p2b1/1p2p1P1/2p1p1p1/6B1/3P4/PPP5/RN1K2nb b kq - 1 19\nWalk each ray for the slider on h1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: h1 black bishop.\nRay NE: edge.\nRay SE: edge.\nRay SW: edge.\nRay NW: g2 empty; f3 empty; e4 empty; d5 empty; c6 empty; b7 empty; a8 black rook: own piece (stop, excluded).\nMoves from rays: h1b7 h1c6 h1d5 h1e4 h1f3 h1g2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "h1", "diagnostic": true, "hard_gate": false, "source_square": "h1"}}
{"example_id": "rules_00298", "split": "rules", "task_type": "legal_moves", "fen": "r1bqk3/1pp2p1p/2np4/p3p3/1b2P2P/2P2Q2/P2P1P2/1RB1KBN1 b q - 0 14", "prompt": "FEN: r1bqk3/1pp2p1p/2np4/p3p3/1b2P2P/2P2Q2/P2P1P2/1RB1KBN1 b q - 0 14\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a5a4 a8a6 a8a7 a8b8 b4a3 b4c3 b4c5 b7b5 b7b6 c6a7 c6b8 c6d4 c6e7 c8d7 c8e6 c8f5 c8g4 c8h3 d6d5 d8d7 d8e7 d8f6 d8g5 d8h4 e8d7 e8e7 e8f8 f7f5 f7f6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00299", "split": "rules", "task_type": "legal_moves", "fen": "2r3k1/5pp1/prn1p2p/3p4/3P4/2P1RNPP/1P3PK1/R7 w - -", "prompt": "FEN: 2r3k1/5pp1/prn1p2p/3p4/3P4/2P1RNPP/1P3PK1/R7 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 a1a4 a1a5 a1a6 a1b1 a1c1 a1d1 a1e1 a1f1 a1g1 a1h1 b2b3 b2b4 c3c4 e3d3 e3e1 e3e2 e3e4 e3e5 e3e6 f3d2 f3e1 f3e5 f3g1 f3g5 f3h2 f3h4 g2f1 g2g1 g2h1 g2h2 g3g4 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00300", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/6k1/8/6K1/4Q3/8/8/8 w - -", "prompt": "FEN: 8/6k1/8/6K1/4Q3/8/8/8 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: e4 white queen; g5 white king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "e4", "piece": "white queen"}, {"square": "g5", "piece": "white king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "e4", "piece": "white queen"}, {"square": "g5", "piece": "white king"}]}}
{"example_id": "rules_00301", "split": "rules", "task_type": "piece_legal_moves", "fen": "5k2/2r5/4K3/8/8/8/8/8 w - -", "prompt": "FEN: 5k2/2r5/4K3/8/8/8/8/8 w - -\nWhat legal moves does the piece on e6 have?", "gold_answer": "e6d5 e6d6 e6e5 e6f5 e6f6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "e6", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "e6", "piece": "king"}}
{"example_id": "rules_00302", "split": "rules", "task_type": "check_detection", "fen": "r1bq1rk1/pppnppbp/3p1np1/8/2PP3B/2N2N2/PP2PPPP/R2QKB1R w KQ - 4 7", "prompt": "FEN: r1bq1rk1/pppnppbp/3p1np1/8/2PP3B/2N2N2/PP2PPPP/R2QKB1R w KQ - 4 7\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00303", "split": "rules", "task_type": "captures", "fen": "2kr2nr/pp1qbppp/4p3/n2pP3/b1pP3P/P1P2NP1/1P1NQPB1/R1B2RK1 w - -", "prompt": "FEN: 2kr2nr/pp1qbppp/4p3/n2pP3/b1pP3P/P1P2NP1/1P1NQPB1/R1B2RK1 w - -\nList all capture moves available.", "gold_answer": "d2c4 e2c4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00304", "split": "rules", "task_type": "special_rules", "fen": "8/5N1k/pp2NP2/2p5/3p2P1/8/PPP5/2K5 w - - 0 55", "prompt": "Given FEN: 8/5N1k/pp2NP2/2p5/3p2P1/8/PPP5/2K5 w - - 0 55\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00305", "split": "rules", "task_type": "legality_check", "fen": "r3k2r/pp2n3/2p4p/4n3/4B2P/2N2K2/PP6/3R4 w - - 0 28", "prompt": "FEN: r3k2r/pp2n3/2p4p/4n3/4B2P/2N2K2/PP6/3R4 w - - 0 28\nIs the move f3g3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f3g3", "_legality_check_reason_label": "legal", "move": "f3g3", "legality_reason_label": "legal"}}
{"example_id": "rules_00306", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rn3rk1/1p1bbp1p/p3p1pB/3pP3/3P4/P1N4q/1P1QBP1P/2K3RR w - - 0 17", "prompt": "FEN: rn3rk1/1p1bbp1p/p3p1pB/3pP3/3P4/P1N4q/1P1QBP1P/2K3RR w - - 0 17\nList pseudo-legal moves from c1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c1: c1b1 c1c2 c1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_00307", "split": "rules", "task_type": "piece_legal_filter", "fen": "4rr2/pq5k/6Rp/2p1b1pP/5p2/3P4/PPP3K1/6R1 w - - 3 32", "prompt": "FEN: 4rr2/pq5k/6Rp/2p1b1pP/5p2/3P4/PPP3K1/6R1 w - - 3 32\nFor the piece on g1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g1: g1a1 g1b1 g1c1 g1d1 g1e1 g1f1 g1h1.\nLegal: none.\nRejected: g1a1 does_not_resolve_check; g1b1 does_not_resolve_check; g1c1 does_not_resolve_check; g1d1 does_not_resolve_check; g1e1 does_not_resolve_check; g1f1 does_not_resolve_check; g1h1 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g1", "diagnostic": true, "hard_gate": false, "source_square": "g1"}}
{"example_id": "rules_00308", "split": "rules", "task_type": "king_safety_filter", "fen": "r2qk2r/4bppp/p1b1p3/2ppPn2/8/BP3N1P/P1P1NPP1/R2Q1RK1 b kq - 0 13", "prompt": "FEN: r2qk2r/4bppp/p1b1p3/2ppPn2/8/BP3N1P/P1P1NPP1/R2Q1RK1 b kq - 0 13\nFor move a6a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a6a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a6a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a6a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00309", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqr1k1/pp2bppp/2n2n2/1Bpp4/8/2NP1N1P/PPP2PP1/R1BQR1K1 b - - 0 10", "prompt": "FEN: r1bqr1k1/pp2bppp/2n2n2/1Bpp4/8/2NP1N1P/PPP2PP1/R1BQR1K1 b - - 0 10\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black pawn; d5 black pawn; c6 black knight; f6 black knight; a7 black pawn; b7 black pawn; e7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black rook; g8 black king.\nMoves by piece:\nc5 black pawn: c5c4\nd5 black pawn: d5d4\nc6 black knight: c6a5 c6b4 c6b8 c6d4 c6e5\nf6 black knight: f6d7 f6e4 f6g4 f6h5\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b6\ne7 black bishop: e7d6 e7f8\nf7 black pawn: no legal moves\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8\nc8 black bishop: c8d7 c8e6 c8f5 c8g4 c8h3\nd8 black queen: d8a5 d8b6 d8c7 d8d6 d8d7\ne8 black rook: e8f8\ng8 black king: g8f8 g8h8\nAll legal moves: a7a5 a7a6 a8b8 b7b6 c5c4 c6a5 c6b4 c6b8 c6d4 c6e5 c8d7 c8e6 c8f5 c8g4 c8h3 d5d4 d8a5 d8b6 d8c7 d8d6 d8d7 e7d6 e7f8 e8f8 f6d7 f6e4 f6g4 f6h5 g7g5 g7g6 g8f8 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": ["c5c4"], "d5": ["d5d4"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5"], "f6": ["f6d7", "f6e4", "f6g4", "f6h5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b6"], "e7": ["e7d6", "e7f8"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7", "c8e6", "c8f5", "c8g4", "c8h3"], "d8": ["d8a5", "d8b6", "d8c7", "d8d6", "d8d7"], "e8": ["e8f8"], "g8": ["g8f8", "g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 b7b6 c5c4 c6a5 c6b4 c6b8 c6d4 c6e5 c8d7 c8e6 c8f5 c8g4 c8h3 d5d4 d8a5 d8b6 d8c7 d8d6 d8d7 e7d6 e7f8 e8f8 f6d7 f6e4 f6g4 f6h5 g7g5 g7g6 g8f8 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": ["c5c4"], "d5": ["d5d4"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5"], "f6": ["f6d7", "f6e4", "f6g4", "f6h5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b6"], "e7": ["e7d6", "e7f8"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7", "c8e6", "c8f5", "c8g4", "c8h3"], "d8": ["d8a5", "d8b6", "d8c7", "d8d6", "d8d7"], "e8": ["e8f8"], "g8": ["g8f8", "g8h8"]}, "legal_moves": "a7a5 a7a6 a8b8 b7b6 c5c4 c6a5 c6b4 c6b8 c6d4 c6e5 c8d7 c8e6 c8f5 c8g4 c8h3 d5d4 d8a5 d8b6 d8c7 d8d6 d8d7 e7d6 e7f8 e8f8 f6d7 f6e4 f6g4 f6h5 g7g5 g7g6 g8f8 g8h8 h7h5 h7h6"}}
{"example_id": "rules_00310", "split": "rules", "task_type": "ray_walk", "fen": "rn1q1rk1/pb3ppp/1ppbpn2/3pN3/2PPP3/2N3P1/PP3PBP/R1BQ1RK1 b - -", "prompt": "FEN: rn1q1rk1/pb3ppp/1ppbpn2/3pN3/2PPP3/2N3P1/PP3PBP/R1BQ1RK1 b - -\nWalk each ray for the slider on d6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d6 black bishop.\nRay NE: e7 empty; f8 black rook: own piece (stop, excluded).\nRay SE: e5 white knight: capture (stop, included).\nRay SW: c5 empty; b4 empty; a3 empty; edge.\nRay NW: c7 empty; b8 black knight: own piece (stop, excluded).\nMoves from rays: d6a3 d6b4 d6c5 d6c7 d6e5 d6e7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "d6", "diagnostic": true, "hard_gate": false, "source_square": "d6"}}
{"example_id": "rules_00311", "split": "rules", "task_type": "legal_moves", "fen": "r4N1k/2R3R1/2p2p2/5p2/2b5/p5P1/4r1KP/8 w - -", "prompt": "FEN: r4N1k/2R3R1/2p2p2/5p2/2b5/p5P1/4r1KP/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: g2f1 g2f3 g2g1 g2h1 g2h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00312", "split": "rules", "task_type": "legal_moves", "fen": "rnb1kbnr/p4ppp/1p1qp3/2P5/8/2N1BN2/PP2PPPP/R2QKB1R b KQkq - 0 7", "prompt": "FEN: rnb1kbnr/p4ppp/1p1qp3/2P5/8/2N1BN2/PP2PPPP/R2QKB1R b KQkq - 0 7\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6b5 b6c5 b8a6 b8c6 b8d7 c8a6 c8b7 c8d7 d6c5 d6c6 d6c7 d6d1 d6d2 d6d3 d6d4 d6d5 d6d7 d6d8 d6e5 d6e7 d6f4 d6g3 d6h2 e6e5 e8d7 e8d8 e8e7 f7f5 f7f6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00313", "split": "rules", "task_type": "side_piece_inventory", "fen": "2r5/6kp/n4pp1/8/8/P6P/5PP1/3R2K1 w - - 1 27", "prompt": "FEN: 2r5/6kp/n4pp1/8/8/P6P/5PP1/3R2K1 w - - 1 27\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: d1 white rook; g1 white king; f2 white pawn; g2 white pawn; a3 white pawn; h3 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "d1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "d1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}]}}
{"example_id": "rules_00314", "split": "rules", "task_type": "piece_legal_moves", "fen": "r4rk1/6bp/1p1q2p1/pPn1p3/2P1PB2/5P1N/2Q1B1PP/R2R2K1 b - - 0 27", "prompt": "FEN: r4rk1/6bp/1p1q2p1/pPn1p3/2P1PB2/5P1N/2Q1B1PP/R2R2K1 b - - 0 27\nWhat legal moves does the piece on a8 have?", "gold_answer": "a8a6 a8a7 a8b8 a8c8 a8d8 a8e8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a8", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "a8", "piece": "rook"}}
{"example_id": "rules_00315", "split": "rules", "task_type": "check_detection", "fen": "rnbqr1k1/pp3ppp/2p1p3/3n4/3P4/B1P1PN2/P3BPPP/R2QK2R w KQ - 0 10", "prompt": "FEN: rnbqr1k1/pp3ppp/2p1p3/3n4/3P4/B1P1PN2/P3BPPP/R2QK2R w KQ - 0 10\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00316", "split": "rules", "task_type": "captures", "fen": "Bn2k1nr/p2p1ppp/bpPb4/8/8/2B3P1/PPK2P1P/RN5R b k - 0 20", "prompt": "FEN: Bn2k1nr/p2p1ppp/bpPb4/8/8/2B3P1/PPK2P1P/RN5R b k - 0 20\nList all capture moves available.", "gold_answer": "b8c6 d6g3 d7c6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00317", "split": "rules", "task_type": "special_rules", "fen": "rnbqkbnr/pp3ppp/4p3/2pP4/8/5N2/PPPPBPPP/RNBQK2R b KQkq - 0 4", "prompt": "Given FEN: rnbqkbnr/pp3ppp/4p3/2pP4/8/5N2/PPPPBPPP/RNBQK2R b KQkq - 0 4\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00318", "split": "rules", "task_type": "legality_check", "fen": "8/1P6/2K5/2R5/8/3k4/1rp5/8 b - - 0 56", "prompt": "FEN: 8/1P6/2K5/2R5/8/3k4/1rp5/8 b - - 0 56\nIs the move c2c1n legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c2c1n", "_legality_check_reason_label": "legal", "move": "c2c1n", "legality_reason_label": "legal"}}
{"example_id": "rules_00319", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5r2/2P4p/p2K2k1/P5p1/6P1/2P5/5p1P/5R2 b - - 0 40", "prompt": "FEN: 5r2/2P4p/p2K2k1/P5p1/6P1/2P5/5p1P/5R2 b - - 0 40\nList pseudo-legal moves from g6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g6: g6f5 g6f6 g6f7 g6g7 g6h5 g6h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g6", "diagnostic": true, "hard_gate": false, "source_square": "g6"}}
{"example_id": "rules_00320", "split": "rules", "task_type": "piece_legal_filter", "fen": "7r/5ppp/4kN2/4p3/1b6/1r2B3/2PK2PP/3R1R2 w - - 1 29", "prompt": "FEN: 7r/5ppp/4kN2/4p3/1b6/1r2B3/2PK2PP/3R1R2 w - - 1 29\nFor the piece on d1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d1: d1a1 d1b1 d1c1 d1e1.\nLegal: none.\nRejected: d1a1 does_not_resolve_check; d1b1 does_not_resolve_check; d1c1 does_not_resolve_check; d1e1 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_00321", "split": "rules", "task_type": "king_safety_filter", "fen": "1r3rk1/2qnbppp/pp1ppn2/2p5/2P2PP1/NPN1PQ2/PB1P3P/R3K2R b KQ - 0 14", "prompt": "FEN: 1r3rk1/2qnbppp/pp1ppn2/2p5/2P2PP1/NPN1PQ2/PB1P3P/R3K2R b KQ - 0 14\nFor move a6a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a6a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a6a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a6a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00322", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnbqkbnr/pp3ppp/3pp3/2p5/4P3/5NP1/PPPP1PBP/RNBQK2R b KQkq - 1 4", "prompt": "FEN: rnbqkbnr/pp3ppp/3pp3/2p5/4P3/5NP1/PPPP1PBP/RNBQK2R b KQkq - 1 4\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black pawn; d6 black pawn; e6 black pawn; a7 black pawn; b7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\nc5 black pawn: c5c4\nd6 black pawn: d6d5\ne6 black pawn: e6e5\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: no legal moves\nb8 black knight: b8a6 b8c6 b8d7\nc8 black bishop: c8d7\nd8 black queen: d8a5 d8b6 d8c7 d8d7 d8e7 d8f6 d8g5 d8h4\ne8 black king: e8d7 e8e7\nf8 black bishop: f8e7\ng8 black knight: g8e7 g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c5c4 c8d7 d6d5 d8a5 d8b6 d8c7 d8d7 d8e7 d8f6 d8g5 d8h4 e6e5 e8d7 e8e7 f7f5 f7f6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": ["c5c4"], "d6": ["d6d5"], "e6": ["e6e5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8c6", "b8d7"], "c8": ["c8d7"], "d8": ["d8a5", "d8b6", "d8c7", "d8d7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8d7", "e8e7"], "f8": ["f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c5c4 c8d7 d6d5 d8a5 d8b6 d8c7 d8d7 d8e7 d8f6 d8g5 d8h4 e6e5 e8d7 e8e7 f7f5 f7f6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": ["c5c4"], "d6": ["d6d5"], "e6": ["e6e5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8c6", "b8d7"], "c8": ["c8d7"], "d8": ["d8a5", "d8b6", "d8c7", "d8d7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8d7", "e8e7"], "f8": ["f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "legal_moves": "a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c5c4 c8d7 d6d5 d8a5 d8b6 d8c7 d8d7 d8e7 d8f6 d8g5 d8h4 e6e5 e8d7 e8e7 f7f5 f7f6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_00323", "split": "rules", "task_type": "ray_walk", "fen": "r1bqkb1r/1p3ppp/p1n2n2/2pp4/P1B5/3P1N2/1PP2PPP/RNBQR1K1 b kq -", "prompt": "FEN: r1bqkb1r/1p3ppp/p1n2n2/2pp4/P1B5/3P1N2/1PP2PPP/RNBQR1K1 b kq -\nWalk each ray for the slider on a8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a8 black rook.\nRay N: edge.\nRay E: b8 empty; c8 black bishop: own piece (stop, excluded).\nRay S: a7 empty; a6 black pawn: own piece (stop, excluded).\nRay W: edge.\nMoves from rays: a8a7 a8b8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a8", "diagnostic": true, "hard_gate": false, "source_square": "a8"}}
{"example_id": "rules_00324", "split": "rules", "task_type": "legal_moves", "fen": "r1bq1rk1/p1ppp1bp/1p3p2/3Pn2Q/8/6N1/PPP2PPP/2KR1BNR w - -", "prompt": "FEN: r1bq1rk1/p1ppp1bp/1p3p2/3Pn2Q/8/6N1/PPP2PPP/2KR1BNR w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 b2b4 c1b1 c1d2 c2c3 c2c4 d1d2 d1d3 d1d4 d1e1 d5d6 f1a6 f1b5 f1c4 f1d3 f1e2 f2f3 f2f4 g1e2 g1f3 g1h3 g3e2 g3e4 g3f5 h2h3 h2h4 h5e2 h5e5 h5e8 h5f3 h5f5 h5f7 h5g4 h5g5 h5g6 h5h3 h5h4 h5h6 h5h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00325", "split": "rules", "task_type": "legal_moves", "fen": "2Q3nr/p2r4/k1p1p2p/q4pp1/1b6/2N3BP/P1P2PP1/6K1 b - - 1 20", "prompt": "FEN: 2Q3nr/p2r4/k1p1p2p/q4pp1/1b6/2N3BP/P1P2PP1/6K1 b - - 1 20\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6b6 d7b7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00326", "split": "rules", "task_type": "side_piece_inventory", "fen": "rn1qk2r/1p3pp1/p3b2p/3pP3/6n1/1PN3P1/PBP2PBP/R2QR1K1 b kq - 2 13", "prompt": "FEN: rn1qk2r/1p3pp1/p3b2p/3pP3/6n1/1PN3P1/PBP2PBP/R2QR1K1 b kq - 2 13\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: g4 black knight; d5 black pawn; a6 black pawn; e6 black bishop; h6 black pawn; b7 black pawn; f7 black pawn; g7 black pawn; a8 black rook; b8 black knight; d8 black queen; e8 black king; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "g4", "piece": "black knight"}, {"square": "d5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "e6", "piece": "black bishop"}, {"square": "h6", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "g4", "piece": "black knight"}, {"square": "d5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "e6", "piece": "black bishop"}, {"square": "h6", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00327", "split": "rules", "task_type": "piece_legal_moves", "fen": "rn1qk2r/ppp2ppp/3bbn2/1B1p2B1/3P4/2N2N2/PPP2PPP/R2QK2R b KQkq - 7 7", "prompt": "FEN: rn1qk2r/ppp2ppp/3bbn2/1B1p2B1/3P4/2N2N2/PPP2PPP/R2QK2R b KQkq - 7 7\nWhat legal moves does the piece on a8 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a8", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "a8", "piece": "rook"}}
{"example_id": "rules_00328", "split": "rules", "task_type": "check_detection", "fen": "rnb1kbnr/ppp3pp/8/4Pp2/4p3/2N2P2/PPP3PP/R1BqKBNR w KQkq -", "prompt": "FEN: rnb1kbnr/ppp3pp/8/4Pp2/4p3/2N2P2/PPP3PP/R1BqKBNR w KQkq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00329", "split": "rules", "task_type": "captures", "fen": "r1b2rk1/1p1n2pp/2p5/p2p1p2/3P4/1Pb2P2/PN4PP/R1BR3K b - - 2 20", "prompt": "FEN: r1b2rk1/1p1n2pp/2p5/p2p1p2/3P4/1Pb2P2/PN4PP/R1BR3K b - - 2 20\nList all capture moves available.", "gold_answer": "c3b2 c3d4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00330", "split": "rules", "task_type": "special_rules", "fen": "1r5k/pb1p1B1p/2p2P2/1p6/4N2P/8/PP3P2/n1K3R1 b - - 0 25", "prompt": "Given FEN: 1r5k/pb1p1B1p/2p2P2/1p6/4N2P/8/PP3P2/n1K3R1 b - - 0 25\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00331", "split": "rules", "task_type": "legality_check", "fen": "rn1qkb1r/pp3pp1/2p1pn1p/3P1b2/8/3P1NP1/PP2PPBP/RNBQ1RK1 b kq -", "prompt": "FEN: rn1qkb1r/pp3pp1/2p1pn1p/3P1b2/8/3P1NP1/PP2PPBP/RNBQ1RK1 b kq -\nIs the move f8d6 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f8d6", "_legality_check_reason_label": "legal", "move": "f8d6", "legality_reason_label": "legal"}}
{"example_id": "rules_00332", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r4r1k/pppb2pp/8/4ppN1/2BnP3/3PQ2P/PPPK2P1/R4R2 w - - 0 19", "prompt": "FEN: r4r1k/pppb2pp/8/4ppN1/2BnP3/3PQ2P/PPPK2P1/R4R2 w - - 0 19\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1 a1c1 a1d1 a1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00333", "split": "rules", "task_type": "piece_legal_filter", "fen": "r6r/pbp1k1pp/3q1n2/1p1pN1B1/3PP3/1QNP4/PP3PPP/R4RK1 b - - 6 14", "prompt": "FEN: r6r/pbp1k1pp/3q1n2/1p1pN1B1/3PP3/1QNP4/PP3PPP/R4RK1 b - - 6 14\nFor the piece on f6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f6: f6d7 f6e4 f6e8 f6g4 f6g8 f6h5.\nLegal: none.\nRejected: f6d7 pinned_piece_exposes_king; f6e4 pinned_piece_exposes_king; f6e8 pinned_piece_exposes_king; f6g4 pinned_piece_exposes_king; f6g8 pinned_piece_exposes_king; f6h5 pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "f6", "diagnostic": true, "hard_gate": false, "source_square": "f6"}}
{"example_id": "rules_00334", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bqk2r/p2pnppp/2p5/2b1p3/2B1P3/2N5/PPP2PPP/R1BQK2R w KQkq - 4 8", "prompt": "FEN: r1bqk2r/p2pnppp/2p5/2b1p3/2B1P3/2N5/PPP2PPP/R1BQK2R w KQkq - 4 8\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00335", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r3k2r/ppN5/2np4/4pbqp/2B3nR/5QP1/PPP3P1/R3K3 b Qkq - 0 19", "prompt": "FEN: r3k2r/ppN5/2np4/4pbqp/2B3nR/5QP1/PPP3P1/R3K3 b Qkq - 0 19\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: g4 black knight; e5 black pawn; f5 black bishop; g5 black queen; h5 black pawn; c6 black knight; d6 black pawn; a7 black pawn; b7 black pawn; a8 black rook; e8 black king; h8 black rook.\nMoves by piece:\ng4 black knight: no legal moves\ne5 black pawn: no legal moves\nf5 black bishop: no legal moves\ng5 black queen: no legal moves\nh5 black pawn: no legal moves\nc6 black knight: no legal moves\nd6 black pawn: no legal moves\na7 black pawn: no legal moves\nb7 black pawn: no legal moves\na8 black rook: no legal moves\ne8 black king: e8d7 e8d8 e8e7 e8f8\nh8 black rook: no legal moves\nAll legal moves: e8d7 e8d8 e8e7 e8f8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"g4": [], "e5": [], "f5": [], "g5": [], "h5": [], "c6": [], "d6": [], "a7": [], "b7": [], "a8": [], "e8": ["e8d7", "e8d8", "e8e7", "e8f8"], "h8": []}, "_legal_moves_by_piece_moves": "e8d7 e8d8 e8e7 e8f8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"g4": [], "e5": [], "f5": [], "g5": [], "h5": [], "c6": [], "d6": [], "a7": [], "b7": [], "a8": [], "e8": ["e8d7", "e8d8", "e8e7", "e8f8"], "h8": []}, "legal_moves": "e8d7 e8d8 e8e7 e8f8"}}
{"example_id": "rules_00336", "split": "rules", "task_type": "ray_walk", "fen": "r1r3k1/3nbppp/p3q3/2p2N1b/Q1N1P3/B6P/P1R2PP1/2R3K1 b - - 4 21", "prompt": "FEN: r1r3k1/3nbppp/p3q3/2p2N1b/Q1N1P3/B6P/P1R2PP1/2R3K1 b - - 4 21\nWalk each ray for the slider on h5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: h5 black bishop.\nRay NE: edge.\nRay SE: edge.\nRay SW: g4 empty; f3 empty; e2 empty; d1 empty; edge.\nRay NW: g6 empty; f7 black pawn: own piece (stop, excluded).\nMoves from rays: h5d1 h5e2 h5f3 h5g4 h5g6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "h5", "diagnostic": true, "hard_gate": false, "source_square": "h5"}}
{"example_id": "rules_00337", "split": "rules", "task_type": "legal_filter_trace", "fen": "5Q2/8/2p5/K1P5/4k1pR/8/2n5/8 b - - 7 59", "prompt": "FEN: 5Q2/8/2p5/K1P5/4k1pR/8/2n5/8 b - - 7 59\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c2 black knight; e4 black king; g4 black pawn; c6 black pawn.\nFilter by piece:\nc2 black knight: pseudo-legal c2a1 c2a3 c2b4 c2d4 c2e1 c2e3 | rejected none | legal c2a1 c2a3 c2b4 c2d4 c2e1 c2e3\ne4 black king: pseudo-legal e4d3 e4d4 e4d5 e4e3 e4e5 e4f3 e4f4 e4f5 | rejected e4f3 king_would_be_in_check; e4f4 king_would_be_in_check; e4f5 king_would_be_in_check | legal e4d3 e4d4 e4d5 e4e3 e4e5\ng4 black pawn: pseudo-legal g4g3 | rejected g4g3 pinned_piece_exposes_king | legal none\nc6 black pawn: pseudo-legal none | rejected none | legal none\nAll legal moves: c2a1 c2a3 c2b4 c2d4 c2e1 c2e3 e4d3 e4d4 e4d5 e4e3 e4e5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00338", "split": "rules", "task_type": "legal_moves", "fen": "rn3rk1/5p1p/p3pqp1/3p3P/2p2PQ1/8/PPnN1P2/1R1K2R1 w - - 0 21", "prompt": "FEN: rn3rk1/5p1p/p3pqp1/3p3P/2p2PQ1/8/PPnN1P2/1R1K2R1 w - - 0 21\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a1 b1c1 b2b3 b2b4 d1c1 d1c2 d1e2 d2b3 d2c4 d2e4 d2f1 d2f3 f2f3 f4f5 g1e1 g1f1 g1g2 g1g3 g1h1 g4e2 g4e6 g4f3 g4f5 g4g2 g4g3 g4g5 g4g6 g4h3 g4h4 h5g6 h5h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00339", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/2pk2p1/1rp5/3p2P1/7P/1P6/1KPr4/R6R b - - 0 38", "prompt": "FEN: 8/2pk2p1/1rp5/3p2P1/7P/1P6/1KPr4/R6R b - - 0 38\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: d2 black rook; d5 black pawn; b6 black rook; c6 black pawn; c7 black pawn; d7 black king; g7 black pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "d2", "piece": "black rook"}, {"square": "d5", "piece": "black pawn"}, {"square": "b6", "piece": "black rook"}, {"square": "c6", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "d7", "piece": "black king"}, {"square": "g7", "piece": "black pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "d2", "piece": "black rook"}, {"square": "d5", "piece": "black pawn"}, {"square": "b6", "piece": "black rook"}, {"square": "c6", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "d7", "piece": "black king"}, {"square": "g7", "piece": "black pawn"}]}}
{"example_id": "rules_00340", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bq1rk1/ppp1bppp/2n1pn2/8/2BP4/P1N1PN1P/1P3PP1/R1BQK2R b KQ - 2 8", "prompt": "FEN: r1bq1rk1/ppp1bppp/2n1pn2/8/2BP4/P1N1PN1P/1P3PP1/R1BQK2R b KQ - 2 8\nWhat legal moves does the piece on a7 have?", "gold_answer": "a7a5 a7a6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a7", "piece": "pawn"}}
{"example_id": "rules_00341", "split": "rules", "task_type": "check_detection", "fen": "r1bqr1k1/pppp1ppp/8/2b1n3/2P5/2N1P3/PP2BPPP/R1BQ1RK1 w - -", "prompt": "FEN: r1bqr1k1/pppp1ppp/8/2b1n3/2P5/2N1P3/PP2BPPP/R1BQ1RK1 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00342", "split": "rules", "task_type": "captures", "fen": "2b3k1/p5bp/1p4p1/4Pp2/P3pB2/1q4Q1/1P3PPP/4R1K1 w - - 0 27", "prompt": "FEN: 2b3k1/p5bp/1p4p1/4Pp2/P3pB2/1q4Q1/1P3PPP/4R1K1 w - - 0 27\nList all capture moves available.", "gold_answer": "e1e4 g3b3 g3g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00343", "split": "rules", "task_type": "special_rules", "fen": "r1b2r2/4qpbk/2pp2pp/pp2n1P1/4PN1P/PBNP2Q1/1PP5/R4RK1 b - - 0 20", "prompt": "Given FEN: r1b2r2/4qpbk/2pp2pp/pp2n1P1/4PN1P/PBNP2Q1/1PP5/R4RK1 b - - 0 20\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00344", "split": "rules", "task_type": "legality_check", "fen": "5bk1/pp4qp/4b1p1/2pN4/8/3P1QP1/PPP3BP/6K1 b - -", "prompt": "FEN: 5bk1/pp4qp/4b1p1/2pN4/8/3P1QP1/PPP3BP/6K1 b - -\nIs the move g7f7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "g7f7", "_legality_check_reason_label": "legal", "move": "g7f7", "legality_reason_label": "legal"}}
{"example_id": "rules_00345", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r3r1k1/pbp2pbp/1p2p1p1/n3P3/2NP4/BP3N2/P6P/R3K3 w Q - 7 22", "prompt": "FEN: r3r1k1/pbp2pbp/1p2p1p1/n3P3/2NP4/BP3N2/P6P/R3K3 w Q - 7 22\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1 a1c1 a1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00346", "split": "rules", "task_type": "piece_legal_filter", "fen": "4r1k1/pp4pp/2rq1n2/3p2N1/4p3/4Q3/PP2RPPP/4R1K1 b - - 1 23", "prompt": "FEN: 4r1k1/pp4pp/2rq1n2/3p2N1/4p3/4Q3/PP2RPPP/4R1K1 b - - 1 23\nFor the piece on g8, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g8: g8f7 g8f8 g8h8.\nLegal: g8f8 g8h8.\nRejected: g8f7 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g8", "diagnostic": true, "hard_gate": false, "source_square": "g8"}}
{"example_id": "rules_00347", "split": "rules", "task_type": "king_safety_filter", "fen": "8/1p4k1/p7/4B1p1/P3b3/7P/5PP1/6K1 b - -", "prompt": "FEN: 8/1p4k1/p7/4B1p1/P3b3/7P/5PP1/6K1 b - -\nFor move a6a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a6a5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a6a5", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "a6a5", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_00348", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnbqkb1r/ppp1np1p/4p1p1/3p4/2PP4/2N2N2/PP2PPPP/R1BQKB1R w KQkq - 0 5", "prompt": "FEN: rnbqkb1r/ppp1np1p/4p1p1/3p4/2PP4/2N2N2/PP2PPPP/R1BQKB1R w KQkq - 0 5\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; e1 white king; f1 white bishop; h1 white rook; a2 white pawn; b2 white pawn; e2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white knight; f3 white knight; c4 white pawn; d4 white pawn.\nMoves by piece:\na1 white rook: a1b1\nc1 white bishop: c1d2 c1e3 c1f4 c1g5 c1h6\nd1 white queen: d1a4 d1b3 d1c2 d1d2 d1d3\ne1 white king: e1d2\nf1 white bishop: no legal moves\nh1 white rook: h1g1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\ne2 white pawn: e2e3 e2e4\nf2 white pawn: no legal moves\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nc3 white knight: c3a4 c3b1 c3b5 c3d5 c3e4\nf3 white knight: f3d2 f3e5 f3g1 f3g5 f3h4\nc4 white pawn: c4c5 c4d5\nd4 white pawn: no legal moves\nAll legal moves: a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d5 c3e4 c4c5 c4d5 d1a4 d1b3 d1c2 d1d2 d1d3 e1d2 e2e3 e2e4 f3d2 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1g1 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1a4", "d1b3", "d1c2", "d1d2", "d1d3"], "e1": ["e1d2"], "f1": [], "h1": ["h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "e2": ["e2e3", "e2e4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c3": ["c3a4", "c3b1", "c3b5", "c3d5", "c3e4"], "f3": ["f3d2", "f3e5", "f3g1", "f3g5", "f3h4"], "c4": ["c4c5", "c4d5"], "d4": []}, "_legal_moves_by_piece_moves": "a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d5 c3e4 c4c5 c4d5 d1a4 d1b3 d1c2 d1d2 d1d3 e1d2 e2e3 e2e4 f3d2 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1g1 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1a4", "d1b3", "d1c2", "d1d2", "d1d3"], "e1": ["e1d2"], "f1": [], "h1": ["h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "e2": ["e2e3", "e2e4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c3": ["c3a4", "c3b1", "c3b5", "c3d5", "c3e4"], "f3": ["f3d2", "f3e5", "f3g1", "f3g5", "f3h4"], "c4": ["c4c5", "c4d5"], "d4": []}, "legal_moves": "a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d5 c3e4 c4c5 c4d5 d1a4 d1b3 d1c2 d1d2 d1d3 e1d2 e2e3 e2e4 f3d2 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1g1 h2h3 h2h4"}}
{"example_id": "rules_00349", "split": "rules", "task_type": "ray_walk", "fen": "8/8/8/1R4K1/8/2R5/8/k7 w - -", "prompt": "FEN: 8/8/8/1R4K1/8/2R5/8/k7 w - -\nWalk each ray for the slider on c3: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c3 white rook.\nRay N: c4 empty; c5 empty; c6 empty; c7 empty; c8 empty; edge.\nRay E: d3 empty; e3 empty; f3 empty; g3 empty; h3 empty; edge.\nRay S: c2 empty; c1 empty; edge.\nRay W: b3 empty; a3 empty; edge.\nMoves from rays: c3a3 c3b3 c3c1 c3c2 c3c4 c3c5 c3c6 c3c7 c3c8 c3d3 c3e3 c3f3 c3g3 c3h3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c3", "diagnostic": true, "hard_gate": false, "source_square": "c3"}}
{"example_id": "rules_00350", "split": "rules", "task_type": "legal_moves", "fen": "r4rk1/3qbp2/n1p3pp/1p1p1b1N/p2P4/P1N1PPQ1/1PB3PP/1R3RK1 w - - 0 24", "prompt": "FEN: r4rk1/3qbp2/n1p3pp/1p1p1b1N/p2P4/P1N1PPQ1/1PB3PP/1R3RK1 w - - 0 24\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b1a1 b1c1 b1d1 b1e1 b2b3 b2b4 c2a4 c2b3 c2d1 c2d3 c2e4 c2f5 c3a2 c3a4 c3b5 c3d1 c3d5 c3e2 c3e4 e3e4 f1c1 f1d1 f1e1 f1f2 f3f4 g1f2 g1h1 g3b8 g3c7 g3d6 g3e1 g3e5 g3f2 g3f4 g3g4 g3g5 g3g6 g3h3 g3h4 h2h3 h2h4 h5f4 h5f6 h5g7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00351", "split": "rules", "task_type": "legal_moves", "fen": "3k4/3rp3/1brpPp2/2pP1Pp1/1pP3Pp/pP2K2P/P7/8 b - -", "prompt": "FEN: 3k4/3rp3/1brpPp2/2pP1Pp1/1pP3Pp/pP2K2P/P7/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b6a5 b6a7 b6c7 c6c7 c6c8 d7a7 d7b7 d7c7 d8c7 d8c8 d8e8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00352", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqkbnr/2p2ppp/1pn1p3/p1PpP3/1P1P4/P7/5PPP/RNBQKBNR w KQkq - 0 8", "prompt": "FEN: r1bqkbnr/2p2ppp/1pn1p3/p1PpP3/1P1P4/P7/5PPP/RNBQKBNR w KQkq - 0 8\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; d1 white queen; e1 white king; f1 white bishop; g1 white knight; h1 white rook; f2 white pawn; g2 white pawn; h2 white pawn; a3 white pawn; b4 white pawn; d4 white pawn; c5 white pawn; e5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "f1", "piece": "white bishop"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "c5", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "f1", "piece": "white bishop"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "c5", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}]}}
{"example_id": "rules_00353", "split": "rules", "task_type": "piece_legal_moves", "fen": "r2q2r1/pp1bk3/4p2Q/3pPp2/8/P1N5/1PP2PPP/R4RK1 b - - 0 18", "prompt": "FEN: r2q2r1/pp1bk3/4p2Q/3pPp2/8/P1N5/1PP2PPP/R4RK1 b - - 0 18\nWhat legal moves does the piece on b7 have?", "gold_answer": "b7b5 b7b6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "b7", "piece": "pawn"}}
{"example_id": "rules_00354", "split": "rules", "task_type": "check_detection", "fen": "r3k1nr/pbppqp1p/1pn3p1/4p1N1/2B1P3/3P1Q2/PPP2PPP/RN3RK1 b kq -", "prompt": "FEN: r3k1nr/pbppqp1p/1pn3p1/4p1N1/2B1P3/3P1Q2/PPP2PPP/RN3RK1 b kq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00355", "split": "rules", "task_type": "captures", "fen": "6k1/p4rbp/1p4p1/8/4p3/2P1B1P1/P1R1P1KP/8 b - - 3 26", "prompt": "FEN: 6k1/p4rbp/1p4p1/8/4p3/2P1B1P1/P1R1P1KP/8 b - - 3 26\nList all capture moves available.", "gold_answer": "g7c3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00356", "split": "rules", "task_type": "special_rules", "fen": "r5k1/pp3ppp/2p3n1/8/6b1/P1P1r1P1/7P/2R1KB1R w K - 0 19", "prompt": "Given FEN: r5k1/pp3ppp/2p3n1/8/6b1/P1P1r1P1/7P/2R1KB1R w K - 0 19\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00357", "split": "rules", "task_type": "legality_check", "fen": "r1bqkbnr/ppp3pp/2np4/5P2/2B1p3/2P2N2/PP1P1PPP/RNBQK2R w KQkq -", "prompt": "FEN: r1bqkbnr/ppp3pp/2np4/5P2/2B1p3/2P2N2/PP1P1PPP/RNBQK2R w KQkq -\nIs the move h2h4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "h2h4", "_legality_check_reason_label": "legal", "move": "h2h4", "legality_reason_label": "legal"}}
{"example_id": "rules_00358", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/8/2K1p3/1pBpP3/1PkP2b1/8/8/8 w - - 17 58", "prompt": "FEN: 8/8/2K1p3/1pBpP3/1PkP2b1/8/8/8 w - - 17 58\nList pseudo-legal moves from c5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c5: c5a7 c5b6 c5d6 c5e7 c5f8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_00359", "split": "rules", "task_type": "piece_legal_filter", "fen": "6r1/1pp5/4n1k1/pP2p3/Pb1pPp2/3P1Pr1/1B3KPR/R7 w - - 5 35", "prompt": "FEN: 6r1/1pp5/4n1k1/pP2p3/Pb1pPp2/3P1Pr1/1B3KPR/R7 w - - 5 35\nFor the piece on f2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f2: f2e1 f2e2 f2e3 f2f1 f2g1 f2g3.\nLegal: f2e2 f2f1 f2g1.\nRejected: f2e1 king_would_be_in_check; f2e3 king_would_be_in_check; f2g3 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "f2", "diagnostic": true, "hard_gate": false, "source_square": "f2"}}
{"example_id": "rules_00360", "split": "rules", "task_type": "king_safety_filter", "fen": "r4rk1/p2b1ppp/3Q1n2/q1p3B1/2B1P3/8/PPP2PPP/R2R2K1 b - - 0 17", "prompt": "FEN: r4rk1/p2b1ppp/3Q1n2/q1p3B1/2B1P3/8/PPP2PPP/R2R2K1 b - - 0 17\nFor move a5a2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a5a2.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a5a2", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a5a2", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00361", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqkbnr/1pp1pppp/p1n5/3pP3/8/5N2/PPPP1PPP/RNBQKB1R w KQkq - 2 4", "prompt": "FEN: r1bqkbnr/1pp1pppp/p1n5/3pP3/8/5N2/PPPP1PPP/RNBQKB1R w KQkq - 2 4\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; d1 white queen; e1 white king; f1 white bishop; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; d2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; f3 white knight; e5 white pawn.\nMoves by piece:\na1 white rook: no legal moves\nb1 white knight: b1a3 b1c3\nc1 white bishop: no legal moves\nd1 white queen: d1e2\ne1 white king: e1e2\nf1 white bishop: f1a6 f1b5 f1c4 f1d3 f1e2\nh1 white rook: h1g1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: c2c3 c2c4\nd2 white pawn: d2d3 d2d4\nf2 white pawn: no legal moves\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nf3 white knight: f3d4 f3g1 f3g5 f3h4\ne5 white pawn: e5e6\nAll legal moves: a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c2c3 c2c4 d1e2 d2d3 d2d4 e1e2 e5e6 f1a6 f1b5 f1c4 f1d3 f1e2 f3d4 f3g1 f3g5 f3h4 g2g3 g2g4 h1g1 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "b1": ["b1a3", "b1c3"], "c1": [], "d1": ["d1e2"], "e1": ["e1e2"], "f1": ["f1a6", "f1b5", "f1c4", "f1d3", "f1e2"], "h1": ["h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "d2": ["d2d3", "d2d4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "f3": ["f3d4", "f3g1", "f3g5", "f3h4"], "e5": ["e5e6"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c2c3 c2c4 d1e2 d2d3 d2d4 e1e2 e5e6 f1a6 f1b5 f1c4 f1d3 f1e2 f3d4 f3g1 f3g5 f3h4 g2g3 g2g4 h1g1 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "b1": ["b1a3", "b1c3"], "c1": [], "d1": ["d1e2"], "e1": ["e1e2"], "f1": ["f1a6", "f1b5", "f1c4", "f1d3", "f1e2"], "h1": ["h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "d2": ["d2d3", "d2d4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "f3": ["f3d4", "f3g1", "f3g5", "f3h4"], "e5": ["e5e6"]}, "legal_moves": "a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c2c3 c2c4 d1e2 d2d3 d2d4 e1e2 e5e6 f1a6 f1b5 f1c4 f1d3 f1e2 f3d4 f3g1 f3g5 f3h4 g2g3 g2g4 h1g1 h2h3 h2h4"}}
{"example_id": "rules_00362", "split": "rules", "task_type": "ray_walk", "fen": "r1bq1rk1/pppnppbp/3p1np1/6B1/3PP3/2PB1N2/PP3PPP/RN1Q1RK1 b - -", "prompt": "FEN: r1bq1rk1/pppnppbp/3p1np1/6B1/3PP3/2PB1N2/PP3PPP/RN1Q1RK1 b - -\nWalk each ray for the slider on g7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: g7 black bishop.\nRay NE: h8 empty; edge.\nRay SE: h6 empty; edge.\nRay SW: f6 black knight: own piece (stop, excluded).\nRay NW: f8 black rook: own piece (stop, excluded).\nMoves from rays: g7h6 g7h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "g7", "diagnostic": true, "hard_gate": false, "source_square": "g7"}}
{"example_id": "rules_00363", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/4k3/8/8/8/3K4/1r6/R7 b - -", "prompt": "FEN: 8/4k3/8/8/8/3K4/1r6/R7 b - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b2 black rook; e7 black king.\nFilter by piece:\nb2 black rook: pseudo-legal b2a2 b2b1 b2b3 b2b4 b2b5 b2b6 b2b7 b2b8 b2c2 b2d2 b2e2 b2f2 b2g2 b2h2 | rejected none | legal b2a2 b2b1 b2b3 b2b4 b2b5 b2b6 b2b7 b2b8 b2c2 b2d2 b2e2 b2f2 b2g2 b2h2\ne7 black king: pseudo-legal e7d6 e7d7 e7d8 e7e6 e7e8 e7f6 e7f7 e7f8 | rejected none | legal e7d6 e7d7 e7d8 e7e6 e7e8 e7f6 e7f7 e7f8\nAll legal moves: b2a2 b2b1 b2b3 b2b4 b2b5 b2b6 b2b7 b2b8 b2c2 b2d2 b2e2 b2f2 b2g2 b2h2 e7d6 e7d7 e7d8 e7e6 e7e8 e7f6 e7f7 e7f8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00364", "split": "rules", "task_type": "legal_moves", "fen": "r4rk1/1p2bppp/2N2n2/2p5/Pp2q3/1P6/1B1PNPPP/R2Q1RK1 b - - 0 18", "prompt": "FEN: r4rk1/1p2bppp/2N2n2/2p5/Pp2q3/1P6/1B1PNPPP/R2Q1RK1 b - - 0 18\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a8a4 a8a5 a8a6 a8a7 a8b8 a8c8 a8d8 a8e8 b7b5 b7b6 b7c6 c5c4 e4b1 e4c2 e4c4 e4c6 e4d3 e4d4 e4d5 e4e2 e4e3 e4e5 e4e6 e4f3 e4f4 e4f5 e4g2 e4g4 e4g6 e4h4 e7d6 e7d8 f6d5 f6d7 f6e8 f6g4 f6h5 f8b8 f8c8 f8d8 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00365", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqkb1r/pppn1ppp/5n2/3pN3/3P4/2NB4/PPP2PPP/R1BQK2R w KQkq -", "prompt": "FEN: r1bqkb1r/pppn1ppp/5n2/3pN3/3P4/2NB4/PPP2PPP/R1BQK2R w KQkq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; e1 white king; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white knight; d3 white bishop; d4 white pawn; e5 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d3", "piece": "white bishop"}, {"square": "d4", "piece": "white pawn"}, {"square": "e5", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d3", "piece": "white bishop"}, {"square": "d4", "piece": "white pawn"}, {"square": "e5", "piece": "white knight"}]}}
{"example_id": "rules_00366", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnb1kbnr/pp2pppp/8/3q4/1p6/5N2/PBPP1PPP/RN1QKB1R b KQkq -", "prompt": "FEN: rnb1kbnr/pp2pppp/8/3q4/1p6/5N2/PBPP1PPP/RN1QKB1R b KQkq -\nWhat legal moves does the piece on d5 have?", "gold_answer": "d5a2 d5a5 d5b3 d5b5 d5c4 d5c5 d5c6 d5d2 d5d3 d5d4 d5d6 d5d7 d5d8 d5e4 d5e5 d5e6 d5f3 d5f5 d5g5 d5h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "d5", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "d5", "piece": "queen"}}
{"example_id": "rules_00367", "split": "rules", "task_type": "check_detection", "fen": "3r3k/1Q3pp1/8/2RN3p/8/8/5PPP/6K1 w - -", "prompt": "FEN: 3r3k/1Q3pp1/8/2RN3p/8/8/5PPP/6K1 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00368", "split": "rules", "task_type": "captures", "fen": "2k5/p1p3p1/6Qp/2P1K3/2qP1PP1/4r2P/8/8 w - - 7 37", "prompt": "FEN: 2k5/p1p3p1/6Qp/2P1K3/2qP1PP1/4r2P/8/8 w - - 7 37\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00369", "split": "rules", "task_type": "special_rules", "fen": "r1bqkbnr/ppp3pp/2B2p2/3pp3/8/1P2P3/PBPP1PPP/RN1QK1NR b KQkq - 0 5", "prompt": "Given FEN: r1bqkbnr/ppp3pp/2B2p2/3pp3/8/1P2P3/PBPP1PPP/RN1QK1NR b KQkq - 0 5\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00370", "split": "rules", "task_type": "legality_check", "fen": "8/1R2kppp/N2np3/p7/3p4/2p4P/5PP1/6K1 b - - 0 39", "prompt": "FEN: 8/1R2kppp/N2np3/p7/3p4/2p4P/5PP1/6K1 b - - 0 39\nIs the move d6b7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "d6b7", "_legality_check_reason_label": "legal", "move": "d6b7", "legality_reason_label": "legal"}}
{"example_id": "rules_00371", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "1k3b2/p1p3pp/1p6/3pr3/5n2/2N3N1/PPP1BP1P/R3K1R1 b Q - 3 20", "prompt": "FEN: 1k3b2/p1p3pp/1p6/3pr3/5n2/2N3N1/PPP1BP1P/R3K1R1 b Q - 3 20\nList pseudo-legal moves from f4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from f4: f4d3 f4e2 f4e6 f4g2 f4g6 f4h3 f4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "f4", "diagnostic": true, "hard_gate": false, "source_square": "f4"}}
{"example_id": "rules_00372", "split": "rules", "task_type": "piece_legal_filter", "fen": "r3k1nr/p1p2ppp/2p5/8/1b1P4/2N5/PP2qPPP/R1B1K2R w KQkq -", "prompt": "FEN: r3k1nr/p1p2ppp/2p5/8/1b1P4/2N5/PP2qPPP/R1B1K2R w KQkq -\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1.\nLegal: none.\nRejected: a1b1 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00373", "split": "rules", "task_type": "king_safety_filter", "fen": "2k1r2r/pp2qpb1/1npp1n1p/4p3/3PP2B/1BP2Q2/PP3PP1/RN2R1K1 b - - 4 16", "prompt": "FEN: 2k1r2r/pp2qpb1/1npp1n1p/4p3/3PP2B/1BP2Q2/PP3PP1/RN2R1K1 b - - 4 16\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00374", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1r2r1k1/1p1bqpp1/p1np1n1p/2p1pP2/2B1P3/P2P1N2/1PPBQ1PP/R4RK1 w - - 4 14", "prompt": "FEN: 1r2r1k1/1p1bqpp1/p1np1n1p/2p1pP2/2B1P3/P2P1N2/1PPBQ1PP/R4RK1 w - - 4 14\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; f1 white rook; g1 white king; b2 white pawn; c2 white pawn; d2 white bishop; e2 white queen; g2 white pawn; h2 white pawn; a3 white pawn; d3 white pawn; f3 white knight; c4 white bishop; e4 white pawn; f5 white pawn.\nMoves by piece:\na1 white rook: a1a2 a1b1 a1c1 a1d1 a1e1\nf1 white rook: f1b1 f1c1 f1d1 f1e1 f1f2\ng1 white king: g1f2 g1h1\nb2 white pawn: b2b3 b2b4\nc2 white pawn: c2c3\nd2 white bishop: d2a5 d2b4 d2c1 d2c3 d2e1 d2e3 d2f4 d2g5 d2h6\ne2 white queen: e2d1 e2e1 e2e3 e2f2\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\na3 white pawn: a3a4\nd3 white pawn: d3d4\nf3 white knight: f3d4 f3e1 f3e5 f3g5 f3h4\nc4 white bishop: c4a2 c4a6 c4b3 c4b5 c4d5 c4e6 c4f7\ne4 white pawn: no legal moves\nf5 white pawn: no legal moves\nAll legal moves: a1a2 a1b1 a1c1 a1d1 a1e1 a3a4 b2b3 b2b4 c2c3 c4a2 c4a6 c4b3 c4b5 c4d5 c4e6 c4f7 d2a5 d2b4 d2c1 d2c3 d2e1 d2e3 d2f4 d2g5 d2h6 d3d4 e2d1 e2e1 e2e3 e2f2 f1b1 f1c1 f1d1 f1e1 f1f2 f3d4 f3e1 f3e5 f3g5 f3h4 g1f2 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1a2", "a1b1", "a1c1", "a1d1", "a1e1"], "f1": ["f1b1", "f1c1", "f1d1", "f1e1", "f1f2"], "g1": ["g1f2", "g1h1"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3"], "d2": ["d2a5", "d2b4", "d2c1", "d2c3", "d2e1", "d2e3", "d2f4", "d2g5", "d2h6"], "e2": ["e2d1", "e2e1", "e2e3", "e2f2"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "a3": ["a3a4"], "d3": ["d3d4"], "f3": ["f3d4", "f3e1", "f3e5", "f3g5", "f3h4"], "c4": ["c4a2", "c4a6", "c4b3", "c4b5", "c4d5", "c4e6", "c4f7"], "e4": [], "f5": []}, "_legal_moves_by_piece_moves": "a1a2 a1b1 a1c1 a1d1 a1e1 a3a4 b2b3 b2b4 c2c3 c4a2 c4a6 c4b3 c4b5 c4d5 c4e6 c4f7 d2a5 d2b4 d2c1 d2c3 d2e1 d2e3 d2f4 d2g5 d2h6 d3d4 e2d1 e2e1 e2e3 e2f2 f1b1 f1c1 f1d1 f1e1 f1f2 f3d4 f3e1 f3e5 f3g5 f3h4 g1f2 g1h1 g2g3 g2g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1a2", "a1b1", "a1c1", "a1d1", "a1e1"], "f1": ["f1b1", "f1c1", "f1d1", "f1e1", "f1f2"], "g1": ["g1f2", "g1h1"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3"], "d2": ["d2a5", "d2b4", "d2c1", "d2c3", "d2e1", "d2e3", "d2f4", "d2g5", "d2h6"], "e2": ["e2d1", "e2e1", "e2e3", "e2f2"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "a3": ["a3a4"], "d3": ["d3d4"], "f3": ["f3d4", "f3e1", "f3e5", "f3g5", "f3h4"], "c4": ["c4a2", "c4a6", "c4b3", "c4b5", "c4d5", "c4e6", "c4f7"], "e4": [], "f5": []}, "legal_moves": "a1a2 a1b1 a1c1 a1d1 a1e1 a3a4 b2b3 b2b4 c2c3 c4a2 c4a6 c4b3 c4b5 c4d5 c4e6 c4f7 d2a5 d2b4 d2c1 d2c3 d2e1 d2e3 d2f4 d2g5 d2h6 d3d4 e2d1 e2e1 e2e3 e2f2 f1b1 f1c1 f1d1 f1e1 f1f2 f3d4 f3e1 f3e5 f3g5 f3h4 g1f2 g1h1 g2g3 g2g4 h2h3 h2h4"}}
{"example_id": "rules_00375", "split": "rules", "task_type": "ray_walk", "fen": "8/8/8/2k1K3/Q7/8/8/8 w - -", "prompt": "FEN: 8/8/8/2k1K3/Q7/8/8/8 w - -\nWalk each ray for the slider on a4: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a4 white queen.\nRay N: a5 empty; a6 empty; a7 empty; a8 empty; edge.\nRay NE: b5 empty; c6 empty; d7 empty; e8 empty; edge.\nRay E: b4 empty; c4 empty; d4 empty; e4 empty; f4 empty; g4 empty; h4 empty; edge.\nRay SE: b3 empty; c2 empty; d1 empty; edge.\nRay S: a3 empty; a2 empty; a1 empty; edge.\nRay SW: edge.\nRay W: edge.\nRay NW: edge.\nMoves from rays: a4a1 a4a2 a4a3 a4a5 a4a6 a4a7 a4a8 a4b3 a4b4 a4b5 a4c2 a4c4 a4c6 a4d1 a4d4 a4d7 a4e4 a4e8 a4f4 a4g4 a4h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a4", "diagnostic": true, "hard_gate": false, "source_square": "a4"}}
{"example_id": "rules_00376", "split": "rules", "task_type": "legal_moves", "fen": "rnbk3r/pp4pp/5q2/3B1n2/4R3/3P1N2/PPP1QPPP/R5K1 b - - 0 15", "prompt": "FEN: rnbk3r/pp4pp/5q2/3B1n2/4R3/3P1N2/PPP1QPPP/R5K1 b - - 0 15\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c8d7 c8e6 d8c7 d8d7 f5d4 f5d6 f5e3 f5e7 f5g3 f5h4 f5h6 f6a6 f6b2 f6b6 f6c3 f6c6 f6d4 f6d6 f6e5 f6e6 f6e7 f6f7 f6f8 f6g5 f6g6 f6h4 f6h6 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00377", "split": "rules", "task_type": "legal_moves", "fen": "5r2/1Q3p1k/4P1pp/8/1R1q1P2/7P/6PK/8 b - -", "prompt": "FEN: 5r2/1Q3p1k/4P1pp/8/1R1q1P2/7P/6PK/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: d4a1 d4a7 d4b2 d4b4 d4b6 d4c3 d4c4 d4c5 d4d1 d4d2 d4d3 d4d5 d4d6 d4d7 d4d8 d4e3 d4e4 d4e5 d4f2 d4f4 d4f6 d4g1 d4g7 d4h8 f8a8 f8b8 f8c8 f8d8 f8e8 f8g8 f8h8 g6g5 h6h5 h7g7 h7g8 h7h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00378", "split": "rules", "task_type": "side_piece_inventory", "fen": "3q2k1/p4pp1/7p/2N1p3/P2p2Q1/1r5P/1r3PPK/R7 b - - 5 38", "prompt": "FEN: 3q2k1/p4pp1/7p/2N1p3/P2p2Q1/1r5P/1r3PPK/R7 b - - 5 38\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: b2 black rook; b3 black rook; d4 black pawn; e5 black pawn; h6 black pawn; a7 black pawn; f7 black pawn; g7 black pawn; d8 black queen; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "b2", "piece": "black rook"}, {"square": "b3", "piece": "black rook"}, {"square": "d4", "piece": "black pawn"}, {"square": "e5", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "d8", "piece": "black queen"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "b2", "piece": "black rook"}, {"square": "b3", "piece": "black rook"}, {"square": "d4", "piece": "black pawn"}, {"square": "e5", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "d8", "piece": "black queen"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_00379", "split": "rules", "task_type": "piece_legal_moves", "fen": "r3bnk1/p1q1b2p/1p2p1p1/3pP3/1P1B1Q2/P1PB4/1N4PP/5RK1 w - -", "prompt": "FEN: r3bnk1/p1q1b2p/1p2p1p1/3pP3/1P1B1Q2/P1PB4/1N4PP/5RK1 w - -\nWhat legal moves does the piece on g2 have?", "gold_answer": "g2g3 g2g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "g2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g2", "piece": "pawn"}}
{"example_id": "rules_00380", "split": "rules", "task_type": "check_detection", "fen": "r2q1rk1/ppp1b1p1/3p3p/4pP2/3QP3/8/PPP3PP/R1B2RK1 w - - 0 14", "prompt": "FEN: r2q1rk1/ppp1b1p1/3p3p/4pP2/3QP3/8/PPP3PP/R1B2RK1 w - - 0 14\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00381", "split": "rules", "task_type": "captures", "fen": "2kr3r/1pp3pp/p2b1p2/3n4/2PpP3/P2B1P1P/1P2K2P/R6R w - - 0 16", "prompt": "FEN: 2kr3r/1pp3pp/p2b1p2/3n4/2PpP3/P2B1P1P/1P2K2P/R6R w - - 0 16\nList all capture moves available.", "gold_answer": "c4d5 e4d5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00382", "split": "rules", "task_type": "special_rules", "fen": "6k1/p1r1bp1p/2p1n1p1/2prP3/2R1NP2/1P2B1P1/P3K2P/2R5 b - -", "prompt": "Given FEN: 6k1/p1r1bp1p/2p1n1p1/2prP3/2R1NP2/1P2B1P1/P3K2P/2R5 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00383", "split": "rules", "task_type": "legality_check", "fen": "8/1pp3r1/p2pk1P1/8/5K2/P7/1PP5/6R1 b - - 8 33", "prompt": "FEN: 8/1pp3r1/p2pk1P1/8/5K2/P7/1PP5/6R1 b - - 8 33\nIs the move g1g3 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g1g3", "_legality_check_reason_label": "wrong_side_piece", "move": "g1g3", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_00384", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1bqr1k1/p3bpp1/2p2n1p/3p4/8/2N1B1P1/PP2PPBP/R2Q1RK1 w - -", "prompt": "FEN: r1bqr1k1/p3bpp1/2p2n1p/3p4/8/2N1B1P1/PP2PPBP/R2Q1RK1 w - -\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1 a1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00385", "split": "rules", "task_type": "piece_legal_filter", "fen": "3R4/6kp/4b1p1/3N4/p3P3/1p6/PPP3P1/6K1 w - - 0 39", "prompt": "FEN: 3R4/6kp/4b1p1/3N4/p3P3/1p6/PPP3P1/6K1 w - - 0 39\nFor the piece on g1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g1: g1f1 g1f2 g1h1 g1h2.\nLegal: g1f1 g1f2 g1h1 g1h2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g1", "diagnostic": true, "hard_gate": false, "source_square": "g1"}}
{"example_id": "rules_00386", "split": "rules", "task_type": "king_safety_filter", "fen": "r2q1rk1/2p1bppp/2pp1nb1/p3p3/4P1PN/1P1P3P/PBPNQP2/R3K2R b KQ - 1 12", "prompt": "FEN: r2q1rk1/2p1bppp/2pp1nb1/p3p3/4P1PN/1P1P3P/PBPNQP2/R3K2R b KQ - 1 12\nFor move a5a4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a5a4.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a5a4", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a5a4", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00387", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnbqkbnr/pppp3p/8/5pp1/4Pp2/5Q2/PPPP2PP/RNB1KBNR w KQkq - 0 6", "prompt": "FEN: rnbqkbnr/pppp3p/8/5pp1/4Pp2/5Q2/PPPP2PP/RNB1KBNR w KQkq - 0 6\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; e1 white king; f1 white bishop; g1 white knight; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; d2 white pawn; g2 white pawn; h2 white pawn; f3 white queen; e4 white pawn.\nMoves by piece:\na1 white rook: no legal moves\nb1 white knight: b1a3 b1c3\nc1 white bishop: no legal moves\ne1 white king: e1d1 e1e2 e1f2\nf1 white bishop: f1a6 f1b5 f1c4 f1d3 f1e2\ng1 white knight: g1e2 g1h3\nh1 white rook: no legal moves\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: c2c3 c2c4\nd2 white pawn: d2d3 d2d4\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nf3 white queen: f3a3 f3b3 f3c3 f3d1 f3d3 f3e2 f3e3 f3f2 f3f4 f3g3 f3g4 f3h3 f3h5\ne4 white pawn: e4e5 e4f5\nAll legal moves: a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c2c3 c2c4 d2d3 d2d4 e1d1 e1e2 e1f2 e4e5 e4f5 f1a6 f1b5 f1c4 f1d3 f1e2 f3a3 f3b3 f3c3 f3d1 f3d3 f3e2 f3e3 f3f2 f3f4 f3g3 f3g4 f3h3 f3h5 g1e2 g1h3 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "b1": ["b1a3", "b1c3"], "c1": [], "e1": ["e1d1", "e1e2", "e1f2"], "f1": ["f1a6", "f1b5", "f1c4", "f1d3", "f1e2"], "g1": ["g1e2", "g1h3"], "h1": [], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "d2": ["d2d3", "d2d4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "f3": ["f3a3", "f3b3", "f3c3", "f3d1", "f3d3", "f3e2", "f3e3", "f3f2", "f3f4", "f3g3", "f3g4", "f3h3", "f3h5"], "e4": ["e4e5", "e4f5"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c2c3 c2c4 d2d3 d2d4 e1d1 e1e2 e1f2 e4e5 e4f5 f1a6 f1b5 f1c4 f1d3 f1e2 f3a3 f3b3 f3c3 f3d1 f3d3 f3e2 f3e3 f3f2 f3f4 f3g3 f3g4 f3h3 f3h5 g1e2 g1h3 g2g3 g2g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "b1": ["b1a3", "b1c3"], "c1": [], "e1": ["e1d1", "e1e2", "e1f2"], "f1": ["f1a6", "f1b5", "f1c4", "f1d3", "f1e2"], "g1": ["g1e2", "g1h3"], "h1": [], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "d2": ["d2d3", "d2d4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "f3": ["f3a3", "f3b3", "f3c3", "f3d1", "f3d3", "f3e2", "f3e3", "f3f2", "f3f4", "f3g3", "f3g4", "f3h3", "f3h5"], "e4": ["e4e5", "e4f5"]}, "legal_moves": "a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c2c3 c2c4 d2d3 d2d4 e1d1 e1e2 e1f2 e4e5 e4f5 f1a6 f1b5 f1c4 f1d3 f1e2 f3a3 f3b3 f3c3 f3d1 f3d3 f3e2 f3e3 f3f2 f3f4 f3g3 f3g4 f3h3 f3h5 g1e2 g1h3 g2g3 g2g4 h2h3 h2h4"}}
{"example_id": "rules_00388", "split": "rules", "task_type": "ray_walk", "fen": "r1bq1b1r/ppp2kpp/2n5/3np3/2B5/5Q2/PPPP1PPP/1NB1K2R b K -", "prompt": "FEN: r1bq1b1r/ppp2kpp/2n5/3np3/2B5/5Q2/PPPP1PPP/1NB1K2R b K -\nWalk each ray for the slider on a8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a8 black rook.\nRay N: edge.\nRay E: b8 empty; c8 black bishop: own piece (stop, excluded).\nRay S: a7 black pawn: own piece (stop, excluded).\nRay W: edge.\nMoves from rays: a8b8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a8", "diagnostic": true, "hard_gate": false, "source_square": "a8"}}
{"example_id": "rules_00389", "split": "rules", "task_type": "legal_moves", "fen": "3rr3/ppq2pkp/2n2p2/8/2P1NPb1/QR2p1P1/P3P1BP/5RK1 b - -", "prompt": "FEN: 3rr3/ppq2pkp/2n2p2/8/2P1NPb1/QR2p1P1/P3P1BP/5RK1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 c7a5 c7b6 c7b8 c7c8 c7d6 c7d7 c7e5 c7e7 c7f4 d8a8 d8b8 d8c8 d8d1 d8d2 d8d3 d8d4 d8d5 d8d6 d8d7 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 e8h8 f6f5 g4c8 g4d7 g4e2 g4e6 g4f3 g4f5 g4h3 g4h5 g7g6 g7g8 g7h6 g7h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00390", "split": "rules", "task_type": "legal_moves", "fen": "r2q1r1k/1pp2p1p/3bb1n1/pP1p1p2/P2Pp2P/2P1P3/1B1NBP2/RN1QK2R w KQ - 1 16", "prompt": "FEN: r2q1r1k/1pp2p1p/3bb1n1/pP1p1p2/P2Pp2P/2P1P3/1B1NBP2/RN1QK2R w KQ - 1 16\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 b1a3 b2a3 b2c1 b5b6 c3c4 d1b3 d1c1 d1c2 d2b3 d2c4 d2e4 d2f1 d2f3 e1f1 e1g1 e2c4 e2d3 e2f1 e2f3 e2g4 e2h5 f2f3 f2f4 h1f1 h1g1 h1h2 h1h3 h4h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00391", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/8/p1p4p/Pp1k1pp1/1P1P4/2P1K1PP/8/8 b - -", "prompt": "FEN: 8/8/p1p4p/Pp1k1pp1/1P1P4/2P1K1PP/8/8 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: b5 black pawn; d5 black king; f5 black pawn; g5 black pawn; a6 black pawn; c6 black pawn; h6 black pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "b5", "piece": "black pawn"}, {"square": "d5", "piece": "black king"}, {"square": "f5", "piece": "black pawn"}, {"square": "g5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "c6", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "b5", "piece": "black pawn"}, {"square": "d5", "piece": "black king"}, {"square": "f5", "piece": "black pawn"}, {"square": "g5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "c6", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}]}}
{"example_id": "rules_00392", "split": "rules", "task_type": "piece_legal_moves", "fen": "5r2/pp5k/6pp/3bq3/3N4/2PQ1p1P/PP3P2/5BK1 w - - 0 40", "prompt": "FEN: 5r2/pp5k/6pp/3bq3/3N4/2PQ1p1P/PP3P2/5BK1 w - - 0 40\nWhat legal moves does the piece on a2 have?", "gold_answer": "a2a3 a2a4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a2", "piece": "pawn"}}
{"example_id": "rules_00393", "split": "rules", "task_type": "check_detection", "fen": "r1b1kb1r/pp1p1ppp/4p3/4q3/2PpN3/P2P2P1/1P2K2P/R2Q1B1R w kq - 0 14", "prompt": "FEN: r1b1kb1r/pp1p1ppp/4p3/4q3/2PpN3/P2P2P1/1P2K2P/R2Q1B1R w kq - 0 14\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00394", "split": "rules", "task_type": "captures", "fen": "rnbqkb1r/pp3ppp/3p1n2/2pP4/5B2/8/PP2PPPP/RN1QKBNR w KQkq -", "prompt": "FEN: rnbqkb1r/pp3ppp/3p1n2/2pP4/5B2/8/PP2PPPP/RN1QKBNR w KQkq -\nList all capture moves available.", "gold_answer": "f4d6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00395", "split": "rules", "task_type": "special_rules", "fen": "r5k1/pp2pp1p/2p3p1/3r4/1b6/1P2B2P/P4PP1/1N3RK1 w - - 1 18", "prompt": "Given FEN: r5k1/pp2pp1p/2p3p1/3r4/1b6/1P2B2P/P4PP1/1N3RK1 w - - 1 18\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00396", "split": "rules", "task_type": "legality_check", "fen": "6k1/4q2p/p1p5/2bpnp2/5P2/P1N5/1PP3PP/4RR1K b - -", "prompt": "FEN: 6k1/4q2p/p1p5/2bpnp2/5P2/P1N5/1PP3PP/4RR1K b - -\nIs the move e7e8 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "e7e8", "_legality_check_reason_label": "legal", "move": "e7e8", "legality_reason_label": "legal"}}
{"example_id": "rules_00397", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/p7/5k1p/3r4/1B6/P5P1/n6P/5K2 w - - 0 35", "prompt": "FEN: 8/p7/5k1p/3r4/1B6/P5P1/n6P/5K2 w - - 0 35\nList pseudo-legal moves from f1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from f1: f1e1 f1e2 f1f2 f1g1 f1g2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "f1", "diagnostic": true, "hard_gate": false, "source_square": "f1"}}
{"example_id": "rules_00398", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/p1p5/3bk3/1p2pn2/1P4N1/2PP4/1P2KP2/R1B4r b - -", "prompt": "FEN: 8/p1p5/3bk3/1p2pn2/1P4N1/2PP4/1P2KP2/R1B4r b - -\nFor the piece on e6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e6: e6d5 e6d7 e6e7 e6f6 e6f7.\nLegal: e6d5 e6d7 e6e7 e6f7.\nRejected: e6f6 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "e6", "diagnostic": true, "hard_gate": false, "source_square": "e6"}}
{"example_id": "rules_00399", "split": "rules", "task_type": "king_safety_filter", "fen": "r2q2k1/1pp2rp1/pb1ppnNp/4p3/4P3/2PP4/PP1Q1PPP/R1B2RK1 w - -", "prompt": "FEN: r2q2k1/1pp2rp1/pb1ppnNp/4p3/4P3/2PP4/PP1Q1PPP/R1B2RK1 w - -\nFor move f2f3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: f2f3.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "f2f3", "_king_safety_filter_reason_label": "pinned_piece_exposes_king", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "f2f3", "legality_reason_label": "pinned_piece_exposes_king", "expected_is_legal": false}}
{"example_id": "rules_00400", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnbqkb1r/pp4p1/3p1n2/2pP3p/2P2p2/1NN1pPP1/PP2P2P/R1BQKB1R w KQkq - 0 10", "prompt": "FEN: rnbqkb1r/pp4p1/3p1n2/2pP3p/2P2p2/1NN1pPP1/PP2P2P/R1BQKB1R w KQkq - 0 10\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; e1 white king; f1 white bishop; h1 white rook; a2 white pawn; b2 white pawn; e2 white pawn; h2 white pawn; b3 white knight; c3 white knight; f3 white pawn; g3 white pawn; c4 white pawn; d5 white pawn.\nMoves by piece:\na1 white rook: a1b1\nc1 white bishop: c1d2 c1e3\nd1 white queen: d1c2 d1d2 d1d3 d1d4\ne1 white king: no legal moves\nf1 white bishop: f1g2 f1h3\nh1 white rook: h1g1\na2 white pawn: a2a3 a2a4\nb2 white pawn: no legal moves\ne2 white pawn: no legal moves\nh2 white pawn: h2h3 h2h4\nb3 white knight: b3a5 b3c5 b3d2 b3d4\nc3 white knight: c3a4 c3b1 c3b5 c3e4\nf3 white pawn: no legal moves\ng3 white pawn: g3f4 g3g4\nc4 white pawn: no legal moves\nd5 white pawn: no legal moves\nAll legal moves: a1b1 a2a3 a2a4 b3a5 b3c5 b3d2 b3d4 c1d2 c1e3 c3a4 c3b1 c3b5 c3e4 d1c2 d1d2 d1d3 d1d4 f1g2 f1h3 g3f4 g3g4 h1g1 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3"], "d1": ["d1c2", "d1d2", "d1d3", "d1d4"], "e1": [], "f1": ["f1g2", "f1h3"], "h1": ["h1g1"], "a2": ["a2a3", "a2a4"], "b2": [], "e2": [], "h2": ["h2h3", "h2h4"], "b3": ["b3a5", "b3c5", "b3d2", "b3d4"], "c3": ["c3a4", "c3b1", "c3b5", "c3e4"], "f3": [], "g3": ["g3f4", "g3g4"], "c4": [], "d5": []}, "_legal_moves_by_piece_moves": "a1b1 a2a3 a2a4 b3a5 b3c5 b3d2 b3d4 c1d2 c1e3 c3a4 c3b1 c3b5 c3e4 d1c2 d1d2 d1d3 d1d4 f1g2 f1h3 g3f4 g3g4 h1g1 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3"], "d1": ["d1c2", "d1d2", "d1d3", "d1d4"], "e1": [], "f1": ["f1g2", "f1h3"], "h1": ["h1g1"], "a2": ["a2a3", "a2a4"], "b2": [], "e2": [], "h2": ["h2h3", "h2h4"], "b3": ["b3a5", "b3c5", "b3d2", "b3d4"], "c3": ["c3a4", "c3b1", "c3b5", "c3e4"], "f3": [], "g3": ["g3f4", "g3g4"], "c4": [], "d5": []}, "legal_moves": "a1b1 a2a3 a2a4 b3a5 b3c5 b3d2 b3d4 c1d2 c1e3 c3a4 c3b1 c3b5 c3e4 d1c2 d1d2 d1d3 d1d4 f1g2 f1h3 g3f4 g3g4 h1g1 h2h3 h2h4"}}
{"example_id": "rules_00401", "split": "rules", "task_type": "ray_walk", "fen": "8/5R2/B6P/1N6/8/8/P4PP1/k5K1 w - - 1 35", "prompt": "FEN: 8/5R2/B6P/1N6/8/8/P4PP1/k5K1 w - - 1 35\nWalk each ray for the slider on a6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a6 white bishop.\nRay NE: b7 empty; c8 empty; edge.\nRay SE: b5 white knight: own piece (stop, excluded).\nRay SW: edge.\nRay NW: edge.\nMoves from rays: a6b7 a6c8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a6", "diagnostic": true, "hard_gate": false, "source_square": "a6"}}
{"example_id": "rules_00402", "split": "rules", "task_type": "legal_moves", "fen": "rn1qk2r/ppp1ppbp/3p1np1/8/2PP1Bb1/4PN1P/PP3PP1/RN1QKB1R b KQkq -", "prompt": "FEN: rn1qk2r/ppp1ppbp/3p1np1/8/2PP1Bb1/4PN1P/PP3PP1/RN1QKB1R b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c7c5 c7c6 d6d5 d8c8 d8d7 e7e5 e7e6 e8d7 e8f8 e8g8 f6d5 f6d7 f6e4 f6g8 f6h5 g4c8 g4d7 g4e6 g4f3 g4f5 g4h3 g4h5 g6g5 g7f8 g7h6 h7h5 h7h6 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00403", "split": "rules", "task_type": "legal_moves", "fen": "5rk1/p1p3pp/8/2p1p3/4b2P/PPP2r2/3KN2R/6R1 w - - 0 32", "prompt": "FEN: 5rk1/p1p3pp/8/2p1p3/4b2P/PPP2r2/3KN2R/6R1 w - - 0 32\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 b3b4 c3c4 d2c1 d2d1 d2e1 e2c1 e2d4 e2f4 e2g3 g1a1 g1b1 g1c1 g1d1 g1e1 g1f1 g1g2 g1g3 g1g4 g1g5 g1g6 g1g7 g1h1 h2f2 h2g2 h2h1 h2h3 h4h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00404", "split": "rules", "task_type": "side_piece_inventory", "fen": "2kr3r/1pq2ppp/p1n2n2/3pp3/2N1P3/2P2P2/PP1Q1BPP/R3K2R w KQ - 0 19", "prompt": "FEN: 2kr3r/1pq2ppp/p1n2n2/3pp3/2N1P3/2P2P2/PP1Q1BPP/R3K2R w KQ - 0 19\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; e1 white king; h1 white rook; a2 white pawn; b2 white pawn; d2 white queen; f2 white bishop; g2 white pawn; h2 white pawn; c3 white pawn; f3 white pawn; c4 white knight; e4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white queen"}, {"square": "f2", "piece": "white bishop"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "f3", "piece": "white pawn"}, {"square": "c4", "piece": "white knight"}, {"square": "e4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white queen"}, {"square": "f2", "piece": "white bishop"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "f3", "piece": "white pawn"}, {"square": "c4", "piece": "white knight"}, {"square": "e4", "piece": "white pawn"}]}}
{"example_id": "rules_00405", "split": "rules", "task_type": "piece_legal_moves", "fen": "r3b1k1/1p2bpp1/2p1p2p/q3P3/2P1BBQ1/pP4P1/P4P1P/3R2K1 b - -", "prompt": "FEN: r3b1k1/1p2bpp1/2p1p2p/q3P3/2P1BBQ1/pP4P1/P4P1P/3R2K1 b - -\nWhat legal moves does the piece on a8 have?", "gold_answer": "a8a6 a8a7 a8b8 a8c8 a8d8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "a8", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "a8", "piece": "rook"}}
{"example_id": "rules_00406", "split": "rules", "task_type": "check_detection", "fen": "r7/1p2kppp/1B6/4P3/4PP1P/8/P2R1K2/2r3NR b - - 2 27", "prompt": "FEN: r7/1p2kppp/1B6/4P3/4PP1P/8/P2R1K2/2r3NR b - - 2 27\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00407", "split": "rules", "task_type": "captures", "fen": "2k2r2/2p3p1/3r2q1/1Q5p/4n3/4B2P/P4PP1/2R1R1K1 w - - 0 30", "prompt": "FEN: 2k2r2/2p3p1/3r2q1/1Q5p/4n3/4B2P/P4PP1/2R1R1K1 w - - 0 30\nList all capture moves available.", "gold_answer": "b5h5 c1c7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00408", "split": "rules", "task_type": "special_rules", "fen": "3qkb1r/1p1n1ppp/p1rPp3/8/P7/2N1B3/1PP2PPP/R2Q1RK1 b k - 0 13", "prompt": "Given FEN: 3qkb1r/1p1n1ppp/p1rPp3/8/P7/2N1B3/1PP2PPP/R2Q1RK1 b k - 0 13\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00409", "split": "rules", "task_type": "legality_check", "fen": "rnbq1rk1/pppppp1p/6pn/8/2PPP3/2N5/PP3PPP/R2QKBNR b KQ - 0 5", "prompt": "FEN: rnbq1rk1/pppppp1p/6pn/8/2PPP3/2N5/PP3PPP/R2QKBNR b KQ - 0 5\nIs the move f6f7 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f6f7", "_legality_check_reason_label": "empty_source", "move": "f6f7", "legality_reason_label": "empty_source"}}
{"example_id": "rules_00410", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r4rk1/1ppq1p2/p2p1nnQ/2bP2N1/3p4/P1PB3P/1P3PP1/R4RK1 b - - 1 18", "prompt": "FEN: r4rk1/1ppq1p2/p2p1nnQ/2bP2N1/3p4/P1PB3P/1P3PP1/R4RK1 b - - 1 18\nList pseudo-legal moves from d4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d4: d4c3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_00411", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1b2rk1/pp2ppbp/2n3p1/q1p5/2BP4/B1P1PN2/P3QPPP/R4RK1 w - -", "prompt": "FEN: r1b2rk1/pp2ppbp/2n3p1/q1p5/2BP4/B1P1PN2/P3QPPP/R4RK1 w - -\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1 a1c1 a1d1 a1e1.\nLegal: a1b1 a1c1 a1d1 a1e1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00412", "split": "rules", "task_type": "king_safety_filter", "fen": "6k1/p7/2p5/1pPn1pp1/8/P1P2BB1/2PK4/8 b - - 1 35", "prompt": "FEN: 6k1/p7/2p5/1pPn1pp1/8/P1P2BB1/2PK4/8 b - - 1 35\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00413", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqk2r/p1p2ppp/2pp4/3nP1b1/2P5/8/PP3PPP/RN1QK1NR w KQkq - 0 10", "prompt": "FEN: r1bqk2r/p1p2ppp/2pp4/3nP1b1/2P5/8/PP3PPP/RN1QK1NR w KQkq - 0 10\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; d1 white queen; e1 white king; g1 white knight; h1 white rook; a2 white pawn; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c4 white pawn; e5 white pawn.\nMoves by piece:\na1 white rook: no legal moves\nb1 white knight: b1a3 b1c3 b1d2\nd1 white queen: d1a4 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1d5 d1e2 d1f3 d1g4 d1h5\ne1 white king: e1e2 e1f1\ng1 white knight: g1e2 g1f3 g1h3\nh1 white rook: no legal moves\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nf2 white pawn: f2f3 f2f4\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nc4 white pawn: c4c5 c4d5\ne5 white pawn: e5d6 e5e6\nAll legal moves: a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c4c5 c4d5 d1a4 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1d5 d1e2 d1f3 d1g4 d1h5 e1e2 e1f1 e5d6 e5e6 f2f3 f2f4 g1e2 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "b1": ["b1a3", "b1c3", "b1d2"], "d1": ["d1a4", "d1b3", "d1c1", "d1c2", "d1d2", "d1d3", "d1d4", "d1d5", "d1e2", "d1f3", "d1g4", "d1h5"], "e1": ["e1e2", "e1f1"], "g1": ["g1e2", "g1f3", "g1h3"], "h1": [], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c4": ["c4c5", "c4d5"], "e5": ["e5d6", "e5e6"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c4c5 c4d5 d1a4 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1d5 d1e2 d1f3 d1g4 d1h5 e1e2 e1f1 e5d6 e5e6 f2f3 f2f4 g1e2 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "b1": ["b1a3", "b1c3", "b1d2"], "d1": ["d1a4", "d1b3", "d1c1", "d1c2", "d1d2", "d1d3", "d1d4", "d1d5", "d1e2", "d1f3", "d1g4", "d1h5"], "e1": ["e1e2", "e1f1"], "g1": ["g1e2", "g1f3", "g1h3"], "h1": [], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c4": ["c4c5", "c4d5"], "e5": ["e5d6", "e5e6"]}, "legal_moves": "a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c4c5 c4d5 d1a4 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1d5 d1e2 d1f3 d1g4 d1h5 e1e2 e1f1 e5d6 e5e6 f2f3 f2f4 g1e2 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4"}}
{"example_id": "rules_00414", "split": "rules", "task_type": "ray_walk", "fen": "r2qk2r/1b1nbpp1/3ppn1p/p1p5/Pp1PP3/1PPBBN2/N3QPPP/R4RK1 w kq - 0 14", "prompt": "FEN: r2qk2r/1b1nbpp1/3ppn1p/p1p5/Pp1PP3/1PPBBN2/N3QPPP/R4RK1 w kq - 0 14\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white knight: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 empty; e1 empty; f1 white rook: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1 a1d1 a1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00415", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/8/4P1p1/3K1r1p/6kP/8/8/8 w - - 1 81", "prompt": "FEN: 8/8/4P1p1/3K1r1p/6kP/8/8/8 w - - 1 81\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: h4 white pawn; d5 white king; e6 white pawn.\nFilter by piece:\nh4 white pawn: pseudo-legal none | rejected none | legal none\nd5 white king: pseudo-legal d5c4 d5c5 d5c6 d5d4 d5d6 d5e4 d5e5 | rejected d5c5 does_not_resolve_check; d5e5 does_not_resolve_check | legal d5c4 d5c6 d5d4 d5d6 d5e4\ne6 white pawn: pseudo-legal e6e7 | rejected e6e7 does_not_resolve_check | legal none\nAll legal moves: d5c4 d5c6 d5d4 d5d6 d5e4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00416", "split": "rules", "task_type": "legal_moves", "fen": "2kr3r/pbp1n1qp/np1b1p2/4p1p1/4P3/P1N1BP2/1PP1N1PP/2KRQB1R w - - 2 16", "prompt": "FEN: 2kr3r/pbp1n1qp/np1b1p2/4p1p1/4P3/P1N1BP2/1PP1N1PP/2KRQB1R w - - 2 16\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 b2b3 b2b4 c1b1 c1d2 c3a2 c3a4 c3b1 c3b5 c3d5 d1d2 d1d3 d1d4 d1d5 d1d6 e1d2 e1f2 e1g3 e1h4 e2d4 e2f4 e2g1 e2g3 e3b6 e3c5 e3d2 e3d4 e3f2 e3f4 e3g1 e3g5 f3f4 g2g3 g2g4 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00417", "split": "rules", "task_type": "side_piece_inventory", "fen": "1K6/1P6/4k3/8/3R4/8/r7/8 b - -", "prompt": "FEN: 1K6/1P6/4k3/8/3R4/8/r7/8 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: a2 black rook; e6 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "a2", "piece": "black rook"}, {"square": "e6", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "a2", "piece": "black rook"}, {"square": "e6", "piece": "black king"}]}}
{"example_id": "rules_00418", "split": "rules", "task_type": "piece_legal_moves", "fen": "r2qk2r/1b3ppp/1pnbpn2/p1p5/2Pp4/PP1P1NP1/1B1NPPBP/R2Q1RK1 w kq -", "prompt": "FEN: r2qk2r/1b3ppp/1pnbpn2/p1p5/2Pp4/PP1P1NP1/1B1NPPBP/R2Q1RK1 w kq -\nWhat legal moves does the piece on f2 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f2", "piece": "pawn"}}
{"example_id": "rules_00419", "split": "rules", "task_type": "check_detection", "fen": "1r3rk1/p4p1p/1qp3p1/4Pb2/4N3/8/PPQ2PP1/1R3RK1 w - -", "prompt": "FEN: 1r3rk1/p4p1p/1qp3p1/4Pb2/4N3/8/PPQ2PP1/1R3RK1 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00420", "split": "rules", "task_type": "captures", "fen": "r2qk2r/pp2bppp/2np4/1N2p3/2B1P3/5b1P/PP2QPP1/R2R2K1 w kq - 0 14", "prompt": "FEN: r2qk2r/pp2bppp/2np4/1N2p3/2B1P3/5b1P/PP2QPP1/R2R2K1 w kq - 0 14\nList all capture moves available.", "gold_answer": "b5a7 b5d6 c4f7 d1d6 e2f3 g2f3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00421", "split": "rules", "task_type": "special_rules", "fen": "r3rbk1/1b3pp1/5n1p/p2q4/P1NNp3/1PB5/5PPP/R2QR1K1 b - -", "prompt": "Given FEN: r3rbk1/1b3pp1/5n1p/p2q4/P1NNp3/1PB5/5PPP/R2QR1K1 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00422", "split": "rules", "task_type": "legality_check", "fen": "rnbqkb1r/p4ppp/1p2pn2/2pP4/1P3P2/P7/1B1PP1PP/RN1QKBNR b KQkq - 0 6", "prompt": "FEN: rnbqkb1r/p4ppp/1p2pn2/2pP4/1P3P2/P7/1B1PP1PP/RN1QKBNR b KQkq - 0 6\nIs the move d5h2 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "d5h2", "_legality_check_reason_label": "wrong_side_piece", "move": "d5h2", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_00423", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "1k6/8/NP6/1K6/8/8/8/8 b - - 8 78", "prompt": "FEN: 1k6/8/NP6/1K6/8/8/8/8 b - - 8 78\nList pseudo-legal moves from b8.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b8: b8a7 b8a8 b8b7 b8c7 b8c8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b8", "diagnostic": true, "hard_gate": false, "source_square": "b8"}}
{"example_id": "rules_00424", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1bqk1nr/p2nppbp/1ppp2p1/8/3PP3/2NB1N2/PPP2PPP/R1BQK2R w KQkq -", "prompt": "FEN: r1bqk1nr/p2nppbp/1ppp2p1/8/3PP3/2NB1N2/PPP2PPP/R1BQK2R w KQkq -\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1.\nLegal: a1b1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00425", "split": "rules", "task_type": "king_safety_filter", "fen": "rn1qk1nr/pbp2pbp/1p1pp1p1/6B1/2PP4/5NP1/PP2PPBP/RN1Q1RK1 b kq - 1 7", "prompt": "FEN: rn1qk1nr/pbp2pbp/1p1pp1p1/6B1/2PP4/5NP1/PP2PPBP/RN1Q1RK1 b kq - 1 7\nFor move e8e7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e8e7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e8e7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e8e7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00426", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r3kbnr/1ppqpppp/p1n5/3p4/3P1B2/P1NQP3/1PP2PPP/R3K1NR b KQkq - 0 7", "prompt": "FEN: r3kbnr/1ppqpppp/p1n5/3p4/3P1B2/P1NQP3/1PP2PPP/R3K1NR b KQkq - 0 7\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; a6 black pawn; c6 black knight; b7 black pawn; c7 black pawn; d7 black queen; e7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; e8 black king; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\nd5 black pawn: no legal moves\na6 black pawn: a6a5\nc6 black knight: c6a5 c6a7 c6b4 c6b8 c6d4 c6d8 c6e5\nb7 black pawn: b7b5 b7b6\nc7 black pawn: no legal moves\nd7 black queen: d7c8 d7d6 d7d8 d7e6 d7f5 d7g4 d7h3\ne7 black pawn: e7e5 e7e6\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8a7 a8b8 a8c8 a8d8\ne8 black king: e8c8 e8d8\nf8 black bishop: no legal moves\ng8 black knight: g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a6a5 a8a7 a8b8 a8c8 a8d8 b7b5 b7b6 c6a5 c6a7 c6b4 c6b8 c6d4 c6d8 c6e5 d7c8 d7d6 d7d8 d7e6 d7f5 d7g4 d7h3 e7e5 e7e6 e8c8 e8d8 f7f5 f7f6 g7g5 g7g6 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d5": [], "a6": ["a6a5"], "c6": ["c6a5", "c6a7", "c6b4", "c6b8", "c6d4", "c6d8", "c6e5"], "b7": ["b7b5", "b7b6"], "c7": [], "d7": ["d7c8", "d7d6", "d7d8", "d7e6", "d7f5", "d7g4", "d7h3"], "e7": ["e7e5", "e7e6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8a7", "a8b8", "a8c8", "a8d8"], "e8": ["e8c8", "e8d8"], "f8": [], "g8": ["g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a6a5 a8a7 a8b8 a8c8 a8d8 b7b5 b7b6 c6a5 c6a7 c6b4 c6b8 c6d4 c6d8 c6e5 d7c8 d7d6 d7d8 d7e6 d7f5 d7g4 d7h3 e7e5 e7e6 e8c8 e8d8 f7f5 f7f6 g7g5 g7g6 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d5": [], "a6": ["a6a5"], "c6": ["c6a5", "c6a7", "c6b4", "c6b8", "c6d4", "c6d8", "c6e5"], "b7": ["b7b5", "b7b6"], "c7": [], "d7": ["d7c8", "d7d6", "d7d8", "d7e6", "d7f5", "d7g4", "d7h3"], "e7": ["e7e5", "e7e6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8a7", "a8b8", "a8c8", "a8d8"], "e8": ["e8c8", "e8d8"], "f8": [], "g8": ["g8f6", "g8h6"], "h8": []}, "legal_moves": "a6a5 a8a7 a8b8 a8c8 a8d8 b7b5 b7b6 c6a5 c6a7 c6b4 c6b8 c6d4 c6d8 c6e5 d7c8 d7d6 d7d8 d7e6 d7f5 d7g4 d7h3 e7e5 e7e6 e8c8 e8d8 f7f5 f7f6 g7g5 g7g6 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_00427", "split": "rules", "task_type": "ray_walk", "fen": "rn2k2r/p3n3/b2Np3/2p1Pp2/2p2B2/5N2/PPP3PP/R4RK1 b kq - 3 18", "prompt": "FEN: rn2k2r/p3n3/b2Np3/2p1Pp2/2p2B2/5N2/PPP3PP/R4RK1 b kq - 3 18\nWalk each ray for the slider on a6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a6 black bishop.\nRay NE: b7 empty; c8 empty; edge.\nRay SE: b5 empty; c4 black pawn: own piece (stop, excluded).\nRay SW: edge.\nRay NW: edge.\nMoves from rays: a6b5 a6b7 a6c8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a6", "diagnostic": true, "hard_gate": false, "source_square": "a6"}}
{"example_id": "rules_00428", "split": "rules", "task_type": "legal_moves", "fen": "4r1k1/2q2ppp/1rp5/7b/1bQ5/1N2PNnP/PP2B1P1/R1R3K1 b - -", "prompt": "FEN: 4r1k1/2q2ppp/1rp5/7b/1bQ5/1N2PNnP/PP2B1P1/R1R3K1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7 b4f8 b6a6 b6b5 b6b7 b6b8 c6c5 c7a7 c7b7 c7b8 c7c8 c7d6 c7d7 c7d8 c7e5 c7e7 c7f4 e8a8 e8b8 e8c8 e8d8 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 g3e2 g3e4 g3f1 g3f5 g3h1 g7g5 g7g6 g8f8 g8h8 h5f3 h5g4 h5g6 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00429", "split": "rules", "task_type": "legal_moves", "fen": "rnbqkb1r/ppp1pppp/8/3p4/3PnP2/4PN2/PPP3PP/RNBQKB1R w KQkq -", "prompt": "FEN: rnbqkb1r/ppp1pppp/8/3p4/3PnP2/4PN2/PPP3PP/RNBQKB1R w KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c1d2 c2c3 c2c4 d1d2 d1d3 d1e2 e1e2 f1a6 f1b5 f1c4 f1d3 f1e2 f3d2 f3e5 f3g1 f3g5 f3h4 f4f5 g2g3 g2g4 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00430", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2q1rk1/pppn1ppp/3p1nb1/6B1/1PP3P1/PQP4P/4Pp2/2KR1BNR w - - 0 14", "prompt": "FEN: r2q1rk1/pppn1ppp/3p1nb1/6B1/1PP3P1/PQP4P/4Pp2/2KR1BNR w - - 0 14\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: c1 white king; d1 white rook; f1 white bishop; g1 white knight; h1 white rook; e2 white pawn; a3 white pawn; b3 white queen; c3 white pawn; h3 white pawn; b4 white pawn; c4 white pawn; g4 white pawn; g5 white bishop.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "c1", "piece": "white king"}, {"square": "d1", "piece": "white rook"}, {"square": "f1", "piece": "white bishop"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "e2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "b3", "piece": "white queen"}, {"square": "c3", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "c4", "piece": "white pawn"}, {"square": "g4", "piece": "white pawn"}, {"square": "g5", "piece": "white bishop"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "c1", "piece": "white king"}, {"square": "d1", "piece": "white rook"}, {"square": "f1", "piece": "white bishop"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "e2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "b3", "piece": "white queen"}, {"square": "c3", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "c4", "piece": "white pawn"}, {"square": "g4", "piece": "white pawn"}, {"square": "g5", "piece": "white bishop"}]}}
{"example_id": "rules_00431", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/3r4/8/5P2/2P3P1/pP3K2/P3R3/2k5 b - - 0 50", "prompt": "FEN: 8/3r4/8/5P2/2P3P1/pP3K2/P3R3/2k5 b - - 0 50\nWhat legal moves does the piece on c1 have?", "gold_answer": "c1b1 c1d1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c1", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "c1", "piece": "king"}}
{"example_id": "rules_00432", "split": "rules", "task_type": "check_detection", "fen": "4k1r1/p1p5/3p4/p2PN2p/4Pb1P/2P5/P5P1/1BQ3K1 b - - 0 24", "prompt": "FEN: 4k1r1/p1p5/3p4/p2PN2p/4Pb1P/2P5/P5P1/1BQ3K1 b - - 0 24\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00433", "split": "rules", "task_type": "captures", "fen": "rnbqk1nr/ppp2ppp/3p1b2/8/2BNP3/8/PPP2PPP/RNBQK2R b KQkq - 2 6", "prompt": "FEN: rnbqk1nr/ppp2ppp/3p1b2/8/2BNP3/8/PPP2PPP/RNBQK2R b KQkq - 2 6\nList all capture moves available.", "gold_answer": "f6d4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00434", "split": "rules", "task_type": "special_rules", "fen": "Q4qk1/5pp1/7p/4p3/P7/1b1BP3/1r3PPP/2R3K1 w - -", "prompt": "Given FEN: Q4qk1/5pp1/7p/4p3/P7/1b1BP3/1r3PPP/2R3K1 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00435", "split": "rules", "task_type": "legality_check", "fen": "r2r2k1/2q3pp/1p3p2/p1p2P1Q/P4p1P/2R5/1PP2PP1/4R1K1 w - -", "prompt": "FEN: r2r2k1/2q3pp/1p3p2/p1p2P1Q/P4p1P/2R5/1PP2PP1/4R1K1 w - -\nIs the move e1f1 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "e1f1", "_legality_check_reason_label": "legal", "move": "e1f1", "legality_reason_label": "legal"}}
{"example_id": "rules_00436", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1bqk1nr/ppppbppp/8/n3N3/2BPP3/2P5/P4PPP/RNBQK2R b KQkq -", "prompt": "FEN: r1bqk1nr/ppppbppp/8/n3N3/2BPP3/2P5/P4PPP/RNBQK2R b KQkq -\nList pseudo-legal moves from a5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a5: a5b3 a5c4 a5c6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_00437", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/8/1R4pk/r6p/7P/6PK/8/8 b - -", "prompt": "FEN: 8/8/1R4pk/r6p/7P/6PK/8/8 b - -\nFor the piece on g6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g6: g6g5.\nLegal: none.\nRejected: g6g5 pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "g6", "diagnostic": true, "hard_gate": false, "source_square": "g6"}}
{"example_id": "rules_00438", "split": "rules", "task_type": "king_safety_filter", "fen": "4n2R/3k2p1/1p6/8/1B1KP1P1/2p2r2/8/8 b - - 1 38", "prompt": "FEN: 4n2R/3k2p1/1p6/8/1B1KP1P1/2p2r2/8/8 b - - 1 38\nFor move d7d6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: d7d6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "d7d6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "d7d6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00439", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1b1k2r/p1p1b1pp/2ppq3/4p3/2P1P3/3Q1N2/PP3PPP/RN3RK1 b kq - 2 11", "prompt": "FEN: r1b1k2r/p1p1b1pp/2ppq3/4p3/2P1P3/3Q1N2/PP3PPP/RN3RK1 b kq - 2 11\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e5 black pawn; c6 black pawn; d6 black pawn; e6 black queen; a7 black pawn; c7 black pawn; e7 black bishop; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; e8 black king; h8 black rook.\nMoves by piece:\ne5 black pawn: no legal moves\nc6 black pawn: c6c5\nd6 black pawn: d6d5\ne6 black queen: e6c4 e6d5 e6d7 e6f5 e6f6 e6f7 e6g4 e6g6 e6g8 e6h3 e6h6\na7 black pawn: a7a5 a7a6\nc7 black pawn: no legal moves\ne7 black bishop: e7d8 e7f6 e7f8 e7g5 e7h4\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8\nc8 black bishop: c8a6 c8b7 c8d7\ne8 black king: e8d7 e8d8 e8f7 e8f8 e8g8\nh8 black rook: h8f8 h8g8\nAll legal moves: a7a5 a7a6 a8b8 c6c5 c8a6 c8b7 c8d7 d6d5 e6c4 e6d5 e6d7 e6f5 e6f6 e6f7 e6g4 e6g6 e6g8 e6h3 e6h6 e7d8 e7f6 e7f8 e7g5 e7h4 e8d7 e8d8 e8f7 e8f8 e8g8 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e5": [], "c6": ["c6c5"], "d6": ["d6d5"], "e6": ["e6c4", "e6d5", "e6d7", "e6f5", "e6f6", "e6f7", "e6g4", "e6g6", "e6g8", "e6h3", "e6h6"], "a7": ["a7a5", "a7a6"], "c7": [], "e7": ["e7d8", "e7f6", "e7f8", "e7g5", "e7h4"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8a6", "c8b7", "c8d7"], "e8": ["e8d7", "e8d8", "e8f7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 c6c5 c8a6 c8b7 c8d7 d6d5 e6c4 e6d5 e6d7 e6f5 e6f6 e6f7 e6g4 e6g6 e6g8 e6h3 e6h6 e7d8 e7f6 e7f8 e7g5 e7h4 e8d7 e8d8 e8f7 e8f8 e8g8 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e5": [], "c6": ["c6c5"], "d6": ["d6d5"], "e6": ["e6c4", "e6d5", "e6d7", "e6f5", "e6f6", "e6f7", "e6g4", "e6g6", "e6g8", "e6h3", "e6h6"], "a7": ["a7a5", "a7a6"], "c7": [], "e7": ["e7d8", "e7f6", "e7f8", "e7g5", "e7h4"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8a6", "c8b7", "c8d7"], "e8": ["e8d7", "e8d8", "e8f7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "legal_moves": "a7a5 a7a6 a8b8 c6c5 c8a6 c8b7 c8d7 d6d5 e6c4 e6d5 e6d7 e6f5 e6f6 e6f7 e6g4 e6g6 e6g8 e6h3 e6h6 e7d8 e7f6 e7f8 e7g5 e7h4 e8d7 e8d8 e8f7 e8f8 e8g8 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8"}}
{"example_id": "rules_00440", "split": "rules", "task_type": "ray_walk", "fen": "r4rk1/pp3ppp/3b1n2/q1p1p3/2Pn4/BPNP3N/P2QBRPP/R3K3 b Q - 3 16", "prompt": "FEN: r4rk1/pp3ppp/3b1n2/q1p1p3/2Pn4/BPNP3N/P2QBRPP/R3K3 b Q - 3 16\nWalk each ray for the slider on a5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a5 black queen.\nRay N: a6 empty; a7 black pawn: own piece (stop, excluded).\nRay NE: b6 empty; c7 empty; d8 empty; edge.\nRay E: b5 empty; c5 black pawn: own piece (stop, excluded).\nRay SE: b4 empty; c3 white knight: capture (stop, included).\nRay S: a4 empty; a3 white bishop: capture (stop, included).\nRay SW: edge.\nRay W: edge.\nRay NW: edge.\nMoves from rays: a5a3 a5a4 a5a6 a5b4 a5b5 a5b6 a5c3 a5c7 a5d8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_00441", "split": "rules", "task_type": "legal_moves", "fen": "r5k1/pp2bq1p/2p3p1/8/2PP2P1/1P2RB1P/P4P2/4R1K1 w - - 2 31", "prompt": "FEN: r5k1/pp2bq1p/2p3p1/8/2PP2P1/1P2RB1P/P4P2/4R1K1 w - - 2 31\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b3b4 c4c5 d4d5 e1a1 e1b1 e1c1 e1d1 e1e2 e1f1 e3c3 e3d3 e3e2 e3e4 e3e5 e3e6 e3e7 f3c6 f3d1 f3d5 f3e2 f3e4 f3g2 f3h1 g1f1 g1g2 g1h1 g1h2 g4g5 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00442", "split": "rules", "task_type": "legal_moves", "fen": "2k4r/ppp5/8/4r1Pp/P4K1P/8/8/7n w - - 0 31", "prompt": "FEN: 2k4r/ppp5/8/4r1Pp/P4K1P/8/8/7n w - - 0 31\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a4a5 f4e5 f4f3 g5g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00443", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2q2k1/1p1b2pp/p2N4/3p1p2/3p1Q2/5P2/PPP4P/4R1K1 w - -", "prompt": "FEN: r2q2k1/1p1b2pp/p2N4/3p1p2/3p1Q2/5P2/PPP4P/4R1K1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: e1 white rook; g1 white king; a2 white pawn; b2 white pawn; c2 white pawn; h2 white pawn; f3 white pawn; f4 white queen; d6 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "f3", "piece": "white pawn"}, {"square": "f4", "piece": "white queen"}, {"square": "d6", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "f3", "piece": "white pawn"}, {"square": "f4", "piece": "white queen"}, {"square": "d6", "piece": "white knight"}]}}
{"example_id": "rules_00444", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b1kb1r/p2n1ppp/1qp1p3/3pP1B1/3Q4/2N2N2/PPP2PPP/R3K2R w KQkq -", "prompt": "FEN: r1b1kb1r/p2n1ppp/1qp1p3/3pP1B1/3Q4/2N2N2/PPP2PPP/R3K2R w KQkq -\nWhat legal moves does the piece on f2 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f2", "piece": "pawn"}}
{"example_id": "rules_00445", "split": "rules", "task_type": "check_detection", "fen": "8/8/8/p7/1k1bNp2/5P2/1p1K4/r7 b - - 1 54", "prompt": "FEN: 8/8/8/p7/1k1bNp2/5P2/1p1K4/r7 b - - 1 54\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00446", "split": "rules", "task_type": "captures", "fen": "r4rk1/ppqn2pp/2pb1n2/3pp3/3P4/3B3P/PPP1NPP1/R1BQ1R1K w - - 0 13", "prompt": "FEN: r4rk1/ppqn2pp/2pb1n2/3pp3/3P4/3B3P/PPP1NPP1/R1BQ1R1K w - - 0 13\nList all capture moves available.", "gold_answer": "d3h7 d4e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00447", "split": "rules", "task_type": "special_rules", "fen": "3rkbnr/p4Np1/b1q1p2p/2p1P3/3p4/1P3N2/P1PQ1PPP/R1B1K2R b KQk - 0 14", "prompt": "Given FEN: 3rkbnr/p4Np1/b1q1p2p/2p1P3/3p4/1P3N2/P1PQ1PPP/R1B1K2R b KQk - 0 14\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00448", "split": "rules", "task_type": "legality_check", "fen": "r6k/ppnq2bp/3p2b1/3Pp3/1P2N2P/P1N2Q2/3B2P1/5RK1 b - -", "prompt": "FEN: r6k/ppnq2bp/3p2b1/3Pp3/1P2N2P/P1N2Q2/3B2P1/5RK1 b - -\nIs the move a8b8 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "a8b8", "_legality_check_reason_label": "legal", "move": "a8b8", "legality_reason_label": "legal"}}
{"example_id": "rules_00449", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2kr1bnr/p1pn1ppp/1p2p3/8/5B2/2NP1N2/PPP2PPP/R3K2R b KQ - 1 10", "prompt": "FEN: 2kr1bnr/p1pn1ppp/1p2p3/8/5B2/2NP1N2/PPP2PPP/R3K2R b KQ - 1 10\nList pseudo-legal moves from b6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b6: b6b5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b6", "diagnostic": true, "hard_gate": false, "source_square": "b6"}}
{"example_id": "rules_00450", "split": "rules", "task_type": "piece_legal_filter", "fen": "1rbq1rk1/5ppp/pn1b1n2/Bp1pN3/2pP4/1PN1P3/P1B2PPP/R2QK2R b KQ - 6 14", "prompt": "FEN: 1rbq1rk1/5ppp/pn1b1n2/Bp1pN3/2pP4/1PN1P3/P1B2PPP/R2QK2R b KQ - 6 14\nFor the piece on c4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c4: c4b3.\nLegal: c4b3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "c4", "diagnostic": true, "hard_gate": false, "source_square": "c4"}}
{"example_id": "rules_00451", "split": "rules", "task_type": "king_safety_filter", "fen": "r7/pbqkn2Q/1p2p3/2ppP3/3P2P1/2P5/PP1NB2P/R4K2 w - - 3 22", "prompt": "FEN: r7/pbqkn2Q/1p2p3/2ppP3/3P2P1/2P5/PP1NB2P/R4K2 w - - 3 22\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00452", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/8/7k/3B1K1P/1p2PPP1/1Pr5/8/8 b - -", "prompt": "FEN: 8/8/7k/3B1K1P/1p2PPP1/1Pr5/8/8 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c3 black rook; b4 black pawn; h6 black king.\nMoves by piece:\nc3 black rook: c3b3 c3c1 c3c2 c3c4 c3c5 c3c6 c3c7 c3c8 c3d3 c3e3 c3f3 c3g3 c3h3\nb4 black pawn: no legal moves\nh6 black king: h6g7 h6h7\nAll legal moves: c3b3 c3c1 c3c2 c3c4 c3c5 c3c6 c3c7 c3c8 c3d3 c3e3 c3f3 c3g3 c3h3 h6g7 h6h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c3": ["c3b3", "c3c1", "c3c2", "c3c4", "c3c5", "c3c6", "c3c7", "c3c8", "c3d3", "c3e3", "c3f3", "c3g3", "c3h3"], "b4": [], "h6": ["h6g7", "h6h7"]}, "_legal_moves_by_piece_moves": "c3b3 c3c1 c3c2 c3c4 c3c5 c3c6 c3c7 c3c8 c3d3 c3e3 c3f3 c3g3 c3h3 h6g7 h6h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c3": ["c3b3", "c3c1", "c3c2", "c3c4", "c3c5", "c3c6", "c3c7", "c3c8", "c3d3", "c3e3", "c3f3", "c3g3", "c3h3"], "b4": [], "h6": ["h6g7", "h6h7"]}, "legal_moves": "c3b3 c3c1 c3c2 c3c4 c3c5 c3c6 c3c7 c3c8 c3d3 c3e3 c3f3 c3g3 c3h3 h6g7 h6h7"}}
{"example_id": "rules_00453", "split": "rules", "task_type": "ray_walk", "fen": "8/4r1pR/2p2k2/3q1b2/1P1P3Q/6P1/5P1P/6K1 b - - 3 47", "prompt": "FEN: 8/4r1pR/2p2k2/3q1b2/1P1P3Q/6P1/5P1P/6K1 b - - 3 47\nWalk each ray for the slider on d5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d5 black queen.\nRay N: d6 empty; d7 empty; d8 empty; edge.\nRay NE: e6 empty; f7 empty; g8 empty; edge.\nRay E: e5 empty; f5 black bishop: own piece (stop, excluded).\nRay SE: e4 empty; f3 empty; g2 empty; h1 empty; edge.\nRay S: d4 white pawn: capture (stop, included).\nRay SW: c4 empty; b3 empty; a2 empty; edge.\nRay W: c5 empty; b5 empty; a5 empty; edge.\nRay NW: c6 black pawn: own piece (stop, excluded).\nMoves from rays: d5a2 d5a5 d5b3 d5b5 d5c4 d5c5 d5d4 d5d6 d5d7 d5d8 d5e4 d5e5 d5e6 d5f3 d5f7 d5g2 d5g8 d5h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_00454", "split": "rules", "task_type": "legal_moves", "fen": "2Q5/k7/8/3R1N2/8/8/8/6K1 w - -", "prompt": "FEN: 2Q5/k7/8/3R1N2/8/8/8/6K1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: c8a6 c8a8 c8b7 c8b8 c8c1 c8c2 c8c3 c8c4 c8c5 c8c6 c8c7 c8d7 c8d8 c8e6 c8e8 c8f8 c8g8 c8h8 d5a5 d5b5 d5c5 d5d1 d5d2 d5d3 d5d4 d5d6 d5d7 d5d8 d5e5 f5d4 f5d6 f5e3 f5e7 f5g3 f5g7 f5h4 f5h6 g1f1 g1f2 g1g2 g1h1 g1h2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00455", "split": "rules", "task_type": "legal_moves", "fen": "4K3/3P4/8/1q6/8/8/8/2k5 w - -", "prompt": "FEN: 4K3/3P4/8/1q6/8/8/8/2k5 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: e8d8 e8e7 e8f7 e8f8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00456", "split": "rules", "task_type": "side_piece_inventory", "fen": "rnbq1rk1/p1p1bppp/1p2pn2/2Pp4/1P1P4/2N1PN2/P4PPP/R1BQKB1R b KQ - 0 7", "prompt": "FEN: rnbq1rk1/p1p1bppp/1p2pn2/2Pp4/1P1P4/2N1PN2/P4PPP/R1BQKB1R b KQ - 0 7\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; b6 black pawn; e6 black pawn; f6 black knight; a7 black pawn; c7 black pawn; e7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; c8 black bishop; d8 black queen; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "d5", "piece": "black pawn"}, {"square": "b6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "d5", "piece": "black pawn"}, {"square": "b6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_00457", "split": "rules", "task_type": "piece_legal_moves", "fen": "rn1qkbnr/ppp3pp/3pp3/8/4P3/2N4P/PP3PP1/R1BQK1NR b KQkq - 0 7", "prompt": "FEN: rn1qkbnr/ppp3pp/3pp3/8/4P3/2N4P/PP3PP1/R1BQK1NR b KQkq - 0 7\nWhat legal moves does the piece on g7 have?", "gold_answer": "g7g5 g7g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "g7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g7", "piece": "pawn"}}
{"example_id": "rules_00458", "split": "rules", "task_type": "check_detection", "fen": "8/4kp1p/1P1qp1pn/8/1nQp2P1/5P2/r1P4P/3RK2R w K - 0 25", "prompt": "FEN: 8/4kp1p/1P1qp1pn/8/1nQp2P1/5P2/r1P4P/3RK2R w K - 0 25\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00459", "split": "rules", "task_type": "captures", "fen": "r1bqkbnr/3n1pp1/p1p1p2p/1p6/3P1B2/2NB1N2/PPP2PPP/R2QR1K1 w kq - 0 10", "prompt": "FEN: r1bqkbnr/3n1pp1/p1p1p2p/1p6/3P1B2/2NB1N2/PPP2PPP/R2QR1K1 w kq - 0 10\nList all capture moves available.", "gold_answer": "c3b5 d3b5 e1e6 f4h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00460", "split": "rules", "task_type": "special_rules", "fen": "r1bqkb1r/pp2pp1p/2np1np1/8/2PpP3/2N2N1P/PP3PP1/R1BQKB1R w KQkq - 0 7", "prompt": "Given FEN: r1bqkb1r/pp2pp1p/2np1np1/8/2PpP3/2N2N1P/PP3PP1/R1BQKB1R w KQkq - 0 7\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00461", "split": "rules", "task_type": "legality_check", "fen": "r3kb1r/ppp1ppp1/5n2/8/3P2P1/2N1B2b/PPPKB2q/R2Q3R b kq - 2 19", "prompt": "FEN: r3kb1r/ppp1ppp1/5n2/8/3P2P1/2N1B2b/PPPKB2q/R2Q3R b kq - 2 19\nIs the move f6e4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f6e4", "_legality_check_reason_label": "legal", "move": "f6e4", "legality_reason_label": "legal"}}
{"example_id": "rules_00462", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "7r/pppR2pp/1k2p3/2b5/5P2/2P3P1/PP4KP/3R4 b - - 4 27", "prompt": "FEN: 7r/pppR2pp/1k2p3/2b5/5P2/2P3P1/PP4KP/3R4 b - - 4 27\nList pseudo-legal moves from c5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c5: c5a3 c5b4 c5d4 c5d6 c5e3 c5e7 c5f2 c5f8 c5g1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_00463", "split": "rules", "task_type": "piece_legal_filter", "fen": "6k1/1p2r1pp/p1p1r3/P1Pp1p1P/6PR/2P1P3/4K1PB/5B2 b - -", "prompt": "FEN: 6k1/1p2r1pp/p1p1r3/P1Pp1p1P/6PR/2P1P3/4K1PB/5B2 b - -\nFor the piece on d5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d5: d5d4.\nLegal: d5d4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_00464", "split": "rules", "task_type": "king_safety_filter", "fen": "r5k1/5ppp/4p3/3nB3/Bb1P4/1P2P3/3N1PPP/5K2 w - - 1 25", "prompt": "FEN: r5k1/5ppp/4p3/3nB3/Bb1P4/1P2P3/3N1PPP/5K2 w - - 1 25\nFor move a4b5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a4b5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a4b5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a4b5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00465", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnb1k2r/pp2n1pp/2p1pp2/q2p4/2PP3B/2P2N2/P1Q1PPPP/R3KB1R w KQkq - 4 9", "prompt": "FEN: rnb1k2r/pp2n1pp/2p1pp2/q2p4/2PP3B/2P2N2/P1Q1PPPP/R3KB1R w KQkq - 4 9\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; e1 white king; f1 white bishop; h1 white rook; a2 white pawn; c2 white queen; e2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white pawn; f3 white knight; c4 white pawn; d4 white pawn; h4 white bishop.\nMoves by piece:\na1 white rook: a1b1 a1c1 a1d1\ne1 white king: e1c1 e1d1 e1d2\nf1 white bishop: no legal moves\nh1 white rook: h1g1\na2 white pawn: a2a3 a2a4\nc2 white queen: c2a4 c2b1 c2b2 c2b3 c2c1 c2d1 c2d2 c2d3 c2e4 c2f5 c2g6 c2h7\ne2 white pawn: e2e3 e2e4\nf2 white pawn: no legal moves\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3\nc3 white pawn: no legal moves\nf3 white knight: f3d2 f3e5 f3g1 f3g5\nc4 white pawn: c4c5 c4d5\nd4 white pawn: no legal moves\nh4 white bishop: h4f6 h4g3 h4g5\nAll legal moves: a1b1 a1c1 a1d1 a2a3 a2a4 c2a4 c2b1 c2b2 c2b3 c2c1 c2d1 c2d2 c2d3 c2e4 c2f5 c2g6 c2h7 c4c5 c4d5 e1c1 e1d1 e1d2 e2e3 e2e4 f3d2 f3e5 f3g1 f3g5 g2g3 g2g4 h1g1 h2h3 h4f6 h4g3 h4g5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1", "a1c1", "a1d1"], "e1": ["e1c1", "e1d1", "e1d2"], "f1": [], "h1": ["h1g1"], "a2": ["a2a3", "a2a4"], "c2": ["c2a4", "c2b1", "c2b2", "c2b3", "c2c1", "c2d1", "c2d2", "c2d3", "c2e4", "c2f5", "c2g6", "c2h7"], "e2": ["e2e3", "e2e4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3"], "c3": [], "f3": ["f3d2", "f3e5", "f3g1", "f3g5"], "c4": ["c4c5", "c4d5"], "d4": [], "h4": ["h4f6", "h4g3", "h4g5"]}, "_legal_moves_by_piece_moves": "a1b1 a1c1 a1d1 a2a3 a2a4 c2a4 c2b1 c2b2 c2b3 c2c1 c2d1 c2d2 c2d3 c2e4 c2f5 c2g6 c2h7 c4c5 c4d5 e1c1 e1d1 e1d2 e2e3 e2e4 f3d2 f3e5 f3g1 f3g5 g2g3 g2g4 h1g1 h2h3 h4f6 h4g3 h4g5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1", "a1c1", "a1d1"], "e1": ["e1c1", "e1d1", "e1d2"], "f1": [], "h1": ["h1g1"], "a2": ["a2a3", "a2a4"], "c2": ["c2a4", "c2b1", "c2b2", "c2b3", "c2c1", "c2d1", "c2d2", "c2d3", "c2e4", "c2f5", "c2g6", "c2h7"], "e2": ["e2e3", "e2e4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3"], "c3": [], "f3": ["f3d2", "f3e5", "f3g1", "f3g5"], "c4": ["c4c5", "c4d5"], "d4": [], "h4": ["h4f6", "h4g3", "h4g5"]}, "legal_moves": "a1b1 a1c1 a1d1 a2a3 a2a4 c2a4 c2b1 c2b2 c2b3 c2c1 c2d1 c2d2 c2d3 c2e4 c2f5 c2g6 c2h7 c4c5 c4d5 e1c1 e1d1 e1d2 e2e3 e2e4 f3d2 f3e5 f3g1 f3g5 g2g3 g2g4 h1g1 h2h3 h4f6 h4g3 h4g5"}}
{"example_id": "rules_00466", "split": "rules", "task_type": "ray_walk", "fen": "r2q1rk1/1pp1bppp/1nn1b3/4p3/p7/P1NPBNP1/1P2PPBP/2RQ1RK1 w - -", "prompt": "FEN: r2q1rk1/1pp1bppp/1nn1b3/4p3/p7/P1NPBNP1/1P2PPBP/2RQ1RK1 w - -\nWalk each ray for the slider on c1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c1 white rook.\nRay N: c2 empty; c3 white knight: own piece (stop, excluded).\nRay E: d1 white queen: own piece (stop, excluded).\nRay S: edge.\nRay W: b1 empty; a1 empty; edge.\nMoves from rays: c1a1 c1b1 c1c2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_00467", "split": "rules", "task_type": "legal_moves", "fen": "r3k1nr/1pp1b1q1/p1n5/4p2p/2NPP1b1/1PP1BN2/P2Q2PP/R4RK1 b - - 2 21", "prompt": "FEN: r3k1nr/1pp1b1q1/p1n5/4p2p/2NPP1b1/1PP1BN2/P2Q2PP/R4RK1 b - - 2 21\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 a8b8 a8c8 a8d8 b7b5 b7b6 c6a5 c6a7 c6b4 c6b8 c6d4 c6d8 e5d4 e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7f8 e7g5 e7h4 e8d7 e8d8 e8f7 e8f8 g4c8 g4d7 g4e6 g4f3 g4f5 g4h3 g7f6 g7f7 g7f8 g7g5 g7g6 g7h6 g7h7 g8f6 g8h6 h5h4 h8h6 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00468", "split": "rules", "task_type": "legal_moves", "fen": "2r3k1/p5pp/p4b2/4N3/1P5P/P5P1/2r2PK1/R3R3 b - - 0 30", "prompt": "FEN: 2r3k1/p5pp/p4b2/4N3/1P5P/P5P1/2r2PK1/R3R3 b - - 0 30\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 c2a2 c2b2 c2c1 c2c3 c2c4 c2c5 c2c6 c2c7 c2d2 c2e2 c2f2 c8a8 c8b8 c8c3 c8c4 c8c5 c8c6 c8c7 c8d8 c8e8 c8f8 f6d8 f6e5 f6e7 f6g5 f6h4 g7g5 g7g6 g8f8 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00469", "split": "rules", "task_type": "side_piece_inventory", "fen": "4k2r/1p6/2b1p2p/2N1P2p/5P1Q/pPp5/Pn4PK/4R3 w - -", "prompt": "FEN: 4k2r/1p6/2b1p2p/2N1P2p/5P1Q/pPp5/Pn4PK/4R3 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: e1 white rook; a2 white pawn; g2 white pawn; h2 white king; b3 white pawn; f4 white pawn; h4 white queen; c5 white knight; e5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "e1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white king"}, {"square": "b3", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "h4", "piece": "white queen"}, {"square": "c5", "piece": "white knight"}, {"square": "e5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "e1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white king"}, {"square": "b3", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "h4", "piece": "white queen"}, {"square": "c5", "piece": "white knight"}, {"square": "e5", "piece": "white pawn"}]}}
{"example_id": "rules_00470", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b2rk1/pp1p1pp1/1q3b1p/1N1Bp3/4P3/1Q1P4/Pp3PPP/R4RK1 w - - 0 14", "prompt": "FEN: r1b2rk1/pp1p1pp1/1q3b1p/1N1Bp3/4P3/1Q1P4/Pp3PPP/R4RK1 w - - 0 14\nWhat legal moves does the piece on g2 have?", "gold_answer": "g2g3 g2g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "g2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g2", "piece": "pawn"}}
{"example_id": "rules_00471", "split": "rules", "task_type": "check_detection", "fen": "r1b1kbnr/ppp1pppp/2n3q1/3P4/Q3P3/2N2N2/PP3PPP/R1B1KB1R w KQkq - 3 9", "prompt": "FEN: r1b1kbnr/ppp1pppp/2n3q1/3P4/Q3P3/2N2N2/PP3PPP/R1B1KB1R w KQkq - 3 9\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00472", "split": "rules", "task_type": "captures", "fen": "3r4/2R2pb1/4pk1p/6p1/4Q3/3P3P/Pr1q2P1/R6K w - -", "prompt": "FEN: 3r4/2R2pb1/4pk1p/6p1/4Q3/3P3P/Pr1q2P1/R6K w - -\nList all capture moves available.", "gold_answer": "c7f7 e4e6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00473", "split": "rules", "task_type": "special_rules", "fen": "rnbqkbnr/ppp2ppp/8/3p4/3p4/P6P/1PP1PPP1/RNBQKBNR w KQkq -", "prompt": "Given FEN: rnbqkbnr/ppp2ppp/8/3p4/3p4/P6P/1PP1PPP1/RNBQKBNR w KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00474", "split": "rules", "task_type": "legality_check", "fen": "8/8/8/8/5K1R/3k4/8/8 b - -", "prompt": "FEN: 8/8/8/8/5K1R/3k4/8/8 b - -\nIs the move d3g4 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "d3g4", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "d3g4", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_00475", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "1r1q1rk1/p3npBp/1pb1p1p1/3p4/4PP2/2N3P1/PPP3BP/R2Q1RK1 b - - 0 14", "prompt": "FEN: 1r1q1rk1/p3npBp/1pb1p1p1/3p4/4PP2/2N3P1/PPP3BP/R2Q1RK1 b - - 0 14\nList pseudo-legal moves from d5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d5: d5d4 d5e4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_00476", "split": "rules", "task_type": "piece_legal_filter", "fen": "2k2b1r/pp4p1/1q1p4/3Qn2p/4N3/8/PPP2PPP/R3R1K1 w - - 2 17", "prompt": "FEN: 2k2b1r/pp4p1/1q1p4/3Qn2p/4N3/8/PPP2PPP/R3R1K1 w - - 2 17\nFor the piece on f2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f2: f2f3 f2f4.\nLegal: none.\nRejected: f2f3 pinned_piece_exposes_king; f2f4 pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "f2", "diagnostic": true, "hard_gate": false, "source_square": "f2"}}
{"example_id": "rules_00477", "split": "rules", "task_type": "king_safety_filter", "fen": "8/6k1/4p3/P2b1q2/8/5P2/5KPP/8 w - - 2 52", "prompt": "FEN: 8/6k1/4p3/P2b1q2/8/5P2/5KPP/8 w - - 2 52\nFor move a5a6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a5a6.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a5a6", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a5a6", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00478", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2r2b1r/p1Nbkpp1/4pnq1/2n3Bp/7P/2P5/PP2QPB1/RN2K2R w KQ -", "prompt": "FEN: 2r2b1r/p1Nbkpp1/4pnq1/2n3Bp/7P/2P5/PP2QPB1/RN2K2R w KQ -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; e1 white king; h1 white rook; a2 white pawn; b2 white pawn; e2 white queen; f2 white pawn; g2 white bishop; c3 white pawn; h4 white pawn; g5 white bishop; c7 white knight.\nMoves by piece:\na1 white rook: no legal moves\nb1 white knight: b1a3 b1d2\ne1 white king: e1d1 e1d2 e1f1 e1g1\nh1 white rook: h1f1 h1g1 h1h2 h1h3\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\ne2 white queen: e2a6 e2b5 e2c2 e2c4 e2d1 e2d2 e2d3 e2e3 e2e4 e2e5 e2e6 e2f1 e2f3 e2g4 e2h5\nf2 white pawn: f2f3 f2f4\ng2 white bishop: g2a8 g2b7 g2c6 g2d5 g2e4 g2f1 g2f3 g2h3\nc3 white pawn: c3c4\nh4 white pawn: no legal moves\ng5 white bishop: g5c1 g5d2 g5e3 g5f4 g5f6 g5h6\nc7 white knight: c7a6 c7a8 c7b5 c7d5 c7e6 c7e8\nAll legal moves: a2a3 a2a4 b1a3 b1d2 b2b3 b2b4 c3c4 c7a6 c7a8 c7b5 c7d5 c7e6 c7e8 e1d1 e1d2 e1f1 e1g1 e2a6 e2b5 e2c2 e2c4 e2d1 e2d2 e2d3 e2e3 e2e4 e2e5 e2e6 e2f1 e2f3 e2g4 e2h5 f2f3 f2f4 g2a8 g2b7 g2c6 g2d5 g2e4 g2f1 g2f3 g2h3 g5c1 g5d2 g5e3 g5f4 g5f6 g5h6 h1f1 h1g1 h1h2 h1h3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "b1": ["b1a3", "b1d2"], "e1": ["e1d1", "e1d2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1", "h1h2", "h1h3"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "e2": ["e2a6", "e2b5", "e2c2", "e2c4", "e2d1", "e2d2", "e2d3", "e2e3", "e2e4", "e2e5", "e2e6", "e2f1", "e2f3", "e2g4", "e2h5"], "f2": ["f2f3", "f2f4"], "g2": ["g2a8", "g2b7", "g2c6", "g2d5", "g2e4", "g2f1", "g2f3", "g2h3"], "c3": ["c3c4"], "h4": [], "g5": ["g5c1", "g5d2", "g5e3", "g5f4", "g5f6", "g5h6"], "c7": ["c7a6", "c7a8", "c7b5", "c7d5", "c7e6", "c7e8"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b1a3 b1d2 b2b3 b2b4 c3c4 c7a6 c7a8 c7b5 c7d5 c7e6 c7e8 e1d1 e1d2 e1f1 e1g1 e2a6 e2b5 e2c2 e2c4 e2d1 e2d2 e2d3 e2e3 e2e4 e2e5 e2e6 e2f1 e2f3 e2g4 e2h5 f2f3 f2f4 g2a8 g2b7 g2c6 g2d5 g2e4 g2f1 g2f3 g2h3 g5c1 g5d2 g5e3 g5f4 g5f6 g5h6 h1f1 h1g1 h1h2 h1h3", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "b1": ["b1a3", "b1d2"], "e1": ["e1d1", "e1d2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1", "h1h2", "h1h3"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "e2": ["e2a6", "e2b5", "e2c2", "e2c4", "e2d1", "e2d2", "e2d3", "e2e3", "e2e4", "e2e5", "e2e6", "e2f1", "e2f3", "e2g4", "e2h5"], "f2": ["f2f3", "f2f4"], "g2": ["g2a8", "g2b7", "g2c6", "g2d5", "g2e4", "g2f1", "g2f3", "g2h3"], "c3": ["c3c4"], "h4": [], "g5": ["g5c1", "g5d2", "g5e3", "g5f4", "g5f6", "g5h6"], "c7": ["c7a6", "c7a8", "c7b5", "c7d5", "c7e6", "c7e8"]}, "legal_moves": "a2a3 a2a4 b1a3 b1d2 b2b3 b2b4 c3c4 c7a6 c7a8 c7b5 c7d5 c7e6 c7e8 e1d1 e1d2 e1f1 e1g1 e2a6 e2b5 e2c2 e2c4 e2d1 e2d2 e2d3 e2e3 e2e4 e2e5 e2e6 e2f1 e2f3 e2g4 e2h5 f2f3 f2f4 g2a8 g2b7 g2c6 g2d5 g2e4 g2f1 g2f3 g2h3 g5c1 g5d2 g5e3 g5f4 g5f6 g5h6 h1f1 h1g1 h1h2 h1h3"}}
{"example_id": "rules_00479", "split": "rules", "task_type": "ray_walk", "fen": "rnbqk1nr/ppp1ppbp/3p2p1/8/3PPB2/8/PPP2PPP/RN1QKBNR w KQkq - 2 4", "prompt": "FEN: rnbqk1nr/ppp1ppbp/3p2p1/8/3PPB2/8/PPP2PPP/RN1QKBNR w KQkq - 2 4\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 white knight: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: none", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00480", "split": "rules", "task_type": "legal_moves", "fen": "r5r1/p2b3k/2np3p/4pp2/1P1P2pq/2PB1P1P/P2Q4/2KR2NR b - - 0 23", "prompt": "FEN: r5r1/p2b3k/2np3p/4pp2/1P1P2pq/2PB1P1P/P2Q4/2KR2NR b - - 0 23\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 a8c8 a8d8 a8e8 a8f8 c6a5 c6b4 c6b8 c6d4 c6d8 c6e7 d6d5 d7c8 d7e6 d7e8 e5d4 e5e4 g4f3 g4g3 g4h3 g8b8 g8c8 g8d8 g8e8 g8f8 g8g5 g8g6 g8g7 g8h8 h4d8 h4e1 h4e7 h4f2 h4f6 h4g3 h4g5 h4h3 h4h5 h6h5 h7g6 h7g7 h7h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00481", "split": "rules", "task_type": "legal_moves", "fen": "r4rk1/5pp1/1p2p2n/p1p1R3/2Pp1Pq1/3P3Q/PP5P/5K2 w - - 0 32", "prompt": "FEN: r4rk1/5pp1/1p2p2n/p1p1R3/2Pp1Pq1/3P3Q/PP5P/5K2 w - - 0 32\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 b2b4 e5c5 e5d5 e5e1 e5e2 e5e3 e5e4 e5e6 e5f5 e5g5 e5h5 f1e1 f1f2 f4f5 h3e3 h3f3 h3g2 h3g3 h3g4 h3h4 h3h5 h3h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00482", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqk2r/ppppn2p/6p1/3Bb2Q/3p4/8/PPP2PPP/RN2R1K1 w kq -", "prompt": "FEN: r1bqk2r/ppppn2p/6p1/3Bb2Q/3p4/8/PPP2PPP/RN2R1K1 w kq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; e1 white rook; g1 white king; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; d5 white bishop; h5 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "d5", "piece": "white bishop"}, {"square": "h5", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "d5", "piece": "white bishop"}, {"square": "h5", "piece": "white queen"}]}}
{"example_id": "rules_00483", "split": "rules", "task_type": "piece_legal_moves", "fen": "6k1/3b2b1/4p2p/1p1P4/p2B2Q1/6P1/PPB2N1K/8 b - -", "prompt": "FEN: 6k1/3b2b1/4p2p/1p1P4/p2B2Q1/6P1/PPB2N1K/8 b - -\nWhat legal moves does the piece on d7 have?", "gold_answer": "d7c6 d7c8 d7e8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "d7", "_piece_legal_moves_piece": "bishop", "diagnostic": true, "hard_gate": false, "source_square": "d7", "piece": "bishop"}}
{"example_id": "rules_00484", "split": "rules", "task_type": "check_detection", "fen": "r4rk1/pp1n1pp1/1q1b1np1/2pp2B1/3P2P1/2PB3P/PP2NP2/R2Q1RK1 b - -", "prompt": "FEN: r4rk1/pp1n1pp1/1q1b1np1/2pp2B1/3P2P1/2PB3P/PP2NP2/R2Q1RK1 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00485", "split": "rules", "task_type": "captures", "fen": "rnbqkb1r/pp3ppp/3p1n2/4p1B1/4P3/2N2N2/PPP2PPP/R2QKB1R b KQkq - 1 7", "prompt": "FEN: rnbqkb1r/pp3ppp/3p1n2/4p1B1/4P3/2N2N2/PPP2PPP/R2QKB1R b KQkq - 1 7\nList all capture moves available.", "gold_answer": "f6e4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00486", "split": "rules", "task_type": "special_rules", "fen": "4kb1r/1pp2ppp/2q1p3/1p1r4/6Q1/6B1/PPP2PPP/3R1RK1 w k -", "prompt": "Given FEN: 4kb1r/1pp2ppp/2q1p3/1p1r4/6Q1/6B1/PPP2PPP/3R1RK1 w k -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00487", "split": "rules", "task_type": "legality_check", "fen": "r1bq1rk1/ppp2ppp/1bnp1n2/4p3/1P2P3/P1N2N2/2PPBPPP/R1BQ1RK1 w - - 1 8", "prompt": "FEN: r1bq1rk1/ppp2ppp/1bnp1n2/4p3/1P2P3/P1N2N2/2PPBPPP/R1BQ1RK1 w - - 1 8\nIs the move b4c1 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b4c1", "_legality_check_reason_label": "own_piece_destination", "move": "b4c1", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_00488", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnbq2k1/pp1pnrbp/2p1p1p1/4PpB1/2PP4/2NB1N2/PP3PPP/R2QK2R w KQ - 2 9", "prompt": "FEN: rnbq2k1/pp1pnrbp/2p1p1p1/4PpB1/2PP4/2NB1N2/PP3PPP/R2QK2R w KQ - 2 9\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1 a1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00489", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnbq1rk1/ppp1bppp/3p1n2/8/3QPB2/2N2N2/PPP2PPP/R3KB1R w KQ -", "prompt": "FEN: rnbq1rk1/ppp1bppp/3p1n2/8/3QPB2/2N2N2/PPP2PPP/R3KB1R w KQ -\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1 a1c1 a1d1.\nLegal: a1b1 a1c1 a1d1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00490", "split": "rules", "task_type": "king_safety_filter", "fen": "8/2p3pk/8/1R1Rp3/2p5/2P2qP1/1P6/3K4 w - - 2 40", "prompt": "FEN: 8/2p3pk/8/1R1Rp3/2p5/2P2qP1/1P6/3K4 w - - 2 40\nFor move b2b3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: b2b3.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "b2b3", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "b2b3", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_00491", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1b2rk1/pp3pbp/2p3p1/3pP3/5P2/2P3P1/PP1N2BP/R1B3qK w - -", "prompt": "FEN: r1b2rk1/pp3pbp/2p3p1/3pP3/5P2/2P3P1/PP1N2BP/R1B3qK w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; h1 white king; a2 white pawn; b2 white pawn; d2 white knight; g2 white bishop; h2 white pawn; c3 white pawn; g3 white pawn; f4 white pawn; e5 white pawn.\nMoves by piece:\na1 white rook: no legal moves\nc1 white bishop: no legal moves\nh1 white king: h1g1\na2 white pawn: no legal moves\nb2 white pawn: no legal moves\nd2 white knight: no legal moves\ng2 white bishop: no legal moves\nh2 white pawn: no legal moves\nc3 white pawn: no legal moves\ng3 white pawn: no legal moves\nf4 white pawn: no legal moves\ne5 white pawn: no legal moves\nAll legal moves: h1g1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "c1": [], "h1": ["h1g1"], "a2": [], "b2": [], "d2": [], "g2": [], "h2": [], "c3": [], "g3": [], "f4": [], "e5": []}, "_legal_moves_by_piece_moves": "h1g1", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "c1": [], "h1": ["h1g1"], "a2": [], "b2": [], "d2": [], "g2": [], "h2": [], "c3": [], "g3": [], "f4": [], "e5": []}, "legal_moves": "h1g1"}}
{"example_id": "rules_00492", "split": "rules", "task_type": "ray_walk", "fen": "r7/8/5k2/6Pp/p3K1p1/R7/8/8 b - - 0 55", "prompt": "FEN: r7/8/5k2/6Pp/p3K1p1/R7/8/8 b - - 0 55\nWalk each ray for the slider on a8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a8 black rook.\nRay N: edge.\nRay E: b8 empty; c8 empty; d8 empty; e8 empty; f8 empty; g8 empty; h8 empty; edge.\nRay S: a7 empty; a6 empty; a5 empty; a4 black pawn: own piece (stop, excluded).\nRay W: edge.\nMoves from rays: a8a5 a8a6 a8a7 a8b8 a8c8 a8d8 a8e8 a8f8 a8g8 a8h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a8", "diagnostic": true, "hard_gate": false, "source_square": "a8"}}
{"example_id": "rules_00493", "split": "rules", "task_type": "legal_moves", "fen": "2kr3r/ppqn1ppp/2pb1nb1/3p2B1/3P2P1/2N2N1P/PPPQBP2/2KR3R w - - 3 13", "prompt": "FEN: 2kr3r/ppqn1ppp/2pb1nb1/3p2B1/3P2P1/2N2N1P/PPPQBP2/2KR3R w - - 3 13\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 b2b4 c1b1 c3a4 c3b1 c3b5 c3d5 c3e4 d1e1 d1f1 d1g1 d2d3 d2e1 d2e3 d2f4 e2a6 e2b5 e2c4 e2d3 e2f1 f3e1 f3e5 f3g1 f3h2 f3h4 g5e3 g5f4 g5f6 g5h4 g5h6 h1e1 h1f1 h1g1 h1h2 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00494", "split": "rules", "task_type": "legal_moves", "fen": "8/8/8/2Q5/1K6/6p1/4qk2/8 b - -", "prompt": "FEN: 8/8/8/2Q5/1K6/6p1/4qk2/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: e2e3 f2e1 f2f1 f2f3 f2g2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00495", "split": "rules", "task_type": "side_piece_inventory", "fen": "r4r2/pb1P1k1p/8/1pp1p3/4P3/6PB/PP3P1P/2KR3R w - - 1 21", "prompt": "FEN: r4r2/pb1P1k1p/8/1pp1p3/4P3/6PB/PP3P1P/2KR3R w - - 1 21\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: c1 white king; d1 white rook; h1 white rook; a2 white pawn; b2 white pawn; f2 white pawn; h2 white pawn; g3 white pawn; h3 white bishop; e4 white pawn; d7 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "c1", "piece": "white king"}, {"square": "d1", "piece": "white rook"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "h3", "piece": "white bishop"}, {"square": "e4", "piece": "white pawn"}, {"square": "d7", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "c1", "piece": "white king"}, {"square": "d1", "piece": "white rook"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "h3", "piece": "white bishop"}, {"square": "e4", "piece": "white pawn"}, {"square": "d7", "piece": "white pawn"}]}}
{"example_id": "rules_00496", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b1k1nr/ppp2ppp/2n5/3q4/3P4/5N2/PP1Q1PPP/RN2KB1R w KQkq -", "prompt": "FEN: r1b1k1nr/ppp2ppp/2n5/3q4/3P4/5N2/PP1Q1PPP/RN2KB1R w KQkq -\nWhat legal moves does the piece on f3 have?", "gold_answer": "f3e5 f3g1 f3g5 f3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f3", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "f3", "piece": "knight"}}
{"example_id": "rules_00497", "split": "rules", "task_type": "check_detection", "fen": "2kr1b1r/ppp1qppp/2n1p3/3n4/3PN1b1/2P2NP1/PP3PBP/R1B1QRK1 b - - 6 11", "prompt": "FEN: 2kr1b1r/ppp1qppp/2n1p3/3n4/3PN1b1/2P2NP1/PP3PBP/R1B1QRK1 b - - 6 11\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00498", "split": "rules", "task_type": "captures", "fen": "1k6/6R1/4r1p1/P6p/5P1P/4K1P1/8/8 w - -", "prompt": "FEN: 1k6/6R1/4r1p1/P6p/5P1P/4K1P1/8/8 w - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00499", "split": "rules", "task_type": "special_rules", "fen": "8/6k1/5R2/1pK1Pn2/1P3P1P/8/8/8 w - - 4 53", "prompt": "Given FEN: 8/6k1/5R2/1pK1Pn2/1P3P1P/8/8/8 w - - 4 53\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00500", "split": "rules", "task_type": "legality_check", "fen": "5rnk/2p3bp/p1Pp4/3P1bBq/1P2pN1N/6RP/3Q1P2/4K3 b - -", "prompt": "FEN: 5rnk/2p3bp/p1Pp4/3P1bBq/1P2pN1N/6RP/3Q1P2/4K3 b - -\nIs the move h5h7 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "h5h7", "_legality_check_reason_label": "own_piece_destination", "move": "h5h7", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_00501", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1bqkb1r/pp3p1p/1n3p2/2pPp3/8/P3PQ2/1B1P1PPP/RN2KB1R b KQkq - 0 11", "prompt": "FEN: r1bqkb1r/pp3p1p/1n3p2/2pPp3/8/P3PQ2/1B1P1PPP/RN2KB1R b KQkq - 0 11\nList pseudo-legal moves from c5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c5: c5c4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_00502", "split": "rules", "task_type": "piece_legal_filter", "fen": "r3k2r/1b1n2p1/p1p1pp2/1p5p/8/P1p5/P3BPPP/R1B2RK1 w kq - 0 17", "prompt": "FEN: r3k2r/1b1n2p1/p1p1pp2/1p5p/8/P1p5/P3BPPP/R1B2RK1 w kq - 0 17\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1.\nLegal: a1b1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00503", "split": "rules", "task_type": "king_safety_filter", "fen": "r1k5/p1p2p2/2pp3p/4q1r1/4Pp1P/1RP2Q2/P1P2PP1/1R4K1 b - -", "prompt": "FEN: r1k5/p1p2p2/2pp3p/4q1r1/4Pp1P/1RP2Q2/P1P2PP1/1R4K1 b - -\nFor move c8b7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c8b7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "c8b7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "c8b7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00504", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "3q1r1k/rp1nbppp/p3p3/3pP2n/3P4/2NB1P2/PPQB1P1P/2KR3R w - -", "prompt": "FEN: 3q1r1k/rp1nbppp/p3p3/3pP2n/3P4/2NB1P2/PPQB1P1P/2KR3R w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c1 white king; d1 white rook; h1 white rook; a2 white pawn; b2 white pawn; c2 white queen; d2 white bishop; f2 white pawn; h2 white pawn; c3 white knight; d3 white bishop; f3 white pawn; d4 white pawn; e5 white pawn.\nMoves by piece:\nc1 white king: c1b1\nd1 white rook: d1e1 d1f1 d1g1\nh1 white rook: h1e1 h1f1 h1g1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white queen: c2a4 c2b1 c2b3\nd2 white bishop: d2e1 d2e3 d2f4 d2g5 d2h6\nf2 white pawn: no legal moves\nh2 white pawn: h2h3 h2h4\nc3 white knight: c3a4 c3b1 c3b5 c3d5 c3e2 c3e4\nd3 white bishop: d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 d3g6 d3h7\nf3 white pawn: f3f4\nd4 white pawn: no legal moves\ne5 white pawn: no legal moves\nAll legal moves: a2a3 a2a4 b2b3 b2b4 c1b1 c2a4 c2b1 c2b3 c3a4 c3b1 c3b5 c3d5 c3e2 c3e4 d1e1 d1f1 d1g1 d2e1 d2e3 d2f4 d2g5 d2h6 d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 d3g6 d3h7 f3f4 h1e1 h1f1 h1g1 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c1": ["c1b1"], "d1": ["d1e1", "d1f1", "d1g1"], "h1": ["h1e1", "h1f1", "h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2a4", "c2b1", "c2b3"], "d2": ["d2e1", "d2e3", "d2f4", "d2g5", "d2h6"], "f2": [], "h2": ["h2h3", "h2h4"], "c3": ["c3a4", "c3b1", "c3b5", "c3d5", "c3e2", "c3e4"], "d3": ["d3a6", "d3b5", "d3c4", "d3e2", "d3e4", "d3f1", "d3f5", "d3g6", "d3h7"], "f3": ["f3f4"], "d4": [], "e5": []}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b2b3 b2b4 c1b1 c2a4 c2b1 c2b3 c3a4 c3b1 c3b5 c3d5 c3e2 c3e4 d1e1 d1f1 d1g1 d2e1 d2e3 d2f4 d2g5 d2h6 d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 d3g6 d3h7 f3f4 h1e1 h1f1 h1g1 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c1": ["c1b1"], "d1": ["d1e1", "d1f1", "d1g1"], "h1": ["h1e1", "h1f1", "h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2a4", "c2b1", "c2b3"], "d2": ["d2e1", "d2e3", "d2f4", "d2g5", "d2h6"], "f2": [], "h2": ["h2h3", "h2h4"], "c3": ["c3a4", "c3b1", "c3b5", "c3d5", "c3e2", "c3e4"], "d3": ["d3a6", "d3b5", "d3c4", "d3e2", "d3e4", "d3f1", "d3f5", "d3g6", "d3h7"], "f3": ["f3f4"], "d4": [], "e5": []}, "legal_moves": "a2a3 a2a4 b2b3 b2b4 c1b1 c2a4 c2b1 c2b3 c3a4 c3b1 c3b5 c3d5 c3e2 c3e4 d1e1 d1f1 d1g1 d2e1 d2e3 d2f4 d2g5 d2h6 d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 d3g6 d3h7 f3f4 h1e1 h1f1 h1g1 h2h3 h2h4"}}
{"example_id": "rules_00505", "split": "rules", "task_type": "ray_walk", "fen": "8/8/8/3R4/3k3p/4N2P/4bPPK/1r1q4 b - -", "prompt": "FEN: 8/8/8/3R4/3k3p/4N2P/4bPPK/1r1q4 b - -\nWalk each ray for the slider on b1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b1 black rook.\nRay N: b2 empty; b3 empty; b4 empty; b5 empty; b6 empty; b7 empty; b8 empty; edge.\nRay E: c1 empty; d1 black queen: own piece (stop, excluded).\nRay S: edge.\nRay W: a1 empty; edge.\nMoves from rays: b1a1 b1b2 b1b3 b1b4 b1b5 b1b6 b1b7 b1b8 b1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_00506", "split": "rules", "task_type": "legal_moves", "fen": "rnbq1rk1/pppp1pb1/7p/3pP1p1/8/3P1N1Q/PPP2PPP/RNB1K2R w KQ - 0 12", "prompt": "FEN: rnbq1rk1/pppp1pb1/7p/3pP1p1/8/3P1N1Q/PPP2PPP/RNB1K2R w KQ - 0 12\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c2c3 c2c4 d3d4 e1d1 e1d2 e1e2 e1f1 e1g1 e5e6 f3d2 f3d4 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h3d7 h3e6 h3f5 h3g3 h3g4 h3h4 h3h5 h3h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00507", "split": "rules", "task_type": "legal_moves", "fen": "r1b4r/ppp3k1/3p4/4qp2/6p1/P5pP/4N1P1/5K2 b - - 1 30", "prompt": "FEN: r1b4r/ppp3k1/3p4/4qp2/6p1/P5pP/4N1P1/5K2 b - - 1 30\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c7c5 c7c6 c8d7 c8e6 d6d5 e5a1 e5a5 e5b2 e5b5 e5c3 e5c5 e5d4 e5d5 e5e2 e5e3 e5e4 e5e6 e5e7 e5e8 e5f4 e5f6 f5f4 g4h3 g7f6 g7f7 g7f8 g7g6 g7g8 g7h6 g7h7 h8d8 h8e8 h8f8 h8g8 h8h3 h8h4 h8h5 h8h6 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00508", "split": "rules", "task_type": "side_piece_inventory", "fen": "5qk1/p1pn3p/6pb/4p2n/3pP3/PP1P2Pb/1BPNN3/R2Q2K1 w - - 2 18", "prompt": "FEN: 5qk1/p1pn3p/6pb/4p2n/3pP3/PP1P2Pb/1BPNN3/R2Q2K1 w - - 2 18\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white queen; g1 white king; b2 white bishop; c2 white pawn; d2 white knight; e2 white knight; a3 white pawn; b3 white pawn; d3 white pawn; g3 white pawn; e4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white bishop"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white knight"}, {"square": "e2", "piece": "white knight"}, {"square": "a3", "piece": "white pawn"}, {"square": "b3", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white bishop"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white knight"}, {"square": "e2", "piece": "white knight"}, {"square": "a3", "piece": "white pawn"}, {"square": "b3", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}]}}
{"example_id": "rules_00509", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnbqk2r/pp3ppp/3b1n2/3p4/3Pp3/6PN/PP2PPBP/RNBQ1RK1 w kq -", "prompt": "FEN: rnbqk2r/pp3ppp/3b1n2/3p4/3Pp3/6PN/PP2PPBP/RNBQ1RK1 w kq -\nWhat legal moves does the piece on g1 have?", "gold_answer": "g1h1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "g1", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "g1", "piece": "king"}}
{"example_id": "rules_00510", "split": "rules", "task_type": "check_detection", "fen": "1r5k/pr3p1p/6pb/3Nnp2/3P4/4P2P/P4PP1/2R2RK1 b - - 5 21", "prompt": "FEN: 1r5k/pr3p1p/6pb/3Nnp2/3P4/4P2P/P4PP1/2R2RK1 b - - 5 21\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00511", "split": "rules", "task_type": "captures", "fen": "B4rk1/p1q1bppp/1p2p3/4P3/Q7/8/PP3PPP/R4RK1 b - - 0 17", "prompt": "FEN: B4rk1/p1q1bppp/1p2p3/4P3/Q7/8/PP3PPP/R4RK1 b - - 0 17\nList all capture moves available.", "gold_answer": "c7e5 f8a8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00512", "split": "rules", "task_type": "special_rules", "fen": "4q3/ppk3pp/1n6/5p2/3p4/5n1P/PPP5/1K1R3Q w - - 0 34", "prompt": "Given FEN: 4q3/ppk3pp/1n6/5p2/3p4/5n1P/PPP5/1K1R3Q w - - 0 34\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00513", "split": "rules", "task_type": "legality_check", "fen": "2r1qrk1/p1pp3p/1p3b2/3P2p1/3pP3/1P4PP/P4PB1/2RQ1RK1 w - -", "prompt": "FEN: 2r1qrk1/p1pp3p/1p3b2/3P2p1/3pP3/1P4PP/P4PB1/2RQ1RK1 w - -\nIs the move d4b1 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "d4b1", "_legality_check_reason_label": "wrong_side_piece", "move": "d4b1", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_00514", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "1n1qk3/N1p2p2/7b/4p3/4Q1pp/7P/PPP2PPB/1K6 b - - 1 26", "prompt": "FEN: 1n1qk3/N1p2p2/7b/4p3/4Q1pp/7P/PPP2PPB/1K6 b - - 1 26\nList pseudo-legal moves from g4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g4: g4g3 g4h3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g4", "diagnostic": true, "hard_gate": false, "source_square": "g4"}}
{"example_id": "rules_00515", "split": "rules", "task_type": "piece_legal_filter", "fen": "5r1k/pp5p/2n3p1/2P4n/4Q3/1NP3qP/PP2P1B1/R6K b - -", "prompt": "FEN: 5r1k/pp5p/2n3p1/2P4n/4Q3/1NP3qP/PP2P1B1/R6K b - -\nFor the piece on g3, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g3: g3b8 g3c3 g3c7 g3d3 g3d6 g3e1 g3e3 g3e5 g3f2 g3f3 g3f4 g3g2 g3g4 g3g5 g3h2 g3h3 g3h4.\nLegal: g3b8 g3c3 g3c7 g3d3 g3d6 g3e1 g3e3 g3e5 g3f2 g3f3 g3f4 g3g2 g3g4 g3g5 g3h2 g3h3 g3h4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "g3", "diagnostic": true, "hard_gate": false, "source_square": "g3"}}
{"example_id": "rules_00516", "split": "rules", "task_type": "king_safety_filter", "fen": "1R5R/4qp2/p3p1pk/8/3p4/5P2/5K2/8 b - - 1 50", "prompt": "FEN: 1R5R/4qp2/p3p1pk/8/3p4/5P2/5K2/8 b - - 1 50\nFor move a6a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a6a5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a6a5", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "a6a5", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_00517", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r2qk2r/pp3pp1/1np1pbp1/8/3P1P1P/3QN1P1/PPP1B3/R3K2R w KQkq - 3 17", "prompt": "FEN: r2qk2r/pp3pp1/1np1pbp1/8/3P1P1P/3QN1P1/PPP1B3/R3K2R w KQkq - 3 17\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; e1 white king; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; e2 white bishop; d3 white queen; e3 white knight; g3 white pawn; d4 white pawn; f4 white pawn; h4 white pawn.\nMoves by piece:\na1 white rook: a1b1 a1c1 a1d1\ne1 white king: e1c1 e1d1 e1d2 e1f1 e1f2 e1g1\nh1 white rook: h1f1 h1g1 h1h2 h1h3\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: c2c3 c2c4\ne2 white bishop: e2d1 e2f1 e2f3 e2g4 e2h5\nd3 white queen: d3a3 d3a6 d3b3 d3b5 d3c3 d3c4 d3d1 d3d2 d3e4 d3f5 d3g6\ne3 white knight: e3c4 e3d1 e3d5 e3f1 e3f5 e3g2 e3g4\ng3 white pawn: g3g4\nd4 white pawn: d4d5\nf4 white pawn: f4f5\nh4 white pawn: h4h5\nAll legal moves: a1b1 a1c1 a1d1 a2a3 a2a4 b2b3 b2b4 c2c3 c2c4 d3a3 d3a6 d3b3 d3b5 d3c3 d3c4 d3d1 d3d2 d3e4 d3f5 d3g6 d4d5 e1c1 e1d1 e1d2 e1f1 e1f2 e1g1 e2d1 e2f1 e2f3 e2g4 e2h5 e3c4 e3d1 e3d5 e3f1 e3f5 e3g2 e3g4 f4f5 g3g4 h1f1 h1g1 h1h2 h1h3 h4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1", "a1c1", "a1d1"], "e1": ["e1c1", "e1d1", "e1d2", "e1f1", "e1f2", "e1g1"], "h1": ["h1f1", "h1g1", "h1h2", "h1h3"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "e2": ["e2d1", "e2f1", "e2f3", "e2g4", "e2h5"], "d3": ["d3a3", "d3a6", "d3b3", "d3b5", "d3c3", "d3c4", "d3d1", "d3d2", "d3e4", "d3f5", "d3g6"], "e3": ["e3c4", "e3d1", "e3d5", "e3f1", "e3f5", "e3g2", "e3g4"], "g3": ["g3g4"], "d4": ["d4d5"], "f4": ["f4f5"], "h4": ["h4h5"]}, "_legal_moves_by_piece_moves": "a1b1 a1c1 a1d1 a2a3 a2a4 b2b3 b2b4 c2c3 c2c4 d3a3 d3a6 d3b3 d3b5 d3c3 d3c4 d3d1 d3d2 d3e4 d3f5 d3g6 d4d5 e1c1 e1d1 e1d2 e1f1 e1f2 e1g1 e2d1 e2f1 e2f3 e2g4 e2h5 e3c4 e3d1 e3d5 e3f1 e3f5 e3g2 e3g4 f4f5 g3g4 h1f1 h1g1 h1h2 h1h3 h4h5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1", "a1c1", "a1d1"], "e1": ["e1c1", "e1d1", "e1d2", "e1f1", "e1f2", "e1g1"], "h1": ["h1f1", "h1g1", "h1h2", "h1h3"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "e2": ["e2d1", "e2f1", "e2f3", "e2g4", "e2h5"], "d3": ["d3a3", "d3a6", "d3b3", "d3b5", "d3c3", "d3c4", "d3d1", "d3d2", "d3e4", "d3f5", "d3g6"], "e3": ["e3c4", "e3d1", "e3d5", "e3f1", "e3f5", "e3g2", "e3g4"], "g3": ["g3g4"], "d4": ["d4d5"], "f4": ["f4f5"], "h4": ["h4h5"]}, "legal_moves": "a1b1 a1c1 a1d1 a2a3 a2a4 b2b3 b2b4 c2c3 c2c4 d3a3 d3a6 d3b3 d3b5 d3c3 d3c4 d3d1 d3d2 d3e4 d3f5 d3g6 d4d5 e1c1 e1d1 e1d2 e1f1 e1f2 e1g1 e2d1 e2f1 e2f3 e2g4 e2h5 e3c4 e3d1 e3d5 e3f1 e3f5 e3g2 e3g4 f4f5 g3g4 h1f1 h1g1 h1h2 h1h3 h4h5"}}
{"example_id": "rules_00518", "split": "rules", "task_type": "ray_walk", "fen": "r4rk1/pp1bqpp1/7p/3pp3/3P4/2P1P2P/P1PQB1P1/R4RK1 w - -", "prompt": "FEN: r4rk1/pp1bqpp1/7p/3pp3/3P4/2P1P2P/P1PQB1P1/R4RK1 w - -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 empty; e1 empty; f1 white rook: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1 a1d1 a1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00519", "split": "rules", "task_type": "legal_moves", "fen": "r4rk1/2p1qppp/p1p1bn2/8/3P4/2B2N2/PPP2PPP/R2QR1K1 b - - 1 12", "prompt": "FEN: r4rk1/2p1qppp/p1p1bn2/8/3P4/2B2N2/PPP2PPP/R2QR1K1 b - - 1 12\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 a8b8 a8c8 a8d8 a8e8 c6c5 e6a2 e6b3 e6c4 e6c8 e6d5 e6d7 e6f5 e6g4 e6h3 e7a3 e7b4 e7c5 e7d6 e7d7 e7d8 e7e8 f6d5 f6d7 f6e4 f6e8 f6g4 f6h5 f8b8 f8c8 f8d8 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00520", "split": "rules", "task_type": "legal_moves", "fen": "r1bqr1k1/pp1nbppp/2pp1n2/3Pp3/2P1P3/2N1BN2/PP2BPPP/R2Q1RK1 b - -", "prompt": "FEN: r1bqr1k1/pp1nbppp/2pp1n2/3Pp3/2P1P3/2N1BN2/PP2BPPP/R2Q1RK1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c6c5 c6d5 d7b6 d7b8 d7c5 d7f8 d8a5 d8b6 d8c7 e7f8 e8f8 f6d5 f6e4 f6g4 f6h5 g7g5 g7g6 g8f8 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00521", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1b1k2r/ppp1qpb1/2n3p1/2np3p/1P1P4/P3PN1P/1B2BPP1/R2QK2R w KQkq - 0 14", "prompt": "FEN: r1b1k2r/ppp1qpb1/2n3p1/2np3p/1P1P4/P3PN1P/1B2BPP1/R2QK2R w KQkq - 0 14\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white queen; e1 white king; h1 white rook; b2 white bishop; e2 white bishop; f2 white pawn; g2 white pawn; a3 white pawn; e3 white pawn; f3 white knight; h3 white pawn; b4 white pawn; d4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "b2", "piece": "white bishop"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "h3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "b2", "piece": "white bishop"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "h3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}]}}
{"example_id": "rules_00522", "split": "rules", "task_type": "piece_legal_moves", "fen": "2b5/2p3pk/3NNnqp/1p1Pp3/4r3/1P1QB1PP/6K1/5R2 b - -", "prompt": "FEN: 2b5/2p3pk/3NNnqp/1p1Pp3/4r3/1P1QB1PP/6K1/5R2 b - -\nWhat legal moves does the piece on g6 have?", "gold_answer": "g6e8 g6f5 g6f7 g6g3 g6g4 g6g5 g6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "g6", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "g6", "piece": "queen"}}
{"example_id": "rules_00523", "split": "rules", "task_type": "check_detection", "fen": "r1bqkbnr/1p1ppppp/p1n5/2p5/B3P3/5N2/PPPP1PPP/RNBQK2R b KQkq - 1 4", "prompt": "FEN: r1bqkbnr/1p1ppppp/p1n5/2p5/B3P3/5N2/PPPP1PPP/RNBQK2R b KQkq - 1 4\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00524", "split": "rules", "task_type": "captures", "fen": "r1bqk2r/pp3ppp/2nbpn2/2pP4/8/1P2PN2/PB1PBPPP/RN1QK2R b KQkq -", "prompt": "FEN: r1bqk2r/pp3ppp/2nbpn2/2pP4/8/1P2PN2/PB1PBPPP/RN1QK2R b KQkq -\nList all capture moves available.", "gold_answer": "d6h2 e6d5 f6d5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00525", "split": "rules", "task_type": "special_rules", "fen": "8/8/8/8/5K2/4N2k/4B3/8 b - -", "prompt": "Given FEN: 8/8/8/8/5K2/4N2k/4B3/8 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00526", "split": "rules", "task_type": "legality_check", "fen": "r6r/3n3p/3P1p1P/p3k3/P1p1p1P1/1p2P3/1PB2P2/R4RK1 w - - 0 27", "prompt": "FEN: r6r/3n3p/3P1p1P/p3k3/P1p1p1P1/1p2P3/1PB2P2/R4RK1 w - - 0 27\nIs the move g1h2 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g1h2", "_legality_check_reason_label": "legal", "move": "g1h2", "legality_reason_label": "legal"}}
{"example_id": "rules_00527", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1b1k1nr/pppp1ppp/1bn2q2/4p3/1PB1P3/P4N2/2PP1PPP/RNBQK2R w KQkq - 1 6", "prompt": "FEN: r1b1k1nr/pppp1ppp/1bn2q2/4p3/1PB1P3/P4N2/2PP1PPP/RNBQK2R w KQkq - 1 6\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1a2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00528", "split": "rules", "task_type": "piece_legal_filter", "fen": "r3k2r/pppb1p1p/1q1p3B/1N1P4/3pP3/7P/PP3PP1/R2QKB1R w KQkq - 1 13", "prompt": "FEN: r3k2r/pppb1p1p/1q1p3B/1N1P4/3pP3/7P/PP3PP1/R2QKB1R w KQkq - 1 13\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1 a1c1.\nLegal: a1b1 a1c1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00529", "split": "rules", "task_type": "king_safety_filter", "fen": "rn1q1rk1/pp2bpp1/2p1bn1p/3p4/3P3B/2NBP3/PPQ2PPP/R3K1NR w KQ -", "prompt": "FEN: rn1q1rk1/pp2bpp1/2p1bn1p/3p4/3P3B/2NBP3/PPQ2PPP/R3K1NR w KQ -\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00530", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1r1q3r/pRNnkpbp/8/2p2Qp1/8/3PP1P1/P1PB2BP/6K1 w - -", "prompt": "FEN: 1r1q3r/pRNnkpbp/8/2p2Qp1/8/3PP1P1/P1PB2BP/6K1 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: g1 white king; a2 white pawn; c2 white pawn; d2 white bishop; g2 white bishop; h2 white pawn; d3 white pawn; e3 white pawn; g3 white pawn; f5 white queen; b7 white rook; c7 white knight.\nMoves by piece:\ng1 white king: g1f1 g1f2 g1h1\na2 white pawn: a2a3 a2a4\nc2 white pawn: c2c3 c2c4\nd2 white bishop: d2a5 d2b4 d2c1 d2c3 d2e1\ng2 white bishop: g2c6 g2d5 g2e4 g2f1 g2f3 g2h1 g2h3\nh2 white pawn: h2h3 h2h4\nd3 white pawn: d3d4\ne3 white pawn: e3e4\ng3 white pawn: g3g4\nf5 white queen: f5c5 f5d5 f5d7 f5e4 f5e5 f5e6 f5f1 f5f2 f5f3 f5f4 f5f6 f5f7 f5g4 f5g5 f5g6 f5h3 f5h7\nb7 white rook: b7a7 b7b1 b7b2 b7b3 b7b4 b7b5 b7b6 b7b8\nc7 white knight: c7a6 c7a8 c7b5 c7d5 c7e6 c7e8\nAll legal moves: a2a3 a2a4 b7a7 b7b1 b7b2 b7b3 b7b4 b7b5 b7b6 b7b8 c2c3 c2c4 c7a6 c7a8 c7b5 c7d5 c7e6 c7e8 d2a5 d2b4 d2c1 d2c3 d2e1 d3d4 e3e4 f5c5 f5d5 f5d7 f5e4 f5e5 f5e6 f5f1 f5f2 f5f3 f5f4 f5f6 f5f7 f5g4 f5g5 f5g6 f5h3 f5h7 g1f1 g1f2 g1h1 g2c6 g2d5 g2e4 g2f1 g2f3 g2h1 g2h3 g3g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"g1": ["g1f1", "g1f2", "g1h1"], "a2": ["a2a3", "a2a4"], "c2": ["c2c3", "c2c4"], "d2": ["d2a5", "d2b4", "d2c1", "d2c3", "d2e1"], "g2": ["g2c6", "g2d5", "g2e4", "g2f1", "g2f3", "g2h1", "g2h3"], "h2": ["h2h3", "h2h4"], "d3": ["d3d4"], "e3": ["e3e4"], "g3": ["g3g4"], "f5": ["f5c5", "f5d5", "f5d7", "f5e4", "f5e5", "f5e6", "f5f1", "f5f2", "f5f3", "f5f4", "f5f6", "f5f7", "f5g4", "f5g5", "f5g6", "f5h3", "f5h7"], "b7": ["b7a7", "b7b1", "b7b2", "b7b3", "b7b4", "b7b5", "b7b6", "b7b8"], "c7": ["c7a6", "c7a8", "c7b5", "c7d5", "c7e6", "c7e8"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b7a7 b7b1 b7b2 b7b3 b7b4 b7b5 b7b6 b7b8 c2c3 c2c4 c7a6 c7a8 c7b5 c7d5 c7e6 c7e8 d2a5 d2b4 d2c1 d2c3 d2e1 d3d4 e3e4 f5c5 f5d5 f5d7 f5e4 f5e5 f5e6 f5f1 f5f2 f5f3 f5f4 f5f6 f5f7 f5g4 f5g5 f5g6 f5h3 f5h7 g1f1 g1f2 g1h1 g2c6 g2d5 g2e4 g2f1 g2f3 g2h1 g2h3 g3g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"g1": ["g1f1", "g1f2", "g1h1"], "a2": ["a2a3", "a2a4"], "c2": ["c2c3", "c2c4"], "d2": ["d2a5", "d2b4", "d2c1", "d2c3", "d2e1"], "g2": ["g2c6", "g2d5", "g2e4", "g2f1", "g2f3", "g2h1", "g2h3"], "h2": ["h2h3", "h2h4"], "d3": ["d3d4"], "e3": ["e3e4"], "g3": ["g3g4"], "f5": ["f5c5", "f5d5", "f5d7", "f5e4", "f5e5", "f5e6", "f5f1", "f5f2", "f5f3", "f5f4", "f5f6", "f5f7", "f5g4", "f5g5", "f5g6", "f5h3", "f5h7"], "b7": ["b7a7", "b7b1", "b7b2", "b7b3", "b7b4", "b7b5", "b7b6", "b7b8"], "c7": ["c7a6", "c7a8", "c7b5", "c7d5", "c7e6", "c7e8"]}, "legal_moves": "a2a3 a2a4 b7a7 b7b1 b7b2 b7b3 b7b4 b7b5 b7b6 b7b8 c2c3 c2c4 c7a6 c7a8 c7b5 c7d5 c7e6 c7e8 d2a5 d2b4 d2c1 d2c3 d2e1 d3d4 e3e4 f5c5 f5d5 f5d7 f5e4 f5e5 f5e6 f5f1 f5f2 f5f3 f5f4 f5f6 f5f7 f5g4 f5g5 f5g6 f5h3 f5h7 g1f1 g1f2 g1h1 g2c6 g2d5 g2e4 g2f1 g2f3 g2h1 g2h3 g3g4 h2h3 h2h4"}}
{"example_id": "rules_00531", "split": "rules", "task_type": "ray_walk", "fen": "3r1rk1/p3bpp1/2p1q2p/2n5/4P3/2N2RB1/PPP1Q1PP/5RK1 w - - 7 21", "prompt": "FEN: 3r1rk1/p3bpp1/2p1q2p/2n5/4P3/2N2RB1/PPP1Q1PP/5RK1 w - - 7 21\nWalk each ray for the slider on f1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: f1 white rook.\nRay N: f2 empty; f3 white rook: own piece (stop, excluded).\nRay E: g1 white king: own piece (stop, excluded).\nRay S: edge.\nRay W: e1 empty; d1 empty; c1 empty; b1 empty; a1 empty; edge.\nMoves from rays: f1a1 f1b1 f1c1 f1d1 f1e1 f1f2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "f1", "diagnostic": true, "hard_gate": false, "source_square": "f1"}}
{"example_id": "rules_00532", "split": "rules", "task_type": "legal_moves", "fen": "rn1qkb1r/ppp1pppp/7n/8/2P1P3/8/PP1Pb1PP/RNBQK1NR w KQkq - 0 6", "prompt": "FEN: rn1qkb1r/ppp1pppp/7n/8/2P1P3/8/PP1Pb1PP/RNBQK1NR w KQkq - 0 6\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c4c5 d1a4 d1b3 d1c2 d1e2 d2d3 d2d4 e1e2 e1f2 e4e5 g1e2 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00533", "split": "rules", "task_type": "legal_moves", "fen": "rnbqkb1r/pppp2p1/5n1p/5p2/2PPp2P/2N4N/PP2PPP1/R1BQKB1R b KQkq -", "prompt": "FEN: rnbqkb1r/pppp2p1/5n1p/5p2/2PPp2P/2N4N/PP2PPP1/R1BQKB1R b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 c7c5 c7c6 d7d5 d7d6 d8e7 e4e3 e8e7 e8f7 f5f4 f6d5 f6g4 f6g8 f6h5 f6h7 f8a3 f8b4 f8c5 f8d6 f8e7 g7g5 g7g6 h6h5 h8g8 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00534", "split": "rules", "task_type": "side_piece_inventory", "fen": "6k1/2r2pp1/5q1p/1p6/2N5/1P2Q3/4bPPR/2q3K1 w - -", "prompt": "FEN: 6k1/2r2pp1/5q1p/1p6/2N5/1P2Q3/4bPPR/2q3K1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: g1 white king; f2 white pawn; g2 white pawn; h2 white rook; b3 white pawn; e3 white queen; c4 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "g1", "piece": "white king"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white rook"}, {"square": "b3", "piece": "white pawn"}, {"square": "e3", "piece": "white queen"}, {"square": "c4", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "g1", "piece": "white king"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white rook"}, {"square": "b3", "piece": "white pawn"}, {"square": "e3", "piece": "white queen"}, {"square": "c4", "piece": "white knight"}]}}
{"example_id": "rules_00535", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/2p2k1p/5pp1/1p1P1P2/7P/p1P5/7r/1K6 w - - 0 44", "prompt": "FEN: 8/2p2k1p/5pp1/1p1P1P2/7P/p1P5/7r/1K6 w - - 0 44\nWhat legal moves does the piece on h4 have?", "gold_answer": "h4h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h4", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "h4", "piece": "pawn"}}
{"example_id": "rules_00536", "split": "rules", "task_type": "check_detection", "fen": "1r2k1nr/p1pp1p2/1p2p1p1/n3P3/3P2P1/2b5/P3N2q/RNBQKR2 w k - 0 16", "prompt": "FEN: 1r2k1nr/p1pp1p2/1p2p1p1/n3P3/3P2P1/2b5/P3N2q/RNBQKR2 w k - 0 16\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00537", "split": "rules", "task_type": "captures", "fen": "8/k7/3Q4/8/8/8/8/7K w - -", "prompt": "FEN: 8/k7/3Q4/8/8/8/8/7K w - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00538", "split": "rules", "task_type": "special_rules", "fen": "3R4/2p1k1pp/p4p2/1p6/n3P3/P1P1N2P/1r3PPK/8 w - -", "prompt": "Given FEN: 3R4/2p1k1pp/p4p2/1p6/n3P3/P1P1N2P/1r3PPK/8 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00539", "split": "rules", "task_type": "legality_check", "fen": "3b4/p2P4/P1K5/8/8/8/6k1/8 w - - 4 66", "prompt": "FEN: 3b4/p2P4/P1K5/8/8/8/6k1/8 w - - 4 66\nIs the move c6b5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c6b5", "_legality_check_reason_label": "legal", "move": "c6b5", "legality_reason_label": "legal"}}
{"example_id": "rules_00540", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rn1q1rk1/pp1b2pp/2p1p3/3p1p2/3P1P1b/1PPBP2P/PBQN4/R1K3Nn w - - 0 16", "prompt": "FEN: rn1q1rk1/pp1b2pp/2p1p3/3p1p2/3P1P1b/1PPBP2P/PBQN4/R1K3Nn w - - 0 16\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00541", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/2B5/8/8/6k1/3B4/3K4/8 w - -", "prompt": "FEN: 8/2B5/8/8/6k1/3B4/3K4/8 w - -\nFor the piece on d2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d2: d2c1 d2c2 d2c3 d2d1 d2e1 d2e2 d2e3.\nLegal: d2c1 d2c2 d2c3 d2d1 d2e1 d2e2 d2e3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "d2", "diagnostic": true, "hard_gate": false, "source_square": "d2"}}
{"example_id": "rules_00542", "split": "rules", "task_type": "king_safety_filter", "fen": "r2q1rk1/1b2bppp/p3pn2/8/1p1N4/2BBP3/PPQ2PPP/R4RK1 w - -", "prompt": "FEN: r2q1rk1/1b2bppp/p3pn2/8/1p1N4/2BBP3/PPQ2PPP/R4RK1 w - -\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00543", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/4k3/8/1N1K4/8/8/8/1B6 b - -", "prompt": "FEN: 8/4k3/8/1N1K4/8/8/8/1B6 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e7 black king.\nMoves by piece:\ne7 black king: e7d7 e7d8 e7e8 e7f6 e7f7 e7f8\nAll legal moves: e7d7 e7d8 e7e8 e7f6 e7f7 e7f8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e7": ["e7d7", "e7d8", "e7e8", "e7f6", "e7f7", "e7f8"]}, "_legal_moves_by_piece_moves": "e7d7 e7d8 e7e8 e7f6 e7f7 e7f8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e7": ["e7d7", "e7d8", "e7e8", "e7f6", "e7f7", "e7f8"]}, "legal_moves": "e7d7 e7d8 e7e8 e7f6 e7f7 e7f8"}}
{"example_id": "rules_00544", "split": "rules", "task_type": "ray_walk", "fen": "r2r2k1/p2b2pp/4p2q/1p1pPp2/5P2/Q1P1P3/P4PBP/3R2RK w - -", "prompt": "FEN: r2r2k1/p2b2pp/4p2q/1p1pPp2/5P2/Q1P1P3/P4PBP/3R2RK w - -\nWalk each ray for the slider on d1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d1 white rook.\nRay N: d2 empty; d3 empty; d4 empty; d5 black pawn: capture (stop, included).\nRay E: e1 empty; f1 empty; g1 white rook: own piece (stop, excluded).\nRay S: edge.\nRay W: c1 empty; b1 empty; a1 empty; edge.\nMoves from rays: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1e1 d1f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_00545", "split": "rules", "task_type": "legal_moves", "fen": "5rk1/1p4pp/2pp4/5p2/3p4/2BP1Q1P/5PPK/2q5 b - - 1 23", "prompt": "FEN: 5rk1/1p4pp/2pp4/5p2/3p4/2BP1Q1P/5PPK/2q5 b - - 1 23\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b7b5 b7b6 c1a1 c1a3 c1b1 c1b2 c1c2 c1c3 c1d1 c1d2 c1e1 c1e3 c1f1 c1f4 c1g1 c1g5 c1h1 c1h6 c6c5 d4c3 d6d5 f5f4 f8a8 f8b8 f8c8 f8d8 f8e8 f8f6 f8f7 g7g5 g7g6 g8f7 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00546", "split": "rules", "task_type": "legal_moves", "fen": "1r4k1/5pp1/4p2p/3pP3/1p1P4/r5P1/2K1NP1P/1R6 w - - 0 35", "prompt": "FEN: 1r4k1/5pp1/4p2p/3pP3/1p1P4/r5P1/2K1NP1P/1R6 w - - 0 35\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b1a1 b1b2 b1b3 b1b4 b1c1 b1d1 b1e1 b1f1 b1g1 b1h1 c2b2 c2c1 c2d1 c2d2 e2c1 e2c3 e2f4 e2g1 f2f3 f2f4 g3g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00547", "split": "rules", "task_type": "side_piece_inventory", "fen": "1rbqk2r/1p1p1p1p/p3pb2/4np2/2PN4/1PN1P2P/P3BPP1/R2QK2R b KQk - 0 13", "prompt": "FEN: 1rbqk2r/1p1p1p1p/p3pb2/4np2/2PN4/1PN1P2P/P3BPP1/R2QK2R b KQk - 0 13\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: e5 black knight; f5 black pawn; a6 black pawn; e6 black pawn; f6 black bishop; b7 black pawn; d7 black pawn; f7 black pawn; h7 black pawn; b8 black rook; c8 black bishop; d8 black queen; e8 black king; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "e5", "piece": "black knight"}, {"square": "f5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black bishop"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "b8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "e5", "piece": "black knight"}, {"square": "f5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black bishop"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "b8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00548", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bq1rk1/pp2bpp1/2np1n1p/2p1p3/2P1P3/2NP1NBP/PP3PP1/R2QKB1R b KQ - 2 9", "prompt": "FEN: r1bq1rk1/pp2bpp1/2np1n1p/2p1p3/2P1P3/2NP1NBP/PP3PP1/R2QKB1R b KQ - 2 9\nWhat legal moves does the piece on f6 have?", "gold_answer": "f6d5 f6d7 f6e4 f6e8 f6g4 f6h5 f6h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f6", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "f6", "piece": "knight"}}
{"example_id": "rules_00549", "split": "rules", "task_type": "check_detection", "fen": "rn1q1rk1/ppp1bppp/4bn2/3p2B1/3P4/2N2N2/PPP1QPPP/2KR1B1R b - - 9 8", "prompt": "FEN: rn1q1rk1/ppp1bppp/4bn2/3p2B1/3P4/2N2N2/PPP1QPPP/2KR1B1R b - - 9 8\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00550", "split": "rules", "task_type": "captures", "fen": "6B1/8/2k5/5p2/pK3P2/P4bP1/1P6/8 w - -", "prompt": "FEN: 6B1/8/2k5/5p2/pK3P2/P4bP1/1P6/8 w - -\nList all capture moves available.", "gold_answer": "b4a4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00551", "split": "rules", "task_type": "special_rules", "fen": "6k1/6p1/6p1/p7/7Q/2q2R1P/P5P1/6K1 b - - 3 39", "prompt": "Given FEN: 6k1/6p1/6p1/p7/7Q/2q2R1P/P5P1/6K1 b - - 3 39\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00552", "split": "rules", "task_type": "legality_check", "fen": "r1bqkbnr/pp1n1ppp/2p5/3pN3/3PP3/2N5/PPP2PPP/R1BQKB1R b KQkq - 0 6", "prompt": "FEN: r1bqkbnr/pp1n1ppp/2p5/3pN3/3PP3/2N5/PPP2PPP/R1BQKB1R b KQkq - 0 6\nIs the move h4a3 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "h4a3", "_legality_check_reason_label": "empty_source", "move": "h4a3", "legality_reason_label": "empty_source"}}
{"example_id": "rules_00553", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnb1k1r1/pp2np1Q/4p3/3pq3/7P/P1p5/2P1NPP1/1RB1KB1R b Kq -", "prompt": "FEN: rnb1k1r1/pp2np1Q/4p3/3pq3/7P/P1p5/2P1NPP1/1RB1KB1R b Kq -\nList pseudo-legal moves from d5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d5: d5d4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_00554", "split": "rules", "task_type": "piece_legal_filter", "fen": "1k2K3/1P6/2q1P3/3p4/3P4/8/8/8 w - - 0 67", "prompt": "FEN: 1k2K3/1P6/2q1P3/3p4/3P4/8/8/8 w - - 0 67\nFor the piece on e6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e6: e6e7.\nLegal: none.\nRejected: e6e7 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "e6", "diagnostic": true, "hard_gate": false, "source_square": "e6"}}
{"example_id": "rules_00555", "split": "rules", "task_type": "king_safety_filter", "fen": "r4rk1/pp2Rpbp/6p1/8/Q4B2/3q3P/P4PP1/4R1K1 b - -", "prompt": "FEN: r4rk1/pp2Rpbp/6p1/8/Q4B2/3q3P/P4PP1/4R1K1 b - -\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00556", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/8/8/3k4/6R1/4K2R/8/8 w - -", "prompt": "FEN: 8/8/8/3k4/6R1/4K2R/8/8 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: e3 white king; h3 white rook; g4 white rook.\nMoves by piece:\ne3 white king: e3d2 e3d3 e3e2 e3f2 e3f3 e3f4\nh3 white rook: h3f3 h3g3 h3h1 h3h2 h3h4 h3h5 h3h6 h3h7 h3h8\ng4 white rook: g4a4 g4b4 g4c4 g4d4 g4e4 g4f4 g4g1 g4g2 g4g3 g4g5 g4g6 g4g7 g4g8 g4h4\nAll legal moves: e3d2 e3d3 e3e2 e3f2 e3f3 e3f4 g4a4 g4b4 g4c4 g4d4 g4e4 g4f4 g4g1 g4g2 g4g3 g4g5 g4g6 g4g7 g4g8 g4h4 h3f3 h3g3 h3h1 h3h2 h3h4 h3h5 h3h6 h3h7 h3h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e3": ["e3d2", "e3d3", "e3e2", "e3f2", "e3f3", "e3f4"], "h3": ["h3f3", "h3g3", "h3h1", "h3h2", "h3h4", "h3h5", "h3h6", "h3h7", "h3h8"], "g4": ["g4a4", "g4b4", "g4c4", "g4d4", "g4e4", "g4f4", "g4g1", "g4g2", "g4g3", "g4g5", "g4g6", "g4g7", "g4g8", "g4h4"]}, "_legal_moves_by_piece_moves": "e3d2 e3d3 e3e2 e3f2 e3f3 e3f4 g4a4 g4b4 g4c4 g4d4 g4e4 g4f4 g4g1 g4g2 g4g3 g4g5 g4g6 g4g7 g4g8 g4h4 h3f3 h3g3 h3h1 h3h2 h3h4 h3h5 h3h6 h3h7 h3h8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e3": ["e3d2", "e3d3", "e3e2", "e3f2", "e3f3", "e3f4"], "h3": ["h3f3", "h3g3", "h3h1", "h3h2", "h3h4", "h3h5", "h3h6", "h3h7", "h3h8"], "g4": ["g4a4", "g4b4", "g4c4", "g4d4", "g4e4", "g4f4", "g4g1", "g4g2", "g4g3", "g4g5", "g4g6", "g4g7", "g4g8", "g4h4"]}, "legal_moves": "e3d2 e3d3 e3e2 e3f2 e3f3 e3f4 g4a4 g4b4 g4c4 g4d4 g4e4 g4f4 g4g1 g4g2 g4g3 g4g5 g4g6 g4g7 g4g8 g4h4 h3f3 h3g3 h3h1 h3h2 h3h4 h3h5 h3h6 h3h7 h3h8"}}
{"example_id": "rules_00557", "split": "rules", "task_type": "ray_walk", "fen": "2r5/4k1pp/b2bpn2/pBp5/8/2N5/PPP2PPP/R1B1R1K1 b - - 3 18", "prompt": "FEN: 2r5/4k1pp/b2bpn2/pBp5/8/2N5/PPP2PPP/R1B1R1K1 b - - 3 18\nWalk each ray for the slider on a6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a6 black bishop.\nRay NE: b7 empty; c8 black rook: own piece (stop, excluded).\nRay SE: b5 white bishop: capture (stop, included).\nRay SW: edge.\nRay NW: edge.\nMoves from rays: a6b5 a6b7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a6", "diagnostic": true, "hard_gate": false, "source_square": "a6"}}
{"example_id": "rules_00558", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/7p/p5pk/1p6/1r3P2/6PK/P4P2/8 w - - 0 39", "prompt": "FEN: 8/7p/p5pk/1p6/1r3P2/6PK/P4P2/8 w - - 0 39\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a2 white pawn; f2 white pawn; g3 white pawn; h3 white king; f4 white pawn.\nFilter by piece:\na2 white pawn: pseudo-legal a2a3 a2a4 | rejected none | legal a2a3 a2a4\nf2 white pawn: pseudo-legal f2f3 | rejected none | legal f2f3\ng3 white pawn: pseudo-legal g3g4 | rejected none | legal g3g4\nh3 white king: pseudo-legal h3g2 h3g4 h3h2 h3h4 | rejected none | legal h3g2 h3g4 h3h2 h3h4\nf4 white pawn: pseudo-legal f4f5 | rejected none | legal f4f5\nAll legal moves: a2a3 a2a4 f2f3 f4f5 g3g4 h3g2 h3g4 h3h2 h3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00559", "split": "rules", "task_type": "legal_moves", "fen": "2kr1b1r/ppp1q1pp/3p1n2/4p3/4P3/PnNP4/1PP2PPP/R1BQ1RK1 b - - 0 11", "prompt": "FEN: 2kr1b1r/ppp1q1pp/3p1n2/4p3/4P3/PnNP4/1PP2PPP/R1BQ1RK1 b - - 0 11\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b3a1 b3a5 b3c1 b3c5 b3d2 b3d4 b7b5 b7b6 c7c5 c7c6 c8b8 c8d7 d6d5 d8d7 d8e8 e7d7 e7e6 e7e8 e7f7 f6d5 f6d7 f6e4 f6e8 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00560", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1b2rk1/1pb1nppp/p2p4/Pq2p3/3PP3/1P2NN2/3B1PPP/R2QR1K1 b - -", "prompt": "FEN: r1b2rk1/1pb1nppp/p2p4/Pq2p3/3PP3/1P2NN2/3B1PPP/R2QR1K1 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: b5 black queen; e5 black pawn; a6 black pawn; d6 black pawn; b7 black pawn; c7 black bishop; e7 black knight; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "b5", "piece": "black queen"}, {"square": "e5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black bishop"}, {"square": "e7", "piece": "black knight"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "b5", "piece": "black queen"}, {"square": "e5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black bishop"}, {"square": "e7", "piece": "black knight"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_00561", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bqr1k1/1p1nbpp1/p4n1p/2pp4/1P1P3B/P1NBPN2/5PPP/R2Q1RK1 b - - 0 12", "prompt": "FEN: r1bqr1k1/1p1nbpp1/p4n1p/2pp4/1P1P3B/P1NBPN2/5PPP/R2Q1RK1 b - - 0 12\nWhat legal moves does the piece on f6 have?", "gold_answer": "f6e4 f6g4 f6h5 f6h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f6", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "f6", "piece": "knight"}}
{"example_id": "rules_00562", "split": "rules", "task_type": "check_detection", "fen": "2rq1rk1/5ppp/Q4b2/1p3P2/3p4/1B6/P1P2PPP/1R2R1K1 b - -", "prompt": "FEN: 2rq1rk1/5ppp/Q4b2/1p3P2/3p4/1B6/P1P2PPP/1R2R1K1 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00563", "split": "rules", "task_type": "captures", "fen": "5n2/1b3k1p/p2p2p1/3Pp1B1/B1P3P1/6PP/8/6K1 w - -", "prompt": "FEN: 5n2/1b3k1p/p2p2p1/3Pp1B1/B1P3P1/6PP/8/6K1 w - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00564", "split": "rules", "task_type": "special_rules", "fen": "8/7p/4q3/6k1/8/6K1/8/8 b - - 8 62", "prompt": "Given FEN: 8/7p/4q3/6k1/8/6K1/8/8 b - - 8 62\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00565", "split": "rules", "task_type": "legality_check", "fen": "rnb2rk1/1p2bppp/2pp1n2/p7/P3PP2/2NBBN2/1qP1Q1PP/R3K2R w KQ -", "prompt": "FEN: rnb2rk1/1p2bppp/2pp1n2/p7/P3PP2/2NBBN2/1qP1Q1PP/R3K2R w KQ -\nIs the move c8b6 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "c8b6", "_legality_check_reason_label": "wrong_side_piece", "move": "c8b6", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_00566", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2qkb1r/ppp1pp1p/2n1b1p1/3n2B1/3P4/P3PN2/1P3PPP/RN1QKB1R b KQkq - 0 7", "prompt": "FEN: r2qkb1r/ppp1pp1p/2n1b1p1/3n2B1/3P4/P3PN2/1P3PPP/RN1QKB1R b KQkq - 0 7\nList pseudo-legal moves from d5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d5: d5b4 d5b6 d5c3 d5e3 d5f4 d5f6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_00567", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1bqk2r/pppp2pp/2n5/1Bb1pp2/8/3P1N2/PPP2KPP/RNBQR3 w kq - 1 8", "prompt": "FEN: r1bqk2r/pppp2pp/2n5/1Bb1pp2/8/3P1N2/PPP2KPP/RNBQR3 w kq - 1 8\nFor the piece on b1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b1: b1a3 b1c3 b1d2.\nLegal: none.\nRejected: b1a3 does_not_resolve_check; b1c3 does_not_resolve_check; b1d2 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_00568", "split": "rules", "task_type": "king_safety_filter", "fen": "8/8/2K5/8/8/5k2/8/4R3 w - -", "prompt": "FEN: 8/8/2K5/8/8/5k2/8/4R3 w - -\nFor move c6b5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c6b5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "c6b5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "c6b5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00569", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnq1k2r/p5pp/2p1pnb1/5p2/B1Q1pP2/B1P3N1/P1P3PP/R3K2R b KQkq - 3 15", "prompt": "FEN: rnq1k2r/p5pp/2p1pnb1/5p2/B1Q1pP2/B1P3N1/P1P3PP/R3K2R b KQkq - 3 15\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e4 black pawn; f5 black pawn; c6 black pawn; e6 black pawn; f6 black knight; g6 black bishop; a7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; c8 black queen; e8 black king; h8 black rook.\nMoves by piece:\ne4 black pawn: e4e3\nf5 black pawn: no legal moves\nc6 black pawn: no legal moves\ne6 black pawn: e6e5\nf6 black knight: f6d5 f6d7 f6g4 f6g8 f6h5\ng6 black bishop: g6f7 g6h5\na7 black pawn: a7a5 a7a6\ng7 black pawn: no legal moves\nh7 black pawn: h7h5 h7h6\na8 black rook: no legal moves\nb8 black knight: b8a6 b8d7\nc8 black queen: c8a6 c8b7 c8c7 c8d7 c8d8\ne8 black king: e8d7 e8d8 e8f7\nh8 black rook: h8f8 h8g8\nAll legal moves: a7a5 a7a6 b8a6 b8d7 c8a6 c8b7 c8c7 c8d7 c8d8 e4e3 e6e5 e8d7 e8d8 e8f7 f6d5 f6d7 f6g4 f6g8 f6h5 g6f7 g6h5 h7h5 h7h6 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e4": ["e4e3"], "f5": [], "c6": [], "e6": ["e6e5"], "f6": ["f6d5", "f6d7", "f6g4", "f6g8", "f6h5"], "g6": ["g6f7", "g6h5"], "a7": ["a7a5", "a7a6"], "g7": [], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8d7"], "c8": ["c8a6", "c8b7", "c8c7", "c8d7", "c8d8"], "e8": ["e8d7", "e8d8", "e8f7"], "h8": ["h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b8a6 b8d7 c8a6 c8b7 c8c7 c8d7 c8d8 e4e3 e6e5 e8d7 e8d8 e8f7 f6d5 f6d7 f6g4 f6g8 f6h5 g6f7 g6h5 h7h5 h7h6 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e4": ["e4e3"], "f5": [], "c6": [], "e6": ["e6e5"], "f6": ["f6d5", "f6d7", "f6g4", "f6g8", "f6h5"], "g6": ["g6f7", "g6h5"], "a7": ["a7a5", "a7a6"], "g7": [], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8d7"], "c8": ["c8a6", "c8b7", "c8c7", "c8d7", "c8d8"], "e8": ["e8d7", "e8d8", "e8f7"], "h8": ["h8f8", "h8g8"]}, "legal_moves": "a7a5 a7a6 b8a6 b8d7 c8a6 c8b7 c8c7 c8d7 c8d8 e4e3 e6e5 e8d7 e8d8 e8f7 f6d5 f6d7 f6g4 f6g8 f6h5 g6f7 g6h5 h7h5 h7h6 h8f8 h8g8"}}
{"example_id": "rules_00570", "split": "rules", "task_type": "ray_walk", "fen": "r3rbk1/1b3Npp/1q1p2n1/2pP4/5R2/1PN3Q1/4P1BP/5R1K w - -", "prompt": "FEN: r3rbk1/1b3Npp/1q1p2n1/2pP4/5R2/1PN3Q1/4P1BP/5R1K w - -\nWalk each ray for the slider on f1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: f1 white rook.\nRay N: f2 empty; f3 empty; f4 white rook: own piece (stop, excluded).\nRay E: g1 empty; h1 white king: own piece (stop, excluded).\nRay S: edge.\nRay W: e1 empty; d1 empty; c1 empty; b1 empty; a1 empty; edge.\nMoves from rays: f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f1g1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "f1", "diagnostic": true, "hard_gate": false, "source_square": "f1"}}
{"example_id": "rules_00571", "split": "rules", "task_type": "legal_moves", "fen": "r4rk1/pp3ppp/8/3b4/3N4/P3P3/1P3PPP/2R2RK1 w - - 2 21", "prompt": "FEN: r4rk1/pp3ppp/8/3b4/3N4/P3P3/1P3PPP/2R2RK1 w - - 2 21\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 b2b3 b2b4 c1a1 c1b1 c1c2 c1c3 c1c4 c1c5 c1c6 c1c7 c1c8 c1d1 c1e1 d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3 d4f5 e3e4 f1d1 f1e1 f2f3 f2f4 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00572", "split": "rules", "task_type": "legal_moves", "fen": "r1bq1rk1/pp2ppbp/2n2np1/8/2B5/P2P1Q2/1PP2PPP/RNB1K1NR w KQ - 1 8", "prompt": "FEN: r1bq1rk1/pp2ppbp/2n2np1/8/2B5/P2P1Q2/1PP2PPP/RNB1K1NR w KQ - 1 8\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a3a4 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c4a2 c4a6 c4b3 c4b5 c4d5 c4e6 c4f7 d3d4 e1d1 e1d2 e1e2 e1f1 f3c6 f3d1 f3d5 f3e2 f3e3 f3e4 f3f4 f3f5 f3f6 f3g3 f3g4 f3h3 f3h5 g1e2 g1h3 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00573", "split": "rules", "task_type": "side_piece_inventory", "fen": "3rn1k1/ppq1pp1p/2p3pQ/7r/3PN3/1P3P2/PB1R1PPP/5RK1 w - -", "prompt": "FEN: 3rn1k1/ppq1pp1p/2p3pQ/7r/3PN3/1P3P2/PB1R1PPP/5RK1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: f1 white rook; g1 white king; a2 white pawn; b2 white bishop; d2 white rook; f2 white pawn; g2 white pawn; h2 white pawn; b3 white pawn; f3 white pawn; d4 white pawn; e4 white knight; h6 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white bishop"}, {"square": "d2", "piece": "white rook"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "b3", "piece": "white pawn"}, {"square": "f3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "e4", "piece": "white knight"}, {"square": "h6", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white bishop"}, {"square": "d2", "piece": "white rook"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "b3", "piece": "white pawn"}, {"square": "f3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "e4", "piece": "white knight"}, {"square": "h6", "piece": "white queen"}]}}
{"example_id": "rules_00574", "split": "rules", "task_type": "piece_legal_moves", "fen": "1r1qkb1r/3bpppp/5n2/p7/1pPP4/4PQ2/3B1PPP/RN2KBNR b KQk - 3 14", "prompt": "FEN: 1r1qkb1r/3bpppp/5n2/p7/1pPP4/4PQ2/3B1PPP/RN2KBNR b KQk - 3 14\nWhat legal moves does the piece on d8 have?", "gold_answer": "d8b6 d8c7 d8c8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "d8", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "d8", "piece": "queen"}}
{"example_id": "rules_00575", "split": "rules", "task_type": "check_detection", "fen": "5r2/6k1/4R3/2p2p2/2B5/1P4K1/5PPP/8 w - - 6 36", "prompt": "FEN: 5r2/6k1/4R3/2p2p2/2B5/1P4K1/5PPP/8 w - - 6 36\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00576", "split": "rules", "task_type": "captures", "fen": "rnb1k1nr/ppp2ppp/8/8/1b6/4qP2/PP1QN1PP/R3KB1R b KQkq - 3 11", "prompt": "FEN: rnb1k1nr/ppp2ppp/8/8/1b6/4qP2/PP1QN1PP/R3KB1R b KQkq - 3 11\nList all capture moves available.", "gold_answer": "b4d2 e3d2 e3e2 e3f3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00577", "split": "rules", "task_type": "special_rules", "fen": "r1bqk2r/pp3pbp/4pnp1/3p4/3Q4/NP3P1N/P1P1P1PP/2KR1B1R w kq - 0 10", "prompt": "Given FEN: r1bqk2r/pp3pbp/4pnp1/3p4/3Q4/NP3P1N/P1P1P1PP/2KR1B1R w kq - 0 10\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00578", "split": "rules", "task_type": "legality_check", "fen": "8/6k1/3p1p2/2p1pP2/2P1P1PR/3P2r1/2K5/8 b - - 16 64", "prompt": "FEN: 8/6k1/3p1p2/2p1pP2/2P1P1PR/3P2r1/2K5/8 b - - 16 64\nIs the move g7g8 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g7g8", "_legality_check_reason_label": "legal", "move": "g7g8", "legality_reason_label": "legal"}}
{"example_id": "rules_00579", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5n2/p3b1k1/1p1p4/3PpRp1/2P5/1P4P1/PB6/6K1 b - - 1 34", "prompt": "FEN: 5n2/p3b1k1/1p1p4/3PpRp1/2P5/1P4P1/PB6/6K1 b - - 1 34\nList pseudo-legal moves from e5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e5: e5e4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e5", "diagnostic": true, "hard_gate": false, "source_square": "e5"}}
{"example_id": "rules_00580", "split": "rules", "task_type": "piece_legal_filter", "fen": "r3kbnr/pp3pp1/q1p4p/4p3/8/2NP1B2/PPPB1PPP/1K1RR3 b kq - 1 16", "prompt": "FEN: r3kbnr/pp3pp1/q1p4p/4p3/8/2NP1B2/PPPB1PPP/1K1RR3 b kq - 1 16\nFor the piece on e5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e5: e5e4.\nLegal: e5e4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "e5", "diagnostic": true, "hard_gate": false, "source_square": "e5"}}
{"example_id": "rules_00581", "split": "rules", "task_type": "king_safety_filter", "fen": "4r3/1p3p1k/p5pp/8/1P3P1P/P3Q3/R5PK/8 b - - 0 38", "prompt": "FEN: 4r3/1p3p1k/p5pp/8/1P3P1P/P3Q3/R5PK/8 b - - 0 38\nFor move a6a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a6a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a6a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a6a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00582", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2K5/4N3/1k6/1B6/8/8/8/8 w - -", "prompt": "FEN: 2K5/4N3/1k6/1B6/8/8/8/8 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: b5 white bishop; e7 white knight; c8 white king.\nMoves by piece:\nb5 white bishop: b5a4 b5a6 b5c4 b5c6 b5d3 b5d7 b5e2 b5e8 b5f1\ne7 white knight: e7c6 e7d5 e7f5 e7g6 e7g8\nc8 white king: c8b8 c8d7 c8d8\nAll legal moves: b5a4 b5a6 b5c4 b5c6 b5d3 b5d7 b5e2 b5e8 b5f1 c8b8 c8d7 c8d8 e7c6 e7d5 e7f5 e7g6 e7g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b5": ["b5a4", "b5a6", "b5c4", "b5c6", "b5d3", "b5d7", "b5e2", "b5e8", "b5f1"], "e7": ["e7c6", "e7d5", "e7f5", "e7g6", "e7g8"], "c8": ["c8b8", "c8d7", "c8d8"]}, "_legal_moves_by_piece_moves": "b5a4 b5a6 b5c4 b5c6 b5d3 b5d7 b5e2 b5e8 b5f1 c8b8 c8d7 c8d8 e7c6 e7d5 e7f5 e7g6 e7g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b5": ["b5a4", "b5a6", "b5c4", "b5c6", "b5d3", "b5d7", "b5e2", "b5e8", "b5f1"], "e7": ["e7c6", "e7d5", "e7f5", "e7g6", "e7g8"], "c8": ["c8b8", "c8d7", "c8d8"]}, "legal_moves": "b5a4 b5a6 b5c4 b5c6 b5d3 b5d7 b5e2 b5e8 b5f1 c8b8 c8d7 c8d8 e7c6 e7d5 e7f5 e7g6 e7g8"}}
{"example_id": "rules_00583", "split": "rules", "task_type": "legal_moves", "fen": "8/4pk1p/3p2p1/5p2/5P1P/p7/Kb6/8 w - - 4 44", "prompt": "FEN: 8/4pk1p/3p2p1/5p2/5P1P/p7/Kb6/8 w - - 4 44\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2b1 a2b3 h4h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": ""}}
{"example_id": "rules_00584", "split": "rules", "task_type": "legal_moves", "fen": "rn1qk2r/pbpp1pp1/1p2pn1p/8/2PP4/2P2NP1/P3PPBP/R1BQK2R w KQkq -", "prompt": "FEN: rn1qk2r/pbpp1pp1/1p2pn1p/8/2PP4/2P2NP1/P3PPBP/R1BQK2R w KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a2a3 a2a4 c1a3 c1b2 c1d2 c1e3 c1f4 c1g5 c1h6 c4c5 d1a4 d1b3 d1c2 d1d2 d1d3 d4d5 e1d2 e1f1 e1g1 e2e3 e2e4 f3d2 f3e5 f3g1 f3g5 f3h4 g2f1 g2h3 g3g4 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00585", "split": "rules", "task_type": "legal_moves", "fen": "5Rb1/p3B3/n6k/6R1/8/PP4p1/2P2PPP/6K1 w - - 2 36", "prompt": "FEN: 5Rb1/p3B3/n6k/6R1/8/PP4p1/2P2PPP/6K1 w - - 2 36\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 b3b4 c2c3 c2c4 e7b4 e7c5 e7d6 e7d8 e7f6 f2f3 f2f4 f2g3 f8a8 f8b8 f8c8 f8d8 f8e8 f8f3 f8f4 f8f5 f8f6 f8f7 f8g8 g1f1 g1h1 g5a5 g5b5 g5c5 g5d5 g5e5 g5f5 g5g3 g5g4 g5g6 g5g7 g5g8 g5h5 h2g3 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00586", "split": "rules", "task_type": "side_piece_inventory", "fen": "rnb2rk1/1p4pp/p3p3/1B1pPp2/1b1N4/2N3Q1/PqPK1PPP/R6R w - - 0 16", "prompt": "FEN: rnb2rk1/1p4pp/p3p3/1B1pPp2/1b1N4/2N3Q1/PqPK1PPP/R6R w - - 0 16\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; h1 white rook; a2 white pawn; c2 white pawn; d2 white king; f2 white pawn; g2 white pawn; h2 white pawn; c3 white knight; g3 white queen; d4 white knight; b5 white bishop; e5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white king"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "g3", "piece": "white queen"}, {"square": "d4", "piece": "white knight"}, {"square": "b5", "piece": "white bishop"}, {"square": "e5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white king"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "g3", "piece": "white queen"}, {"square": "d4", "piece": "white knight"}, {"square": "b5", "piece": "white bishop"}, {"square": "e5", "piece": "white pawn"}]}}
{"example_id": "rules_00587", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnbq1rk1/1p3pp1/p4n1p/P2p3P/1P2p3/2P1PPb1/4B1P1/RNBQK1NR w KQ - 2 13", "prompt": "FEN: rnbq1rk1/1p3pp1/p4n1p/P2p3P/1P2p3/2P1PPb1/4B1P1/RNBQK1NR w KQ - 2 13\nWhat legal moves does the piece on b1 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b1", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "b1", "piece": "knight"}}
{"example_id": "rules_00588", "split": "rules", "task_type": "check_detection", "fen": "r4rk1/pp1b1p1p/2p1p1p1/3p4/2qPn3/2P2Q2/2B1RPPP/5K2 w - - 3 22", "prompt": "FEN: r4rk1/pp1b1p1p/2p1p1p1/3p4/2qPn3/2P2Q2/2B1RPPP/5K2 w - - 3 22\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00589", "split": "rules", "task_type": "captures", "fen": "r7/6p1/3p2k1/2pP2p1/p1P5/6p1/1P3K2/6R1 w - - 0 46", "prompt": "FEN: r7/6p1/3p2k1/2pP2p1/p1P5/6p1/1P3K2/6R1 w - - 0 46\nList all capture moves available.", "gold_answer": "f2g3 g1g3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00590", "split": "rules", "task_type": "special_rules", "fen": "1nbq1rk1/1pp1p1b1/5p1n/2pP2p1/4P2p/B2B1N1P/4NPP1/3QK2R w K - 0 15", "prompt": "Given FEN: 1nbq1rk1/1pp1p1b1/5p1n/2pP2p1/4P2p/B2B1N1P/4NPP1/3QK2R w K - 0 15\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00591", "split": "rules", "task_type": "legality_check", "fen": "8/8/5k2/8/2BN1K2/8/8/8 w - -", "prompt": "FEN: 8/8/5k2/8/2BN1K2/8/8/8 w - -\nIs the move c4b3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "c4b3", "_legality_check_reason_label": "legal", "move": "c4b3", "legality_reason_label": "legal"}}
{"example_id": "rules_00592", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2kr1bnr/p7/1p1p1p1p/P1pQ2p1/4P3/2B2N1P/1PP2PP1/R3R1K1 b - - 0 17", "prompt": "FEN: 2kr1bnr/p7/1p1p1p1p/P1pQ2p1/4P3/2B2N1P/1PP2PP1/R3R1K1 b - - 0 17\nList pseudo-legal moves from c5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c5: c5c4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_00593", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1bq1rk1/1p2ppbp/3p1np1/p7/2P1P3/1PN1B3/P2QBPPP/R3K2R b KQ -", "prompt": "FEN: r1bq1rk1/1p2ppbp/3p1np1/p7/2P1P3/1PN1B3/P2QBPPP/R3K2R b KQ -\nFor the piece on a5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a5: a5a4.\nLegal: a5a4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_00594", "split": "rules", "task_type": "king_safety_filter", "fen": "r5k1/1pp4p/pb1pp2p/4p3/PP2P3/2PP1N2/5rPP/R4R1K b - - 1 17", "prompt": "FEN: r5k1/1pp4p/pb1pp2p/4p3/PP2P3/2PP1N2/5rPP/R4R1K b - - 1 17\nFor move a6a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a6a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a6a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a6a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00595", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rn1q1rk1/pbpp1pbp/1p2p1p1/4n3/2P5/2NP1NPP/PP3PB1/R1BQK2R w KQ - 0 10", "prompt": "FEN: rn1q1rk1/pbpp1pbp/1p2p1p1/4n3/2P5/2NP1NPP/PP3PB1/R1BQK2R w KQ - 0 10\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; e1 white king; h1 white rook; a2 white pawn; b2 white pawn; f2 white pawn; g2 white bishop; c3 white knight; d3 white pawn; f3 white knight; g3 white pawn; h3 white pawn; c4 white pawn.\nMoves by piece:\na1 white rook: a1b1\nc1 white bishop: c1d2 c1e3 c1f4 c1g5 c1h6\nd1 white queen: d1a4 d1b3 d1c2 d1d2 d1e2\ne1 white king: e1d2 e1e2 e1f1 e1g1\nh1 white rook: h1f1 h1g1 h1h2\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nf2 white pawn: no legal moves\ng2 white bishop: g2f1\nc3 white knight: c3a4 c3b1 c3b5 c3d5 c3e2 c3e4\nd3 white pawn: d3d4\nf3 white knight: f3d2 f3d4 f3e5 f3g1 f3g5 f3h2 f3h4\ng3 white pawn: g3g4\nh3 white pawn: h3h4\nc4 white pawn: c4c5\nAll legal moves: a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d5 c3e2 c3e4 c4c5 d1a4 d1b3 d1c2 d1d2 d1e2 d3d4 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3g5 f3h2 f3h4 g2f1 g3g4 h1f1 h1g1 h1h2 h3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1a4", "d1b3", "d1c2", "d1d2", "d1e2"], "e1": ["e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1", "h1h2"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": [], "g2": ["g2f1"], "c3": ["c3a4", "c3b1", "c3b5", "c3d5", "c3e2", "c3e4"], "d3": ["d3d4"], "f3": ["f3d2", "f3d4", "f3e5", "f3g1", "f3g5", "f3h2", "f3h4"], "g3": ["g3g4"], "h3": ["h3h4"], "c4": ["c4c5"]}, "_legal_moves_by_piece_moves": "a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d5 c3e2 c3e4 c4c5 d1a4 d1b3 d1c2 d1d2 d1e2 d3d4 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3g5 f3h2 f3h4 g2f1 g3g4 h1f1 h1g1 h1h2 h3h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1a4", "d1b3", "d1c2", "d1d2", "d1e2"], "e1": ["e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1", "h1h2"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": [], "g2": ["g2f1"], "c3": ["c3a4", "c3b1", "c3b5", "c3d5", "c3e2", "c3e4"], "d3": ["d3d4"], "f3": ["f3d2", "f3d4", "f3e5", "f3g1", "f3g5", "f3h2", "f3h4"], "g3": ["g3g4"], "h3": ["h3h4"], "c4": ["c4c5"]}, "legal_moves": "a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d5 c3e2 c3e4 c4c5 d1a4 d1b3 d1c2 d1d2 d1e2 d3d4 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3g5 f3h2 f3h4 g2f1 g3g4 h1f1 h1g1 h1h2 h3h4"}}
{"example_id": "rules_00596", "split": "rules", "task_type": "ray_walk", "fen": "8/8/Bk6/8/6QP/p5P1/P5K1/8 w - - 1 55", "prompt": "FEN: 8/8/Bk6/8/6QP/p5P1/P5K1/8 w - - 1 55\nWalk each ray for the slider on g4: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: g4 white queen.\nRay N: g5 empty; g6 empty; g7 empty; g8 empty; edge.\nRay NE: h5 empty; edge.\nRay E: h4 white pawn: own piece (stop, excluded).\nRay SE: h3 empty; edge.\nRay S: g3 white pawn: own piece (stop, excluded).\nRay SW: f3 empty; e2 empty; d1 empty; edge.\nRay W: f4 empty; e4 empty; d4 empty; c4 empty; b4 empty; a4 empty; edge.\nRay NW: f5 empty; e6 empty; d7 empty; c8 empty; edge.\nMoves from rays: g4a4 g4b4 g4c4 g4c8 g4d1 g4d4 g4d7 g4e2 g4e4 g4e6 g4f3 g4f4 g4f5 g4g5 g4g6 g4g7 g4g8 g4h3 g4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "g4", "diagnostic": true, "hard_gate": false, "source_square": "g4"}}
{"example_id": "rules_00597", "split": "rules", "task_type": "legal_moves", "fen": "8/8/1pk3K1/8/8/7q/6p1/5r2 b - - 1 68", "prompt": "FEN: 8/8/1pk3K1/8/8/7q/6p1/5r2 b - - 1 68\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b6b5 c6b5 c6b7 c6c5 c6c7 c6d5 c6d6 c6d7 f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f1f4 f1f5 f1f6 f1f7 f1f8 f1g1 f1h1 g2g1b g2g1n g2g1q g2g1r h3a3 h3b3 h3c3 h3c8 h3d3 h3d7 h3e3 h3e6 h3f3 h3f5 h3g3 h3g4 h3h1 h3h2 h3h4 h3h5 h3h6 h3h7 h3h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00598", "split": "rules", "task_type": "legal_moves", "fen": "8/3kbK2/6p1/6Pp/1p5P/1R6/8/8 w - - 4 60", "prompt": "FEN: 8/3kbK2/6p1/6Pp/1p5P/1R6/8/8 w - - 4 60\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b3a3 b3b1 b3b2 b3b4 b3c3 b3d3 b3e3 b3f3 b3g3 b3h3 f7g6 f7g7 f7g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00599", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1b2rk1/pp4p1/4p2p/2qpnpNQ/7R/P2B4/2P3PP/1R5K w - - 2 20", "prompt": "FEN: r1b2rk1/pp4p1/4p2p/2qpnpNQ/7R/P2B4/2P3PP/1R5K w - - 2 20\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: b1 white rook; h1 white king; c2 white pawn; g2 white pawn; h2 white pawn; a3 white pawn; d3 white bishop; h4 white rook; g5 white knight; h5 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "h1", "piece": "white king"}, {"square": "c2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "h4", "piece": "white rook"}, {"square": "g5", "piece": "white knight"}, {"square": "h5", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "h1", "piece": "white king"}, {"square": "c2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "h4", "piece": "white rook"}, {"square": "g5", "piece": "white knight"}, {"square": "h5", "piece": "white queen"}]}}
{"example_id": "rules_00600", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/8/1b6/1b6/8/8/2k5/K7 b - -", "prompt": "FEN: 8/8/1b6/1b6/8/8/2k5/K7 b - -\nWhat legal moves does the piece on b6 have?", "gold_answer": "b6a5 b6a7 b6c5 b6c7 b6d4 b6d8 b6e3 b6f2 b6g1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "b6", "_piece_legal_moves_piece": "bishop", "diagnostic": true, "hard_gate": false, "source_square": "b6", "piece": "bishop"}}
{"example_id": "rules_00601", "split": "rules", "task_type": "check_detection", "fen": "1r3rk1/2pq1p1p/2n2Qp1/1p1pP1N1/3P2b1/2P4P/2B2P2/R3R1K1 b - -", "prompt": "FEN: 1r3rk1/2pq1p1p/2n2Qp1/1p1pP1N1/3P2b1/2P4P/2B2P2/R3R1K1 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00602", "split": "rules", "task_type": "captures", "fen": "r1bq1r1k/pp2bppp/4pn2/8/3N1B2/P1NB4/1P3PPP/R2Q1RK1 w - -", "prompt": "FEN: r1bq1r1k/pp2bppp/4pn2/8/3N1B2/P1NB4/1P3PPP/R2Q1RK1 w - -\nList all capture moves available.", "gold_answer": "d3h7 d4e6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00603", "split": "rules", "task_type": "special_rules", "fen": "3q1r1k/4N1pp/5P2/3pR3/3P4/r2Q4/7P/6K1 b - -", "prompt": "Given FEN: 3q1r1k/4N1pp/5P2/3pR3/3P4/r2Q4/7P/6K1 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00604", "split": "rules", "task_type": "legality_check", "fen": "r5k1/2b3p1/p1p4p/6r1/8/1P6/1B3PP1/3R1RK1 w - - 3 28", "prompt": "FEN: r5k1/2b3p1/p1p4p/6r1/8/1P6/1B3PP1/3R1RK1 w - - 3 28\nIs the move b2c1 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b2c1", "_legality_check_reason_label": "legal", "move": "b2c1", "legality_reason_label": "legal"}}
{"example_id": "rules_00605", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2r5/1b3kp1/pP2p2p/5p2/1QP1pP2/1P2P1R1/P1r3PP/2b3K1 w - -", "prompt": "FEN: 2r5/1b3kp1/pP2p2p/5p2/1QP1pP2/1P2P1R1/P1r3PP/2b3K1 w - -\nList pseudo-legal moves from g1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g1: g1f1 g1f2 g1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g1", "diagnostic": true, "hard_gate": false, "source_square": "g1"}}
{"example_id": "rules_00606", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1b2rk1/1p1n2pp/p2p4/3P1pq1/1PP1P3/2NB4/P5PP/R2Q1R1K b - -", "prompt": "FEN: r1b2rk1/1p1n2pp/p2p4/3P1pq1/1PP1P3/2NB4/P5PP/R2Q1R1K b - -\nFor the piece on f5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f5: f5e4 f5f4.\nLegal: f5e4 f5f4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "f5", "diagnostic": true, "hard_gate": false, "source_square": "f5"}}
{"example_id": "rules_00607", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbqkbnr/pp2p1pp/2p2p2/4N2Q/4P3/2p5/PPPP1PPP/R1B1KB1R b KQkq -", "prompt": "FEN: rnbqkbnr/pp2p1pp/2p2p2/4N2Q/4P3/2p5/PPPP1PPP/R1B1KB1R b KQkq -\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_00608", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/6k1/4Q1p1/2p5/1pNb1P1p/6qP/rP4P1/4R2K w - -", "prompt": "FEN: 8/6k1/4Q1p1/2p5/1pNb1P1p/6qP/rP4P1/4R2K w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: e1 white rook; h1 white king; b2 white pawn; g2 white pawn; h3 white pawn; c4 white knight; f4 white pawn; e6 white queen.\nMoves by piece:\ne1 white rook: e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1f1 e1g1\nh1 white king: no legal moves\nb2 white pawn: b2b3\ng2 white pawn: no legal moves\nh3 white pawn: no legal moves\nc4 white knight: c4a3 c4a5 c4b6 c4d2 c4d6 c4e3 c4e5\nf4 white pawn: f4f5\ne6 white queen: e6a6 e6b6 e6c6 e6c8 e6d5 e6d6 e6d7 e6e2 e6e3 e6e4 e6e5 e6e7 e6e8 e6f5 e6f6 e6f7 e6g4 e6g6 e6g8\nAll legal moves: b2b3 c4a3 c4a5 c4b6 c4d2 c4d6 c4e3 c4e5 e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1f1 e1g1 e6a6 e6b6 e6c6 e6c8 e6d5 e6d6 e6d7 e6e2 e6e3 e6e4 e6e5 e6e7 e6e8 e6f5 e6f6 e6f7 e6g4 e6g6 e6g8 f4f5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e1": ["e1a1", "e1b1", "e1c1", "e1d1", "e1e2", "e1e3", "e1e4", "e1e5", "e1f1", "e1g1"], "h1": [], "b2": ["b2b3"], "g2": [], "h3": [], "c4": ["c4a3", "c4a5", "c4b6", "c4d2", "c4d6", "c4e3", "c4e5"], "f4": ["f4f5"], "e6": ["e6a6", "e6b6", "e6c6", "e6c8", "e6d5", "e6d6", "e6d7", "e6e2", "e6e3", "e6e4", "e6e5", "e6e7", "e6e8", "e6f5", "e6f6", "e6f7", "e6g4", "e6g6", "e6g8"]}, "_legal_moves_by_piece_moves": "b2b3 c4a3 c4a5 c4b6 c4d2 c4d6 c4e3 c4e5 e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1f1 e1g1 e6a6 e6b6 e6c6 e6c8 e6d5 e6d6 e6d7 e6e2 e6e3 e6e4 e6e5 e6e7 e6e8 e6f5 e6f6 e6f7 e6g4 e6g6 e6g8 f4f5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e1": ["e1a1", "e1b1", "e1c1", "e1d1", "e1e2", "e1e3", "e1e4", "e1e5", "e1f1", "e1g1"], "h1": [], "b2": ["b2b3"], "g2": [], "h3": [], "c4": ["c4a3", "c4a5", "c4b6", "c4d2", "c4d6", "c4e3", "c4e5"], "f4": ["f4f5"], "e6": ["e6a6", "e6b6", "e6c6", "e6c8", "e6d5", "e6d6", "e6d7", "e6e2", "e6e3", "e6e4", "e6e5", "e6e7", "e6e8", "e6f5", "e6f6", "e6f7", "e6g4", "e6g6", "e6g8"]}, "legal_moves": "b2b3 c4a3 c4a5 c4b6 c4d2 c4d6 c4e3 c4e5 e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1f1 e1g1 e6a6 e6b6 e6c6 e6c8 e6d5 e6d6 e6d7 e6e2 e6e3 e6e4 e6e5 e6e7 e6e8 e6f5 e6f6 e6f7 e6g4 e6g6 e6g8 f4f5"}}
{"example_id": "rules_00609", "split": "rules", "task_type": "ray_walk", "fen": "r1Bqk2r/6pp/p2p1n2/2p1n3/Pb2P3/2N2P2/1P1B2PP/R2QK1NR b KQkq -", "prompt": "FEN: r1Bqk2r/6pp/p2p1n2/2p1n3/Pb2P3/2N2P2/1P1B2PP/R2QK1NR b KQkq -\nWalk each ray for the slider on b4: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b4 black bishop.\nRay NE: c5 black pawn: own piece (stop, excluded).\nRay SE: c3 white knight: capture (stop, included).\nRay SW: a3 empty; edge.\nRay NW: a5 empty; edge.\nMoves from rays: b4a3 b4a5 b4c3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_00610", "split": "rules", "task_type": "legal_filter_trace", "fen": "r7/3k4/3p2p1/ppq1P3/4K3/8/3r2PP/4q3 w - - 1 47", "prompt": "FEN: r7/3k4/3p2p1/ppq1P3/4K3/8/3r2PP/4q3 w - - 1 47\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: g2 white pawn; h2 white pawn; e4 white king; e5 white pawn.\nFilter by piece:\ng2 white pawn: pseudo-legal g2g3 g2g4 | rejected g2g3 does_not_resolve_check; g2g4 does_not_resolve_check | legal none\nh2 white pawn: pseudo-legal h2h3 h2h4 | rejected h2h3 does_not_resolve_check; h2h4 does_not_resolve_check | legal none\ne4 white king: pseudo-legal e4d3 e4d4 e4d5 e4e3 e4f3 e4f4 e4f5 | rejected e4d3 does_not_resolve_check; e4d4 does_not_resolve_check; e4d5 does_not_resolve_check; e4e3 does_not_resolve_check; e4f5 does_not_resolve_check | legal e4f3 e4f4\ne5 white pawn: pseudo-legal e5d6 e5e6 | rejected e5d6 does_not_resolve_check; e5e6 does_not_resolve_check | legal none\nAll legal moves: e4f3 e4f4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00611", "split": "rules", "task_type": "legal_moves", "fen": "rnbq1rk1/1p3pbp/p1p1p1p1/3pP3/2PP2P1/2N1PN2/PP5P/R1Q1KB1R w KQ - 0 11", "prompt": "FEN: rnbq1rk1/1p3pbp/p1p1p1p1/3pP3/2PP2P1/2N1PN2/PP5P/R1Q1KB1R w KQ - 0 11\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a2a3 a2a4 b2b3 b2b4 c1b1 c1c2 c1d1 c1d2 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 c4c5 c4d5 e1d1 e1d2 e1e2 e1f2 e3e4 f1d3 f1e2 f1g2 f1h3 f3d2 f3g1 f3g5 f3h4 g4g5 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00612", "split": "rules", "task_type": "side_piece_inventory", "fen": "5R2/2k1P3/4K3/8/8/8/8/4r3 w - -", "prompt": "FEN: 5R2/2k1P3/4K3/8/8/8/8/4r3 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: e6 white king; e7 white pawn; f8 white rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "e6", "piece": "white king"}, {"square": "e7", "piece": "white pawn"}, {"square": "f8", "piece": "white rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "e6", "piece": "white king"}, {"square": "e7", "piece": "white pawn"}, {"square": "f8", "piece": "white rook"}]}}
{"example_id": "rules_00613", "split": "rules", "task_type": "piece_legal_moves", "fen": "rn1qk1nr/pp3pbp/2p3p1/2Ppp3/3P2b1/3BPN2/PP3PPP/RNBQK2R w KQkq - 0 7", "prompt": "FEN: rn1qk1nr/pp3pbp/2p3p1/2Ppp3/3P2b1/3BPN2/PP3PPP/RNBQK2R w KQkq - 0 7\nWhat legal moves does the piece on f3 have?", "gold_answer": "f3d2 f3e5 f3g1 f3g5 f3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f3", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "f3", "piece": "knight"}}
{"example_id": "rules_00614", "split": "rules", "task_type": "check_detection", "fen": "1r2r1k1/p2n1ppp/2p2p2/q1Pp4/3P3N/P2QP3/5PPP/5RK1 b - - 2 18", "prompt": "FEN: 1r2r1k1/p2n1ppp/2p2p2/q1Pp4/3P3N/P2QP3/5PPP/5RK1 b - - 2 18\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00615", "split": "rules", "task_type": "captures", "fen": "5K2/8/1k6/1P3P2/2Pp4/8/p1P5/8 w - -", "prompt": "FEN: 5K2/8/1k6/1P3P2/2Pp4/8/p1P5/8 w - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00616", "split": "rules", "task_type": "special_rules", "fen": "3r3k/6p1/4Bq1p/1pQ2P1P/2n2P2/2P5/3r4/6RK w - - 1 40", "prompt": "Given FEN: 3r3k/6p1/4Bq1p/1pQ2P1P/2n2P2/2P5/3r4/6RK w - - 1 40\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00617", "split": "rules", "task_type": "legality_check", "fen": "r2qkbnr/pp1b1ppp/2n1p3/3p4/2pP4/4PN2/PPP2PPP/RNBQKB1R w KQkq -", "prompt": "FEN: r2qkbnr/pp1b1ppp/2n1p3/3p4/2pP4/4PN2/PPP2PPP/RNBQKB1R w KQkq -\nIs the move b7h1 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "b7h1", "_legality_check_reason_label": "wrong_side_piece", "move": "b7h1", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_00618", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "6k1/3b3p/1pp3p1/3p1p2/r6q/8/8/6K1 b - - 3 46", "prompt": "FEN: 6k1/3b3p/1pp3p1/3p1p2/r6q/8/8/6K1 b - - 3 46\nList pseudo-legal moves from a4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a4: a4a1 a4a2 a4a3 a4a5 a4a6 a4a7 a4a8 a4b4 a4c4 a4d4 a4e4 a4f4 a4g4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a4", "diagnostic": true, "hard_gate": false, "source_square": "a4"}}
{"example_id": "rules_00619", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnbqk2r/pp3ppp/4pn2/3p4/1bPP4/2N2N2/PP2BPPP/R1BQK2R b KQkq -", "prompt": "FEN: rnbqk2r/pp3ppp/4pn2/3p4/1bPP4/2N2N2/PP2BPPP/R1BQK2R b KQkq -\nFor the piece on b4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b4: b4a3 b4a5 b4c3 b4c5 b4d6 b4e7 b4f8.\nLegal: b4a3 b4a5 b4c3 b4c5 b4d6 b4e7 b4f8.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_00620", "split": "rules", "task_type": "king_safety_filter", "fen": "2rk1r2/p1p4p/1p2Qpp1/2n5/5B2/8/PPP2PPP/R3K2R w KQ - 6 21", "prompt": "FEN: 2rk1r2/p1p4p/1p2Qpp1/2n5/5B2/8/PPP2PPP/R3K2R w KQ - 6 21\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00621", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2r3k1/pp3ppp/4p3/3pP3/1B3Pn1/5N2/PKbN2PP/R7 b - -", "prompt": "FEN: 2r3k1/pp3ppp/4p3/3pP3/1B3Pn1/5N2/PKbN2PP/R7 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c2 black bishop; g4 black knight; d5 black pawn; e6 black pawn; a7 black pawn; b7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; c8 black rook; g8 black king.\nMoves by piece:\nc2 black bishop: c2a4 c2b1 c2b3 c2d1 c2d3 c2e4 c2f5 c2g6\ng4 black knight: g4e3 g4e5 g4f2 g4f6 g4h2 g4h6\nd5 black pawn: d5d4\ne6 black pawn: no legal moves\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\nc8 black rook: c8a8 c8b8 c8c3 c8c4 c8c5 c8c6 c8c7 c8d8 c8e8 c8f8\ng8 black king: g8h8\nAll legal moves: a7a5 a7a6 b7b5 b7b6 c2a4 c2b1 c2b3 c2d1 c2d3 c2e4 c2f5 c2g6 c8a8 c8b8 c8c3 c8c4 c8c5 c8c6 c8c7 c8d8 c8e8 c8f8 d5d4 f7f5 f7f6 g4e3 g4e5 g4f2 g4f6 g4h2 g4h6 g7g5 g7g6 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c2": ["c2a4", "c2b1", "c2b3", "c2d1", "c2d3", "c2e4", "c2f5", "c2g6"], "g4": ["g4e3", "g4e5", "g4f2", "g4f6", "g4h2", "g4h6"], "d5": ["d5d4"], "e6": [], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8a8", "c8b8", "c8c3", "c8c4", "c8c5", "c8c6", "c8c7", "c8d8", "c8e8", "c8f8"], "g8": ["g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7b5 b7b6 c2a4 c2b1 c2b3 c2d1 c2d3 c2e4 c2f5 c2g6 c8a8 c8b8 c8c3 c8c4 c8c5 c8c6 c8c7 c8d8 c8e8 c8f8 d5d4 f7f5 f7f6 g4e3 g4e5 g4f2 g4f6 g4h2 g4h6 g7g5 g7g6 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c2": ["c2a4", "c2b1", "c2b3", "c2d1", "c2d3", "c2e4", "c2f5", "c2g6"], "g4": ["g4e3", "g4e5", "g4f2", "g4f6", "g4h2", "g4h6"], "d5": ["d5d4"], "e6": [], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8a8", "c8b8", "c8c3", "c8c4", "c8c5", "c8c6", "c8c7", "c8d8", "c8e8", "c8f8"], "g8": ["g8h8"]}, "legal_moves": "a7a5 a7a6 b7b5 b7b6 c2a4 c2b1 c2b3 c2d1 c2d3 c2e4 c2f5 c2g6 c8a8 c8b8 c8c3 c8c4 c8c5 c8c6 c8c7 c8d8 c8e8 c8f8 d5d4 f7f5 f7f6 g4e3 g4e5 g4f2 g4f6 g4h2 g4h6 g7g5 g7g6 g8h8 h7h5 h7h6"}}
{"example_id": "rules_00622", "split": "rules", "task_type": "ray_walk", "fen": "1r2kbnr/p2n2pp/q3p3/1pp5/2Np1P2/3P3P/PP3PB1/R1B1QK1R w k - 0 16", "prompt": "FEN: 1r2kbnr/p2n2pp/q3p3/1pp5/2Np1P2/3P3P/PP3PB1/R1B1QK1R w k - 0 16\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 white bishop: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00623", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/pp4pn/2nb2bp/4pN2/1P1pP3/P1PB3P/1B1N1PP1/R3QRK1 b - - 0 18", "prompt": "FEN: r2q1rk1/pp4pn/2nb2bp/4pN2/1P1pP3/P1PB3P/1B1N1PP1/R3QRK1 b - - 0 18\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 a8c8 b7b5 b7b6 c6a5 c6b4 c6b8 c6e7 d4c3 d6b4 d6b8 d6c5 d6c7 d6e7 d8a5 d8b6 d8b8 d8c7 d8c8 d8d7 d8e7 d8e8 d8f6 d8g5 d8h4 f8e8 f8f5 f8f6 f8f7 g6e8 g6f5 g6f7 g6h5 g8f7 g8h8 h6h5 h7f6 h7g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00624", "split": "rules", "task_type": "legal_moves", "fen": "8/8/p3k3/1p3pp1/1P1K3p/P4P1P/6P1/8 w - -", "prompt": "FEN: 8/8/p3k3/1p3pp1/1P1K3p/P4P1P/6P1/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 d4c3 d4c5 d4d3 d4e3 f3f4 g2g3 g2g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00625", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1b2rk1/pp1q2pp/3b4/3Ppp2/1n6/2N5/PP3PPP/RBBQ1RK1 w - -", "prompt": "FEN: r1b2rk1/pp1q2pp/3b4/3Ppp2/1n6/2N5/PP3PPP/RBBQ1RK1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white bishop; c1 white bishop; d1 white queen; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white knight; d5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white bishop"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white bishop"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d5", "piece": "white pawn"}]}}
{"example_id": "rules_00626", "split": "rules", "task_type": "piece_legal_moves", "fen": "5rk1/ppp2p2/4r2p/3p2p1/3P4/P1q2PB1/3nRQPP/6KR b - - 3 24", "prompt": "FEN: 5rk1/ppp2p2/4r2p/3p2p1/3P4/P1q2PB1/3nRQPP/6KR b - - 3 24\nWhat legal moves does the piece on d5 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "d5", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "d5", "piece": "pawn"}}
{"example_id": "rules_00627", "split": "rules", "task_type": "check_detection", "fen": "rnbq1rk1/pp3pb1/2p1p1pp/3pPn2/3P4/2PB1N2/PP1N1PPP/R1BQ1RK1 b - - 3 10", "prompt": "FEN: rnbq1rk1/pp3pb1/2p1p1pp/3pPn2/3P4/2PB1N2/PP1N1PPP/R1BQ1RK1 b - - 3 10\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00628", "split": "rules", "task_type": "captures", "fen": "r2q1rk1/ppp1bppp/2np4/3npb2/2P5/PP1P2P1/1B1QPPBP/R3K1NR w KQ - 0 11", "prompt": "FEN: r2q1rk1/ppp1bppp/2np4/3npb2/2P5/PP1P2P1/1B1QPPBP/R3K1NR w KQ - 0 11\nList all capture moves available.", "gold_answer": "b2e5 c4d5 g2d5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00629", "split": "rules", "task_type": "special_rules", "fen": "4k3/4P3/3K4/8/3B4/8/8/1n6 w - -", "prompt": "Given FEN: 4k3/4P3/3K4/8/3B4/8/8/1n6 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00630", "split": "rules", "task_type": "legality_check", "fen": "r1bqkb1r/p2p2pp/1pn1pn2/5p2/2P5/P1PBPN1P/2Q2PP1/R1B1K2R w KQkq - 0 11", "prompt": "FEN: r1bqkb1r/p2p2pp/1pn1pn2/5p2/2P5/P1PBPN1P/2Q2PP1/R1B1K2R w KQkq - 0 11\nIs the move f1g5 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f1g5", "_legality_check_reason_label": "empty_source", "move": "f1g5", "legality_reason_label": "empty_source"}}
{"example_id": "rules_00631", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1bqkb1r/pppn1ppp/3p1n2/4P3/2B1P3/2N5/PPP2PPP/R1BQK1NR b KQkq -", "prompt": "FEN: r1bqkb1r/pppn1ppp/3p1n2/4P3/2B1P3/2N5/PPP2PPP/R1BQK1NR b KQkq -\nList pseudo-legal moves from d6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d6: d6d5 d6e5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d6", "diagnostic": true, "hard_gate": false, "source_square": "d6"}}
{"example_id": "rules_00632", "split": "rules", "task_type": "piece_legal_filter", "fen": "2kr1bnr/ppp2ppp/2b3q1/4B3/1P1p4/P3P1N1/2PP1PPP/RN1Q1RK1 b - - 1 10", "prompt": "FEN: 2kr1bnr/ppp2ppp/2b3q1/4B3/1P1p4/P3P1N1/2PP1PPP/RN1Q1RK1 b - - 1 10\nFor the piece on d4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d4: d4d3 d4e3.\nLegal: d4d3 d4e3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_00633", "split": "rules", "task_type": "king_safety_filter", "fen": "r3kb1r/ppp3pp/3p1B2/4pq2/4N1b1/3PQNP1/PPP2PBP/R4RK1 w kq - 1 13", "prompt": "FEN: r3kb1r/ppp3pp/3p1B2/4pq2/4N1b1/3PQNP1/PPP2PBP/R4RK1 w kq - 1 13\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00634", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnbqk2r/1p2npp1/p3p2p/2Pp4/3P4/3B1N2/PP1N1PPP/R2Q1RK1 b kq - 1 10", "prompt": "FEN: rnbqk2r/1p2npp1/p3p2p/2Pp4/3P4/3B1N2/PP1N1PPP/R2Q1RK1 b kq - 1 10\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; a6 black pawn; e6 black pawn; h6 black pawn; b7 black pawn; e7 black knight; f7 black pawn; g7 black pawn; a8 black rook; b8 black knight; c8 black bishop; d8 black queen; e8 black king; h8 black rook.\nMoves by piece:\nd5 black pawn: no legal moves\na6 black pawn: a6a5\ne6 black pawn: e6e5\nh6 black pawn: h6h5\nb7 black pawn: b7b5 b7b6\ne7 black knight: e7c6 e7f5 e7g6 e7g8\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\na8 black rook: a8a7\nb8 black knight: b8c6 b8d7\nc8 black bishop: c8d7\nd8 black queen: d8a5 d8b6 d8c7 d8d6 d8d7\ne8 black king: e8d7 e8f8 e8g8\nh8 black rook: h8f8 h8g8 h8h7\nAll legal moves: a6a5 a8a7 b7b5 b7b6 b8c6 b8d7 c8d7 d8a5 d8b6 d8c7 d8d6 d8d7 e6e5 e7c6 e7f5 e7g6 e7g8 e8d7 e8f8 e8g8 f7f5 f7f6 g7g5 g7g6 h6h5 h8f8 h8g8 h8h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d5": [], "a6": ["a6a5"], "e6": ["e6e5"], "h6": ["h6h5"], "b7": ["b7b5", "b7b6"], "e7": ["e7c6", "e7f5", "e7g6", "e7g8"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "a8": ["a8a7"], "b8": ["b8c6", "b8d7"], "c8": ["c8d7"], "d8": ["d8a5", "d8b6", "d8c7", "d8d6", "d8d7"], "e8": ["e8d7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8", "h8h7"]}, "_legal_moves_by_piece_moves": "a6a5 a8a7 b7b5 b7b6 b8c6 b8d7 c8d7 d8a5 d8b6 d8c7 d8d6 d8d7 e6e5 e7c6 e7f5 e7g6 e7g8 e8d7 e8f8 e8g8 f7f5 f7f6 g7g5 g7g6 h6h5 h8f8 h8g8 h8h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d5": [], "a6": ["a6a5"], "e6": ["e6e5"], "h6": ["h6h5"], "b7": ["b7b5", "b7b6"], "e7": ["e7c6", "e7f5", "e7g6", "e7g8"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "a8": ["a8a7"], "b8": ["b8c6", "b8d7"], "c8": ["c8d7"], "d8": ["d8a5", "d8b6", "d8c7", "d8d6", "d8d7"], "e8": ["e8d7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8", "h8h7"]}, "legal_moves": "a6a5 a8a7 b7b5 b7b6 b8c6 b8d7 c8d7 d8a5 d8b6 d8c7 d8d6 d8d7 e6e5 e7c6 e7f5 e7g6 e7g8 e8d7 e8f8 e8g8 f7f5 f7f6 g7g5 g7g6 h6h5 h8f8 h8g8 h8h7"}}
{"example_id": "rules_00635", "split": "rules", "task_type": "ray_walk", "fen": "r1b1k2r/pppp1pp1/5q1p/2b1p3/2BnP3/2NP1N2/PPP2PPP/R2QK2R w KQkq - 4 8", "prompt": "FEN: r1b1k2r/pppp1pp1/5q1p/2b1p3/2BnP3/2NP1N2/PPP2PPP/R2QK2R w KQkq - 4 8\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 white queen: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00636", "split": "rules", "task_type": "legal_moves", "fen": "r2qk1nr/1b1nppbp/p2p2p1/1pp5/3PP3/2PBBN1P/PP1N1PP1/R2Q1RK1 b kq -", "prompt": "FEN: r2qk1nr/1b1nppbp/p2p2p1/1pp5/3PP3/2PBBN1P/PP1N1PP1/R2Q1RK1 b kq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 a8b8 a8c8 b5b4 b7c6 b7c8 b7d5 b7e4 c5c4 c5d4 d6d5 d7b6 d7b8 d7e5 d7f6 d7f8 d8a5 d8b6 d8b8 d8c7 d8c8 e7e5 e7e6 e8f8 f7f5 f7f6 g6g5 g7d4 g7e5 g7f6 g7f8 g7h6 g8f6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00637", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/pp2bppp/8/n2R3b/8/3B1N1P/PP3PP1/R1BQ2K1 b - -", "prompt": "FEN: r2q1rk1/pp2bppp/8/n2R3b/8/3B1N1P/PP3PP1/R1BQ2K1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a5b3 a5c4 a5c6 a7a6 a8b8 a8c8 b7b5 b7b6 d8b6 d8b8 d8c7 d8c8 d8d5 d8d6 d8d7 d8e8 e7a3 e7b4 e7c5 e7d6 e7f6 e7g5 e7h4 f7f5 f7f6 f8e8 g7g5 g7g6 g8h8 h5f3 h5g4 h5g6 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00638", "split": "rules", "task_type": "side_piece_inventory", "fen": "r5k1/1p2q1p1/p6p/2p1b3/6P1/1P1Q4/Pp5P/1R3r1K w - - 0 27", "prompt": "FEN: r5k1/1p2q1p1/p6p/2p1b3/6P1/1P1Q4/Pp5P/1R3r1K w - - 0 27\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: b1 white rook; h1 white king; a2 white pawn; h2 white pawn; b3 white pawn; d3 white queen; g4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "h1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "b3", "piece": "white pawn"}, {"square": "d3", "piece": "white queen"}, {"square": "g4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "h1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "b3", "piece": "white pawn"}, {"square": "d3", "piece": "white queen"}, {"square": "g4", "piece": "white pawn"}]}}
{"example_id": "rules_00639", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/8/8/8/8/5k2/1r6/2R2K2 b - -", "prompt": "FEN: 8/8/8/8/8/5k2/1r6/2R2K2 b - -\nWhat legal moves does the piece on b2 have?", "gold_answer": "b2a2 b2b1 b2b3 b2b4 b2b5 b2b6 b2b7 b2b8 b2c2 b2d2 b2e2 b2f2 b2g2 b2h2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "b2", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "b2", "piece": "rook"}}
{"example_id": "rules_00640", "split": "rules", "task_type": "check_detection", "fen": "5R2/5ppk/6p1/3b4/3B1P2/7P/2r3PK/8 w - - 9 49", "prompt": "FEN: 5R2/5ppk/6p1/3b4/3B1P2/7P/2r3PK/8 w - - 9 49\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00641", "split": "rules", "task_type": "captures", "fen": "3r1rk1/1pR3pp/p2Pp1qn/1b2p3/8/P3B1NP/1P1Q1PP1/4KB1R w K - 6 23", "prompt": "FEN: 3r1rk1/1pR3pp/p2Pp1qn/1b2p3/8/P3B1NP/1P1Q1PP1/4KB1R w K - 6 23\nList all capture moves available.", "gold_answer": "c7b7 c7g7 e3h6 f1b5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00642", "split": "rules", "task_type": "special_rules", "fen": "3r1rk1/pp2q1pp/1n2bp2/2p5/3n1p2/BPN1Q1P1/P2PP1BP/2R2RK1 w - -", "prompt": "Given FEN: 3r1rk1/pp2q1pp/1n2bp2/2p5/3n1p2/BPN1Q1P1/P2PP1BP/2R2RK1 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00643", "split": "rules", "task_type": "legality_check", "fen": "5rk1/1Np1R2p/3p4/3P2p1/P1P5/5p2/1P1B1K1r/R7 w - -", "prompt": "FEN: 5rk1/1Np1R2p/3p4/3P2p1/P1P5/5p2/1P1B1K1r/R7 w - -\nIs the move f3g6 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f3g6", "_legality_check_reason_label": "wrong_side_piece", "move": "f3g6", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_00644", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/1p2b3/p1p1k2p/2P3p1/3PK3/P4PPP/1P6/8 w - - 4 41", "prompt": "FEN: 8/1p2b3/p1p1k2p/2P3p1/3PK3/P4PPP/1P6/8 w - - 4 41\nList pseudo-legal moves from b2.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b2: b2b3 b2b4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b2", "diagnostic": true, "hard_gate": false, "source_square": "b2"}}
{"example_id": "rules_00645", "split": "rules", "task_type": "piece_legal_filter", "fen": "3Q4/8/P5p1/4p1Kp/2p1k2P/8/P7/8 b - - 0 50", "prompt": "FEN: 3Q4/8/P5p1/4p1Kp/2p1k2P/8/P7/8 b - - 0 50\nFor the piece on e4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e4: e4d3 e4d4 e4d5 e4e3 e4f3 e4f4 e4f5.\nLegal: e4e3 e4f3.\nRejected: e4d3 king_would_be_in_check; e4d4 king_would_be_in_check; e4d5 king_would_be_in_check; e4f4 king_would_be_in_check; e4f5 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "e4", "diagnostic": true, "hard_gate": false, "source_square": "e4"}}
{"example_id": "rules_00646", "split": "rules", "task_type": "king_safety_filter", "fen": "6r1/k2b1p2/Pp1p4/3PpPb1/2P1P1pr/1N1n2N1/6BP/R4K1R b - - 9 34", "prompt": "FEN: 6r1/k2b1p2/Pp1p4/3PpPb1/2P1P1pr/1N1n2N1/6BP/R4K1R b - - 9 34\nFor move a7a6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "a7a6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00647", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/2p1R1p1/R5k1/1p1pnr1p/1PnB4/2P5/6P1/6K1 b - - 0 41", "prompt": "FEN: 8/2p1R1p1/R5k1/1p1pnr1p/1PnB4/2P5/6P1/6K1 b - - 0 41\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c4 black knight; b5 black pawn; d5 black pawn; e5 black knight; f5 black rook; h5 black pawn; g6 black king; c7 black pawn; g7 black pawn.\nMoves by piece:\nc4 black knight: c4b6 c4d6\nb5 black pawn: no legal moves\nd5 black pawn: no legal moves\ne5 black knight: e5c6\nf5 black rook: f5f6\nh5 black pawn: no legal moves\ng6 black king: g6g5 g6h7\nc7 black pawn: c7c6\ng7 black pawn: no legal moves\nAll legal moves: c4b6 c4d6 c7c6 e5c6 f5f6 g6g5 g6h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c4": ["c4b6", "c4d6"], "b5": [], "d5": [], "e5": ["e5c6"], "f5": ["f5f6"], "h5": [], "g6": ["g6g5", "g6h7"], "c7": ["c7c6"], "g7": []}, "_legal_moves_by_piece_moves": "c4b6 c4d6 c7c6 e5c6 f5f6 g6g5 g6h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c4": ["c4b6", "c4d6"], "b5": [], "d5": [], "e5": ["e5c6"], "f5": ["f5f6"], "h5": [], "g6": ["g6g5", "g6h7"], "c7": ["c7c6"], "g7": []}, "legal_moves": "c4b6 c4d6 c7c6 e5c6 f5f6 g6g5 g6h7"}}
{"example_id": "rules_00648", "split": "rules", "task_type": "ray_walk", "fen": "8/Q7/P3knp1/7p/4r2P/8/3PK3/8 w - - 3 46", "prompt": "FEN: 8/Q7/P3knp1/7p/4r2P/8/3PK3/8 w - - 3 46\nWalk each ray for the slider on a7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a7 white queen.\nRay N: a8 empty; edge.\nRay NE: b8 empty; edge.\nRay E: b7 empty; c7 empty; d7 empty; e7 empty; f7 empty; g7 empty; h7 empty; edge.\nRay SE: b6 empty; c5 empty; d4 empty; e3 empty; f2 empty; g1 empty; edge.\nRay S: a6 white pawn: own piece (stop, excluded).\nRay SW: edge.\nRay W: edge.\nRay NW: edge.\nMoves from rays: a7a8 a7b6 a7b7 a7b8 a7c5 a7c7 a7d4 a7d7 a7e3 a7e7 a7f2 a7f7 a7g1 a7g7 a7h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a7", "diagnostic": true, "hard_gate": false, "source_square": "a7"}}
{"example_id": "rules_00649", "split": "rules", "task_type": "legal_filter_trace", "fen": "3r2k1/3q1p2/6p1/2p1P1B1/4P1Q1/1P5P/r2p2P1/3R2K1 w - - 2 31", "prompt": "FEN: 3r2k1/3q1p2/6p1/2p1P1B1/4P1Q1/1P5P/r2p2P1/3R2K1 w - - 2 31\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: d1 white rook; g1 white king; g2 white pawn; b3 white pawn; h3 white pawn; e4 white pawn; g4 white queen; e5 white pawn; g5 white bishop.\nFilter by piece:\nd1 white rook: pseudo-legal d1a1 d1b1 d1c1 d1d2 d1e1 d1f1 | rejected none | legal d1a1 d1b1 d1c1 d1d2 d1e1 d1f1\ng1 white king: pseudo-legal g1f1 g1f2 g1h1 g1h2 | rejected none | legal g1f1 g1f2 g1h1 g1h2\ng2 white pawn: pseudo-legal g2g3 | rejected none | legal g2g3\nb3 white pawn: pseudo-legal b3b4 | rejected none | legal b3b4\nh3 white pawn: pseudo-legal h3h4 | rejected none | legal h3h4\ne4 white pawn: pseudo-legal none | rejected none | legal none\ng4 white queen: pseudo-legal g4d7 g4e2 g4e6 g4f3 g4f4 g4f5 g4g3 g4h4 g4h5 | rejected none | legal g4d7 g4e2 g4e6 g4f3 g4f4 g4f5 g4g3 g4h4 g4h5\ne5 white pawn: pseudo-legal e5e6 | rejected none | legal e5e6\ng5 white bishop: pseudo-legal g5d2 g5d8 g5e3 g5e7 g5f4 g5f6 g5h4 g5h6 | rejected none | legal g5d2 g5d8 g5e3 g5e7 g5f4 g5f6 g5h4 g5h6\nAll legal moves: b3b4 d1a1 d1b1 d1c1 d1d2 d1e1 d1f1 e5e6 g1f1 g1f2 g1h1 g1h2 g2g3 g4d7 g4e2 g4e6 g4f3 g4f4 g4f5 g4g3 g4h4 g4h5 g5d2 g5d8 g5e3 g5e7 g5f4 g5f6 g5h4 g5h6 h3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00650", "split": "rules", "task_type": "legal_moves", "fen": "8/8/8/8/p1k5/P3KQ2/8/8 w - - 5 68", "prompt": "FEN: 8/8/8/8/p1k5/P3KQ2/8/8 w - - 5 68\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: e3d2 e3e2 e3e4 e3f2 e3f4 f3a8 f3b7 f3c6 f3d1 f3d5 f3e2 f3e4 f3f1 f3f2 f3f4 f3f5 f3f6 f3f7 f3f8 f3g2 f3g3 f3g4 f3h1 f3h3 f3h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00651", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2q1rk1/ppp2ppp/2n5/5n2/1bBP2b1/2N1BN2/PP3PPP/R2Q1RK1 w - -", "prompt": "FEN: r2q1rk1/ppp2ppp/2n5/5n2/1bBP2b1/2N1BN2/PP3PPP/R2Q1RK1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white queen; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white knight; e3 white bishop; f3 white knight; c4 white bishop; d4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "e3", "piece": "white bishop"}, {"square": "f3", "piece": "white knight"}, {"square": "c4", "piece": "white bishop"}, {"square": "d4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "e3", "piece": "white bishop"}, {"square": "f3", "piece": "white knight"}, {"square": "c4", "piece": "white bishop"}, {"square": "d4", "piece": "white pawn"}]}}
{"example_id": "rules_00652", "split": "rules", "task_type": "piece_legal_moves", "fen": "k7/3R4/2n5/5p1Q/5B1K/2q4P/5PP1/7r b - -", "prompt": "FEN: k7/3R4/2n5/5p1Q/5B1K/2q4P/5PP1/7r b - -\nWhat legal moves does the piece on a8 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "a8", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "a8", "piece": "king"}}
{"example_id": "rules_00653", "split": "rules", "task_type": "check_detection", "fen": "1r5k/1br3pp/2q2p2/p1bpp3/P7/1PP1BP1P/5QP1/1NRR2K1 b - -", "prompt": "FEN: 1r5k/1br3pp/2q2p2/p1bpp3/P7/1PP1BP1P/5QP1/1NRR2K1 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00654", "split": "rules", "task_type": "captures", "fen": "8/pp4kp/4R3/5P2/3p4/P7/1P3r1P/7K w - -", "prompt": "FEN: 8/pp4kp/4R3/5P2/3p4/P7/1P3r1P/7K w - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00655", "split": "rules", "task_type": "special_rules", "fen": "5rk1/p1R3p1/2p1p2p/2p5/8/4K3/P1P3P1/8 b - - 3 27", "prompt": "Given FEN: 5rk1/p1R3p1/2p1p2p/2p5/8/4K3/P1P3P1/8 b - - 3 27\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00656", "split": "rules", "task_type": "legality_check", "fen": "3r2rk/pp2bp2/3p3p/4pP2/8/2P2N1P/PP1R1PP1/3R2K1 b - - 2 30", "prompt": "FEN: 3r2rk/pp2bp2/3p3p/4pP2/8/2P2N1P/PP1R1PP1/3R2K1 b - - 2 30\nIs the move a7a6 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "a7a6", "_legality_check_reason_label": "legal", "move": "a7a6", "legality_reason_label": "legal"}}
{"example_id": "rules_00657", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/1p6/8/1KP1n1R1/4k1p1/8/8/8 b - - 4 52", "prompt": "FEN: 8/1p6/8/1KP1n1R1/4k1p1/8/8/8 b - - 4 52\nList pseudo-legal moves from e4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e4: e4d3 e4d4 e4d5 e4e3 e4f3 e4f4 e4f5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e4", "diagnostic": true, "hard_gate": false, "source_square": "e4"}}
{"example_id": "rules_00658", "split": "rules", "task_type": "piece_legal_filter", "fen": "2qr3k/3rb1p1/1p1p3p/p1pR2P1/P1Q1PP2/1P2BK2/2P5/3R4 b - - 0 27", "prompt": "FEN: 2qr3k/3rb1p1/1p1p3p/p1pR2P1/P1Q1PP2/1P2BK2/2P5/3R4 b - - 0 27\nFor the piece on b6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b6: b6b5.\nLegal: b6b5.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b6", "diagnostic": true, "hard_gate": false, "source_square": "b6"}}
{"example_id": "rules_00659", "split": "rules", "task_type": "king_safety_filter", "fen": "4rk2/p1pnp1b1/1p1p1p2/8/3PNP2/2P1PR2/PP4PK/1R6 b - - 0 20", "prompt": "FEN: 4rk2/p1pnp1b1/1p1p1p2/8/3PNP2/2P1PR2/PP4PK/1R6 b - - 0 20\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00660", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnb2k1N/pppp1Bpp/1b6/8/3Pn3/8/PPP2PPP/RNB1K2R w KQ - 0 11", "prompt": "FEN: rnb2k1N/pppp1Bpp/1b6/8/3Pn3/8/PPP2PPP/RNB1K2R w KQ - 0 11\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; e1 white king; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; d4 white pawn; f7 white bishop; h8 white knight.\nMoves by piece:\na1 white rook: no legal moves\nb1 white knight: b1a3 b1c3 b1d2\nc1 white bishop: c1d2 c1e3 c1f4 c1g5 c1h6\ne1 white king: e1d1 e1e2 e1f1 e1g1\nh1 white rook: h1f1 h1g1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: c2c3 c2c4\nf2 white pawn: f2f3 f2f4\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nd4 white pawn: d4d5\nf7 white bishop: f7b3 f7c4 f7d5 f7e6 f7e8 f7g6 f7g8 f7h5\nh8 white knight: h8g6\nAll legal moves: a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c2c4 d4d5 e1d1 e1e2 e1f1 e1g1 f2f3 f2f4 f7b3 f7c4 f7d5 f7e6 f7e8 f7g6 f7g8 f7h5 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4 h8g6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "b1": ["b1a3", "b1c3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "e1": ["e1d1", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "d4": ["d4d5"], "f7": ["f7b3", "f7c4", "f7d5", "f7e6", "f7e8", "f7g6", "f7g8", "f7h5"], "h8": ["h8g6"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c2c4 d4d5 e1d1 e1e2 e1f1 e1g1 f2f3 f2f4 f7b3 f7c4 f7d5 f7e6 f7e8 f7g6 f7g8 f7h5 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4 h8g6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "b1": ["b1a3", "b1c3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "e1": ["e1d1", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "d4": ["d4d5"], "f7": ["f7b3", "f7c4", "f7d5", "f7e6", "f7e8", "f7g6", "f7g8", "f7h5"], "h8": ["h8g6"]}, "legal_moves": "a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c2c4 d4d5 e1d1 e1e2 e1f1 e1g1 f2f3 f2f4 f7b3 f7c4 f7d5 f7e6 f7e8 f7g6 f7g8 f7h5 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4 h8g6"}}
{"example_id": "rules_00661", "split": "rules", "task_type": "ray_walk", "fen": "r3k2r/ppqnbppp/2p1p3/3PPnB1/3P4/3Q1N2/PP1N1PPP/R4RK1 b kq - 0 11", "prompt": "FEN: r3k2r/ppqnbppp/2p1p3/3PPnB1/3P4/3Q1N2/PP1N1PPP/R4RK1 b kq - 0 11\nWalk each ray for the slider on c7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c7 black queen.\nRay N: c8 empty; edge.\nRay NE: d8 empty; edge.\nRay E: d7 black knight: own piece (stop, excluded).\nRay SE: d6 empty; e5 white pawn: capture (stop, included).\nRay S: c6 black pawn: own piece (stop, excluded).\nRay SW: b6 empty; a5 empty; edge.\nRay W: b7 black pawn: own piece (stop, excluded).\nRay NW: b8 empty; edge.\nMoves from rays: c7a5 c7b6 c7b8 c7c8 c7d6 c7d8 c7e5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "c7", "diagnostic": true, "hard_gate": false, "source_square": "c7"}}
{"example_id": "rules_00662", "split": "rules", "task_type": "legal_moves", "fen": "r1b1k2r/pp1p1pqp/3Np3/8/8/1P6/P1P1BPPP/2b1K2R b Kkq - 1 15", "prompt": "FEN: r1b1k2r/pp1p1pqp/3Np3/8/8/1P6/P1P1BPPP/2b1K2R b Kkq - 1 15\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: e8d8 e8e7 e8f8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00663", "split": "rules", "task_type": "legal_moves", "fen": "8/5Q2/8/4K1k1/8/8/8/8 w - -", "prompt": "FEN: 8/5Q2/8/4K1k1/8/8/8/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: e5d4 e5d5 e5d6 e5e4 e5e6 f7a2 f7a7 f7b3 f7b7 f7c4 f7c7 f7d5 f7d7 f7e6 f7e7 f7e8 f7f1 f7f2 f7f3 f7f4 f7f5 f7f6 f7f8 f7g6 f7g7 f7g8 f7h5 f7h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00664", "split": "rules", "task_type": "side_piece_inventory", "fen": "2r3k1/1b3ppp/8/1p4PK/7P/1P3N2/P3q3/8 b - - 3 36", "prompt": "FEN: 2r3k1/1b3ppp/8/1p4PK/7P/1P3N2/P3q3/8 b - - 3 36\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: e2 black queen; b5 black pawn; b7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; c8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "e2", "piece": "black queen"}, {"square": "b5", "piece": "black pawn"}, {"square": "b7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "c8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "e2", "piece": "black queen"}, {"square": "b5", "piece": "black pawn"}, {"square": "b7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "c8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_00665", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/6k1/4Bpp1/1R4b1/p3P3/P2n2N1/1P1rK1P1/8 w - - 3 38", "prompt": "FEN: 8/6k1/4Bpp1/1R4b1/p3P3/P2n2N1/1P1rK1P1/8 w - - 3 38\nWhat legal moves does the piece on e4 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "e4", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "e4", "piece": "pawn"}}
{"example_id": "rules_00666", "split": "rules", "task_type": "check_detection", "fen": "r2qk1nr/ppp2ppp/3p4/2bNp2b/2BnP3/5N1P/PPPP1PP1/R1BQ1RK1 w kq -", "prompt": "FEN: r2qk1nr/ppp2ppp/3p4/2bNp2b/2BnP3/5N1P/PPPP1PP1/R1BQ1RK1 w kq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00667", "split": "rules", "task_type": "captures", "fen": "r3k2r/p1p2ppp/2qb1n2/4p1N1/2b5/2N5/P1PPQPPP/R1B2RK1 w kq -", "prompt": "FEN: r3k2r/p1p2ppp/2qb1n2/4p1N1/2b5/2N5/P1PPQPPP/R1B2RK1 w kq -\nList all capture moves available.", "gold_answer": "e2c4 e2e5 g5f7 g5h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00668", "split": "rules", "task_type": "special_rules", "fen": "rnb1kb1r/pp1p1ppp/1q1Pp3/2p5/2P1nB2/8/PPQ1PPPP/RN2KBNR b KQkq -", "prompt": "Given FEN: rnb1kb1r/pp1p1ppp/1q1Pp3/2p5/2P1nB2/8/PPQ1PPPP/RN2KBNR b KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00669", "split": "rules", "task_type": "legality_check", "fen": "8/3r1k1p/1p3ppP/1N1nP3/P7/1P4P1/3R4/6K1 b - - 0 41", "prompt": "FEN: 8/3r1k1p/1p3ppP/1N1nP3/P7/1P4P1/3R4/6K1 b - - 0 41\nIs the move g6g5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g6g5", "_legality_check_reason_label": "legal", "move": "g6g5", "legality_reason_label": "legal"}}
{"example_id": "rules_00670", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnbqk1nr/pppp1ppp/8/4p3/1bP5/P1N5/1P1PPPPP/R1BQKBNR b KQkq - 0 3", "prompt": "FEN: rnbqk1nr/pppp1ppp/8/4p3/1bP5/P1N5/1P1PPPPP/R1BQKBNR b KQkq - 0 3\nList pseudo-legal moves from b4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b4: b4a3 b4a5 b4c3 b4c5 b4d6 b4e7 b4f8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_00671", "split": "rules", "task_type": "piece_legal_filter", "fen": "r4rk1/3n1pp1/1q1p3p/pp2p3/2bPP2N/2P1P1P1/1PB1Q2P/R4RK1 w - - 3 21", "prompt": "FEN: r4rk1/3n1pp1/1q1p3p/pp2p3/2bPP2N/2P1P1P1/1PB1Q2P/R4RK1 w - - 3 21\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1a2 a1a3 a1a4 a1a5 a1b1 a1c1 a1d1 a1e1.\nLegal: a1a2 a1a3 a1a4 a1a5 a1b1 a1c1 a1d1 a1e1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00672", "split": "rules", "task_type": "king_safety_filter", "fen": "rn2kb1r/pbpp1nq1/1p2pp2/7p/1P2P2P/P1PP1pP1/3NN3/R1BQKB1R b KQkq - 1 13", "prompt": "FEN: rn2kb1r/pbpp1nq1/1p2pp2/7p/1P2P2P/P1PP1pP1/3NN3/R1BQKB1R b KQkq - 1 13\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00673", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqk2r/pppp1ppp/1nn5/4P3/1b6/1BN2N2/PP3PPP/R1BQK2R w KQkq -", "prompt": "FEN: r1bqk2r/pppp1ppp/1nn5/4P3/1b6/1BN2N2/PP3PPP/R1BQK2R w KQkq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; e1 white king; h1 white rook; a2 white pawn; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; b3 white bishop; c3 white knight; f3 white knight; e5 white pawn.\nMoves by piece:\na1 white rook: a1b1\nc1 white bishop: c1d2 c1e3 c1f4 c1g5 c1h6\nd1 white queen: d1c2 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1e2\ne1 white king: e1d2 e1e2 e1f1 e1g1\nh1 white rook: h1f1 h1g1\na2 white pawn: a2a3 a2a4\nb2 white pawn: no legal moves\nf2 white pawn: no legal moves\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nb3 white bishop: b3a4 b3c2 b3c4 b3d5 b3e6 b3f7\nc3 white knight: no legal moves\nf3 white knight: f3d2 f3d4 f3g1 f3g5 f3h4\ne5 white pawn: e5e6\nAll legal moves: a1b1 a2a3 a2a4 b3a4 b3c2 b3c4 b3d5 b3e6 b3f7 c1d2 c1e3 c1f4 c1g5 c1h6 d1c2 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1e2 e1d2 e1e2 e1f1 e1g1 e5e6 f3d2 f3d4 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1c2", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1d7", "d1e2"], "e1": ["e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1"], "a2": ["a2a3", "a2a4"], "b2": [], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "b3": ["b3a4", "b3c2", "b3c4", "b3d5", "b3e6", "b3f7"], "c3": [], "f3": ["f3d2", "f3d4", "f3g1", "f3g5", "f3h4"], "e5": ["e5e6"]}, "_legal_moves_by_piece_moves": "a1b1 a2a3 a2a4 b3a4 b3c2 b3c4 b3d5 b3e6 b3f7 c1d2 c1e3 c1f4 c1g5 c1h6 d1c2 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1e2 e1d2 e1e2 e1f1 e1g1 e5e6 f3d2 f3d4 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1c2", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1d7", "d1e2"], "e1": ["e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1"], "a2": ["a2a3", "a2a4"], "b2": [], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "b3": ["b3a4", "b3c2", "b3c4", "b3d5", "b3e6", "b3f7"], "c3": [], "f3": ["f3d2", "f3d4", "f3g1", "f3g5", "f3h4"], "e5": ["e5e6"]}, "legal_moves": "a1b1 a2a3 a2a4 b3a4 b3c2 b3c4 b3d5 b3e6 b3f7 c1d2 c1e3 c1f4 c1g5 c1h6 d1c2 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1e2 e1d2 e1e2 e1f1 e1g1 e5e6 f3d2 f3d4 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4"}}
{"example_id": "rules_00674", "split": "rules", "task_type": "ray_walk", "fen": "3r3k/N5p1/7p/5pq1/2r1p3/6P1/PPPn1PQ1/2RR3K b - -", "prompt": "FEN: 3r3k/N5p1/7p/5pq1/2r1p3/6P1/PPPn1PQ1/2RR3K b - -\nWalk each ray for the slider on c4: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c4 black rook.\nRay N: c5 empty; c6 empty; c7 empty; c8 empty; edge.\nRay E: d4 empty; e4 black pawn: own piece (stop, excluded).\nRay S: c3 empty; c2 white pawn: capture (stop, included).\nRay W: b4 empty; a4 empty; edge.\nMoves from rays: c4a4 c4b4 c4c2 c4c3 c4c5 c4c6 c4c7 c4c8 c4d4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c4", "diagnostic": true, "hard_gate": false, "source_square": "c4"}}
{"example_id": "rules_00675", "split": "rules", "task_type": "legal_moves", "fen": "r1b1r1k1/2B1bppp/2p1n3/p1p5/P1Pp4/3P2P1/1P1N1P1P/2KR1B1R w - - 1 17", "prompt": "FEN: r1b1r1k1/2B1bppp/2p1n3/p1p5/P1Pp4/3P2P1/1P1N1P1P/2KR1B1R w - - 1 17\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b2b3 b2b4 c1b1 c1c2 c7a5 c7b6 c7b8 c7d6 c7d8 c7e5 c7f4 d1e1 d2b1 d2b3 d2e4 d2f3 f1e2 f1g2 f1h3 f2f3 f2f4 g3g4 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00676", "split": "rules", "task_type": "legal_moves", "fen": "8/k7/8/1K6/1B6/1B6/8/8 b - -", "prompt": "FEN: 8/k7/8/1K6/1B6/1B6/8/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a8 a7b7 a7b8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00677", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bb3r/pp2Q1p1/2p1p1k1/8/3P1p2/2P5/PP3PPP/4RRK1 w - -", "prompt": "FEN: r1bb3r/pp2Q1p1/2p1p1k1/8/3P1p2/2P5/PP3PPP/4RRK1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: e1 white rook; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white pawn; d4 white pawn; e7 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "e1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "e7", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "e1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "e7", "piece": "white queen"}]}}
{"example_id": "rules_00678", "split": "rules", "task_type": "piece_legal_moves", "fen": "2k4r/2p5/p1b2p2/2P4p/3r2pP/2N3R1/PP1K1P2/8 w - - 0 29", "prompt": "FEN: 2k4r/2p5/p1b2p2/2P4p/3r2pP/2N3R1/PP1K1P2/8 w - - 0 29\nWhat legal moves does the piece on b2 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "b2", "piece": "pawn"}}
{"example_id": "rules_00679", "split": "rules", "task_type": "check_detection", "fen": "r2qr1k1/1ppbbp2/2n1p1pp/4P3/p2PBP2/2P3QP/PP1N2P1/R1B2RK1 w - - 0 19", "prompt": "FEN: r2qr1k1/1ppbbp2/2n1p1pp/4P3/p2PBP2/2P3QP/PP1N2P1/R1B2RK1 w - - 0 19\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00680", "split": "rules", "task_type": "captures", "fen": "rn3rk1/pb4b1/1p2pPp1/2pp1nB1/3P4/2PB4/PP4PP/RN3RK1 b - - 0 17", "prompt": "FEN: rn3rk1/pb4b1/1p2pPp1/2pp1nB1/3P4/2PB4/PP4PP/RN3RK1 b - - 0 17\nList all capture moves available.", "gold_answer": "c5d4 f5d4 f8f6 g7f6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00681", "split": "rules", "task_type": "special_rules", "fen": "r1q2rk1/1pp2p1b/p4B2/8/3n2PQ/P1NP1P2/1PP2K1P/4R3 w - - 3 31", "prompt": "Given FEN: r1q2rk1/1pp2p1b/p4B2/8/3n2PQ/P1NP1P2/1PP2K1P/4R3 w - - 3 31\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00682", "split": "rules", "task_type": "legality_check", "fen": "r1bqk2r/pp1nppbp/5np1/1B2N3/3Q4/2N5/PPP2PPP/R1B1K2R w KQkq -", "prompt": "FEN: r1bqk2r/pp1nppbp/5np1/1B2N3/3Q4/2N5/PPP2PPP/R1B1K2R w KQkq -\nIs the move c3a4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "c3a4", "_legality_check_reason_label": "legal", "move": "c3a4", "legality_reason_label": "legal"}}
{"example_id": "rules_00683", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnb1kbnr/pppp1ppp/8/4p3/6Pq/5P2/PPPPP2P/RNBQKBNR w KQkq - 1 3", "prompt": "FEN: rnb1kbnr/pppp1ppp/8/4p3/6Pq/5P2/PPPPP2P/RNBQKBNR w KQkq - 1 3\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a3 b1c3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_openings", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_00684", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1b2rk1/1p3p1p/p1npp1p1/2p1b1qn/4P3/NP1B3Q/P1PP1P1P/1R2K1NR w K - 0 14", "prompt": "FEN: r1b2rk1/1p3p1p/p1npp1p1/2p1b1qn/4P3/NP1B3Q/P1PP1P1P/1R2K1NR w K - 0 14\nFor the piece on b1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b1: b1a1 b1b2 b1c1 b1d1.\nLegal: b1a1 b1b2 b1c1 b1d1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_00685", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbqkbnr/1p1ppppp/p1p5/8/3P4/5N2/PPP1PPPP/RNBQKB1R w KQkq -", "prompt": "FEN: rnbqkbnr/1p1ppppp/p1p5/8/3P4/5N2/PPP1PPPP/RNBQKB1R w KQkq -\nFor move a2a3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a2a3.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a2a3", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a2a3", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00686", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1b4q/ppk2p2/1n1p4/2pPpPQ1/2P4r/2P4P/P1B2PK1/1RB4R b - -", "prompt": "FEN: r1b4q/ppk2p2/1n1p4/2pPpPQ1/2P4r/2P4P/P1B2PK1/1RB4R b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: h4 black rook; c5 black pawn; e5 black pawn; b6 black knight; d6 black pawn; a7 black pawn; b7 black pawn; c7 black king; f7 black pawn; a8 black rook; c8 black bishop; h8 black queen.\nMoves by piece:\nh4 black rook: h4c4 h4d4 h4e4 h4f4 h4g4 h4h3 h4h5 h4h6 h4h7\nc5 black pawn: no legal moves\ne5 black pawn: e5e4\nb6 black knight: b6a4 b6c4 b6d5 b6d7\nd6 black pawn: no legal moves\na7 black pawn: a7a5 a7a6\nb7 black pawn: no legal moves\nc7 black king: c7b8 c7d7\nf7 black pawn: f7f6\na8 black rook: a8b8\nc8 black bishop: c8d7 c8e6 c8f5\nh8 black queen: h8d8 h8e8 h8f6 h8f8 h8g7 h8g8 h8h5 h8h6 h8h7\nAll legal moves: a7a5 a7a6 a8b8 b6a4 b6c4 b6d5 b6d7 c7b8 c7d7 c8d7 c8e6 c8f5 e5e4 f7f6 h4c4 h4d4 h4e4 h4f4 h4g4 h4h3 h4h5 h4h6 h4h7 h8d8 h8e8 h8f6 h8f8 h8g7 h8g8 h8h5 h8h6 h8h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"h4": ["h4c4", "h4d4", "h4e4", "h4f4", "h4g4", "h4h3", "h4h5", "h4h6", "h4h7"], "c5": [], "e5": ["e5e4"], "b6": ["b6a4", "b6c4", "b6d5", "b6d7"], "d6": [], "a7": ["a7a5", "a7a6"], "b7": [], "c7": ["c7b8", "c7d7"], "f7": ["f7f6"], "a8": ["a8b8"], "c8": ["c8d7", "c8e6", "c8f5"], "h8": ["h8d8", "h8e8", "h8f6", "h8f8", "h8g7", "h8g8", "h8h5", "h8h6", "h8h7"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 b6a4 b6c4 b6d5 b6d7 c7b8 c7d7 c8d7 c8e6 c8f5 e5e4 f7f6 h4c4 h4d4 h4e4 h4f4 h4g4 h4h3 h4h5 h4h6 h4h7 h8d8 h8e8 h8f6 h8f8 h8g7 h8g8 h8h5 h8h6 h8h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"h4": ["h4c4", "h4d4", "h4e4", "h4f4", "h4g4", "h4h3", "h4h5", "h4h6", "h4h7"], "c5": [], "e5": ["e5e4"], "b6": ["b6a4", "b6c4", "b6d5", "b6d7"], "d6": [], "a7": ["a7a5", "a7a6"], "b7": [], "c7": ["c7b8", "c7d7"], "f7": ["f7f6"], "a8": ["a8b8"], "c8": ["c8d7", "c8e6", "c8f5"], "h8": ["h8d8", "h8e8", "h8f6", "h8f8", "h8g7", "h8g8", "h8h5", "h8h6", "h8h7"]}, "legal_moves": "a7a5 a7a6 a8b8 b6a4 b6c4 b6d5 b6d7 c7b8 c7d7 c8d7 c8e6 c8f5 e5e4 f7f6 h4c4 h4d4 h4e4 h4f4 h4g4 h4h3 h4h5 h4h6 h4h7 h8d8 h8e8 h8f6 h8f8 h8g7 h8g8 h8h5 h8h6 h8h7"}}
{"example_id": "rules_00687", "split": "rules", "task_type": "ray_walk", "fen": "3r1rk1/2p2ppn/p1n1q1b1/1pp1p1Pp/4P2P/2PP1N2/PPB1QP2/R2R1NK1 w - -", "prompt": "FEN: 3r1rk1/2p2ppn/p1n1q1b1/1pp1p1Pp/4P2P/2PP1N2/PPB1QP2/R2R1NK1 w - -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 white rook: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00688", "split": "rules", "task_type": "legal_moves", "fen": "2r2rk1/p6p/1p2pq2/3p4/2nP4/1Q4P1/P3pP1P/4RK2 w - - 0 30", "prompt": "FEN: 2r2rk1/p6p/1p2pq2/3p4/2nP4/1Q4P1/P3pP1P/4RK2 w - - 0 30\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: e1e2 f1e2 f1g1 f1g2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00689", "split": "rules", "task_type": "legal_moves", "fen": "rn1qk1nr/1bp2pbp/p2pp1p1/1p2P3/P2P1P2/2NB1N2/1PP3PP/R1BQK2R b KQkq -", "prompt": "FEN: rn1qk1nr/1bp2pbp/p2pp1p1/1p2P3/P2P1P2/2NB1N2/1PP3PP/R1BQK2R b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 b5a4 b5b4 b7c6 b7c8 b7d5 b7e4 b7f3 b8c6 b8d7 c7c5 c7c6 d6d5 d6e5 d8c8 d8d7 d8e7 d8f6 d8g5 d8h4 e8d7 e8e7 e8f8 f7f5 f7f6 g6g5 g7e5 g7f6 g7f8 g7h6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00690", "split": "rules", "task_type": "side_piece_inventory", "fen": "r3rbk1/1pqn1ppp/p4nb1/3PpNB1/1p2P3/3BN1QP/P1P3P1/R4R1K w - - 0 21", "prompt": "FEN: r3rbk1/1pqn1ppp/p4nb1/3PpNB1/1p2P3/3BN1QP/P1P3P1/R4R1K w - - 0 21\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; f1 white rook; h1 white king; a2 white pawn; c2 white pawn; g2 white pawn; d3 white bishop; e3 white knight; g3 white queen; h3 white pawn; e4 white pawn; d5 white pawn; f5 white knight; g5 white bishop.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "h1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "e3", "piece": "white knight"}, {"square": "g3", "piece": "white queen"}, {"square": "h3", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}, {"square": "d5", "piece": "white pawn"}, {"square": "f5", "piece": "white knight"}, {"square": "g5", "piece": "white bishop"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "h1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "e3", "piece": "white knight"}, {"square": "g3", "piece": "white queen"}, {"square": "h3", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}, {"square": "d5", "piece": "white pawn"}, {"square": "f5", "piece": "white knight"}, {"square": "g5", "piece": "white bishop"}]}}
{"example_id": "rules_00691", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b1kb1r/pp3ppp/8/1Bpn4/8/1P6/P1P2PPP/RNB1K2R b KQkq - 1 10", "prompt": "FEN: r1b1kb1r/pp3ppp/8/1Bpn4/8/1P6/P1P2PPP/RNB1K2R b KQkq - 1 10\nWhat legal moves does the piece on c8 have?", "gold_answer": "c8d7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c8", "_piece_legal_moves_piece": "bishop", "diagnostic": true, "hard_gate": false, "source_square": "c8", "piece": "bishop"}}
{"example_id": "rules_00692", "split": "rules", "task_type": "check_detection", "fen": "2bk1b1r/ppNp1ppp/n1pQ3n/4P3/qP6/P3PN2/2P2PPP/R1B1KB1R w KQ - 5 13", "prompt": "FEN: 2bk1b1r/ppNp1ppp/n1pQ3n/4P3/qP6/P3PN2/2P2PPP/R1B1KB1R w KQ - 5 13\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00693", "split": "rules", "task_type": "captures", "fen": "7r/p7/1p3pk1/2pPpN2/P1P1PpP1/1P3B2/6K1/8 b - - 4 40", "prompt": "FEN: 7r/p7/1p3pk1/2pPpN2/P1P1PpP1/1P3B2/6K1/8 b - - 4 40\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00694", "split": "rules", "task_type": "special_rules", "fen": "8/p2p1N1k/bp3Qp1/2nP4/2P5/2N1P3/PPB5/R5K1 w - - 1 27", "prompt": "Given FEN: 8/p2p1N1k/bp3Qp1/2nP4/2P5/2N1P3/PPB5/R5K1 w - - 1 27\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00695", "split": "rules", "task_type": "legality_check", "fen": "r4rk1/2p2p2/p3p1pp/1p2P3/3P1R2/P1N1P1qP/BP4bN/R4K2 w - - 4 24", "prompt": "FEN: r4rk1/2p2p2/p3p1pp/1p2P3/3P1R2/P1N1P1qP/BP4bN/R4K2 w - - 4 24\nIs the move f1e2 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f1e2", "_legality_check_reason_label": "legal", "move": "f1e2", "legality_reason_label": "legal"}}
{"example_id": "rules_00696", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2qk2r/pbpnbpp1/1p1ppn1p/8/3PP3/2NB1N2/PPPB1PPP/R2Q1RK1 w kq - 2 9", "prompt": "FEN: r2qk2r/pbpnbpp1/1p1ppn1p/8/3PP3/2NB1N2/PPPB1PPP/R2Q1RK1 w kq - 2 9\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1 a1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00697", "split": "rules", "task_type": "piece_legal_filter", "fen": "r7/p2k1pp1/p1p1p2p/8/1R2P3/2PN1P2/P5PP/2K5 w - - 2 33", "prompt": "FEN: r7/p2k1pp1/p1p1p2p/8/1R2P3/2PN1P2/P5PP/2K5 w - - 2 33\nFor the piece on c1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c1: c1b1 c1b2 c1c2 c1d1 c1d2.\nLegal: c1b1 c1b2 c1c2 c1d1 c1d2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_00698", "split": "rules", "task_type": "king_safety_filter", "fen": "r3k2r/pbqnbppp/3ppn2/1pp5/4P3/2PPBNP1/PP1N1PBP/R2Q1RK1 w kq - 1 10", "prompt": "FEN: r3k2r/pbqnbppp/3ppn2/1pp5/4P3/2PPBNP1/PP1N1PBP/R2Q1RK1 w kq - 1 10\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00699", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1k2r2r/1ppn3p/p2p1b1B/4pN1p/4n3/5N2/PPP2PPP/2R1R1K1 b - - 5 18", "prompt": "FEN: 1k2r2r/1ppn3p/p2p1b1B/4pN1p/4n3/5N2/PPP2PPP/2R1R1K1 b - - 5 18\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e4 black knight; e5 black pawn; h5 black pawn; a6 black pawn; d6 black pawn; f6 black bishop; b7 black pawn; c7 black pawn; d7 black knight; h7 black pawn; b8 black king; e8 black rook; h8 black rook.\nMoves by piece:\ne4 black knight: e4c3 e4c5 e4d2 e4f2 e4g3 e4g5\ne5 black pawn: no legal moves\nh5 black pawn: h5h4\na6 black pawn: a6a5\nd6 black pawn: d6d5\nf6 black bishop: f6d8 f6e7 f6g5 f6g7 f6h4\nb7 black pawn: b7b5 b7b6\nc7 black pawn: c7c5 c7c6\nd7 black knight: d7b6 d7c5 d7f8\nh7 black pawn: no legal moves\nb8 black king: b8a7 b8a8 b8c8\ne8 black rook: e8c8 e8d8 e8e6 e8e7 e8f8 e8g8\nh8 black rook: h8f8 h8g8\nAll legal moves: a6a5 b7b5 b7b6 b8a7 b8a8 b8c8 c7c5 c7c6 d6d5 d7b6 d7c5 d7f8 e4c3 e4c5 e4d2 e4f2 e4g3 e4g5 e8c8 e8d8 e8e6 e8e7 e8f8 e8g8 f6d8 f6e7 f6g5 f6g7 f6h4 h5h4 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e4": ["e4c3", "e4c5", "e4d2", "e4f2", "e4g3", "e4g5"], "e5": [], "h5": ["h5h4"], "a6": ["a6a5"], "d6": ["d6d5"], "f6": ["f6d8", "f6e7", "f6g5", "f6g7", "f6h4"], "b7": ["b7b5", "b7b6"], "c7": ["c7c5", "c7c6"], "d7": ["d7b6", "d7c5", "d7f8"], "h7": [], "b8": ["b8a7", "b8a8", "b8c8"], "e8": ["e8c8", "e8d8", "e8e6", "e8e7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "a6a5 b7b5 b7b6 b8a7 b8a8 b8c8 c7c5 c7c6 d6d5 d7b6 d7c5 d7f8 e4c3 e4c5 e4d2 e4f2 e4g3 e4g5 e8c8 e8d8 e8e6 e8e7 e8f8 e8g8 f6d8 f6e7 f6g5 f6g7 f6h4 h5h4 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e4": ["e4c3", "e4c5", "e4d2", "e4f2", "e4g3", "e4g5"], "e5": [], "h5": ["h5h4"], "a6": ["a6a5"], "d6": ["d6d5"], "f6": ["f6d8", "f6e7", "f6g5", "f6g7", "f6h4"], "b7": ["b7b5", "b7b6"], "c7": ["c7c5", "c7c6"], "d7": ["d7b6", "d7c5", "d7f8"], "h7": [], "b8": ["b8a7", "b8a8", "b8c8"], "e8": ["e8c8", "e8d8", "e8e6", "e8e7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "legal_moves": "a6a5 b7b5 b7b6 b8a7 b8a8 b8c8 c7c5 c7c6 d6d5 d7b6 d7c5 d7f8 e4c3 e4c5 e4d2 e4f2 e4g3 e4g5 e8c8 e8d8 e8e6 e8e7 e8f8 e8g8 f6d8 f6e7 f6g5 f6g7 f6h4 h5h4 h8f8 h8g8"}}
{"example_id": "rules_00700", "split": "rules", "task_type": "ray_walk", "fen": "b7/8/4k3/2K5/7Q/8/8/8 b - -", "prompt": "FEN: b7/8/4k3/2K5/7Q/8/8/8 b - -\nWalk each ray for the slider on a8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a8 black bishop.\nRay NE: edge.\nRay SE: b7 empty; c6 empty; d5 empty; e4 empty; f3 empty; g2 empty; h1 empty; edge.\nRay SW: edge.\nRay NW: edge.\nMoves from rays: a8b7 a8c6 a8d5 a8e4 a8f3 a8g2 a8h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a8", "diagnostic": true, "hard_gate": false, "source_square": "a8"}}
{"example_id": "rules_00701", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/3nn1kp/4q1p1/1r2p3/8/Q3P1B1/5PPP/5RK1 w - -", "prompt": "FEN: 8/3nn1kp/4q1p1/1r2p3/8/Q3P1B1/5PPP/5RK1 w - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: f1 white rook; g1 white king; f2 white pawn; g2 white pawn; h2 white pawn; a3 white queen; e3 white pawn; g3 white bishop.\nFilter by piece:\nf1 white rook: pseudo-legal f1a1 f1b1 f1c1 f1d1 f1e1 | rejected none | legal f1a1 f1b1 f1c1 f1d1 f1e1\ng1 white king: pseudo-legal g1h1 | rejected none | legal g1h1\nf2 white pawn: pseudo-legal f2f3 f2f4 | rejected none | legal f2f3 f2f4\ng2 white pawn: pseudo-legal none | rejected none | legal none\nh2 white pawn: pseudo-legal h2h3 h2h4 | rejected none | legal h2h3 h2h4\na3 white queen: pseudo-legal a3a1 a3a2 a3a4 a3a5 a3a6 a3a7 a3a8 a3b2 a3b3 a3b4 a3c1 a3c3 a3c5 a3d3 a3d6 a3e7 | rejected none | legal a3a1 a3a2 a3a4 a3a5 a3a6 a3a7 a3a8 a3b2 a3b3 a3b4 a3c1 a3c3 a3c5 a3d3 a3d6 a3e7\ne3 white pawn: pseudo-legal e3e4 | rejected none | legal e3e4\ng3 white bishop: pseudo-legal g3e5 g3f4 g3h4 | rejected none | legal g3e5 g3f4 g3h4\nAll legal moves: a3a1 a3a2 a3a4 a3a5 a3a6 a3a7 a3a8 a3b2 a3b3 a3b4 a3c1 a3c3 a3c5 a3d3 a3d6 a3e7 e3e4 f1a1 f1b1 f1c1 f1d1 f1e1 f2f3 f2f4 g1h1 g3e5 g3f4 g3h4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00702", "split": "rules", "task_type": "legal_moves", "fen": "rn2kbnr/ppp1qppp/8/4p3/4P1b1/5NP1/PPPP2BP/RNBQK2R w KQkq - 2 7", "prompt": "FEN: rn2kbnr/ppp1qppp/8/4p3/4P1b1/5NP1/PPPP2BP/RNBQK2R w KQkq - 2 7\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c2c3 c2c4 d1e2 d2d3 d2d4 e1e2 e1f1 e1f2 e1g1 f3d4 f3e5 f3g1 f3g5 f3h4 g2f1 g2h3 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00703", "split": "rules", "task_type": "side_piece_inventory", "fen": "1b4k1/5p2/p4Qp1/8/1Pr5/2P4P/P3RPK1/5R2 w - - 3 32", "prompt": "FEN: 1b4k1/5p2/p4Qp1/8/1Pr5/2P4P/P3RPK1/5R2 w - - 3 32\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: f1 white rook; a2 white pawn; e2 white rook; f2 white pawn; g2 white king; c3 white pawn; h3 white pawn; b4 white pawn; f6 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "f1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "e2", "piece": "white rook"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white king"}, {"square": "c3", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "f6", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "f1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "e2", "piece": "white rook"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white king"}, {"square": "c3", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "f6", "piece": "white queen"}]}}
{"example_id": "rules_00704", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b1k2r/ppqn1ppp/3bpn2/3p2B1/8/2NP1N2/PPP1BPPP/R2Q1RK1 w kq - 3 9", "prompt": "FEN: r1b1k2r/ppqn1ppp/3bpn2/3p2B1/8/2NP1N2/PPP1BPPP/R2Q1RK1 w kq - 3 9\nWhat legal moves does the piece on f1 have?", "gold_answer": "f1e1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f1", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "f1", "piece": "rook"}}
{"example_id": "rules_00705", "split": "rules", "task_type": "check_detection", "fen": "r2q1rk1/pppn1pp1/5n1p/3p1B2/1b1P4/2N4P/PPP3PN/R1BQ1RK1 b - - 0 12", "prompt": "FEN: r2q1rk1/pppn1pp1/5n1p/3p1B2/1b1P4/2N4P/PPP3PN/R1BQ1RK1 b - - 0 12\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00706", "split": "rules", "task_type": "captures", "fen": "7k/8/7p/3P3p/Pr3P2/8/6P1/R5K1 b - -", "prompt": "FEN: 7k/8/7p/3P3p/Pr3P2/8/6P1/R5K1 b - -\nList all capture moves available.", "gold_answer": "b4a4 b4f4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00707", "split": "rules", "task_type": "special_rules", "fen": "2r5/p2R2pp/kp3b2/4n3/1B6/8/P5PP/1K2R3 w - - 8 34", "prompt": "Given FEN: 2r5/p2R2pp/kp3b2/4n3/1B6/8/P5PP/1K2R3 w - - 8 34\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00708", "split": "rules", "task_type": "legality_check", "fen": "2r1q1k1/pb5p/1pprpQp1/8/3P2P1/1P1R4/P4PBP/3R2K1 w - -", "prompt": "FEN: 2r1q1k1/pb5p/1pprpQp1/8/3P2P1/1P1R4/P4PBP/3R2K1 w - -\nIs the move d1b1 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "d1b1", "_legality_check_reason_label": "legal", "move": "d1b1", "legality_reason_label": "legal"}}
{"example_id": "rules_00709", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5rk1/1r1nqp1n/pp2p1pP/2pP4/8/1P1P4/PBP1B3/1K1R3R b - - 0 23", "prompt": "FEN: 5rk1/1r1nqp1n/pp2p1pP/2pP4/8/1P1P4/PBP1B3/1K1R3R b - - 0 23\nList pseudo-legal moves from c5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c5: c5c4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_00710", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/2K5/5k2/2P5/8/8/r7/4R3 w - -", "prompt": "FEN: 8/2K5/5k2/2P5/8/8/r7/4R3 w - -\nFor the piece on e1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e1: e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1e8 e1f1 e1g1 e1h1.\nLegal: e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1e8 e1f1 e1g1 e1h1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "e1", "diagnostic": true, "hard_gate": false, "source_square": "e1"}}
{"example_id": "rules_00711", "split": "rules", "task_type": "king_safety_filter", "fen": "8/2p3k1/p7/2P1NKP1/1P6/P4R2/8/7r b - - 6 53", "prompt": "FEN: 8/2p3k1/p7/2P1NKP1/1P6/P4R2/8/7r b - - 6 53\nFor move g7f6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: g7f6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "g7f6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "g7f6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00712", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r2qkbnr/p4ppp/2p5/3pp3/6b1/5N2/PPPP1PPP/RNB1QRK1 b kq - 1 8", "prompt": "FEN: r2qkbnr/p4ppp/2p5/3pp3/6b1/5N2/PPPP1PPP/RNB1QRK1 b kq - 1 8\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: g4 black bishop; d5 black pawn; e5 black pawn; c6 black pawn; a7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\ng4 black bishop: g4c8 g4d7 g4e6 g4f3 g4f5 g4h3 g4h5\nd5 black pawn: d5d4\ne5 black pawn: e5e4\nc6 black pawn: c6c5\na7 black pawn: a7a5 a7a6\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8 a8c8\nd8 black queen: d8a5 d8b6 d8b8 d8c7 d8c8 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4\ne8 black king: e8d7 e8e7\nf8 black bishop: f8a3 f8b4 f8c5 f8d6 f8e7\ng8 black knight: g8e7 g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a7a5 a7a6 a8b8 a8c8 c6c5 d5d4 d8a5 d8b6 d8b8 d8c7 d8c8 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e5e4 e8d7 e8e7 f7f5 f7f6 f8a3 f8b4 f8c5 f8d6 f8e7 g4c8 g4d7 g4e6 g4f3 g4f5 g4h3 g4h5 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"g4": ["g4c8", "g4d7", "g4e6", "g4f3", "g4f5", "g4h3", "g4h5"], "d5": ["d5d4"], "e5": ["e5e4"], "c6": ["c6c5"], "a7": ["a7a5", "a7a6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8", "a8c8"], "d8": ["d8a5", "d8b6", "d8b8", "d8c7", "d8c8", "d8d6", "d8d7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8d7", "e8e7"], "f8": ["f8a3", "f8b4", "f8c5", "f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 a8c8 c6c5 d5d4 d8a5 d8b6 d8b8 d8c7 d8c8 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e5e4 e8d7 e8e7 f7f5 f7f6 f8a3 f8b4 f8c5 f8d6 f8e7 g4c8 g4d7 g4e6 g4f3 g4f5 g4h3 g4h5 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"g4": ["g4c8", "g4d7", "g4e6", "g4f3", "g4f5", "g4h3", "g4h5"], "d5": ["d5d4"], "e5": ["e5e4"], "c6": ["c6c5"], "a7": ["a7a5", "a7a6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8", "a8c8"], "d8": ["d8a5", "d8b6", "d8b8", "d8c7", "d8c8", "d8d6", "d8d7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8d7", "e8e7"], "f8": ["f8a3", "f8b4", "f8c5", "f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "legal_moves": "a7a5 a7a6 a8b8 a8c8 c6c5 d5d4 d8a5 d8b6 d8b8 d8c7 d8c8 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e5e4 e8d7 e8e7 f7f5 f7f6 f8a3 f8b4 f8c5 f8d6 f8e7 g4c8 g4d7 g4e6 g4f3 g4f5 g4h3 g4h5 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_00713", "split": "rules", "task_type": "ray_walk", "fen": "rnbqk2r/ppp1bppp/8/8/1n6/2N2N2/PPPPQPPP/R1B1KB1R w KQkq -", "prompt": "FEN: rnbqk2r/ppp1bppp/8/8/1n6/2N2N2/PPPPQPPP/R1B1KB1R w KQkq -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 white bishop: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00714", "split": "rules", "task_type": "legal_moves", "fen": "r1b2rk1/pp2npb1/2n1p1pp/2P1P3/2Qq1P2/N6N/PP4PP/R1B1KB1R w KQ - 3 12", "prompt": "FEN: r1b2rk1/pp2npb1/2n1p1pp/2P1P3/2Qq1P2/N6N/PP4PP/R1B1KB1R w KQ - 3 12\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a3b1 a3b5 a3c2 b2b3 b2b4 c1d2 c1e3 c4a4 c4a6 c4b3 c4b4 c4b5 c4c2 c4c3 c4d3 c4d4 c4d5 c4e2 c4e6 e1e2 f1d3 f1e2 f4f5 g2g3 g2g4 h1g1 h3f2 h3g1 h3g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00715", "split": "rules", "task_type": "legal_moves", "fen": "rnb2rk1/pp1p3p/2p3q1/4p3/4P3/1P1P4/P1PQB1P1/4K1NR b K - 1 16", "prompt": "FEN: rnb2rk1/pp1p3p/2p3q1/4p3/4P3/1P1P4/P1PQB1P1/4K1NR b K - 1 16\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 c6c5 d7d5 d7d6 f8d8 f8e8 f8f1 f8f2 f8f3 f8f4 f8f5 f8f6 f8f7 g6d6 g6e4 g6e6 g6e8 g6f5 g6f6 g6f7 g6g2 g6g3 g6g4 g6g5 g6g7 g6h5 g6h6 g8f7 g8g7 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00716", "split": "rules", "task_type": "side_piece_inventory", "fen": "rnbq1rk1/pp1pppbp/5np1/2P5/4P3/P1N2N2/1PP2PPP/R1BQKB1R b KQ -", "prompt": "FEN: rnbq1rk1/pp1pppbp/5np1/2P5/4P3/P1N2N2/1PP2PPP/R1BQKB1R b KQ -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: f6 black knight; g6 black pawn; a7 black pawn; b7 black pawn; d7 black pawn; e7 black pawn; f7 black pawn; g7 black bishop; h7 black pawn; a8 black rook; b8 black knight; c8 black bishop; d8 black queen; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "f6", "piece": "black knight"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black pawn"}, {"square": "e7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black bishop"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "f6", "piece": "black knight"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black pawn"}, {"square": "e7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black bishop"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_00717", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b1kbnr/1p1p1p1p/1p6/4P1p1/5p2/1PP2N2/1P4PP/RNB2RK1 w kq - 0 13", "prompt": "FEN: r1b1kbnr/1p1p1p1p/1p6/4P1p1/5p2/1PP2N2/1P4PP/RNB2RK1 w kq - 0 13\nWhat legal moves does the piece on h2 have?", "gold_answer": "h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "h2", "piece": "pawn"}}
{"example_id": "rules_00718", "split": "rules", "task_type": "check_detection", "fen": "1r1k4/1Pn5/2P1p3/3pP3/1R1P1r1p/4q3/7Q/1R5K b - - 3 48", "prompt": "FEN: 1r1k4/1Pn5/2P1p3/3pP3/1R1P1r1p/4q3/7Q/1R5K b - - 3 48\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00719", "split": "rules", "task_type": "captures", "fen": "r3kbnr/pppq1ppp/3p4/8/1n2P3/3Q1N2/PPP2PPP/RNB1K2R w KQkq -", "prompt": "FEN: r3kbnr/pppq1ppp/3p4/8/1n2P3/3Q1N2/PPP2PPP/RNB1K2R w KQkq -\nList all capture moves available.", "gold_answer": "d3d6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00720", "split": "rules", "task_type": "special_rules", "fen": "3r4/7k/6p1/5pK1/5P2/8/8/8 w - -", "prompt": "Given FEN: 3r4/7k/6p1/5pK1/5P2/8/8/8 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00721", "split": "rules", "task_type": "legality_check", "fen": "5r1k/1ppq1rpp/1p6/4p3/4P1Q1/3Pp1R1/PPP3PP/5RK1 w - -", "prompt": "FEN: 5r1k/1ppq1rpp/1p6/4p3/4P1Q1/3Pp1R1/PPP3PP/5RK1 w - -\nIs the move g3h3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "g3h3", "_legality_check_reason_label": "legal", "move": "g3h3", "legality_reason_label": "legal"}}
{"example_id": "rules_00722", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnbqk1nr/pp2ppbp/3p2p1/2P5/2B1P3/5N2/PPP2PPP/RNBQK2R b KQkq - 0 5", "prompt": "FEN: rnbqk1nr/pp2ppbp/3p2p1/2P5/2B1P3/5N2/PPP2PPP/RNBQK2R b KQkq - 0 5\nList pseudo-legal moves from d6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d6: d6c5 d6d5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d6", "diagnostic": true, "hard_gate": false, "source_square": "d6"}}
{"example_id": "rules_00723", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn1q1rk1/pp3ppp/2pbbn2/4p3/4P3/3Q4/PPPPB1PP/RNB1K1NR w KQ - 4 10", "prompt": "FEN: rn1q1rk1/pp3ppp/2pbbn2/4p3/4P3/3Q4/PPPPB1PP/RNB1K1NR w KQ - 4 10\nFor the piece on b1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b1: b1a3 b1c3.\nLegal: b1a3 b1c3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_00724", "split": "rules", "task_type": "king_safety_filter", "fen": "r4rk1/1b3ppp/1qp5/p1bpPB2/5P2/P1P2KP1/1P5P/R1BQ3R b - - 0 18", "prompt": "FEN: r4rk1/1b3ppp/1qp5/p1bpPB2/5P2/P1P2KP1/1P5P/R1BQ3R b - - 0 18\nFor move a5a4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a5a4.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a5a4", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a5a4", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00725", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r4rk1/2p3pp/p3pp2/1p2N3/6R1/2P5/P1P2PPP/3R2K1 w - - 0 19", "prompt": "FEN: r4rk1/2p3pp/p3pp2/1p2N3/6R1/2P5/P1P2PPP/3R2K1 w - - 0 19\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: d1 white rook; g1 white king; a2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white pawn; g4 white rook; e5 white knight.\nMoves by piece:\nd1 white rook: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1\ng1 white king: g1f1 g1h1\na2 white pawn: a2a3 a2a4\nc2 white pawn: no legal moves\nf2 white pawn: f2f3 f2f4\ng2 white pawn: g2g3\nh2 white pawn: h2h3 h2h4\nc3 white pawn: c3c4\ng4 white rook: g4a4 g4b4 g4c4 g4d4 g4e4 g4f4 g4g3 g4g5 g4g6 g4g7 g4h4\ne5 white knight: e5c4 e5c6 e5d3 e5d7 e5f3 e5f7 e5g6\nAll legal moves: a2a3 a2a4 c3c4 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 e5c4 e5c6 e5d3 e5d7 e5f3 e5f7 e5g6 f2f3 f2f4 g1f1 g1h1 g2g3 g4a4 g4b4 g4c4 g4d4 g4e4 g4f4 g4g3 g4g5 g4g6 g4g7 g4h4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d1": ["d1a1", "d1b1", "d1c1", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1d7", "d1d8", "d1e1", "d1f1"], "g1": ["g1f1", "g1h1"], "a2": ["a2a3", "a2a4"], "c2": [], "f2": ["f2f3", "f2f4"], "g2": ["g2g3"], "h2": ["h2h3", "h2h4"], "c3": ["c3c4"], "g4": ["g4a4", "g4b4", "g4c4", "g4d4", "g4e4", "g4f4", "g4g3", "g4g5", "g4g6", "g4g7", "g4h4"], "e5": ["e5c4", "e5c6", "e5d3", "e5d7", "e5f3", "e5f7", "e5g6"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 c3c4 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 e5c4 e5c6 e5d3 e5d7 e5f3 e5f7 e5g6 f2f3 f2f4 g1f1 g1h1 g2g3 g4a4 g4b4 g4c4 g4d4 g4e4 g4f4 g4g3 g4g5 g4g6 g4g7 g4h4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d1": ["d1a1", "d1b1", "d1c1", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1d7", "d1d8", "d1e1", "d1f1"], "g1": ["g1f1", "g1h1"], "a2": ["a2a3", "a2a4"], "c2": [], "f2": ["f2f3", "f2f4"], "g2": ["g2g3"], "h2": ["h2h3", "h2h4"], "c3": ["c3c4"], "g4": ["g4a4", "g4b4", "g4c4", "g4d4", "g4e4", "g4f4", "g4g3", "g4g5", "g4g6", "g4g7", "g4h4"], "e5": ["e5c4", "e5c6", "e5d3", "e5d7", "e5f3", "e5f7", "e5g6"]}, "legal_moves": "a2a3 a2a4 c3c4 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 e5c4 e5c6 e5d3 e5d7 e5f3 e5f7 e5g6 f2f3 f2f4 g1f1 g1h1 g2g3 g4a4 g4b4 g4c4 g4d4 g4e4 g4f4 g4g3 g4g5 g4g6 g4g7 g4h4 h2h3 h2h4"}}
{"example_id": "rules_00726", "split": "rules", "task_type": "ray_walk", "fen": "7r/1pk2ppp/pn2p3/B1p1P3/P3PPPb/1P1r3P/4N1K1/R6R b - - 1 22", "prompt": "FEN: 7r/1pk2ppp/pn2p3/B1p1P3/P3PPPb/1P1r3P/4N1K1/R6R b - - 1 22\nWalk each ray for the slider on d3: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d3 black rook.\nRay N: d4 empty; d5 empty; d6 empty; d7 empty; d8 empty; edge.\nRay E: e3 empty; f3 empty; g3 empty; h3 white pawn: capture (stop, included).\nRay S: d2 empty; d1 empty; edge.\nRay W: c3 empty; b3 white pawn: capture (stop, included).\nMoves from rays: d3b3 d3c3 d3d1 d3d2 d3d4 d3d5 d3d6 d3d7 d3d8 d3e3 d3f3 d3g3 d3h3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "d3", "diagnostic": true, "hard_gate": false, "source_square": "d3"}}
{"example_id": "rules_00727", "split": "rules", "task_type": "legal_moves", "fen": "3q1r1k/5r1p/2np3Q/p2N2p1/2B1pP1b/1PP5/4K2R/7R w - -", "prompt": "FEN: 3q1r1k/5r1p/2np3Q/p2N2p1/2B1pP1b/1PP5/4K2R/7R w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b3b4 c4a6 c4b5 c4d3 d5b4 d5b6 d5c7 d5e3 d5e7 d5f6 e2d1 e2d2 e2e3 e2f1 f4f5 f4g5 h1a1 h1b1 h1c1 h1d1 h1e1 h1f1 h1g1 h2f2 h2g2 h2h3 h2h4 h6d6 h6e6 h6f6 h6f8 h6g5 h6g6 h6g7 h6h4 h6h5 h6h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00728", "split": "rules", "task_type": "legal_moves", "fen": "4r1k1/q4p1p/2Ppp1p1/2p2n2/2B3P1/2P2Q1P/1P3P2/4R1K1 b - -", "prompt": "FEN: 4r1k1/q4p1p/2Ppp1p1/2p2n2/2B3P1/2P2Q1P/1P3P2/4R1K1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a1 a7a2 a7a3 a7a4 a7a5 a7a6 a7a8 a7b6 a7b7 a7b8 a7c7 a7d7 a7e7 d6d5 e6e5 e8a8 e8b8 e8c8 e8d8 e8e7 e8f8 f5d4 f5e3 f5e7 f5g3 f5g7 f5h4 f5h6 f7f6 g6g5 g8f8 g8g7 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00729", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqkbnr/pp2pppp/2n5/3B4/4P3/2N5/PP3PPP/R1BQK1NR b KQkq -", "prompt": "FEN: r1bqkbnr/pp2pppp/2n5/3B4/4P3/2N5/PP3PPP/R1BQK1NR b KQkq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c6 black knight; a7 black pawn; b7 black pawn; e7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "e7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "e7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00730", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b3k1/6pp/6r1/p1ppQp1N/1p5P/4P1P1/qPP2P2/2KR3R w - - 0 23", "prompt": "FEN: r1b3k1/6pp/6r1/p1ppQp1N/1p5P/4P1P1/qPP2P2/2KR3R w - - 0 23\nWhat legal moves does the piece on e5 have?", "gold_answer": "e5b8 e5c3 e5c7 e5d4 e5d5 e5d6 e5e4 e5e6 e5e7 e5e8 e5f4 e5f5 e5f6 e5g7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "e5", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "e5", "piece": "queen"}}
{"example_id": "rules_00731", "split": "rules", "task_type": "check_detection", "fen": "8/5k2/7p/4K1pP/4P1P1/8/8/8 b - -", "prompt": "FEN: 8/5k2/7p/4K1pP/4P1P1/8/8/8 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00732", "split": "rules", "task_type": "captures", "fen": "8/3k4/R4R2/8/8/4K3/8/8 w - -", "prompt": "FEN: 8/3k4/R4R2/8/8/4K3/8/8 w - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00733", "split": "rules", "task_type": "special_rules", "fen": "r3k1r1/p2bbp1p/2pp2qp/8/4PPn1/6N1/PP2B1PP/R2QNRK1 w q - 1 20", "prompt": "Given FEN: r3k1r1/p2bbp1p/2pp2qp/8/4PPn1/6N1/PP2B1PP/R2QNRK1 w q - 1 20\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00734", "split": "rules", "task_type": "legality_check", "fen": "r1bqk2r/pppp1ppp/5n2/4N3/1bBnP3/2N5/PPPP1PPP/R1BQK2R b KQkq -", "prompt": "FEN: r1bqk2r/pppp1ppp/5n2/4N3/1bBnP3/2N5/PPPP1PPP/R1BQK2R b KQkq -\nIs the move a7a6 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "a7a6", "_legality_check_reason_label": "legal", "move": "a7a6", "legality_reason_label": "legal"}}
{"example_id": "rules_00735", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r6n/1pp4k/p1n1p1q1/3pP1p1/1P1P3p/P2r2N1/4NP1P/R1R3K1 w - - 0 28", "prompt": "FEN: r6n/1pp4k/p1n1p1q1/3pP1p1/1P1P3p/P2r2N1/4NP1P/R1R3K1 w - - 0 28\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1a2 a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00736", "split": "rules", "task_type": "piece_legal_filter", "fen": "2kr1b1r/pbp1q1pp/1p3n2/4p3/8/2NB1N2/PPP2PPP/R2QK2R w KQ - 0 12", "prompt": "FEN: 2kr1b1r/pbp1q1pp/1p3n2/4p3/8/2NB1N2/PPP2PPP/R2QK2R w KQ - 0 12\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1 a1c1.\nLegal: a1b1 a1c1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00737", "split": "rules", "task_type": "king_safety_filter", "fen": "rr4k1/5bp1/3p1p1p/p7/P2pp1P1/1P3R1P/3B1P2/1R4K1 w - - 0 31", "prompt": "FEN: rr4k1/5bp1/3p1p1p/p7/P2pp1P1/1P3R1P/3B1P2/1R4K1 w - - 0 31\nFor move b1a1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: b1a1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "b1a1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "b1a1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00738", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/5R2/5p1p/5P2/1p1pPk2/1PrP4/2P1B3/2K5 b - - 0 44", "prompt": "FEN: 8/5R2/5p1p/5P2/1p1pPk2/1PrP4/2P1B3/2K5 b - - 0 44\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c3 black rook; b4 black pawn; d4 black pawn; f4 black king; f6 black pawn; h6 black pawn.\nMoves by piece:\nc3 black rook: c3b3 c3c2 c3c4 c3c5 c3c6 c3c7 c3c8 c3d3\nb4 black pawn: no legal moves\nd4 black pawn: no legal moves\nf4 black king: f4e3 f4e5 f4g3 f4g5\nf6 black pawn: no legal moves\nh6 black pawn: h6h5\nAll legal moves: c3b3 c3c2 c3c4 c3c5 c3c6 c3c7 c3c8 c3d3 f4e3 f4e5 f4g3 f4g5 h6h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c3": ["c3b3", "c3c2", "c3c4", "c3c5", "c3c6", "c3c7", "c3c8", "c3d3"], "b4": [], "d4": [], "f4": ["f4e3", "f4e5", "f4g3", "f4g5"], "f6": [], "h6": ["h6h5"]}, "_legal_moves_by_piece_moves": "c3b3 c3c2 c3c4 c3c5 c3c6 c3c7 c3c8 c3d3 f4e3 f4e5 f4g3 f4g5 h6h5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c3": ["c3b3", "c3c2", "c3c4", "c3c5", "c3c6", "c3c7", "c3c8", "c3d3"], "b4": [], "d4": [], "f4": ["f4e3", "f4e5", "f4g3", "f4g5"], "f6": [], "h6": ["h6h5"]}, "legal_moves": "c3b3 c3c2 c3c4 c3c5 c3c6 c3c7 c3c8 c3d3 f4e3 f4e5 f4g3 f4g5 h6h5"}}
{"example_id": "rules_00739", "split": "rules", "task_type": "ray_walk", "fen": "3nk3/2R1bp1p/4p1p1/1P6/r7/5BP1/1B3P1P/6K1 w - -", "prompt": "FEN: 3nk3/2R1bp1p/4p1p1/1P6/r7/5BP1/1B3P1P/6K1 w - -\nWalk each ray for the slider on b2: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b2 white bishop.\nRay NE: c3 empty; d4 empty; e5 empty; f6 empty; g7 empty; h8 empty; edge.\nRay SE: c1 empty; edge.\nRay SW: a1 empty; edge.\nRay NW: a3 empty; edge.\nMoves from rays: b2a1 b2a3 b2c1 b2c3 b2d4 b2e5 b2f6 b2g7 b2h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "b2", "diagnostic": true, "hard_gate": false, "source_square": "b2"}}
{"example_id": "rules_00740", "split": "rules", "task_type": "legal_moves", "fen": "6k1/p4p1p/1bp3r1/5Q2/P1q2P2/6N1/6PP/5R1K w - - 1 36", "prompt": "FEN: 6k1/p4p1p/1bp3r1/5Q2/P1q2P2/6N1/6PP/5R1K w - - 1 36\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a4a5 f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f1g1 f5a5 f5b1 f5b5 f5c2 f5c5 f5c8 f5d3 f5d5 f5d7 f5e4 f5e5 f5e6 f5f6 f5f7 f5g4 f5g5 f5g6 f5h3 f5h5 g3e2 g3e4 g3h5 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00741", "split": "rules", "task_type": "legal_moves", "fen": "1k1r3r/pppqbpp1/3pb2p/8/3Q2P1/2P1B2P/PPP2PB1/2KR3R b - -", "prompt": "FEN: 1k1r3r/pppqbpp1/3pb2p/8/3Q2P1/2P1B2P/PPP2PB1/2KR3R b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a8 b8c8 c7c5 c7c6 d6d5 d7a4 d7b5 d7c6 d7c8 d7e8 d8c8 d8e8 d8f8 d8g8 e6a2 e6b3 e6c4 e6d5 e6f5 e6g4 e7f6 e7f8 e7g5 e7h4 f7f5 f7f6 g7g5 g7g6 h6h5 h8e8 h8f8 h8g8 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00742", "split": "rules", "task_type": "side_piece_inventory", "fen": "r4r2/1q2bpk1/n1p3p1/p3p2p/P1Q1P3/1NP1B2P/1P2R1PK/5R2 b - -", "prompt": "FEN: r4r2/1q2bpk1/n1p3p1/p3p2p/P1Q1P3/1NP1B2P/1P2R1PK/5R2 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: a5 black pawn; e5 black pawn; h5 black pawn; a6 black knight; c6 black pawn; g6 black pawn; b7 black queen; e7 black bishop; f7 black pawn; g7 black king; a8 black rook; f8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "a5", "piece": "black pawn"}, {"square": "e5", "piece": "black pawn"}, {"square": "h5", "piece": "black pawn"}, {"square": "a6", "piece": "black knight"}, {"square": "c6", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "b7", "piece": "black queen"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black king"}, {"square": "a8", "piece": "black rook"}, {"square": "f8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "a5", "piece": "black pawn"}, {"square": "e5", "piece": "black pawn"}, {"square": "h5", "piece": "black pawn"}, {"square": "a6", "piece": "black knight"}, {"square": "c6", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "b7", "piece": "black queen"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black king"}, {"square": "a8", "piece": "black rook"}, {"square": "f8", "piece": "black rook"}]}}
{"example_id": "rules_00743", "split": "rules", "task_type": "piece_legal_moves", "fen": "rn3rk1/pp3ppp/3b2b1/2pp1B2/3P2P1/4BP2/PPP1N2P/R3K2R b KQ - 1 13", "prompt": "FEN: rn3rk1/pp3ppp/3b2b1/2pp1B2/3P2P1/4BP2/PPP1N2P/R3K2R b KQ - 1 13\nWhat legal moves does the piece on g7 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "g7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g7", "piece": "pawn"}}
{"example_id": "rules_00744", "split": "rules", "task_type": "check_detection", "fen": "r3r1k1/2q2ppp/p1bbp3/1p1p2B1/3Nn3/1B4P1/PPP2P1P/R2QR1K1 w - - 5 20", "prompt": "FEN: r3r1k1/2q2ppp/p1bbp3/1p1p2B1/3Nn3/1B4P1/PPP2P1P/R2QR1K1 w - - 5 20\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00745", "split": "rules", "task_type": "captures", "fen": "r6r/ppp1kpp1/6b1/4P2p/8/3PR3/PPP2P2/4R1K1 w - - 0 22", "prompt": "FEN: r6r/ppp1kpp1/6b1/4P2p/8/3PR3/PPP2P2/4R1K1 w - - 0 22\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00746", "split": "rules", "task_type": "special_rules", "fen": "8/8/p2k3p/1p3p2/1P1bp3/P5P1/4B2P/2K5 b - -", "prompt": "Given FEN: 8/8/p2k3p/1p3p2/1P1bp3/P5P1/4B2P/2K5 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00747", "split": "rules", "task_type": "legality_check", "fen": "r4rk1/pppb1ppp/2n2q2/1N6/8/2N5/PPP2PPP/R2QR1K1 b - -", "prompt": "FEN: r4rk1/pppb1ppp/2n2q2/1N6/8/2N5/PPP2PPP/R2QR1K1 b - -\nIs the move f4d2 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f4d2", "_legality_check_reason_label": "empty_source", "move": "f4d2", "legality_reason_label": "empty_source"}}
{"example_id": "rules_00748", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "4r1k1/6pp/5p2/2R2N2/4P3/P2P2P1/5PKP/8 b - -", "prompt": "FEN: 4r1k1/6pp/5p2/2R2N2/4P3/P2P2P1/5PKP/8 b - -\nList pseudo-legal moves from g7.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g7: g7g5 g7g6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g7", "diagnostic": true, "hard_gate": false, "source_square": "g7"}}
{"example_id": "rules_00749", "split": "rules", "task_type": "piece_legal_filter", "fen": "r3rk2/1p3ppp/p1n5/b7/B7/2P2P1P/P2B1P2/3R1RK1 b - -", "prompt": "FEN: r3rk2/1p3ppp/p1n5/b7/B7/2P2P1P/P2B1P2/3R1RK1 b - -\nFor the piece on a5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a5: a5b4 a5b6 a5c3 a5c7 a5d8.\nLegal: a5b4 a5b6 a5c3 a5c7 a5d8.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_00750", "split": "rules", "task_type": "king_safety_filter", "fen": "6rr/bbqpkp1p/pp2pp1Q/4n2B/4P3/1NN5/PPP2PPP/3R1R1K b - - 9 17", "prompt": "FEN: 6rr/bbqpkp1p/pp2pp1Q/4n2B/4P3/1NN5/PPP2PPP/3R1R1K b - - 9 17\nFor move e7d6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e7d6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e7d6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e7d6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00751", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2krr3/1p3bpp/p2p1p2/2p1n3/4P3/1PP1P2P/P2N2P1/2KRN2R b - -", "prompt": "FEN: 2krr3/1p3bpp/p2p1p2/2p1n3/4P3/1PP1P2P/P2N2P1/2KRN2R b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black pawn; e5 black knight; a6 black pawn; d6 black pawn; f6 black pawn; b7 black pawn; f7 black bishop; g7 black pawn; h7 black pawn; c8 black king; d8 black rook; e8 black rook.\nMoves by piece:\nc5 black pawn: c5c4\ne5 black knight: e5c4 e5c6 e5d3 e5d7 e5f3 e5g4 e5g6\na6 black pawn: a6a5\nd6 black pawn: d6d5\nf6 black pawn: f6f5\nb7 black pawn: b7b5 b7b6\nf7 black bishop: f7b3 f7c4 f7d5 f7e6 f7g6 f7g8 f7h5\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\nc8 black king: c8b8 c8c7 c8d7\nd8 black rook: d8d7\ne8 black rook: e8e6 e8e7 e8f8 e8g8 e8h8\nAll legal moves: a6a5 b7b5 b7b6 c5c4 c8b8 c8c7 c8d7 d6d5 d8d7 e5c4 e5c6 e5d3 e5d7 e5f3 e5g4 e5g6 e8e6 e8e7 e8f8 e8g8 e8h8 f6f5 f7b3 f7c4 f7d5 f7e6 f7g6 f7g8 f7h5 g7g5 g7g6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": ["c5c4"], "e5": ["e5c4", "e5c6", "e5d3", "e5d7", "e5f3", "e5g4", "e5g6"], "a6": ["a6a5"], "d6": ["d6d5"], "f6": ["f6f5"], "b7": ["b7b5", "b7b6"], "f7": ["f7b3", "f7c4", "f7d5", "f7e6", "f7g6", "f7g8", "f7h5"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8b8", "c8c7", "c8d7"], "d8": ["d8d7"], "e8": ["e8e6", "e8e7", "e8f8", "e8g8", "e8h8"]}, "_legal_moves_by_piece_moves": "a6a5 b7b5 b7b6 c5c4 c8b8 c8c7 c8d7 d6d5 d8d7 e5c4 e5c6 e5d3 e5d7 e5f3 e5g4 e5g6 e8e6 e8e7 e8f8 e8g8 e8h8 f6f5 f7b3 f7c4 f7d5 f7e6 f7g6 f7g8 f7h5 g7g5 g7g6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": ["c5c4"], "e5": ["e5c4", "e5c6", "e5d3", "e5d7", "e5f3", "e5g4", "e5g6"], "a6": ["a6a5"], "d6": ["d6d5"], "f6": ["f6f5"], "b7": ["b7b5", "b7b6"], "f7": ["f7b3", "f7c4", "f7d5", "f7e6", "f7g6", "f7g8", "f7h5"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8b8", "c8c7", "c8d7"], "d8": ["d8d7"], "e8": ["e8e6", "e8e7", "e8f8", "e8g8", "e8h8"]}, "legal_moves": "a6a5 b7b5 b7b6 c5c4 c8b8 c8c7 c8d7 d6d5 d8d7 e5c4 e5c6 e5d3 e5d7 e5f3 e5g4 e5g6 e8e6 e8e7 e8f8 e8g8 e8h8 f6f5 f7b3 f7c4 f7d5 f7e6 f7g6 f7g8 f7h5 g7g5 g7g6 h7h5 h7h6"}}
{"example_id": "rules_00752", "split": "rules", "task_type": "ray_walk", "fen": "r3kbnr/ppp2ppp/2np4/6q1/3pQ1b1/N3P3/PPP2PPP/R1B1KB1R b KQkq - 3 7", "prompt": "FEN: r3kbnr/ppp2ppp/2np4/6q1/3pQ1b1/N3P3/PPP2PPP/R1B1KB1R b KQkq - 3 7\nWalk each ray for the slider on g4: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: g4 black bishop.\nRay NE: h5 empty; edge.\nRay SE: h3 empty; edge.\nRay SW: f3 empty; e2 empty; d1 empty; edge.\nRay NW: f5 empty; e6 empty; d7 empty; c8 empty; edge.\nMoves from rays: g4c8 g4d1 g4d7 g4e2 g4e6 g4f3 g4f5 g4h3 g4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "g4", "diagnostic": true, "hard_gate": false, "source_square": "g4"}}
{"example_id": "rules_00753", "split": "rules", "task_type": "legal_moves", "fen": "rnb1kbnr/pp3ppp/3pp3/q7/3PP3/p2B1N2/2P2PPP/RNBQK2R w KQkq -", "prompt": "FEN: rnb1kbnr/pp3ppp/3pp3/q7/3PP3/p2B1N2/2P2PPP/RNBQK2R w KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b1c3 b1d2 c1d2 c2c3 d1d2 e1e2 e1f1 f3d2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00754", "split": "rules", "task_type": "legal_moves", "fen": "2kr3r/pp3ppp/4b3/4Pp2/1B1q4/P7/1P3PPP/2RQ1RK1 b - -", "prompt": "FEN: 2kr3r/pp3ppp/4b3/4Pp2/1B1q4/P7/1P3PPP/2RQ1RK1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: c8b8 c8d7 d4c3 d4c4 d4c5 e6c4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00755", "split": "rules", "task_type": "side_piece_inventory", "fen": "4k2r/p4p2/7p/3pPN2/8/4BPb1/1r4P1/2R3K1 w - -", "prompt": "FEN: 4k2r/p4p2/7p/3pPN2/8/4BPb1/1r4P1/2R3K1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: c1 white rook; g1 white king; g2 white pawn; e3 white bishop; f3 white pawn; e5 white pawn; f5 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "c1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "g2", "piece": "white pawn"}, {"square": "e3", "piece": "white bishop"}, {"square": "f3", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}, {"square": "f5", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "c1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "g2", "piece": "white pawn"}, {"square": "e3", "piece": "white bishop"}, {"square": "f3", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}, {"square": "f5", "piece": "white knight"}]}}
{"example_id": "rules_00756", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bqkb1r/pppp1pp1/4pn1p/8/2BQP3/1P6/P1P2PPP/RNB1K1NR w KQkq - 0 6", "prompt": "FEN: r1bqkb1r/pppp1pp1/4pn1p/8/2BQP3/1P6/P1P2PPP/RNB1K1NR w KQkq - 0 6\nWhat legal moves does the piece on a2 have?", "gold_answer": "a2a3 a2a4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a2", "piece": "pawn"}}
{"example_id": "rules_00757", "split": "rules", "task_type": "check_detection", "fen": "r4rk1/4ppbp/pq1p1np1/1p6/4P3/P1P4P/1P1NQPP1/R1B2RK1 w - - 2 16", "prompt": "FEN: r4rk1/4ppbp/pq1p1np1/1p6/4P3/P1P4P/1P1NQPP1/R1B2RK1 w - - 2 16\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00758", "split": "rules", "task_type": "captures", "fen": "8/8/2k1BK2/8/2N5/8/8/8 w - -", "prompt": "FEN: 8/8/2k1BK2/8/2N5/8/8/8 w - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00759", "split": "rules", "task_type": "special_rules", "fen": "8/8/1k6/8/2K5/8/2N5/6B1 b - -", "prompt": "Given FEN: 8/8/1k6/8/2K5/8/2N5/6B1 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00760", "split": "rules", "task_type": "legality_check", "fen": "r6r/1ppb1k2/p3pbp1/2Pn1pq1/1P1Pp3/P3P1P1/1B1NBPK1/1R1Q3R b - - 1 24", "prompt": "FEN: r6r/1ppb1k2/p3pbp1/2Pn1pq1/1P1Pp3/P3P1P1/1B1NBPK1/1R1Q3R b - - 1 24\nIs the move f7e7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f7e7", "_legality_check_reason_label": "legal", "move": "f7e7", "legality_reason_label": "legal"}}
{"example_id": "rules_00761", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2qk2r/ppp1bppp/2np1n2/8/4P1b1/3B1N2/PPP2PPP/RNBQ1RK1 b kq - 6 8", "prompt": "FEN: r2qk2r/ppp1bppp/2np1n2/8/4P1b1/3B1N2/PPP2PPP/RNBQ1RK1 b kq - 6 8\nList pseudo-legal moves from g4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g4: g4c8 g4d7 g4e6 g4f3 g4f5 g4h3 g4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g4", "diagnostic": true, "hard_gate": false, "source_square": "g4"}}
{"example_id": "rules_00762", "split": "rules", "task_type": "piece_legal_filter", "fen": "r3k1nr/3n4/3p4/1p1P1b2/p7/2N3Kp/PPP4R/4R3 b kq - 3 31", "prompt": "FEN: r3k1nr/3n4/3p4/1p1P1b2/p7/2N3Kp/PPP4R/4R3 b kq - 3 31\nFor the piece on a4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a4: a4a3.\nLegal: none.\nRejected: a4a3 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a4", "diagnostic": true, "hard_gate": false, "source_square": "a4"}}
{"example_id": "rules_00763", "split": "rules", "task_type": "king_safety_filter", "fen": "1r6/6pk/pp2R2p/3p4/PP2p3/4PP2/6PP/6K1 b - - 0 32", "prompt": "FEN: 1r6/6pk/pp2R2p/3p4/PP2p3/4PP2/6PP/6K1 b - - 0 32\nFor move h7g6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: h7g6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "h7g6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "h7g6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00764", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rn2kbnr/pbpp2q1/1p2pp2/6pp/3PP3/2PB4/PP1NNPPP/R1BQK2R b KQkq - 3 9", "prompt": "FEN: rn2kbnr/pbpp2q1/1p2pp2/6pp/3PP3/2PB4/PP1NNPPP/R1BQK2R b KQkq - 3 9\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: g5 black pawn; h5 black pawn; b6 black pawn; e6 black pawn; f6 black pawn; a7 black pawn; b7 black bishop; c7 black pawn; d7 black pawn; g7 black queen; a8 black rook; b8 black knight; e8 black king; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\ng5 black pawn: g5g4\nh5 black pawn: h5h4\nb6 black pawn: b6b5\ne6 black pawn: e6e5\nf6 black pawn: f6f5\na7 black pawn: a7a5 a7a6\nb7 black bishop: b7a6 b7c6 b7c8 b7d5 b7e4\nc7 black pawn: c7c5 c7c6\nd7 black pawn: d7d5 d7d6\ng7 black queen: g7e7 g7f7 g7g6 g7h6 g7h7\na8 black rook: no legal moves\nb8 black knight: b8a6 b8c6\ne8 black king: e8d8 e8e7 e8f7\nf8 black bishop: f8a3 f8b4 f8c5 f8d6 f8e7\ng8 black knight: g8e7 g8h6\nh8 black rook: h8h6 h8h7\nAll legal moves: a7a5 a7a6 b6b5 b7a6 b7c6 b7c8 b7d5 b7e4 b8a6 b8c6 c7c5 c7c6 d7d5 d7d6 e6e5 e8d8 e8e7 e8f7 f6f5 f8a3 f8b4 f8c5 f8d6 f8e7 g5g4 g7e7 g7f7 g7g6 g7h6 g7h7 g8e7 g8h6 h5h4 h8h6 h8h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"g5": ["g5g4"], "h5": ["h5h4"], "b6": ["b6b5"], "e6": ["e6e5"], "f6": ["f6f5"], "a7": ["a7a5", "a7a6"], "b7": ["b7a6", "b7c6", "b7c8", "b7d5", "b7e4"], "c7": ["c7c5", "c7c6"], "d7": ["d7d5", "d7d6"], "g7": ["g7e7", "g7f7", "g7g6", "g7h6", "g7h7"], "a8": [], "b8": ["b8a6", "b8c6"], "e8": ["e8d8", "e8e7", "e8f7"], "f8": ["f8a3", "f8b4", "f8c5", "f8d6", "f8e7"], "g8": ["g8e7", "g8h6"], "h8": ["h8h6", "h8h7"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b6b5 b7a6 b7c6 b7c8 b7d5 b7e4 b8a6 b8c6 c7c5 c7c6 d7d5 d7d6 e6e5 e8d8 e8e7 e8f7 f6f5 f8a3 f8b4 f8c5 f8d6 f8e7 g5g4 g7e7 g7f7 g7g6 g7h6 g7h7 g8e7 g8h6 h5h4 h8h6 h8h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"g5": ["g5g4"], "h5": ["h5h4"], "b6": ["b6b5"], "e6": ["e6e5"], "f6": ["f6f5"], "a7": ["a7a5", "a7a6"], "b7": ["b7a6", "b7c6", "b7c8", "b7d5", "b7e4"], "c7": ["c7c5", "c7c6"], "d7": ["d7d5", "d7d6"], "g7": ["g7e7", "g7f7", "g7g6", "g7h6", "g7h7"], "a8": [], "b8": ["b8a6", "b8c6"], "e8": ["e8d8", "e8e7", "e8f7"], "f8": ["f8a3", "f8b4", "f8c5", "f8d6", "f8e7"], "g8": ["g8e7", "g8h6"], "h8": ["h8h6", "h8h7"]}, "legal_moves": "a7a5 a7a6 b6b5 b7a6 b7c6 b7c8 b7d5 b7e4 b8a6 b8c6 c7c5 c7c6 d7d5 d7d6 e6e5 e8d8 e8e7 e8f7 f6f5 f8a3 f8b4 f8c5 f8d6 f8e7 g5g4 g7e7 g7f7 g7g6 g7h6 g7h7 g8e7 g8h6 h5h4 h8h6 h8h7"}}
{"example_id": "rules_00765", "split": "rules", "task_type": "ray_walk", "fen": "5r2/1p4k1/6pp/1Np5/6P1/8/1nP1R1P1/6K1 w - -", "prompt": "FEN: 5r2/1p4k1/6pp/1Np5/6P1/8/1nP1R1P1/6K1 w - -\nWalk each ray for the slider on e2: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e2 white rook.\nRay N: e3 empty; e4 empty; e5 empty; e6 empty; e7 empty; e8 empty; edge.\nRay E: f2 empty; g2 white pawn: own piece (stop, excluded).\nRay S: e1 empty; edge.\nRay W: d2 empty; c2 white pawn: own piece (stop, excluded).\nMoves from rays: e2d2 e2e1 e2e3 e2e4 e2e5 e2e6 e2e7 e2e8 e2f2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "e2", "diagnostic": true, "hard_gate": false, "source_square": "e2"}}
{"example_id": "rules_00766", "split": "rules", "task_type": "legal_moves", "fen": "r2qk2r/pbpnbppp/1p3n2/3p4/3P4/1P2PNP1/PB3PBP/RN1QK2R b KQkq -", "prompt": "FEN: r2qk2r/pbpnbppp/1p3n2/3p4/3P4/1P2PNP1/PB3PBP/RN1QK2R b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 a8c8 b6b5 b7a6 b7c6 b7c8 c7c5 c7c6 d7b8 d7c5 d7e5 d7f8 d8b8 d8c8 e7a3 e7b4 e7c5 e7d6 e7f8 e8f8 e8g8 f6e4 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00767", "split": "rules", "task_type": "legal_moves", "fen": "n1r2b1r/pp1n1kp1/3p1p1p/PPpPp3/2P1P3/3B3P/3B1PP1/RN3RK1 b - - 0 17", "prompt": "FEN: n1r2b1r/pp1n1kp1/3p1p1p/PPpPp3/2P1P3/3B3P/3B1PP1/RN3RK1 b - - 0 17\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a6 a8b6 a8c7 b7b6 c8b8 c8c6 c8c7 c8d8 c8e8 d7b6 d7b8 f6f5 f7e7 f7e8 f7g6 f7g8 f8e7 g7g5 g7g6 h6h5 h8g8 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00768", "split": "rules", "task_type": "side_piece_inventory", "fen": "r3kb1r/ppq2ppp/2n1pn2/3p4/3P4/1QN1PP2/PP1B1P1P/2KR1B1R b kq -", "prompt": "FEN: r3kb1r/ppq2ppp/2n1pn2/3p4/3P4/1QN1PP2/PP1B1P1P/2KR1B1R b kq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; c6 black knight; e6 black pawn; f6 black knight; a7 black pawn; b7 black pawn; c7 black queen; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; e8 black king; f8 black bishop; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "d5", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black queen"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "d5", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black queen"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00769", "split": "rules", "task_type": "piece_legal_moves", "fen": "r5k1/pp3ppp/3P4/P7/qP6/2P5/3BQ2P/2K1R3 b - - 33 46", "prompt": "FEN: r5k1/pp3ppp/3P4/P7/qP6/2P5/3BQ2P/2K1R3 b - - 33 46\nWhat legal moves does the piece on b7 have?", "gold_answer": "b7b5 b7b6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "b7", "piece": "pawn"}}
{"example_id": "rules_00770", "split": "rules", "task_type": "check_detection", "fen": "r2qkbnr/pp3ppp/2n1p3/3p4/3P2b1/2P2N2/PP2BPPP/RNBQ1RK1 b kq -", "prompt": "FEN: r2qkbnr/pp3ppp/2n1p3/3p4/3P2b1/2P2N2/PP2BPPP/RNBQ1RK1 b kq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00771", "split": "rules", "task_type": "captures", "fen": "7r/p7/1p2p1p1/5Pk1/8/5R1P/PPP5/2K5 b - - 0 28", "prompt": "FEN: 7r/p7/1p2p1p1/5Pk1/8/5R1P/PPP5/2K5 b - - 0 28\nList all capture moves available.", "gold_answer": "e6f5 g6f5 h8h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00772", "split": "rules", "task_type": "special_rules", "fen": "r1b2rk1/1p2nppp/1pn5/4P3/5B2/5N2/PP3PPP/R3KB1R w KQ - 4 13", "prompt": "Given FEN: r1b2rk1/1p2nppp/1pn5/4P3/5B2/5N2/PP3PPP/R3KB1R w KQ - 4 13\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: queenside.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00773", "split": "rules", "task_type": "legality_check", "fen": "r2q2k1/1b1nbppp/4p3/p2pP3/N2B1P2/1P1B4/P3Q1PP/2R3K1 w - -", "prompt": "FEN: r2q2k1/1b1nbppp/4p3/p2pP3/N2B1P2/1P1B4/P3Q1PP/2R3K1 w - -\nIs the move h5e6 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "h5e6", "_legality_check_reason_label": "empty_source", "move": "h5e6", "legality_reason_label": "empty_source"}}
{"example_id": "rules_00774", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rq2r1k1/p1p1bpp1/3p1n1p/2p5/4PP1B/1PNQ4/P1P3PP/R4RK1 w - - 0 15", "prompt": "FEN: rq2r1k1/p1p1bpp1/3p1n1p/2p5/4PP1B/1PNQ4/P1P3PP/R4RK1 w - - 0 15\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1 a1c1 a1d1 a1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00775", "split": "rules", "task_type": "piece_legal_filter", "fen": "4r3/p6p/1p3kp1/3R4/8/5NP1/PP3P1P/6K1 b - - 0 25", "prompt": "FEN: 4r3/p6p/1p3kp1/3R4/8/5NP1/PP3P1P/6K1 b - - 0 25\nFor the piece on f6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f6: f6e5 f6e6 f6e7 f6f5 f6f7 f6g5 f6g7.\nLegal: f6e6 f6e7 f6f7 f6g7.\nRejected: f6e5 king_would_be_in_check; f6f5 king_would_be_in_check; f6g5 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "f6", "diagnostic": true, "hard_gate": false, "source_square": "f6"}}
{"example_id": "rules_00776", "split": "rules", "task_type": "king_safety_filter", "fen": "r1b2r1k/p1p1n1pp/2pb1pq1/3p4/4P2P/1PN1P3/PBPPQ3/2R1KN2 b - - 0 16", "prompt": "FEN: r1b2r1k/p1p1n1pp/2pb1pq1/3p4/4P2P/1PN1P3/PBPPQ3/2R1KN2 b - - 0 16\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00777", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bq1rk1/pp2bppp/1n2pn2/8/2PN3Q/2NBB3/PP3PPP/R4RK1 w - - 6 14", "prompt": "FEN: r1bq1rk1/pp2bppp/1n2pn2/8/2PN3Q/2NBB3/PP3PPP/R4RK1 w - - 6 14\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white knight; d3 white bishop; e3 white bishop; c4 white pawn; d4 white knight; h4 white queen.\nMoves by piece:\na1 white rook: a1b1 a1c1 a1d1 a1e1\nf1 white rook: f1b1 f1c1 f1d1 f1e1\ng1 white king: g1h1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nf2 white pawn: f2f3 f2f4\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3\nc3 white knight: c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4\nd3 white bishop: d3b1 d3c2 d3e2 d3e4 d3f5 d3g6 d3h7\ne3 white bishop: e3c1 e3d2 e3f4 e3g5 e3h6\nc4 white pawn: c4c5\nd4 white knight: d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3 d4f5\nh4 white queen: h4e4 h4f4 h4f6 h4g3 h4g4 h4g5 h4h3 h4h5 h4h6 h4h7\nAll legal moves: a1b1 a1c1 a1d1 a1e1 a2a3 a2a4 b2b3 b2b4 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 c4c5 d3b1 d3c2 d3e2 d3e4 d3f5 d3g6 d3h7 d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3 d4f5 e3c1 e3d2 e3f4 e3g5 e3h6 f1b1 f1c1 f1d1 f1e1 f2f3 f2f4 g1h1 g2g3 g2g4 h2h3 h4e4 h4f4 h4f6 h4g3 h4g4 h4g5 h4h3 h4h5 h4h6 h4h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1", "a1c1", "a1d1", "a1e1"], "f1": ["f1b1", "f1c1", "f1d1", "f1e1"], "g1": ["g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3"], "c3": ["c3a4", "c3b1", "c3b5", "c3d1", "c3d5", "c3e2", "c3e4"], "d3": ["d3b1", "d3c2", "d3e2", "d3e4", "d3f5", "d3g6", "d3h7"], "e3": ["e3c1", "e3d2", "e3f4", "e3g5", "e3h6"], "c4": ["c4c5"], "d4": ["d4b3", "d4b5", "d4c2", "d4c6", "d4e2", "d4e6", "d4f3", "d4f5"], "h4": ["h4e4", "h4f4", "h4f6", "h4g3", "h4g4", "h4g5", "h4h3", "h4h5", "h4h6", "h4h7"]}, "_legal_moves_by_piece_moves": "a1b1 a1c1 a1d1 a1e1 a2a3 a2a4 b2b3 b2b4 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 c4c5 d3b1 d3c2 d3e2 d3e4 d3f5 d3g6 d3h7 d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3 d4f5 e3c1 e3d2 e3f4 e3g5 e3h6 f1b1 f1c1 f1d1 f1e1 f2f3 f2f4 g1h1 g2g3 g2g4 h2h3 h4e4 h4f4 h4f6 h4g3 h4g4 h4g5 h4h3 h4h5 h4h6 h4h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1", "a1c1", "a1d1", "a1e1"], "f1": ["f1b1", "f1c1", "f1d1", "f1e1"], "g1": ["g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3"], "c3": ["c3a4", "c3b1", "c3b5", "c3d1", "c3d5", "c3e2", "c3e4"], "d3": ["d3b1", "d3c2", "d3e2", "d3e4", "d3f5", "d3g6", "d3h7"], "e3": ["e3c1", "e3d2", "e3f4", "e3g5", "e3h6"], "c4": ["c4c5"], "d4": ["d4b3", "d4b5", "d4c2", "d4c6", "d4e2", "d4e6", "d4f3", "d4f5"], "h4": ["h4e4", "h4f4", "h4f6", "h4g3", "h4g4", "h4g5", "h4h3", "h4h5", "h4h6", "h4h7"]}, "legal_moves": "a1b1 a1c1 a1d1 a1e1 a2a3 a2a4 b2b3 b2b4 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 c4c5 d3b1 d3c2 d3e2 d3e4 d3f5 d3g6 d3h7 d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3 d4f5 e3c1 e3d2 e3f4 e3g5 e3h6 f1b1 f1c1 f1d1 f1e1 f2f3 f2f4 g1h1 g2g3 g2g4 h2h3 h4e4 h4f4 h4f6 h4g3 h4g4 h4g5 h4h3 h4h5 h4h6 h4h7"}}
{"example_id": "rules_00778", "split": "rules", "task_type": "ray_walk", "fen": "r1bqk2r/pp1pppbp/2n2np1/2p5/4P3/P1NP4/1PP1NPPP/R1BQKB1R w KQkq -", "prompt": "FEN: r1bqk2r/pp1pppbp/2n2np1/2p5/4P3/P1NP4/1PP1NPPP/R1BQKB1R w KQkq -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 empty; a3 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 white bishop: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1a2 a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00779", "split": "rules", "task_type": "legal_moves", "fen": "rn2kb1r/pp3ppp/2p1pn2/2Pp1b2/3P4/1qN2NP1/PP2PP1P/R1B1KB1R w KQkq -", "prompt": "FEN: rn2kb1r/pp3ppp/2p1pn2/2Pp1b2/3P4/1qN2NP1/PP2PP1P/R1B1KB1R w KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a2a3 a2a4 a2b3 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d1 c3d5 c3e4 e1d2 e2e3 e2e4 f1g2 f1h3 f3d2 f3e5 f3g1 f3g5 f3h4 g3g4 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00780", "split": "rules", "task_type": "legal_moves", "fen": "r1bqk2r/p2pnpbp/2p3p1/4p3/3pP3/2P2N2/PP3PPP/RNBQR1K1 w kq -", "prompt": "FEN: r1bqk2r/p2pnpbp/2p3p1/4p3/3pP3/2P2N2/PP3PPP/RNBQR1K1 w kq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3c4 c3d4 d1a4 d1b3 d1c2 d1d2 d1d3 d1d4 d1e2 e1e2 e1e3 e1f1 f3d2 f3d4 f3e5 f3g5 f3h4 g1f1 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00781", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqkb1r/ppp2ppp/2n1pn2/8/P7/1PN3P1/2PP1PBP/R1BQK1NR b KQkq - 0 7", "prompt": "FEN: r1bqkb1r/ppp2ppp/2n1pn2/8/P7/1PN3P1/2PP1PBP/R1BQK1NR b KQkq - 0 7\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c6 black knight; e6 black pawn; f6 black knight; a7 black pawn; b7 black pawn; c7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c6", "piece": "black knight"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c6", "piece": "black knight"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00782", "split": "rules", "task_type": "piece_legal_moves", "fen": "5r1k/8/p2b1q1p/1p3pp1/3Pp3/PQ2P1P1/3B1P1P/R2B1RK1 w - - 0 30", "prompt": "FEN: 5r1k/8/p2b1q1p/1p3pp1/3Pp3/PQ2P1P1/3B1P1P/R2B1RK1 w - - 0 30\nWhat legal moves does the piece on g1 have?", "gold_answer": "g1g2 g1h1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "g1", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "g1", "piece": "king"}}
{"example_id": "rules_00783", "split": "rules", "task_type": "check_detection", "fen": "2k4r/1pb4p/2p3p1/5p2/P3p3/1Q5P/2P2PP1/3R2K1 w - - 0 29", "prompt": "FEN: 2k4r/1pb4p/2p3p1/5p2/P3p3/1Q5P/2P2PP1/3R2K1 w - - 0 29\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00784", "split": "rules", "task_type": "captures", "fen": "rq4k1/1b1nbrpp/p2p4/3P1BP1/1p1B1P1P/5Q2/PPP5/2K1R2R b - -", "prompt": "FEN: rq4k1/1b1nbrpp/p2p4/3P1BP1/1p1B1P1P/5Q2/PPP5/2K1R2R b - -\nList all capture moves available.", "gold_answer": "b7d5 e7g5 f7f5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00785", "split": "rules", "task_type": "special_rules", "fen": "rnb1kbnr/ppp2ppp/2q5/4p3/8/2N2P2/PPPP2PP/R1BQKBNR w KQkq - 2 5", "prompt": "Given FEN: rnb1kbnr/ppp2ppp/2q5/4p3/8/2N2P2/PPPP2PP/R1BQKBNR w KQkq - 2 5\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00786", "split": "rules", "task_type": "legality_check", "fen": "5r1k/p3q2p/2p5/8/2p1P3/4b3/PPP3PP/4R2K w - - 2 27", "prompt": "FEN: 5r1k/p3q2p/2p5/8/2p1P3/4b3/PPP3PP/4R2K w - - 2 27\nIs the move g2g4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g2g4", "_legality_check_reason_label": "legal", "move": "g2g4", "legality_reason_label": "legal"}}
{"example_id": "rules_00787", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1b4r/p2n1kpp/1p1Bp3/3p4/3P4/3BP3/P2K1PPP/2R4R b - -", "prompt": "FEN: r1b4r/p2n1kpp/1p1Bp3/3p4/3P4/3BP3/P2K1PPP/2R4R b - -\nList pseudo-legal moves from b6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b6: b6b5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b6", "diagnostic": true, "hard_gate": false, "source_square": "b6"}}
{"example_id": "rules_00788", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2r2k1/pp2Qp1p/6p1/8/4P3/2q2PP1/P4RKP/R7 w - -", "prompt": "FEN: r2r2k1/pp2Qp1p/6p1/8/4P3/2q2PP1/P4RKP/R7 w - -\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1 a1c1 a1d1 a1e1 a1f1 a1g1 a1h1.\nLegal: a1b1 a1c1 a1d1 a1e1 a1f1 a1g1 a1h1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00789", "split": "rules", "task_type": "king_safety_filter", "fen": "8/6k1/8/4P2p/2B2K2/8/1p6/8 w - -", "prompt": "FEN: 8/6k1/8/4P2p/2B2K2/8/1p6/8 w - -\nFor move f4g4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: f4g4.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "f4g4", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "f4g4", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00790", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "3k3r/N2q1ppp/Qp2p3/3p4/1b1Pn3/8/PP3PPP/2R2RK1 b - - 0 21", "prompt": "FEN: 3k3r/N2q1ppp/Qp2p3/3p4/1b1Pn3/8/PP3PPP/2R2RK1 b - - 0 21\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b4 black bishop; e4 black knight; d5 black pawn; b6 black pawn; e6 black pawn; d7 black queen; f7 black pawn; g7 black pawn; h7 black pawn; d8 black king; h8 black rook.\nMoves by piece:\nb4 black bishop: b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7 b4f8\ne4 black knight: e4c3 e4c5 e4d2 e4d6 e4f2 e4f6 e4g3 e4g5\nd5 black pawn: no legal moves\nb6 black pawn: b6b5\ne6 black pawn: e6e5\nd7 black queen: d7a4 d7a7 d7b5 d7b7 d7c6 d7c7 d7c8 d7d6 d7e7 d7e8\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\nd8 black king: d8e7 d8e8\nh8 black rook: h8e8 h8f8 h8g8\nAll legal moves: b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7 b4f8 b6b5 d7a4 d7a7 d7b5 d7b7 d7c6 d7c7 d7c8 d7d6 d7e7 d7e8 d8e7 d8e8 e4c3 e4c5 e4d2 e4d6 e4f2 e4f6 e4g3 e4g5 e6e5 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b4": ["b4a3", "b4a5", "b4c3", "b4c5", "b4d2", "b4d6", "b4e1", "b4e7", "b4f8"], "e4": ["e4c3", "e4c5", "e4d2", "e4d6", "e4f2", "e4f6", "e4g3", "e4g5"], "d5": [], "b6": ["b6b5"], "e6": ["e6e5"], "d7": ["d7a4", "d7a7", "d7b5", "d7b7", "d7c6", "d7c7", "d7c8", "d7d6", "d7e7", "d7e8"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "d8": ["d8e7", "d8e8"], "h8": ["h8e8", "h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7 b4f8 b6b5 d7a4 d7a7 d7b5 d7b7 d7c6 d7c7 d7c8 d7d6 d7e7 d7e8 d8e7 d8e8 e4c3 e4c5 e4d2 e4d6 e4f2 e4f6 e4g3 e4g5 e6e5 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b4": ["b4a3", "b4a5", "b4c3", "b4c5", "b4d2", "b4d6", "b4e1", "b4e7", "b4f8"], "e4": ["e4c3", "e4c5", "e4d2", "e4d6", "e4f2", "e4f6", "e4g3", "e4g5"], "d5": [], "b6": ["b6b5"], "e6": ["e6e5"], "d7": ["d7a4", "d7a7", "d7b5", "d7b7", "d7c6", "d7c7", "d7c8", "d7d6", "d7e7", "d7e8"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "d8": ["d8e7", "d8e8"], "h8": ["h8e8", "h8f8", "h8g8"]}, "legal_moves": "b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7 b4f8 b6b5 d7a4 d7a7 d7b5 d7b7 d7c6 d7c7 d7c8 d7d6 d7e7 d7e8 d8e7 d8e8 e4c3 e4c5 e4d2 e4d6 e4f2 e4f6 e4g3 e4g5 e6e5 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8"}}
{"example_id": "rules_00791", "split": "rules", "task_type": "ray_walk", "fen": "B7/p5pp/4p3/1p2p1k1/8/3rb2P/6P1/5R1K w - - 3 31", "prompt": "FEN: B7/p5pp/4p3/1p2p1k1/8/3rb2P/6P1/5R1K w - - 3 31\nWalk each ray for the slider on f1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: f1 white rook.\nRay N: f2 empty; f3 empty; f4 empty; f5 empty; f6 empty; f7 empty; f8 empty; edge.\nRay E: g1 empty; h1 white king: own piece (stop, excluded).\nRay S: edge.\nRay W: e1 empty; d1 empty; c1 empty; b1 empty; a1 empty; edge.\nMoves from rays: f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f1f4 f1f5 f1f6 f1f7 f1f8 f1g1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "f1", "diagnostic": true, "hard_gate": false, "source_square": "f1"}}
{"example_id": "rules_00792", "split": "rules", "task_type": "legal_moves", "fen": "r4k1r/1pRQ1ppp/p3p3/3p1b2/3P4/4PP2/PP2BKR1/7q b - -", "prompt": "FEN: r4k1r/1pRQ1ppp/p3p3/3p1b2/3P4/4PP2/PP2BKR1/7q b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 a8b8 a8c8 a8d8 a8e8 b7b5 b7b6 e6e5 f5b1 f5c2 f5d3 f5e4 f5g4 f5g6 f5h3 f7f6 f8g8 g7g5 g7g6 h1a1 h1b1 h1c1 h1d1 h1e1 h1f1 h1g1 h1g2 h1h2 h1h3 h1h4 h1h5 h1h6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00793", "split": "rules", "task_type": "legal_moves", "fen": "8/8/1k6/3R4/8/2K5/8/8 w - -", "prompt": "FEN: 8/8/1k6/3R4/8/2K5/8/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: c3b2 c3b3 c3b4 c3c2 c3c4 c3d2 c3d3 c3d4 d5a5 d5b5 d5c5 d5d1 d5d2 d5d3 d5d4 d5d6 d5d7 d5d8 d5e5 d5f5 d5g5 d5h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00794", "split": "rules", "task_type": "side_piece_inventory", "fen": "3Q2k1/2r2pp1/7p/Np6/8/1P6/5PP1/q2b2KR b - -", "prompt": "FEN: 3Q2k1/2r2pp1/7p/Np6/8/1P6/5PP1/q2b2KR b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: a1 black queen; d1 black bishop; b5 black pawn; h6 black pawn; c7 black rook; f7 black pawn; g7 black pawn; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "a1", "piece": "black queen"}, {"square": "d1", "piece": "black bishop"}, {"square": "b5", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "c7", "piece": "black rook"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "a1", "piece": "black queen"}, {"square": "d1", "piece": "black bishop"}, {"square": "b5", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "c7", "piece": "black rook"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_00795", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/8/p7/8/8/5kr1/P1K1R1p1/6B1 w - - 16 63", "prompt": "FEN: 8/8/p7/8/8/5kr1/P1K1R1p1/6B1 w - - 16 63\nWhat legal moves does the piece on c2 have?", "gold_answer": "c2b1 c2b2 c2b3 c2c1 c2c3 c2d1 c2d2 c2d3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c2", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "c2", "piece": "king"}}
{"example_id": "rules_00796", "split": "rules", "task_type": "check_detection", "fen": "r3kb1r/pp1bnppp/1q2p3/3pP3/1n1P1P2/5N2/PPB3PP/RNBQK2R w KQkq - 5 10", "prompt": "FEN: r3kb1r/pp1bnppp/1q2p3/3pP3/1n1P1P2/5N2/PPB3PP/RNBQK2R w KQkq - 5 10\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00797", "split": "rules", "task_type": "captures", "fen": "r1bq1rk1/pp3ppp/2pp4/4p3/3bP3/3PN2P/PPP2PP1/R1BQ1RK1 b - - 1 11", "prompt": "FEN: r1bq1rk1/pp3ppp/2pp4/4p3/3bP3/3PN2P/PPP2PP1/R1BQ1RK1 b - - 1 11\nList all capture moves available.", "gold_answer": "c8h3 d4b2 d4e3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00798", "split": "rules", "task_type": "special_rules", "fen": "r3kbnr/pp2pppp/3p4/qN1P4/4P3/5Q2/P4PPP/1R3RK1 b kq - 3 14", "prompt": "Given FEN: r3kbnr/pp2pppp/3p4/qN1P4/4P3/5Q2/P4PPP/1R3RK1 b kq - 3 14\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: queenside.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00799", "split": "rules", "task_type": "legality_check", "fen": "8/1b3Qpk/p2bpp1p/1p1q4/3Pp3/1P2B1P1/P6P/2R3K1 b - -", "prompt": "FEN: 8/1b3Qpk/p2bpp1p/1p1q4/3Pp3/1P2B1P1/P6P/2R3K1 b - -\nIs the move b7a8 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "b7a8", "_legality_check_reason_label": "legal", "move": "b7a8", "legality_reason_label": "legal"}}
{"example_id": "rules_00800", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2qk2r/ppp3pp/2n2p2/1Bbnp3/4Q3/3P1b2/PPP2PPP/RNB2RK1 w kq - 0 10", "prompt": "FEN: r2qk2r/ppp3pp/2n2p2/1Bbnp3/4Q3/3P1b2/PPP2PPP/RNB2RK1 w kq - 0 10\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a3 b1c3 b1d2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_00801", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/8/6kp/R7/4p3/4P1K1/5rP1/8 b - - 5 42", "prompt": "FEN: 8/8/6kp/R7/4p3/4P1K1/5rP1/8 b - - 5 42\nFor the piece on g6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g6: g6f5 g6f6 g6f7 g6g5 g6g7 g6h5 g6h7.\nLegal: g6f6 g6f7 g6g7 g6h7.\nRejected: g6f5 king_would_be_in_check; g6g5 king_would_be_in_check; g6h5 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g6", "diagnostic": true, "hard_gate": false, "source_square": "g6"}}
{"example_id": "rules_00802", "split": "rules", "task_type": "king_safety_filter", "fen": "8/8/5k2/4n1p1/1pp1Np2/6P1/2K4P/B7 b - - 1 44", "prompt": "FEN: 8/8/5k2/4n1p1/1pp1Np2/6P1/2K4P/B7 b - - 1 44\nFor move b4b3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: b4b3.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "b4b3", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "b4b3", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_00803", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/1p6/7p/p7/2Pp1k2/1P2pB2/P6P/4K3 b - - 0 50", "prompt": "FEN: 8/1p6/7p/p7/2Pp1k2/1P2pB2/P6P/4K3 b - - 0 50\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e3 black pawn; d4 black pawn; f4 black king; a5 black pawn; h6 black pawn; b7 black pawn.\nMoves by piece:\ne3 black pawn: e3e2\nd4 black pawn: d4d3\nf4 black king: f4e5 f4f3 f4f5 f4g5\na5 black pawn: a5a4\nh6 black pawn: h6h5\nb7 black pawn: b7b5 b7b6\nAll legal moves: a5a4 b7b5 b7b6 d4d3 e3e2 f4e5 f4f3 f4f5 f4g5 h6h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e3": ["e3e2"], "d4": ["d4d3"], "f4": ["f4e5", "f4f3", "f4f5", "f4g5"], "a5": ["a5a4"], "h6": ["h6h5"], "b7": ["b7b5", "b7b6"]}, "_legal_moves_by_piece_moves": "a5a4 b7b5 b7b6 d4d3 e3e2 f4e5 f4f3 f4f5 f4g5 h6h5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e3": ["e3e2"], "d4": ["d4d3"], "f4": ["f4e5", "f4f3", "f4f5", "f4g5"], "a5": ["a5a4"], "h6": ["h6h5"], "b7": ["b7b5", "b7b6"]}, "legal_moves": "a5a4 b7b5 b7b6 d4d3 e3e2 f4e5 f4f3 f4f5 f4g5 h6h5"}}
{"example_id": "rules_00804", "split": "rules", "task_type": "ray_walk", "fen": "rn1kr3/pp3ppp/2pb4/2P2b2/1P2p3/2N5/P1BN1PPP/R1n2RK1 w - - 0 15", "prompt": "FEN: rn1kr3/pp3ppp/2pb4/2P2b2/1P2p3/2N5/P1BN1PPP/R1n2RK1 w - - 0 15\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 black knight: capture (stop, included).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00805", "split": "rules", "task_type": "legal_moves", "fen": "rnbq1rk1/pp1pn1bp/2p1p1p1/6B1/2B1P3/N1P2N2/PP3PPP/R2QK2R w KQ - 0 9", "prompt": "FEN: rnbq1rk1/pp1pn1bp/2p1p1p1/6B1/2B1P3/N1P2N2/PP3PPP/R2QK2R w KQ - 0 9\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a3b1 a3b5 a3c2 b2b3 b2b4 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 d1a4 d1b1 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1e2 e1d2 e1e2 e1f1 e1g1 e4e5 f3d2 f3d4 f3e5 f3g1 f3h4 g2g3 g2g4 g5c1 g5d2 g5e3 g5e7 g5f4 g5f6 g5h4 g5h6 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00806", "split": "rules", "task_type": "legal_moves", "fen": "B3n3/2p1k3/8/2P1ppp1/8/1P1K2P1/1P3P2/8 w - -", "prompt": "FEN: B3n3/2p1k3/8/2P1ppp1/8/1P1K2P1/1P3P2/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a8b7 a8c6 a8d5 a8e4 a8f3 a8g2 a8h1 b3b4 c5c6 d3c2 d3c3 d3c4 d3d2 d3e2 d3e3 f2f3 f2f4 g3g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00807", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/2k3rp/p2pQ1p1/1p6/3PP3/3K4/PP6/6R1 w - - 2 35", "prompt": "FEN: 8/2k3rp/p2pQ1p1/1p6/3PP3/3K4/PP6/6R1 w - - 2 35\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: g1 white rook; a2 white pawn; b2 white pawn; d3 white king; d4 white pawn; e4 white pawn; e6 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "g1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "d3", "piece": "white king"}, {"square": "d4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}, {"square": "e6", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "g1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "d3", "piece": "white king"}, {"square": "d4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}, {"square": "e6", "piece": "white queen"}]}}
{"example_id": "rules_00808", "split": "rules", "task_type": "piece_legal_moves", "fen": "3R2k1/2R5/1B5p/Pb6/r6P/4P1P1/5P2/6K1 b - - 6 36", "prompt": "FEN: 3R2k1/2R5/1B5p/Pb6/r6P/4P1P1/5P2/6K1 b - - 6 36\nWhat legal moves does the piece on h6 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h6", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "h6", "piece": "pawn"}}
{"example_id": "rules_00809", "split": "rules", "task_type": "check_detection", "fen": "2n4r/7p/p1n1k1p1/1pp1P1B1/7P/4N1P1/PPP5/6K1 b - - 0 24", "prompt": "FEN: 2n4r/7p/p1n1k1p1/1pp1P1B1/7P/4N1P1/PPP5/6K1 b - - 0 24\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00810", "split": "rules", "task_type": "captures", "fen": "r2q1rk1/ppp3p1/1nn1p1pp/2P5/2p4P/1P4P1/PB2QPB1/R4RK1 b - -", "prompt": "FEN: r2q1rk1/ppp3p1/1nn1p1pp/2P5/2p4P/1P4P1/PB2QPB1/R4RK1 b - -\nList all capture moves available.", "gold_answer": "c4b3 d8h4 f8f2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00811", "split": "rules", "task_type": "special_rules", "fen": "r4rk1/2pqbp1p/p1p1bp2/3p4/3N4/4Q2P/PPP2PP1/R1B1R1K1 w - -", "prompt": "Given FEN: r4rk1/2pqbp1p/p1p1bp2/3p4/3N4/4Q2P/PPP2PP1/R1B1R1K1 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00812", "split": "rules", "task_type": "legality_check", "fen": "5rk1/1pp2ppp/1p2b3/1P2q3/3N4/2P1rP2/1Q3KPP/1N5R w - - 5 24", "prompt": "FEN: 5rk1/1pp2ppp/1p2b3/1P2q3/3N4/2P1rP2/1Q3KPP/1N5R w - - 5 24\nIs the move b5c6 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b5c6", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "b5c6", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_00813", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnbqkbnr/pp3ppp/2p1p3/3P4/2B5/3P1N2/PPP2PPP/RNBQK2R b KQkq - 0 5", "prompt": "FEN: rnbqkbnr/pp3ppp/2p1p3/3P4/2B5/3P1N2/PPP2PPP/RNBQK2R b KQkq - 0 5\nList pseudo-legal moves from c6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c6: c6c5 c6d5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_00814", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn2kb1r/ppq2ppp/2p1pn2/8/1P1N4/P1N5/2PPQPPP/R1B2RK1 b kq - 0 10", "prompt": "FEN: rn2kb1r/ppq2ppp/2p1pn2/8/1P1N4/P1N5/2PPQPPP/R1B2RK1 b kq - 0 10\nFor the piece on c6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c6: c6c5.\nLegal: c6c5.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_00815", "split": "rules", "task_type": "king_safety_filter", "fen": "rn1q1rk1/pbp1bpp1/1p2p2p/3pP3/3Pn3/2PB1Q1N/PP3PPP/RNB1R1K1 b - - 2 10", "prompt": "FEN: rn1q1rk1/pbp1bpp1/1p2p2p/3pP3/3Pn3/2PB1Q1N/PP3PPP/RNB1R1K1 b - - 2 10\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00816", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rn3r2/pb3k1p/1pp1q1pB/2b2p2/2Q3N1/P1N3P1/1P2PP1P/R2R2K1 w - - 1 22", "prompt": "FEN: rn3r2/pb3k1p/1pp1q1pB/2b2p2/2Q3N1/P1N3P1/1P2PP1P/R2R2K1 w - - 1 22\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white rook; g1 white king; b2 white pawn; e2 white pawn; f2 white pawn; h2 white pawn; a3 white pawn; c3 white knight; g3 white pawn; c4 white queen; g4 white knight; h6 white bishop.\nMoves by piece:\na1 white rook: a1a2 a1b1 a1c1\nd1 white rook: d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1\ng1 white king: g1f1 g1g2 g1h1\nb2 white pawn: b2b3 b2b4\ne2 white pawn: e2e3 e2e4\nf2 white pawn: no legal moves\nh2 white pawn: h2h3 h2h4\na3 white pawn: a3a4\nc3 white knight: c3a2 c3a4 c3b1 c3b5 c3d5 c3e4\ng3 white pawn: no legal moves\nc4 white queen: c4a2 c4a4 c4a6 c4b3 c4b4 c4b5 c4c5 c4d3 c4d4 c4d5 c4e4 c4e6 c4f4\ng4 white knight: g4e3 g4e5 g4f6\nh6 white bishop: h6c1 h6d2 h6e3 h6f4 h6f8 h6g5 h6g7\nAll legal moves: a1a2 a1b1 a1c1 a3a4 b2b3 b2b4 c3a2 c3a4 c3b1 c3b5 c3d5 c3e4 c4a2 c4a4 c4a6 c4b3 c4b4 c4b5 c4c5 c4d3 c4d4 c4d5 c4e4 c4e6 c4f4 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 e2e3 e2e4 g1f1 g1g2 g1h1 g4e3 g4e5 g4f6 h2h3 h2h4 h6c1 h6d2 h6e3 h6f4 h6f8 h6g5 h6g7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1a2", "a1b1", "a1c1"], "d1": ["d1b1", "d1c1", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1d7", "d1d8", "d1e1", "d1f1"], "g1": ["g1f1", "g1g2", "g1h1"], "b2": ["b2b3", "b2b4"], "e2": ["e2e3", "e2e4"], "f2": [], "h2": ["h2h3", "h2h4"], "a3": ["a3a4"], "c3": ["c3a2", "c3a4", "c3b1", "c3b5", "c3d5", "c3e4"], "g3": [], "c4": ["c4a2", "c4a4", "c4a6", "c4b3", "c4b4", "c4b5", "c4c5", "c4d3", "c4d4", "c4d5", "c4e4", "c4e6", "c4f4"], "g4": ["g4e3", "g4e5", "g4f6"], "h6": ["h6c1", "h6d2", "h6e3", "h6f4", "h6f8", "h6g5", "h6g7"]}, "_legal_moves_by_piece_moves": "a1a2 a1b1 a1c1 a3a4 b2b3 b2b4 c3a2 c3a4 c3b1 c3b5 c3d5 c3e4 c4a2 c4a4 c4a6 c4b3 c4b4 c4b5 c4c5 c4d3 c4d4 c4d5 c4e4 c4e6 c4f4 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 e2e3 e2e4 g1f1 g1g2 g1h1 g4e3 g4e5 g4f6 h2h3 h2h4 h6c1 h6d2 h6e3 h6f4 h6f8 h6g5 h6g7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1a2", "a1b1", "a1c1"], "d1": ["d1b1", "d1c1", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1d7", "d1d8", "d1e1", "d1f1"], "g1": ["g1f1", "g1g2", "g1h1"], "b2": ["b2b3", "b2b4"], "e2": ["e2e3", "e2e4"], "f2": [], "h2": ["h2h3", "h2h4"], "a3": ["a3a4"], "c3": ["c3a2", "c3a4", "c3b1", "c3b5", "c3d5", "c3e4"], "g3": [], "c4": ["c4a2", "c4a4", "c4a6", "c4b3", "c4b4", "c4b5", "c4c5", "c4d3", "c4d4", "c4d5", "c4e4", "c4e6", "c4f4"], "g4": ["g4e3", "g4e5", "g4f6"], "h6": ["h6c1", "h6d2", "h6e3", "h6f4", "h6f8", "h6g5", "h6g7"]}, "legal_moves": "a1a2 a1b1 a1c1 a3a4 b2b3 b2b4 c3a2 c3a4 c3b1 c3b5 c3d5 c3e4 c4a2 c4a4 c4a6 c4b3 c4b4 c4b5 c4c5 c4d3 c4d4 c4d5 c4e4 c4e6 c4f4 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 e2e3 e2e4 g1f1 g1g2 g1h1 g4e3 g4e5 g4f6 h2h3 h2h4 h6c1 h6d2 h6e3 h6f4 h6f8 h6g5 h6g7"}}
{"example_id": "rules_00817", "split": "rules", "task_type": "ray_walk", "fen": "8/3K4/8/4k3/6B1/2r2p2/8/8 b - -", "prompt": "FEN: 8/3K4/8/4k3/6B1/2r2p2/8/8 b - -\nWalk each ray for the slider on c3: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c3 black rook.\nRay N: c4 empty; c5 empty; c6 empty; c7 empty; c8 empty; edge.\nRay E: d3 empty; e3 empty; f3 black pawn: own piece (stop, excluded).\nRay S: c2 empty; c1 empty; edge.\nRay W: b3 empty; a3 empty; edge.\nMoves from rays: c3a3 c3b3 c3c1 c3c2 c3c4 c3c5 c3c6 c3c7 c3c8 c3d3 c3e3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c3", "diagnostic": true, "hard_gate": false, "source_square": "c3"}}
{"example_id": "rules_00818", "split": "rules", "task_type": "legal_moves", "fen": "1r4k1/1r3pb1/4q2P/2pNp1p1/p1P3P1/8/PP4RQ/2K1R3 b - -", "prompt": "FEN: 1r4k1/1r3pb1/4q2P/2pNp1p1/p1P3P1/8/PP4RQ/2K1R3 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a4a3 b7a7 b7b2 b7b3 b7b4 b7b5 b7b6 b7c7 b7d7 b7e7 b8a8 b8c8 b8d8 b8e8 b8f8 e5e4 e6a6 e6b6 e6c6 e6c8 e6d5 e6d6 e6d7 e6e7 e6e8 e6f5 e6f6 e6g4 e6g6 e6h6 f7f5 f7f6 g7f6 g7f8 g7h6 g7h8 g8f8 g8h7 g8h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00819", "split": "rules", "task_type": "legal_moves", "fen": "rnb2r1k/pp3pp1/4pnB1/3pP3/3p4/2N4N/PPP2PP1/R3K2R w KQ -", "prompt": "FEN: rnb2r1k/pp3pp1/4pnB1/3pP3/3p4/2N4N/PPP2PP1/R3K2R w KQ -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a1d1 a2a3 a2a4 b2b3 b2b4 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 e1c1 e1d1 e1d2 e1e2 e1f1 e1g1 e5f6 f2f3 f2f4 g2g3 g2g4 g6d3 g6e4 g6f5 g6f7 g6h5 g6h7 h1f1 h1g1 h1h2 h3f4 h3g1 h3g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00820", "split": "rules", "task_type": "side_piece_inventory", "fen": "5rk1/6pp/3Qp2n/3p4/2pP1PP1/5N1P/P7/5K2 b - - 3 27", "prompt": "FEN: 5rk1/6pp/3Qp2n/3p4/2pP1PP1/5N1P/P7/5K2 b - - 3 27\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c4 black pawn; d5 black pawn; e6 black pawn; h6 black knight; g7 black pawn; h7 black pawn; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c4", "piece": "black pawn"}, {"square": "d5", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "h6", "piece": "black knight"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c4", "piece": "black pawn"}, {"square": "d5", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "h6", "piece": "black knight"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_00821", "split": "rules", "task_type": "piece_legal_moves", "fen": "5rk1/pp4pp/4p3/2p1p3/2P1P3/1P6/P3r1PP/R1BR2K1 w - - 1 21", "prompt": "FEN: 5rk1/pp4pp/4p3/2p1p3/2P1P3/1P6/P3r1PP/R1BR2K1 w - - 1 21\nWhat legal moves does the piece on e4 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "e4", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "e4", "piece": "pawn"}}
{"example_id": "rules_00822", "split": "rules", "task_type": "check_detection", "fen": "rnbqkb1r/ppp2ppp/3pp2n/4P3/3P4/5N1P/PPP2PP1/RNBQKB1R w KQkq - 0 6", "prompt": "FEN: rnbqkb1r/ppp2ppp/3pp2n/4P3/3P4/5N1P/PPP2PP1/RNBQKB1R w KQkq - 0 6\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00823", "split": "rules", "task_type": "captures", "fen": "5k2/5p2/4r3/1p6/1Pb5/6K1/3R4/8 b - - 5 53", "prompt": "FEN: 5k2/5p2/4r3/1p6/1Pb5/6K1/3R4/8 b - - 5 53\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00824", "split": "rules", "task_type": "special_rules", "fen": "8/8/8/R4Q2/6rP/6Pk/4K3/8 w - - 0 57", "prompt": "Given FEN: 8/8/8/R4Q2/6rP/6Pk/4K3/8 w - - 0 57\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00825", "split": "rules", "task_type": "legality_check", "fen": "r1b1k2r/pp3pbp/1q1p2p1/4p1B1/2P1P3/2Pn2PP/PP3QB1/R3K1NR w - -", "prompt": "FEN: r1b1k2r/pp3pbp/1q1p2p1/4p1B1/2P1P3/2Pn2PP/PP3QB1/R3K1NR w - -\nIs the move e1f1 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "e1f1", "_legality_check_reason_label": "legal", "move": "e1f1", "legality_reason_label": "legal"}}
{"example_id": "rules_00826", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r3k1nr/3qbppp/3pp3/p3P3/1p1N1P2/8/PPP3PP/RNBQK2R b KQkq - 0 14", "prompt": "FEN: r3k1nr/3qbppp/3pp3/p3P3/1p1N1P2/8/PPP3PP/RNBQK2R b KQkq - 0 14\nList pseudo-legal moves from b4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b4: b4b3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_00827", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2q1rk1/pp3ppp/8/4b3/3pN3/5Q1P/PP3PP1/R3R1K1 b - - 3 17", "prompt": "FEN: r2q1rk1/pp3ppp/8/4b3/3pN3/5Q1P/PP3PP1/R3R1K1 b - - 3 17\nFor the piece on d4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d4: d4d3.\nLegal: d4d3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_00828", "split": "rules", "task_type": "king_safety_filter", "fen": "r3r1k1/pp1q1ppp/2nb1n2/2p3B1/3p4/1B1P1P1P/PPPQNP2/2K1R2R w - - 1 15", "prompt": "FEN: r3r1k1/pp1q1ppp/2nb1n2/2p3B1/3p4/1B1P1P1P/PPPQNP2/2K1R2R w - - 1 15\nFor move a2a3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a2a3.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a2a3", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a2a3", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00829", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqkbnr/pp3ppp/2n1p3/2PpP3/6Q1/2N5/PPP2PPP/R1B1KBNR b KQkq -", "prompt": "FEN: r1bqkbnr/pp3ppp/2n1p3/2PpP3/6Q1/2N5/PPP2PPP/R1B1KBNR b KQkq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; c6 black knight; e6 black pawn; a7 black pawn; b7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\nd5 black pawn: d5d4\nc6 black knight: c6a5 c6b4 c6b8 c6d4 c6e5 c6e7\ne6 black pawn: no legal moves\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8\nc8 black bishop: c8d7\nd8 black queen: d8a5 d8b6 d8c7 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4\ne8 black king: e8d7 e8e7\nf8 black bishop: f8c5 f8d6 f8e7\ng8 black knight: g8e7 g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 c8d7 d5d4 d8a5 d8b6 d8c7 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e8d7 e8e7 f7f5 f7f6 f8c5 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d5": ["d5d4"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5", "c6e7"], "e6": [], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7"], "d8": ["d8a5", "d8b6", "d8c7", "d8d6", "d8d7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8d7", "e8e7"], "f8": ["f8c5", "f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 c8d7 d5d4 d8a5 d8b6 d8c7 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e8d7 e8e7 f7f5 f7f6 f8c5 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d5": ["d5d4"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5", "c6e7"], "e6": [], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7"], "d8": ["d8a5", "d8b6", "d8c7", "d8d6", "d8d7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8d7", "e8e7"], "f8": ["f8c5", "f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "legal_moves": "a7a5 a7a6 a8b8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 c8d7 d5d4 d8a5 d8b6 d8c7 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e8d7 e8e7 f7f5 f7f6 f8c5 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_00830", "split": "rules", "task_type": "ray_walk", "fen": "8/7R/3p2p1/4p1k1/1b2P2P/3P1K2/8/8 b - - 0 48", "prompt": "FEN: 8/7R/3p2p1/4p1k1/1b2P2P/3P1K2/8/8 b - - 0 48\nWalk each ray for the slider on b4: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b4 black bishop.\nRay NE: c5 empty; d6 black pawn: own piece (stop, excluded).\nRay SE: c3 empty; d2 empty; e1 empty; edge.\nRay SW: a3 empty; edge.\nRay NW: a5 empty; edge.\nMoves from rays: b4a3 b4a5 b4c3 b4c5 b4d2 b4e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_00831", "split": "rules", "task_type": "legal_moves", "fen": "5r1k/4p1bp/1R3p2/3Q2p1/3P3P/R3P1B1/5PPK/2r2n2 w - - 1 27", "prompt": "FEN: 5r1k/4p1bp/1R3p2/3Q2p1/3P3P/R3P1B1/5PPK/2r2n2 w - - 1 27\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: h2g1 h2h1 h2h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00832", "split": "rules", "task_type": "legal_moves", "fen": "2rq1rk1/pb1nbp1p/1p1Np1p1/4P3/2P5/P2B4/1B2QPPP/R4RK1 b - -", "prompt": "FEN: 2rq1rk1/pb1nbp1p/1p1Np1p1/4P3/2P5/P2B4/1B2QPPP/R4RK1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6b5 b7a6 b7a8 b7c6 b7d5 b7e4 b7f3 b7g2 c8a8 c8b8 c8c4 c8c5 c8c6 c8c7 d7b8 d7c5 d7e5 d7f6 d8c7 d8e8 e7d6 e7f6 e7g5 e7h4 f7f5 f7f6 f8e8 g6g5 g8g7 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00833", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqk2r/p2nppbp/2pp1np1/1p4B1/3PPP2/2N5/PPPQ2PP/2KR1BNR w kq -", "prompt": "FEN: r1bqk2r/p2nppbp/2pp1np1/1p4B1/3PPP2/2N5/PPPQ2PP/2KR1BNR w kq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: c1 white king; d1 white rook; f1 white bishop; g1 white knight; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; d2 white queen; g2 white pawn; h2 white pawn; c3 white knight; d4 white pawn; e4 white pawn; f4 white pawn; g5 white bishop.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "c1", "piece": "white king"}, {"square": "d1", "piece": "white rook"}, {"square": "f1", "piece": "white bishop"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white queen"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "g5", "piece": "white bishop"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "c1", "piece": "white king"}, {"square": "d1", "piece": "white rook"}, {"square": "f1", "piece": "white bishop"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white queen"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "g5", "piece": "white bishop"}]}}
{"example_id": "rules_00834", "split": "rules", "task_type": "piece_legal_moves", "fen": "r2qkb1r/pbpp1ppp/1pn2n2/8/8/P1N1P2P/1PP2PP1/R1BQKBNR b KQkq - 2 7", "prompt": "FEN: r2qkb1r/pbpp1ppp/1pn2n2/8/8/P1N1P2P/1PP2PP1/R1BQKBNR b KQkq - 2 7\nWhat legal moves does the piece on f7 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f7", "piece": "pawn"}}
{"example_id": "rules_00835", "split": "rules", "task_type": "check_detection", "fen": "5k2/bp6/p2Pp1p1/Pb5p/1P6/7P/5PP1/R2QR1K1 b - - 1 29", "prompt": "FEN: 5k2/bp6/p2Pp1p1/Pb5p/1P6/7P/5PP1/R2QR1K1 b - - 1 29\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00836", "split": "rules", "task_type": "captures", "fen": "r2qk2r/1pp1bppp/p2p3n/8/2B1P1b1/3P1n2/PPP3PP/RNBQ1RK1 w kq - 0 10", "prompt": "FEN: r2qk2r/1pp1bppp/p2p3n/8/2B1P1b1/3P1n2/PPP3PP/RNBQ1RK1 w kq - 0 10\nList all capture moves available.", "gold_answer": "d1f3 f1f3 g2f3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00837", "split": "rules", "task_type": "special_rules", "fen": "rn2kbnr/1pq1pppp/p1p5/3P1b2/P2P4/1Q2P3/1P3PPP/RNB1KBNR b KQkq -", "prompt": "Given FEN: rn2kbnr/1pq1pppp/p1p5/3P1b2/P2P4/1Q2P3/1P3PPP/RNB1KBNR b KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00838", "split": "rules", "task_type": "legality_check", "fen": "rn5r/pp2b2p/2pkbn2/3p2p1/3Pp3/1PN1P1N1/P5PP/R1B1KB1R b KQ - 1 14", "prompt": "FEN: rn5r/pp2b2p/2pkbn2/3p2p1/3Pp3/1PN1P1N1/P5PP/R1B1KB1R b KQ - 1 14\nIs the move c6c5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c6c5", "_legality_check_reason_label": "legal", "move": "c6c5", "legality_reason_label": "legal"}}
{"example_id": "rules_00839", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r5k1/pp5p/8/n2q4/3B4/3B4/P5PP/4rRK1 w - -", "prompt": "FEN: r5k1/pp5p/8/n2q4/3B4/3B4/P5PP/4rRK1 w - -\nList pseudo-legal moves from f1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from f1: f1e1 f1f2 f1f3 f1f4 f1f5 f1f6 f1f7 f1f8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "f1", "diagnostic": true, "hard_gate": false, "source_square": "f1"}}
{"example_id": "rules_00840", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1bqkb1r/ppp1nppp/2n1p3/3p4/3P1P2/3QP3/PPP1N1PP/RNB1KB1R b KQkq - 2 5", "prompt": "FEN: r1bqkb1r/ppp1nppp/2n1p3/3p4/3P1P2/3QP3/PPP1N1PP/RNB1KB1R b KQkq - 2 5\nFor the piece on c6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c6: c6a5 c6b4 c6b8 c6d4 c6e5.\nLegal: c6a5 c6b4 c6b8 c6d4 c6e5.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_00841", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbq1rk1/p1pp1ppp/1p2pn2/8/1bPP4/P1N1P3/1P2NPPP/R1BQKB1R b KQ -", "prompt": "FEN: rnbq1rk1/p1pp1ppp/1p2pn2/8/1bPP4/P1N1P3/1P2NPPP/R1BQKB1R b KQ -\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00842", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/8/8/8/3K3R/1k6/8/6R1 w - -", "prompt": "FEN: 8/8/8/8/3K3R/1k6/8/6R1 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: g1 white rook; d4 white king; h4 white rook.\nMoves by piece:\ng1 white rook: g1a1 g1b1 g1c1 g1d1 g1e1 g1f1 g1g2 g1g3 g1g4 g1g5 g1g6 g1g7 g1g8 g1h1\nd4 white king: d4c5 d4d3 d4d5 d4e3 d4e4 d4e5\nh4 white rook: h4e4 h4f4 h4g4 h4h1 h4h2 h4h3 h4h5 h4h6 h4h7 h4h8\nAll legal moves: d4c5 d4d3 d4d5 d4e3 d4e4 d4e5 g1a1 g1b1 g1c1 g1d1 g1e1 g1f1 g1g2 g1g3 g1g4 g1g5 g1g6 g1g7 g1g8 g1h1 h4e4 h4f4 h4g4 h4h1 h4h2 h4h3 h4h5 h4h6 h4h7 h4h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"g1": ["g1a1", "g1b1", "g1c1", "g1d1", "g1e1", "g1f1", "g1g2", "g1g3", "g1g4", "g1g5", "g1g6", "g1g7", "g1g8", "g1h1"], "d4": ["d4c5", "d4d3", "d4d5", "d4e3", "d4e4", "d4e5"], "h4": ["h4e4", "h4f4", "h4g4", "h4h1", "h4h2", "h4h3", "h4h5", "h4h6", "h4h7", "h4h8"]}, "_legal_moves_by_piece_moves": "d4c5 d4d3 d4d5 d4e3 d4e4 d4e5 g1a1 g1b1 g1c1 g1d1 g1e1 g1f1 g1g2 g1g3 g1g4 g1g5 g1g6 g1g7 g1g8 g1h1 h4e4 h4f4 h4g4 h4h1 h4h2 h4h3 h4h5 h4h6 h4h7 h4h8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"g1": ["g1a1", "g1b1", "g1c1", "g1d1", "g1e1", "g1f1", "g1g2", "g1g3", "g1g4", "g1g5", "g1g6", "g1g7", "g1g8", "g1h1"], "d4": ["d4c5", "d4d3", "d4d5", "d4e3", "d4e4", "d4e5"], "h4": ["h4e4", "h4f4", "h4g4", "h4h1", "h4h2", "h4h3", "h4h5", "h4h6", "h4h7", "h4h8"]}, "legal_moves": "d4c5 d4d3 d4d5 d4e3 d4e4 d4e5 g1a1 g1b1 g1c1 g1d1 g1e1 g1f1 g1g2 g1g3 g1g4 g1g5 g1g6 g1g7 g1g8 g1h1 h4e4 h4f4 h4g4 h4h1 h4h2 h4h3 h4h5 h4h6 h4h7 h4h8"}}
{"example_id": "rules_00843", "split": "rules", "task_type": "ray_walk", "fen": "rn1qkbnr/1bp2ppp/pp1pp3/3P4/4P3/5N2/PPP1BPPP/RNBQK2R b KQkq - 0 6", "prompt": "FEN: rn1qkbnr/1bp2ppp/pp1pp3/3P4/4P3/5N2/PPP1BPPP/RNBQK2R b KQkq - 0 6\nWalk each ray for the slider on b7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b7 black bishop.\nRay NE: c8 empty; edge.\nRay SE: c6 empty; d5 white pawn: capture (stop, included).\nRay SW: a6 black pawn: own piece (stop, excluded).\nRay NW: a8 black rook: own piece (stop, excluded).\nMoves from rays: b7c6 b7c8 b7d5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "b7", "diagnostic": true, "hard_gate": false, "source_square": "b7"}}
{"example_id": "rules_00844", "split": "rules", "task_type": "legal_moves", "fen": "r2qk1nr/ppp2pp1/2B3b1/2b1p2p/4P1P1/2PP1N1P/PP3P2/RNBQK2R b KQkq - 0 9", "prompt": "FEN: r2qk1nr/ppp2pp1/2B3b1/2b1p2p/4P1P1/2PP1N1P/PP3P2/RNBQK2R b KQkq - 0 9\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b7c6 d8d7 e8e7 e8f8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00845", "split": "rules", "task_type": "legal_moves", "fen": "8/8/1p6/p1p5/P1P2K1N/1Pk5/8/8 w - -", "prompt": "FEN: 8/8/1p6/p1p5/P1P2K1N/1Pk5/8/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b3b4 f4e3 f4e4 f4e5 f4f3 f4f5 f4g3 f4g4 f4g5 h4f3 h4f5 h4g2 h4g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00846", "split": "rules", "task_type": "side_piece_inventory", "fen": "r3r1k1/pp1q1ppp/3b4/2p5/1n6/3PP1P1/PP3PBP/R1BQ1RK1 w - - 3 15", "prompt": "FEN: r3r1k1/pp1q1ppp/3b4/2p5/1n6/3PP1P1/PP3PBP/R1BQ1RK1 w - - 3 15\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; f2 white pawn; g2 white bishop; h2 white pawn; d3 white pawn; e3 white pawn; g3 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white bishop"}, {"square": "h2", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white bishop"}, {"square": "h2", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}]}}
{"example_id": "rules_00847", "split": "rules", "task_type": "piece_legal_moves", "fen": "2k5/B5bp/1prp2p1/8/4PP2/P2P4/1P4R1/1K1R4 w - - 0 32", "prompt": "FEN: 2k5/B5bp/1prp2p1/8/4PP2/P2P4/1P4R1/1K1R4 w - - 0 32\nWhat legal moves does the piece on b2 have?", "gold_answer": "b2b3 b2b4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "b2", "piece": "pawn"}}
{"example_id": "rules_00848", "split": "rules", "task_type": "check_detection", "fen": "r1q3k1/bpp1nrp1/3pNn1p/p3p3/4P3/1QPP3P/PP3PP1/R1B1RNK1 w - -", "prompt": "FEN: r1q3k1/bpp1nrp1/3pNn1p/p3p3/4P3/1QPP3P/PP3PP1/R1B1RNK1 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00849", "split": "rules", "task_type": "captures", "fen": "6K1/7P/p5k1/6r1/8/8/8/7R b - -", "prompt": "FEN: 6K1/7P/p5k1/6r1/8/8/8/7R b - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00850", "split": "rules", "task_type": "special_rules", "fen": "4r3/ppp3pp/2k2n2/8/2B5/1P3N2/P1P3PP/2KR4 w - - 0 20", "prompt": "Given FEN: 4r3/ppp3pp/2k2n2/8/2B5/1P3N2/P1P3PP/2KR4 w - - 0 20\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00851", "split": "rules", "task_type": "legality_check", "fen": "8/8/6P1/5K1k/8/8/8/6Q1 w - - 3 73", "prompt": "FEN: 8/8/6P1/5K1k/8/8/8/6Q1 w - - 3 73\nIs the move g1d1 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g1d1", "_legality_check_reason_label": "legal", "move": "g1d1", "legality_reason_label": "legal"}}
{"example_id": "rules_00852", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2K5/5r2/2kP4/4BP2/p7/P7/8/8 b - -", "prompt": "FEN: 2K5/5r2/2kP4/4BP2/p7/P7/8/8 b - -\nList pseudo-legal moves from c6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c6: c6b5 c6b6 c6b7 c6c5 c6c7 c6d5 c6d6 c6d7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_00853", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/8/3p1k1p/7q/6p1/6P1/3q4/6K1 b - - 5 53", "prompt": "FEN: 8/8/3p1k1p/7q/6p1/6P1/3q4/6K1 b - - 5 53\nFor the piece on d2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d2: d2a2 d2a5 d2b2 d2b4 d2c1 d2c2 d2c3 d2d1 d2d3 d2d4 d2d5 d2e1 d2e2 d2e3 d2f2 d2f4 d2g2 d2g5 d2h2.\nLegal: d2a2 d2a5 d2b2 d2b4 d2c1 d2c2 d2c3 d2d1 d2d3 d2d4 d2d5 d2e1 d2e2 d2e3 d2f2 d2f4 d2g2 d2g5 d2h2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "d2", "diagnostic": true, "hard_gate": false, "source_square": "d2"}}
{"example_id": "rules_00854", "split": "rules", "task_type": "king_safety_filter", "fen": "QRK5/6k1/2P5/8/8/8/8/2r5 b - -", "prompt": "FEN: QRK5/6k1/2P5/8/8/8/8/2r5 b - -\nFor move c1a1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c1a1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "c1a1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "c1a1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00855", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqk2r/ppp1nppp/2n5/3P4/1bBP4/2N2N2/PP3PPP/R1BQK2R b KQkq -", "prompt": "FEN: r1bqk2r/ppp1nppp/2n5/3P4/1bBP4/2N2N2/PP3PPP/R1BQK2R b KQkq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b4 black bishop; c6 black knight; a7 black pawn; b7 black pawn; c7 black pawn; e7 black knight; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black king; h8 black rook.\nMoves by piece:\nb4 black bishop: b4a3 b4a5 b4c3 b4c5 b4d6\nc6 black knight: c6a5 c6b8 c6d4 c6e5\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nc7 black pawn: no legal moves\ne7 black knight: e7d5 e7f5 e7g6 e7g8\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8\nc8 black bishop: c8d7 c8e6 c8f5 c8g4 c8h3\nd8 black queen: d8d5 d8d6 d8d7\ne8 black king: e8d7 e8f8 e8g8\nh8 black rook: h8f8 h8g8\nAll legal moves: a7a5 a7a6 a8b8 b4a3 b4a5 b4c3 b4c5 b4d6 b7b5 b7b6 c6a5 c6b8 c6d4 c6e5 c8d7 c8e6 c8f5 c8g4 c8h3 d8d5 d8d6 d8d7 e7d5 e7f5 e7g6 e7g8 e8d7 e8f8 e8g8 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b4": ["b4a3", "b4a5", "b4c3", "b4c5", "b4d6"], "c6": ["c6a5", "c6b8", "c6d4", "c6e5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": [], "e7": ["e7d5", "e7f5", "e7g6", "e7g8"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7", "c8e6", "c8f5", "c8g4", "c8h3"], "d8": ["d8d5", "d8d6", "d8d7"], "e8": ["e8d7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 b4a3 b4a5 b4c3 b4c5 b4d6 b7b5 b7b6 c6a5 c6b8 c6d4 c6e5 c8d7 c8e6 c8f5 c8g4 c8h3 d8d5 d8d6 d8d7 e7d5 e7f5 e7g6 e7g8 e8d7 e8f8 e8g8 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b4": ["b4a3", "b4a5", "b4c3", "b4c5", "b4d6"], "c6": ["c6a5", "c6b8", "c6d4", "c6e5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": [], "e7": ["e7d5", "e7f5", "e7g6", "e7g8"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7", "c8e6", "c8f5", "c8g4", "c8h3"], "d8": ["d8d5", "d8d6", "d8d7"], "e8": ["e8d7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "legal_moves": "a7a5 a7a6 a8b8 b4a3 b4a5 b4c3 b4c5 b4d6 b7b5 b7b6 c6a5 c6b8 c6d4 c6e5 c8d7 c8e6 c8f5 c8g4 c8h3 d8d5 d8d6 d8d7 e7d5 e7f5 e7g6 e7g8 e8d7 e8f8 e8g8 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8"}}
{"example_id": "rules_00856", "split": "rules", "task_type": "ray_walk", "fen": "r1bq1rk1/pp1nppb1/3p3p/2p3pn/2PP4/2N1PNB1/PPQ1BPPP/R3K2R w KQ -", "prompt": "FEN: r1bq1rk1/pp1nppb1/3p3p/2p3pn/2PP4/2N1PNB1/PPQ1BPPP/R3K2R w KQ -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 empty; e1 white king: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1 a1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00857", "split": "rules", "task_type": "legal_moves", "fen": "8/pp2kp1p/r2r2p1/2p1p3/1PPnP3/5P2/P2R1KPP/1R3B2 b - -", "prompt": "FEN: 8/pp2kp1p/r2r2p1/2p1p3/1PPnP3/5P2/P2R1KPP/1R3B2 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a2 a6a3 a6a4 a6a5 a6b6 a6c6 b7b5 b7b6 c5b4 d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3 d4f5 d6b6 d6c6 d6d5 d6d7 d6d8 d6e6 d6f6 e7d7 e7d8 e7e6 e7e8 e7f6 e7f8 f7f5 f7f6 g6g5 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00858", "split": "rules", "task_type": "legal_moves", "fen": "rq2kb1r/pb1p1ppp/2p1p3/2P1P3/1n2NP2/8/PP4PP/R1BQKB1R b KQkq -", "prompt": "FEN: rq2kb1r/pb1p1ppp/2p1p3/2P1P3/1n2NP2/8/PP4PP/R1BQKB1R b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b4a2 b4a6 b4c2 b4d3 b4d5 b7a6 b7c8 b8c7 b8c8 b8d6 b8d8 b8e5 d7d5 d7d6 e8d8 e8e7 f7f5 f7f6 f8c5 f8d6 f8e7 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00859", "split": "rules", "task_type": "side_piece_inventory", "fen": "1kr4r/pp2qp2/3p1n1p/4p1p1/3pP3/P2P1QBP/1PP2PP1/2R2RK1 b - - 1 17", "prompt": "FEN: 1kr4r/pp2qp2/3p1n1p/4p1p1/3pP3/P2P1QBP/1PP2PP1/2R2RK1 b - - 1 17\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: d4 black pawn; e5 black pawn; g5 black pawn; d6 black pawn; f6 black knight; h6 black pawn; a7 black pawn; b7 black pawn; e7 black queen; f7 black pawn; b8 black king; c8 black rook; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "d4", "piece": "black pawn"}, {"square": "e5", "piece": "black pawn"}, {"square": "g5", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "e7", "piece": "black queen"}, {"square": "f7", "piece": "black pawn"}, {"square": "b8", "piece": "black king"}, {"square": "c8", "piece": "black rook"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "d4", "piece": "black pawn"}, {"square": "e5", "piece": "black pawn"}, {"square": "g5", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "e7", "piece": "black queen"}, {"square": "f7", "piece": "black pawn"}, {"square": "b8", "piece": "black king"}, {"square": "c8", "piece": "black rook"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00860", "split": "rules", "task_type": "piece_legal_moves", "fen": "q4rk1/rb1n1ppp/p3p3/2bP4/PpB1QB2/5N2/1P3PPP/2R1K2R w K -", "prompt": "FEN: q4rk1/rb1n1ppp/p3p3/2bP4/PpB1QB2/5N2/1P3PPP/2R1K2R w K -\nWhat legal moves does the piece on f4 have?", "gold_answer": "f4b8 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4g5 f4h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f4", "_piece_legal_moves_piece": "bishop", "diagnostic": true, "hard_gate": false, "source_square": "f4", "piece": "bishop"}}
{"example_id": "rules_00861", "split": "rules", "task_type": "check_detection", "fen": "r1b1k2r/pp2np1p/2pp1qp1/4p3/4Q1P1/1PB1P2P/P1P1BP2/2KR2NR b kq - 1 14", "prompt": "FEN: r1b1k2r/pp2np1p/2pp1qp1/4p3/4Q1P1/1PB1P2P/P1P1BP2/2KR2NR b kq - 1 14\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00862", "split": "rules", "task_type": "captures", "fen": "8/3R2k1/5pp1/p5Pp/5P1b/8/4K3/8 b - -", "prompt": "FEN: 8/3R2k1/5pp1/p5Pp/5P1b/8/4K3/8 b - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00863", "split": "rules", "task_type": "special_rules", "fen": "r1bqkb1r/pp3ppp/2n2n2/2pp4/3P4/5N2/PPP1BPPP/RNBQK2R w KQkq -", "prompt": "Given FEN: r1bqkb1r/pp3ppp/2n2n2/2pp4/3P4/5N2/PPP1BPPP/RNBQK2R w KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00864", "split": "rules", "task_type": "legality_check", "fen": "r1bqk1nr/p2p1ppp/1pn5/1Bb1p3/4P3/4QN2/PPP2PPP/RNB1K2R w KQkq - 2 7", "prompt": "FEN: r1bqk1nr/p2p1ppp/1pn5/1Bb1p3/4P3/4QN2/PPP2PPP/RNB1K2R w KQkq - 2 7\nIs the move e3b3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "e3b3", "_legality_check_reason_label": "legal", "move": "e3b3", "legality_reason_label": "legal"}}
{"example_id": "rules_00865", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1b2rk1/ppp2pp1/2nbpq1p/3p4/3P4/P1NBPN2/1PP2PPP/R2QK2R w KQ - 3 9", "prompt": "FEN: r1b2rk1/ppp2pp1/2nbpq1p/3p4/3P4/P1NBPN2/1PP2PPP/R2QK2R w KQ - 3 9\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1a2 a1b1 a1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00866", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2qk2r/4bpp1/p1np1n1p/1p6/PPp1P3/2P5/2B1QPPP/RNB1R1K1 w kq - 1 15", "prompt": "FEN: r2qk2r/4bpp1/p1np1n1p/1p6/PPp1P3/2P5/2B1QPPP/RNB1R1K1 w kq - 1 15\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1a2 a1a3.\nLegal: a1a2 a1a3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00867", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bq1rk1/ppp2ppp/2nb1n2/4p3/2BP4/P1N1PN2/1P3PPP/R1BQR1K1 w - - 0 10", "prompt": "FEN: r1bq1rk1/ppp2ppp/2nb1n2/4p3/2BP4/P1N1PN2/1P3PPP/R1BQR1K1 w - - 0 10\nFor move a1a2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1a2.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1a2", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1a2", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00868", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2rq1rk1/pp1bbpp1/2n1pn1p/8/2N5/1P2P1P1/PB2NPBP/R2Q1RK1 b - - 2 13", "prompt": "FEN: 2rq1rk1/pp1bbpp1/2n1pn1p/8/2N5/1P2P1P1/PB2NPBP/R2Q1RK1 b - - 2 13\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c6 black knight; e6 black pawn; f6 black knight; h6 black pawn; a7 black pawn; b7 black pawn; d7 black bishop; e7 black bishop; f7 black pawn; g7 black pawn; c8 black rook; d8 black queen; f8 black rook; g8 black king.\nMoves by piece:\nc6 black knight: c6a5 c6b4 c6b8 c6d4 c6e5\ne6 black pawn: e6e5\nf6 black knight: f6d5 f6e4 f6e8 f6g4 f6h5 f6h7\nh6 black pawn: h6h5\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nd7 black bishop: d7e8\ne7 black bishop: e7a3 e7b4 e7c5 e7d6\nf7 black pawn: no legal moves\ng7 black pawn: g7g5 g7g6\nc8 black rook: c8a8 c8b8 c8c7\nd8 black queen: d8a5 d8b6 d8c7 d8e8\nf8 black rook: f8e8\ng8 black king: g8h7 g8h8\nAll legal moves: a7a5 a7a6 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 c8a8 c8b8 c8c7 d7e8 d8a5 d8b6 d8c7 d8e8 e6e5 e7a3 e7b4 e7c5 e7d6 f6d5 f6e4 f6e8 f6g4 f6h5 f6h7 f8e8 g7g5 g7g6 g8h7 g8h8 h6h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5"], "e6": ["e6e5"], "f6": ["f6d5", "f6e4", "f6e8", "f6g4", "f6h5", "f6h7"], "h6": ["h6h5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "d7": ["d7e8"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6"], "f7": [], "g7": ["g7g5", "g7g6"], "c8": ["c8a8", "c8b8", "c8c7"], "d8": ["d8a5", "d8b6", "d8c7", "d8e8"], "f8": ["f8e8"], "g8": ["g8h7", "g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 c8a8 c8b8 c8c7 d7e8 d8a5 d8b6 d8c7 d8e8 e6e5 e7a3 e7b4 e7c5 e7d6 f6d5 f6e4 f6e8 f6g4 f6h5 f6h7 f8e8 g7g5 g7g6 g8h7 g8h8 h6h5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5"], "e6": ["e6e5"], "f6": ["f6d5", "f6e4", "f6e8", "f6g4", "f6h5", "f6h7"], "h6": ["h6h5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "d7": ["d7e8"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6"], "f7": [], "g7": ["g7g5", "g7g6"], "c8": ["c8a8", "c8b8", "c8c7"], "d8": ["d8a5", "d8b6", "d8c7", "d8e8"], "f8": ["f8e8"], "g8": ["g8h7", "g8h8"]}, "legal_moves": "a7a5 a7a6 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 c8a8 c8b8 c8c7 d7e8 d8a5 d8b6 d8c7 d8e8 e6e5 e7a3 e7b4 e7c5 e7d6 f6d5 f6e4 f6e8 f6g4 f6h5 f6h7 f8e8 g7g5 g7g6 g8h7 g8h8 h6h5"}}
{"example_id": "rules_00869", "split": "rules", "task_type": "ray_walk", "fen": "8/1k6/R7/7R/3K4/8/8/8 w - -", "prompt": "FEN: 8/1k6/R7/7R/3K4/8/8/8 w - -\nWalk each ray for the slider on h5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: h5 white rook.\nRay N: h6 empty; h7 empty; h8 empty; edge.\nRay E: edge.\nRay S: h4 empty; h3 empty; h2 empty; h1 empty; edge.\nRay W: g5 empty; f5 empty; e5 empty; d5 empty; c5 empty; b5 empty; a5 empty; edge.\nMoves from rays: h5a5 h5b5 h5c5 h5d5 h5e5 h5f5 h5g5 h5h1 h5h2 h5h3 h5h4 h5h6 h5h7 h5h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "h5", "diagnostic": true, "hard_gate": false, "source_square": "h5"}}
{"example_id": "rules_00870", "split": "rules", "task_type": "legal_moves", "fen": "8/1p4p1/p1p1r1p1/P1PpNkP1/1PnP1P2/4P3/4K3/7R w - - 5 46", "prompt": "FEN: 8/1p4p1/p1p1r1p1/P1PpNkP1/1PnP1P2/4P3/4K3/7R w - - 5 46\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b4b5 e2d1 e2d3 e2e1 e2f1 e2f2 e2f3 e3e4 e5c4 e5c6 e5d3 e5d7 e5f3 e5f7 e5g4 e5g6 h1a1 h1b1 h1c1 h1d1 h1e1 h1f1 h1g1 h1h2 h1h3 h1h4 h1h5 h1h6 h1h7 h1h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00871", "split": "rules", "task_type": "legal_moves", "fen": "r4r2/1p1nq1bk/2ppbnpp/4pp2/1PP5/2NPPNP1/2QB1PBP/1R2R1K1 w - -", "prompt": "FEN: r4r2/1p1nq1bk/2ppbnpp/4pp2/1PP5/2NPPNP1/2QB1PBP/1R2R1K1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b1a1 b1b2 b1b3 b1c1 b1d1 b4b5 c2a2 c2a4 c2b2 c2b3 c2c1 c2d1 c3a2 c3a4 c3b5 c3d1 c3d5 c3e2 c3e4 c4c5 d2c1 d3d4 e1c1 e1d1 e1e2 e1f1 e3e4 f3d4 f3e5 f3g5 f3h4 g1f1 g1h1 g2f1 g2h1 g2h3 g3g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00872", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/6p1/1p6/2p5/2P3k1/1P4P1/6K1/8 b - -", "prompt": "FEN: 8/6p1/1p6/2p5/2P3k1/1P4P1/6K1/8 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: g4 black king; c5 black pawn; b6 black pawn; g7 black pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "g4", "piece": "black king"}, {"square": "c5", "piece": "black pawn"}, {"square": "b6", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "g4", "piece": "black king"}, {"square": "c5", "piece": "black pawn"}, {"square": "b6", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}]}}
{"example_id": "rules_00873", "split": "rules", "task_type": "piece_legal_moves", "fen": "k1q1r1r1/p4p2/1pp1b2Q/7p/P7/4PB1P/1PP3P1/3R1RK1 b - - 2 24", "prompt": "FEN: k1q1r1r1/p4p2/1pp1b2Q/7p/P7/4PB1P/1PP3P1/3R1RK1 b - - 2 24\nWhat legal moves does the piece on c6 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c6", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "c6", "piece": "pawn"}}
{"example_id": "rules_00874", "split": "rules", "task_type": "check_detection", "fen": "rn2k1nr/1b1p1pp1/p2qp2p/4P3/Nb6/3B1N2/1PPB1PPP/R2Q1RK1 b kq - 0 12", "prompt": "FEN: rn2k1nr/1b1p1pp1/p2qp2p/4P3/Nb6/3B1N2/1PPB1PPP/R2Q1RK1 b kq - 0 12\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00875", "split": "rules", "task_type": "captures", "fen": "rnbqk2r/ppp2ppp/5n2/2bpp3/4P3/P1NP3P/1PP2PP1/R1BQKBNR w KQkq - 0 6", "prompt": "FEN: rnbqk2r/ppp2ppp/5n2/2bpp3/4P3/P1NP3P/1PP2PP1/R1BQKBNR w KQkq - 0 6\nList all capture moves available.", "gold_answer": "c3d5 e4d5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00876", "split": "rules", "task_type": "special_rules", "fen": "r1b1k2r/b1p3pp/p2q1p1n/Ppp1p3/1P2P3/B1P2N1P/3P1PP1/RN1Q1RK1 w kq b6 0 13", "prompt": "Given FEN: r1b1k2r/b1p3pp/p2q1p1n/Ppp1p3/1P2P3/B1P2N1P/3P1PP1/RN1Q1RK1 w kq b6 0 13\nList any special moves available (castling, en passant, promotion).", "gold_answer": "En passant possible: a5b6.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00877", "split": "rules", "task_type": "legality_check", "fen": "5r2/pbp3k1/1p2p2n/4N1r1/3PPP1n/2PB2N1/PP2RKP1/4R3 b - - 0 28", "prompt": "FEN: 5r2/pbp3k1/1p2p2n/4N1r1/3PPP1n/2PB2N1/PP2RKP1/4R3 b - - 0 28\nIs the move f3d8 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f3d8", "_legality_check_reason_label": "empty_source", "move": "f3d8", "legality_reason_label": "empty_source"}}
{"example_id": "rules_00878", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2q1rk1/pp1bbpp1/2B4p/3p1N2/6PP/8/PPP1QP2/R1B1K1R1 b Q -", "prompt": "FEN: r2q1rk1/pp1bbpp1/2B4p/3p1N2/6PP/8/PPP1QP2/R1B1K1R1 b Q -\nList pseudo-legal moves from d5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d5: d5d4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_00879", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/p7/1p6/8/kpQN1P1P/8/P7/4K3 b - - 0 38", "prompt": "FEN: 8/p7/1p6/8/kpQN1P1P/8/P7/4K3 b - - 0 38\nFor the piece on a4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a4: a4a3 a4a5 a4b3 a4b5.\nLegal: a4a3 a4a5.\nRejected: a4b3 king_would_be_in_check; a4b5 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a4", "diagnostic": true, "hard_gate": false, "source_square": "a4"}}
{"example_id": "rules_00880", "split": "rules", "task_type": "king_safety_filter", "fen": "8/5p2/R5kp/6p1/6P1/2r5/6KP/8 b - - 6 55", "prompt": "FEN: 8/5p2/R5kp/6p1/6P1/2r5/6KP/8 b - - 6 55\nFor move c3a3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c3a3.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "c3a3", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "c3a3", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_00881", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r3k2r/p1q1bpp1/2pp1nb1/1p2p3/2B1P3/2NP1P1N/PPP1Q3/1K1R3R w kq - 0 20", "prompt": "FEN: r3k2r/p1q1bpp1/2pp1nb1/1p2p3/2B1P3/2NP1P1N/PPP1Q3/1K1R3R w kq - 0 20\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: b1 white king; d1 white rook; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; e2 white queen; c3 white knight; d3 white pawn; f3 white pawn; h3 white knight; c4 white bishop; e4 white pawn.\nMoves by piece:\nb1 white king: b1a1 b1c1\nd1 white rook: d1c1 d1d2 d1e1 d1f1 d1g1\nh1 white rook: h1e1 h1f1 h1g1 h1h2\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: no legal moves\ne2 white queen: e2d2 e2e1 e2e3 e2f1 e2f2 e2g2 e2h2\nc3 white knight: c3a4 c3b5 c3d5\nd3 white pawn: d3d4\nf3 white pawn: f3f4\nh3 white knight: h3f2 h3f4 h3g1 h3g5\nc4 white bishop: c4b3 c4b5 c4d5 c4e6 c4f7\ne4 white pawn: no legal moves\nAll legal moves: a2a3 a2a4 b1a1 b1c1 b2b3 b2b4 c3a4 c3b5 c3d5 c4b3 c4b5 c4d5 c4e6 c4f7 d1c1 d1d2 d1e1 d1f1 d1g1 d3d4 e2d2 e2e1 e2e3 e2f1 e2f2 e2g2 e2h2 f3f4 h1e1 h1f1 h1g1 h1h2 h3f2 h3f4 h3g1 h3g5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b1": ["b1a1", "b1c1"], "d1": ["d1c1", "d1d2", "d1e1", "d1f1", "d1g1"], "h1": ["h1e1", "h1f1", "h1g1", "h1h2"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": [], "e2": ["e2d2", "e2e1", "e2e3", "e2f1", "e2f2", "e2g2", "e2h2"], "c3": ["c3a4", "c3b5", "c3d5"], "d3": ["d3d4"], "f3": ["f3f4"], "h3": ["h3f2", "h3f4", "h3g1", "h3g5"], "c4": ["c4b3", "c4b5", "c4d5", "c4e6", "c4f7"], "e4": []}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b1a1 b1c1 b2b3 b2b4 c3a4 c3b5 c3d5 c4b3 c4b5 c4d5 c4e6 c4f7 d1c1 d1d2 d1e1 d1f1 d1g1 d3d4 e2d2 e2e1 e2e3 e2f1 e2f2 e2g2 e2h2 f3f4 h1e1 h1f1 h1g1 h1h2 h3f2 h3f4 h3g1 h3g5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b1": ["b1a1", "b1c1"], "d1": ["d1c1", "d1d2", "d1e1", "d1f1", "d1g1"], "h1": ["h1e1", "h1f1", "h1g1", "h1h2"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": [], "e2": ["e2d2", "e2e1", "e2e3", "e2f1", "e2f2", "e2g2", "e2h2"], "c3": ["c3a4", "c3b5", "c3d5"], "d3": ["d3d4"], "f3": ["f3f4"], "h3": ["h3f2", "h3f4", "h3g1", "h3g5"], "c4": ["c4b3", "c4b5", "c4d5", "c4e6", "c4f7"], "e4": []}, "legal_moves": "a2a3 a2a4 b1a1 b1c1 b2b3 b2b4 c3a4 c3b5 c3d5 c4b3 c4b5 c4d5 c4e6 c4f7 d1c1 d1d2 d1e1 d1f1 d1g1 d3d4 e2d2 e2e1 e2e3 e2f1 e2f2 e2g2 e2h2 f3f4 h1e1 h1f1 h1g1 h1h2 h3f2 h3f4 h3g1 h3g5"}}
{"example_id": "rules_00882", "split": "rules", "task_type": "ray_walk", "fen": "1k6/8/P1Q5/3p4/1P1P2K1/8/8/8 w - -", "prompt": "FEN: 1k6/8/P1Q5/3p4/1P1P2K1/8/8/8 w - -\nWalk each ray for the slider on c6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c6 white queen.\nRay N: c7 empty; c8 empty; edge.\nRay NE: d7 empty; e8 empty; edge.\nRay E: d6 empty; e6 empty; f6 empty; g6 empty; h6 empty; edge.\nRay SE: d5 black pawn: capture (stop, included).\nRay S: c5 empty; c4 empty; c3 empty; c2 empty; c1 empty; edge.\nRay SW: b5 empty; a4 empty; edge.\nRay W: b6 empty; a6 white pawn: own piece (stop, excluded).\nRay NW: b7 empty; a8 empty; edge.\nMoves from rays: c6a4 c6a8 c6b5 c6b6 c6b7 c6c1 c6c2 c6c3 c6c4 c6c5 c6c7 c6c8 c6d5 c6d6 c6d7 c6e6 c6e8 c6f6 c6g6 c6h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_00883", "split": "rules", "task_type": "legal_moves", "fen": "r1b2rk1/pp1nq1bp/2p1p1p1/3pP3/8/2NB1N2/PPP1QPPP/R4RK1 b - - 3 12", "prompt": "FEN: r1b2rk1/pp1nq1bp/2p1p1p1/3pP3/8/2NB1N2/PPP1QPPP/R4RK1 b - - 3 12\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c6c5 d5d4 d7b6 d7b8 d7c5 d7e5 d7f6 e7a3 e7b4 e7c5 e7d6 e7d8 e7e8 e7f6 e7f7 e7g5 e7h4 f8d8 f8e8 f8f3 f8f4 f8f5 f8f6 f8f7 g6g5 g7e5 g7f6 g7h6 g7h8 g8f7 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00884", "split": "rules", "task_type": "legal_moves", "fen": "8/8/4k3/5p2/3K2Pp/8/P5P1/8 b - -", "prompt": "FEN: 8/8/4k3/5p2/3K2Pp/8/P5P1/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: e6d6 e6d7 e6e7 e6f6 e6f7 f5f4 f5g4 h4h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00885", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/5k2/p7/4P1P1/1r6/5P2/2pK4/8 w - - 0 51", "prompt": "FEN: 8/5k2/p7/4P1P1/1r6/5P2/2pK4/8 w - - 0 51\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: d2 white king; f3 white pawn; e5 white pawn; g5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "d2", "piece": "white king"}, {"square": "f3", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}, {"square": "g5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "d2", "piece": "white king"}, {"square": "f3", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}, {"square": "g5", "piece": "white pawn"}]}}
{"example_id": "rules_00886", "split": "rules", "task_type": "piece_legal_moves", "fen": "r3kbnr/p1pnpppp/b7/8/2pP4/4P3/P4PPP/RNB1KBNR w KQkq - 0 8", "prompt": "FEN: r3kbnr/p1pnpppp/b7/8/2pP4/4P3/P4PPP/RNB1KBNR w KQkq - 0 8\nWhat legal moves does the piece on h1 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h1", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "h1", "piece": "rook"}}
{"example_id": "rules_00887", "split": "rules", "task_type": "check_detection", "fen": "8/5kpp/p3p3/Pp1p1n2/1P1P1P1P/5P2/2r2B2/1R3K2 b - -", "prompt": "FEN: 8/5kpp/p3p3/Pp1p1n2/1P1P1P1P/5P2/2r2B2/1R3K2 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00888", "split": "rules", "task_type": "captures", "fen": "3r1r1k/3P2pp/1R6/5p2/4pP2/4Q2P/6PK/1q1q4 w - - 0 38", "prompt": "FEN: 3r1r1k/3P2pp/1R6/5p2/4pP2/4Q2P/6PK/1q1q4 w - - 0 38\nList all capture moves available.", "gold_answer": "b6b1 e3e4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00889", "split": "rules", "task_type": "special_rules", "fen": "3r2r1/pp5p/2k5/8/8/1P4N1/P1P2PpP/R5K1 w - - 5 30", "prompt": "Given FEN: 3r2r1/pp5p/2k5/8/8/1P4N1/P1P2PpP/R5K1 w - - 5 30\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00890", "split": "rules", "task_type": "legality_check", "fen": "3r2k1/5ppp/1p2p3/2b1P3/8/2N2P2/PP3P1P/5RK1 w - - 0 21", "prompt": "FEN: 3r2k1/5ppp/1p2p3/2b1P3/8/2N2P2/PP3P1P/5RK1 w - - 0 21\nIs the move c3b1 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c3b1", "_legality_check_reason_label": "legal", "move": "c3b1", "legality_reason_label": "legal"}}
{"example_id": "rules_00891", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1bqkb1r/pp1n1ppp/2p2n2/3p2B1/P2P4/2N2N2/1P2PPPP/R2QKB1R b KQkq -", "prompt": "FEN: r1bqkb1r/pp1n1ppp/2p2n2/3p2B1/P2P4/2N2N2/1P2PPPP/R2QKB1R b KQkq -\nList pseudo-legal moves from c6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c6: c6c5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_00892", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnbqkbnr/pp3ppp/2p1p3/8/2pP4/P1N2N2/1P2PPPP/R1BQKB1R b KQkq -", "prompt": "FEN: rnbqkbnr/pp3ppp/2p1p3/8/2pP4/P1N2N2/1P2PPPP/R1BQKB1R b KQkq -\nFor the piece on c6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c6: c6c5.\nLegal: c6c5.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_00893", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bqk1nr/1pp2ppp/p1nbp3/8/3Pp3/4Q3/PPP2PPP/RNB1KBNR w KQkq - 0 7", "prompt": "FEN: r1bqk1nr/1pp2ppp/p1nbp3/8/3Pp3/4Q3/PPP2PPP/RNB1KBNR w KQkq - 0 7\nFor move a2a3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a2a3.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a2a3", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a2a3", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00894", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r5r1/3k2pp/pn1qp3/1pR5/1P1P2Q1/P7/1B4PP/4R1K1 b - -", "prompt": "FEN: r5r1/3k2pp/pn1qp3/1pR5/1P1P2Q1/P7/1B4PP/4R1K1 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b5 black pawn; a6 black pawn; b6 black knight; d6 black queen; e6 black pawn; d7 black king; g7 black pawn; h7 black pawn; a8 black rook; g8 black rook.\nMoves by piece:\nb5 black pawn: no legal moves\na6 black pawn: a6a5\nb6 black knight: b6a4 b6c4 b6c8 b6d5\nd6 black queen: d6b8 d6c5 d6c6 d6c7 d6d4 d6d5 d6e5 d6e7 d6f4 d6f8 d6g3 d6h2\ne6 black pawn: no legal moves\nd7 black king: d7d8 d7e7 d7e8\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8a7 a8b8 a8c8 a8d8 a8e8 a8f8\ng8 black rook: g8b8 g8c8 g8d8 g8e8 g8f8 g8h8\nAll legal moves: a6a5 a8a7 a8b8 a8c8 a8d8 a8e8 a8f8 b6a4 b6c4 b6c8 b6d5 d6b8 d6c5 d6c6 d6c7 d6d4 d6d5 d6e5 d6e7 d6f4 d6f8 d6g3 d6h2 d7d8 d7e7 d7e8 g7g5 g7g6 g8b8 g8c8 g8d8 g8e8 g8f8 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b5": [], "a6": ["a6a5"], "b6": ["b6a4", "b6c4", "b6c8", "b6d5"], "d6": ["d6b8", "d6c5", "d6c6", "d6c7", "d6d4", "d6d5", "d6e5", "d6e7", "d6f4", "d6f8", "d6g3", "d6h2"], "e6": [], "d7": ["d7d8", "d7e7", "d7e8"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8a7", "a8b8", "a8c8", "a8d8", "a8e8", "a8f8"], "g8": ["g8b8", "g8c8", "g8d8", "g8e8", "g8f8", "g8h8"]}, "_legal_moves_by_piece_moves": "a6a5 a8a7 a8b8 a8c8 a8d8 a8e8 a8f8 b6a4 b6c4 b6c8 b6d5 d6b8 d6c5 d6c6 d6c7 d6d4 d6d5 d6e5 d6e7 d6f4 d6f8 d6g3 d6h2 d7d8 d7e7 d7e8 g7g5 g7g6 g8b8 g8c8 g8d8 g8e8 g8f8 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b5": [], "a6": ["a6a5"], "b6": ["b6a4", "b6c4", "b6c8", "b6d5"], "d6": ["d6b8", "d6c5", "d6c6", "d6c7", "d6d4", "d6d5", "d6e5", "d6e7", "d6f4", "d6f8", "d6g3", "d6h2"], "e6": [], "d7": ["d7d8", "d7e7", "d7e8"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8a7", "a8b8", "a8c8", "a8d8", "a8e8", "a8f8"], "g8": ["g8b8", "g8c8", "g8d8", "g8e8", "g8f8", "g8h8"]}, "legal_moves": "a6a5 a8a7 a8b8 a8c8 a8d8 a8e8 a8f8 b6a4 b6c4 b6c8 b6d5 d6b8 d6c5 d6c6 d6c7 d6d4 d6d5 d6e5 d6e7 d6f4 d6f8 d6g3 d6h2 d7d8 d7e7 d7e8 g7g5 g7g6 g8b8 g8c8 g8d8 g8e8 g8f8 g8h8 h7h5 h7h6"}}
{"example_id": "rules_00895", "split": "rules", "task_type": "ray_walk", "fen": "6k1/6pp/2p5/p7/P2rr3/5K2/4N2P/b7 b - - 1 36", "prompt": "FEN: 6k1/6pp/2p5/p7/P2rr3/5K2/4N2P/b7 b - - 1 36\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 black bishop.\nRay NE: b2 empty; c3 empty; d4 black rook: own piece (stop, excluded).\nRay SE: edge.\nRay SW: edge.\nRay NW: edge.\nMoves from rays: a1b2 a1c3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00896", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/6k1/2b3p1/5p2/2K5/8/8/8 w - - 0 52", "prompt": "FEN: 8/6k1/2b3p1/5p2/2K5/8/8/8 w - - 0 52\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c4 white king.\nFilter by piece:\nc4 white king: pseudo-legal c4b3 c4b4 c4b5 c4c3 c4c5 c4d3 c4d4 c4d5 | rejected c4b5 king_would_be_in_check; c4d5 king_would_be_in_check | legal c4b3 c4b4 c4c3 c4c5 c4d3 c4d4\nAll legal moves: c4b3 c4b4 c4c3 c4c5 c4d3 c4d4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00897", "split": "rules", "task_type": "legal_moves", "fen": "rnbqkb1r/pp2pppp/2p2n2/2Pp4/3P4/7P/PP2PPP1/RNBQKBNR b KQkq - 0 4", "prompt": "FEN: rnbqkb1r/pp2pppp/2p2n2/2Pp4/3P4/7P/PP2PPP1/RNBQKBNR b KQkq - 0 4\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8d7 c8d7 c8e6 c8f5 c8g4 c8h3 d8a5 d8b6 d8c7 d8d6 d8d7 e7e5 e7e6 e8d7 f6d7 f6e4 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00898", "split": "rules", "task_type": "side_piece_inventory", "fen": "5rk1/1R1R1pNp/6p1/p7/8/1P3pP1/r2nP1KP/8 w - -", "prompt": "FEN: 5rk1/1R1R1pNp/6p1/p7/8/1P3pP1/r2nP1KP/8 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: e2 white pawn; g2 white king; h2 white pawn; b3 white pawn; g3 white pawn; b7 white rook; d7 white rook; g7 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "e2", "piece": "white pawn"}, {"square": "g2", "piece": "white king"}, {"square": "h2", "piece": "white pawn"}, {"square": "b3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "b7", "piece": "white rook"}, {"square": "d7", "piece": "white rook"}, {"square": "g7", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "e2", "piece": "white pawn"}, {"square": "g2", "piece": "white king"}, {"square": "h2", "piece": "white pawn"}, {"square": "b3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "b7", "piece": "white rook"}, {"square": "d7", "piece": "white rook"}, {"square": "g7", "piece": "white knight"}]}}
{"example_id": "rules_00899", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bqkbnr/pp3ppp/2np4/4p3/4P3/5N2/PPP1BPPP/RNBQK2R b KQkq -", "prompt": "FEN: r1bqkbnr/pp3ppp/2np4/4p3/4P3/5N2/PPP1BPPP/RNBQK2R b KQkq -\nWhat legal moves does the piece on a7 have?", "gold_answer": "a7a5 a7a6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "a7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a7", "piece": "pawn"}}
{"example_id": "rules_00900", "split": "rules", "task_type": "check_detection", "fen": "8/6pp/p1P5/P1r4k/4r3/1p3P2/3Kb2P/8 b - -", "prompt": "FEN: 8/6pp/p1P5/P1r4k/4r3/1p3P2/3Kb2P/8 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00901", "split": "rules", "task_type": "captures", "fen": "r7/1N6/p2P1pk1/4p1p1/6P1/1Pn4r/P5KP/R4R2 b - - 0 26", "prompt": "FEN: r7/1N6/p2P1pk1/4p1p1/6P1/1Pn4r/P5KP/R4R2 b - - 0 26\nList all capture moves available.", "gold_answer": "c3a2 h3h2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00902", "split": "rules", "task_type": "special_rules", "fen": "r1bq1rk1/1pp1bpp1/p1np3p/3Np3/P1B1P3/3PQ2N/1PP2PPP/2KR3R w - - 3 13", "prompt": "Given FEN: r1bq1rk1/1pp1bpp1/p1np3p/3Np3/P1B1P3/3PQ2N/1PP2PPP/2KR3R w - - 3 13\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00903", "split": "rules", "task_type": "legality_check", "fen": "r1bq1rkb/p4p1p/3p2pP/1p2p1P1/4P3/2P1BQ2/PP3P2/RN2K2R b KQ - 1 17", "prompt": "FEN: r1bq1rkb/p4p1p/3p2pP/1p2p1P1/4P3/2P1BQ2/PP3P2/RN2K2R b KQ - 1 17\nIs the move b5b4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b5b4", "_legality_check_reason_label": "legal", "move": "b5b4", "legality_reason_label": "legal"}}
{"example_id": "rules_00904", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r4rk1/1p1n1pp1/2ppb1qp/p3p3/P1P1P3/1B1P1Q1P/2P2PPN/R4RK1 b - - 0 15", "prompt": "FEN: r4rk1/1p1n1pp1/2ppb1qp/p3p3/P1P1P3/1B1P1Q1P/2P2PPN/R4RK1 b - - 0 15\nList pseudo-legal moves from c6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c6: c6c5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_00905", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2qkbnr/pp3ppp/2B5/2p1p3/3pP3/5QNP/PPPP1PP1/R1B1K2R b KQkq -", "prompt": "FEN: r2qkbnr/pp3ppp/2B5/2p1p3/3pP3/5QNP/PPPP1PP1/R1B1K2R b KQkq -\nFor the piece on d4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d4: d4d3.\nLegal: none.\nRejected: d4d3 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_00906", "split": "rules", "task_type": "king_safety_filter", "fen": "6k1/R5p1/1p3p2/8/8/7P/P2rr1PK/6R1 b - -", "prompt": "FEN: 6k1/R5p1/1p3p2/8/8/7P/P2rr1PK/6R1 b - -\nFor move g8f7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: g8f7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "g8f7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "g8f7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00907", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r2qr1k1/bp2n1pn/2p2p1p/p2p1P2/1PPPp1PN/P3B2P/5PB1/R2Q1RK1 w - -", "prompt": "FEN: r2qr1k1/bp2n1pn/2p2p1p/p2p1P2/1PPPp1PN/P3B2P/5PB1/R2Q1RK1 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white queen; f1 white rook; g1 white king; f2 white pawn; g2 white bishop; a3 white pawn; e3 white bishop; h3 white pawn; b4 white pawn; c4 white pawn; d4 white pawn; g4 white pawn; h4 white knight; f5 white pawn.\nMoves by piece:\na1 white rook: a1a2 a1b1 a1c1\nd1 white queen: d1a4 d1b1 d1b3 d1c1 d1c2 d1d2 d1d3 d1e1 d1e2 d1f3\nf1 white rook: f1e1\ng1 white king: g1h1 g1h2\nf2 white pawn: f2f3 f2f4\ng2 white bishop: g2e4 g2f3 g2h1\na3 white pawn: a3a4\ne3 white bishop: e3c1 e3d2 e3f4 e3g5 e3h6\nh3 white pawn: no legal moves\nb4 white pawn: b4a5 b4b5\nc4 white pawn: c4c5 c4d5\nd4 white pawn: no legal moves\ng4 white pawn: g4g5\nh4 white knight: h4f3 h4g6\nf5 white pawn: no legal moves\nAll legal moves: a1a2 a1b1 a1c1 a3a4 b4a5 b4b5 c4c5 c4d5 d1a4 d1b1 d1b3 d1c1 d1c2 d1d2 d1d3 d1e1 d1e2 d1f3 e3c1 e3d2 e3f4 e3g5 e3h6 f1e1 f2f3 f2f4 g1h1 g1h2 g2e4 g2f3 g2h1 g4g5 h4f3 h4g6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1a2", "a1b1", "a1c1"], "d1": ["d1a4", "d1b1", "d1b3", "d1c1", "d1c2", "d1d2", "d1d3", "d1e1", "d1e2", "d1f3"], "f1": ["f1e1"], "g1": ["g1h1", "g1h2"], "f2": ["f2f3", "f2f4"], "g2": ["g2e4", "g2f3", "g2h1"], "a3": ["a3a4"], "e3": ["e3c1", "e3d2", "e3f4", "e3g5", "e3h6"], "h3": [], "b4": ["b4a5", "b4b5"], "c4": ["c4c5", "c4d5"], "d4": [], "g4": ["g4g5"], "h4": ["h4f3", "h4g6"], "f5": []}, "_legal_moves_by_piece_moves": "a1a2 a1b1 a1c1 a3a4 b4a5 b4b5 c4c5 c4d5 d1a4 d1b1 d1b3 d1c1 d1c2 d1d2 d1d3 d1e1 d1e2 d1f3 e3c1 e3d2 e3f4 e3g5 e3h6 f1e1 f2f3 f2f4 g1h1 g1h2 g2e4 g2f3 g2h1 g4g5 h4f3 h4g6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1a2", "a1b1", "a1c1"], "d1": ["d1a4", "d1b1", "d1b3", "d1c1", "d1c2", "d1d2", "d1d3", "d1e1", "d1e2", "d1f3"], "f1": ["f1e1"], "g1": ["g1h1", "g1h2"], "f2": ["f2f3", "f2f4"], "g2": ["g2e4", "g2f3", "g2h1"], "a3": ["a3a4"], "e3": ["e3c1", "e3d2", "e3f4", "e3g5", "e3h6"], "h3": [], "b4": ["b4a5", "b4b5"], "c4": ["c4c5", "c4d5"], "d4": [], "g4": ["g4g5"], "h4": ["h4f3", "h4g6"], "f5": []}, "legal_moves": "a1a2 a1b1 a1c1 a3a4 b4a5 b4b5 c4c5 c4d5 d1a4 d1b1 d1b3 d1c1 d1c2 d1d2 d1d3 d1e1 d1e2 d1f3 e3c1 e3d2 e3f4 e3g5 e3h6 f1e1 f2f3 f2f4 g1h1 g1h2 g2e4 g2f3 g2h1 g4g5 h4f3 h4g6"}}
{"example_id": "rules_00908", "split": "rules", "task_type": "ray_walk", "fen": "6k1/5pp1/1K5p/6P1/7P/8/2r5/3r4 b - - 2 41", "prompt": "FEN: 6k1/5pp1/1K5p/6P1/7P/8/2r5/3r4 b - - 2 41\nWalk each ray for the slider on d1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d1 black rook.\nRay N: d2 empty; d3 empty; d4 empty; d5 empty; d6 empty; d7 empty; d8 empty; edge.\nRay E: e1 empty; f1 empty; g1 empty; h1 empty; edge.\nRay S: edge.\nRay W: c1 empty; b1 empty; a1 empty; edge.\nMoves from rays: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 d1g1 d1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_00909", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/1p6/3pk3/4p1n1/2B2N2/P7/1P6/2K5 b - - 4 37", "prompt": "FEN: 8/1p6/3pk3/4p1n1/2B2N2/P7/1P6/2K5 b - - 4 37\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e5 black pawn; g5 black knight; d6 black pawn; e6 black king; b7 black pawn.\nFilter by piece:\ne5 black pawn: pseudo-legal e5e4 e5f4 | rejected e5e4 does_not_resolve_check; e5f4 does_not_resolve_check | legal none\ng5 black knight: pseudo-legal g5e4 g5f3 g5f7 g5h3 g5h7 | rejected g5e4 does_not_resolve_check; g5f3 does_not_resolve_check; g5f7 does_not_resolve_check; g5h3 does_not_resolve_check; g5h7 does_not_resolve_check | legal none\nd6 black pawn: pseudo-legal d6d5 | rejected d6d5 does_not_resolve_check | legal none\ne6 black king: pseudo-legal e6d5 e6d7 e6e7 e6f5 e6f6 e6f7 | rejected e6d5 does_not_resolve_check; e6f7 does_not_resolve_check | legal e6d7 e6e7 e6f5 e6f6\nb7 black pawn: pseudo-legal b7b5 b7b6 | rejected b7b5 does_not_resolve_check; b7b6 does_not_resolve_check | legal none\nAll legal moves: e6d7 e6e7 e6f5 e6f6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00910", "split": "rules", "task_type": "legal_moves", "fen": "rn4k1/p4rpp/1pp2pb1/3p1n2/N2P4/4PN1P/PP2BPP1/2R2RK1 w - - 0 19", "prompt": "FEN: rn4k1/p4rpp/1pp2pb1/3p1n2/N2P4/4PN1P/PP2BPP1/2R2RK1 w - - 0 19\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a4b6 a4c3 a4c5 b2b3 b2b4 c1a1 c1b1 c1c2 c1c3 c1c4 c1c5 c1c6 c1d1 c1e1 e2a6 e2b5 e2c4 e2d1 e2d3 e3e4 f1d1 f1e1 f3d2 f3e1 f3e5 f3g5 f3h2 f3h4 g1h1 g1h2 g2g3 g2g4 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00911", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2q1rk1/pppnbbpp/1n2p3/5p2/2PP4/1P1B1P2/P2N2PP/RNBQR1K1 b - - 0 13", "prompt": "FEN: r2q1rk1/pppnbbpp/1n2p3/5p2/2PP4/1P1B1P2/P2N2PP/RNBQR1K1 b - - 0 13\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: f5 black pawn; b6 black knight; e6 black pawn; a7 black pawn; b7 black pawn; c7 black pawn; d7 black knight; e7 black bishop; f7 black bishop; g7 black pawn; h7 black pawn; a8 black rook; d8 black queen; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "f5", "piece": "black pawn"}, {"square": "b6", "piece": "black knight"}, {"square": "e6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black bishop"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "f5", "piece": "black pawn"}, {"square": "b6", "piece": "black knight"}, {"square": "e6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black bishop"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_00912", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bqk2r/2pn2b1/1p1p2pp/pP1Ppn2/P1B2P1N/4B3/2P1N1PP/R2Q1RK1 w kq - 0 16", "prompt": "FEN: r1bqk2r/2pn2b1/1p1p2pp/pP1Ppn2/P1B2P1N/4B3/2P1N1PP/R2Q1RK1 w kq - 0 16\nWhat legal moves does the piece on h4 have?", "gold_answer": "h4f3 h4f5 h4g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h4", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "h4", "piece": "knight"}}
{"example_id": "rules_00913", "split": "rules", "task_type": "check_detection", "fen": "r4rk1/p1p1pp2/7b/5q1p/8/5N2/PP2QPPP/1K1R3R w - - 0 19", "prompt": "FEN: r4rk1/p1p1pp2/7b/5q1p/8/5N2/PP2QPPP/1K1R3R w - - 0 19\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00914", "split": "rules", "task_type": "captures", "fen": "8/8/4r3/8/6P1/6KP/8/k7 w - - 0 54", "prompt": "FEN: 8/8/4r3/8/6P1/6KP/8/k7 w - - 0 54\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00915", "split": "rules", "task_type": "special_rules", "fen": "6r1/2kp4/p3p3/2p5/2P1PpPR/5K2/P1n5/8 b - - 5 37", "prompt": "Given FEN: 6r1/2kp4/p3p3/2p5/2P1PpPR/5K2/P1n5/8 b - - 5 37\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00916", "split": "rules", "task_type": "legality_check", "fen": "rnbqkb1r/pppp1pp1/8/4P2p/2P1P1n1/8/PP3PPP/RNBQKBNR w KQkq -", "prompt": "FEN: rnbqkb1r/pppp1pp1/8/4P2p/2P1P1n1/8/PP3PPP/RNBQKBNR w KQkq -\nIs the move g1e8 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "g1e8", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "g1e8", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_00917", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1b1k1nr/ppB1pp2/5n1p/6p1/2N5/2N5/PP2PPPP/3RKB1R b K - 0 13", "prompt": "FEN: r1b1k1nr/ppB1pp2/5n1p/6p1/2N5/2N5/PP2PPPP/3RKB1R b K - 0 13\nList pseudo-legal moves from g5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g5: g5g4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g5", "diagnostic": true, "hard_gate": false, "source_square": "g5"}}
{"example_id": "rules_00918", "split": "rules", "task_type": "piece_legal_filter", "fen": "2kr3r/pp2bppp/8/5b2/2Bn1P2/2N5/PPPB2PP/2KR3R b - -", "prompt": "FEN: 2kr3r/pp2bppp/8/5b2/2Bn1P2/2N5/PPPB2PP/2KR3R b - -\nFor the piece on d4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d4: d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3.\nLegal: d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_00919", "split": "rules", "task_type": "king_safety_filter", "fen": "7k/5b1P/8/1K1p1B2/1P1P4/8/5P2/8 b - -", "prompt": "FEN: 7k/5b1P/8/1K1p1B2/1P1P4/8/5P2/8 b - -\nFor move h8g8, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: h8g8.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "h8g8", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "h8g8", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00920", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r2q1rk1/1pp1bppp/p2p1nb1/4p3/4P1P1/1PNPBN1P/1PPQ1P2/R4RK1 w - -", "prompt": "FEN: r2q1rk1/1pp1bppp/p2p1nb1/4p3/4P1P1/1PNPBN1P/1PPQ1P2/R4RK1 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; f1 white rook; g1 white king; b2 white pawn; c2 white pawn; d2 white queen; f2 white pawn; b3 white pawn; c3 white knight; d3 white pawn; e3 white bishop; f3 white knight; h3 white pawn; e4 white pawn; g4 white pawn.\nMoves by piece:\na1 white rook: a1a2 a1a3 a1a4 a1a5 a1a6 a1b1 a1c1 a1d1 a1e1\nf1 white rook: f1b1 f1c1 f1d1 f1e1\ng1 white king: g1g2 g1h1 g1h2\nb2 white pawn: no legal moves\nc2 white pawn: no legal moves\nd2 white queen: d2c1 d2d1 d2e1 d2e2\nf2 white pawn: no legal moves\nb3 white pawn: b3b4\nc3 white knight: c3a2 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2\nd3 white pawn: d3d4\ne3 white bishop: e3a7 e3b6 e3c5 e3d4 e3f4 e3g5 e3h6\nf3 white knight: f3d4 f3e1 f3e5 f3g5 f3h2 f3h4\nh3 white pawn: h3h4\ne4 white pawn: no legal moves\ng4 white pawn: g4g5\nAll legal moves: a1a2 a1a3 a1a4 a1a5 a1a6 a1b1 a1c1 a1d1 a1e1 b3b4 c3a2 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 d2c1 d2d1 d2e1 d2e2 d3d4 e3a7 e3b6 e3c5 e3d4 e3f4 e3g5 e3h6 f1b1 f1c1 f1d1 f1e1 f3d4 f3e1 f3e5 f3g5 f3h2 f3h4 g1g2 g1h1 g1h2 g4g5 h3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1a2", "a1a3", "a1a4", "a1a5", "a1a6", "a1b1", "a1c1", "a1d1", "a1e1"], "f1": ["f1b1", "f1c1", "f1d1", "f1e1"], "g1": ["g1g2", "g1h1", "g1h2"], "b2": [], "c2": [], "d2": ["d2c1", "d2d1", "d2e1", "d2e2"], "f2": [], "b3": ["b3b4"], "c3": ["c3a2", "c3a4", "c3b1", "c3b5", "c3d1", "c3d5", "c3e2"], "d3": ["d3d4"], "e3": ["e3a7", "e3b6", "e3c5", "e3d4", "e3f4", "e3g5", "e3h6"], "f3": ["f3d4", "f3e1", "f3e5", "f3g5", "f3h2", "f3h4"], "h3": ["h3h4"], "e4": [], "g4": ["g4g5"]}, "_legal_moves_by_piece_moves": "a1a2 a1a3 a1a4 a1a5 a1a6 a1b1 a1c1 a1d1 a1e1 b3b4 c3a2 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 d2c1 d2d1 d2e1 d2e2 d3d4 e3a7 e3b6 e3c5 e3d4 e3f4 e3g5 e3h6 f1b1 f1c1 f1d1 f1e1 f3d4 f3e1 f3e5 f3g5 f3h2 f3h4 g1g2 g1h1 g1h2 g4g5 h3h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1a2", "a1a3", "a1a4", "a1a5", "a1a6", "a1b1", "a1c1", "a1d1", "a1e1"], "f1": ["f1b1", "f1c1", "f1d1", "f1e1"], "g1": ["g1g2", "g1h1", "g1h2"], "b2": [], "c2": [], "d2": ["d2c1", "d2d1", "d2e1", "d2e2"], "f2": [], "b3": ["b3b4"], "c3": ["c3a2", "c3a4", "c3b1", "c3b5", "c3d1", "c3d5", "c3e2"], "d3": ["d3d4"], "e3": ["e3a7", "e3b6", "e3c5", "e3d4", "e3f4", "e3g5", "e3h6"], "f3": ["f3d4", "f3e1", "f3e5", "f3g5", "f3h2", "f3h4"], "h3": ["h3h4"], "e4": [], "g4": ["g4g5"]}, "legal_moves": "a1a2 a1a3 a1a4 a1a5 a1a6 a1b1 a1c1 a1d1 a1e1 b3b4 c3a2 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 d2c1 d2d1 d2e1 d2e2 d3d4 e3a7 e3b6 e3c5 e3d4 e3f4 e3g5 e3h6 f1b1 f1c1 f1d1 f1e1 f3d4 f3e1 f3e5 f3g5 f3h2 f3h4 g1g2 g1h1 g1h2 g4g5 h3h4"}}
{"example_id": "rules_00921", "split": "rules", "task_type": "ray_walk", "fen": "q5k1/5pp1/pp5p/8/1P3N2/6P1/P1Q2R1P/4r1K1 w - -", "prompt": "FEN: q5k1/5pp1/pp5p/8/1P3N2/6P1/P1Q2R1P/4r1K1 w - -\nWalk each ray for the slider on c2: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c2 white queen.\nRay N: c3 empty; c4 empty; c5 empty; c6 empty; c7 empty; c8 empty; edge.\nRay NE: d3 empty; e4 empty; f5 empty; g6 empty; h7 empty; edge.\nRay E: d2 empty; e2 empty; f2 white rook: own piece (stop, excluded).\nRay SE: d1 empty; edge.\nRay S: c1 empty; edge.\nRay SW: b1 empty; edge.\nRay W: b2 empty; a2 white pawn: own piece (stop, excluded).\nRay NW: b3 empty; a4 empty; edge.\nMoves from rays: c2a4 c2b1 c2b2 c2b3 c2c1 c2c3 c2c4 c2c5 c2c6 c2c7 c2c8 c2d1 c2d2 c2d3 c2e2 c2e4 c2f5 c2g6 c2h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c2", "diagnostic": true, "hard_gate": false, "source_square": "c2"}}
{"example_id": "rules_00922", "split": "rules", "task_type": "legal_filter_trace", "fen": "r1b2rk1/8/1pR1p1p1/p4pBp/2P2P1P/1P6/P1B3P1/4R1K1 b - - 0 24", "prompt": "FEN: r1b2rk1/8/1pR1p1p1/p4pBp/2P2P1P/1P6/P1B3P1/4R1K1 b - - 0 24\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a5 black pawn; f5 black pawn; h5 black pawn; b6 black pawn; e6 black pawn; g6 black pawn; a8 black rook; c8 black bishop; f8 black rook; g8 black king.\nFilter by piece:\na5 black pawn: pseudo-legal a5a4 | rejected none | legal a5a4\nf5 black pawn: pseudo-legal none | rejected none | legal none\nh5 black pawn: pseudo-legal none | rejected none | legal none\nb6 black pawn: pseudo-legal b6b5 | rejected none | legal b6b5\ne6 black pawn: pseudo-legal e6e5 | rejected none | legal e6e5\ng6 black pawn: pseudo-legal none | rejected none | legal none\na8 black rook: pseudo-legal a8a6 a8a7 a8b8 | rejected none | legal a8a6 a8a7 a8b8\nc8 black bishop: pseudo-legal c8a6 c8b7 c8d7 | rejected none | legal c8a6 c8b7 c8d7\nf8 black rook: pseudo-legal f8d8 f8e8 f8f6 f8f7 | rejected none | legal f8d8 f8e8 f8f6 f8f7\ng8 black king: pseudo-legal g8f7 g8g7 g8h7 g8h8 | rejected none | legal g8f7 g8g7 g8h7 g8h8\nAll legal moves: a5a4 a8a6 a8a7 a8b8 b6b5 c8a6 c8b7 c8d7 e6e5 f8d8 f8e8 f8f6 f8f7 g8f7 g8g7 g8h7 g8h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00923", "split": "rules", "task_type": "legal_moves", "fen": "4k2r/p3ppbp/2p3p1/5b2/2N2P2/B1n3N1/P7/3R1K2 w k - 0 24", "prompt": "FEN: 4k2r/p3ppbp/2p3p1/5b2/2N2P2/B1n3N1/P7/3R1K2 w k - 0 24\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3b2 a3b4 a3c1 a3c5 a3d6 a3e7 c4a5 c4b2 c4b6 c4d2 c4d6 c4e3 c4e5 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 f1e1 f1f2 f1g1 f1g2 g3e2 g3e4 g3f5 g3h1 g3h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00924", "split": "rules", "task_type": "side_piece_inventory", "fen": "rnbqkb1r/ppp3pp/3p1n2/4pP2/8/2NP1N2/PPP2PPP/R1BQKB1R b KQkq -", "prompt": "FEN: rnbqkb1r/ppp3pp/3p1n2/4pP2/8/2NP1N2/PPP2PPP/R1BQKB1R b KQkq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: e5 black pawn; d6 black pawn; f6 black knight; a7 black pawn; b7 black pawn; c7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00925", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/7k/R3P1p1/3P1P1b/7P/P3K3/8/8 w - - 0 47", "prompt": "FEN: 8/7k/R3P1p1/3P1P1b/7P/P3K3/8/8 w - - 0 47\nWhat legal moves does the piece on f5 have?", "gold_answer": "f5f6 f5g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f5", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f5", "piece": "pawn"}}
{"example_id": "rules_00926", "split": "rules", "task_type": "check_detection", "fen": "6k1/1p3ppp/2p5/3p2P1/4pP1P/5n2/r1KP1P2/1N5R w - - 1 31", "prompt": "FEN: 6k1/1p3ppp/2p5/3p2P1/4pP1P/5n2/r1KP1P2/1N5R w - - 1 31\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00927", "split": "rules", "task_type": "captures", "fen": "r3kb1r/ppp1pppp/5n2/5b2/3n1P2/4qN2/PPP1N1PP/R2QKB1R w KQkq - 2 10", "prompt": "FEN: r3kb1r/ppp1pppp/5n2/5b2/3n1P2/4qN2/PPP1N1PP/R2QKB1R w KQkq - 2 10\nList all capture moves available.", "gold_answer": "d1d4 f3d4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00928", "split": "rules", "task_type": "special_rules", "fen": "8/1p5Q/5k2/p2p4/3q3P/4R1P1/8/6K1 w - -", "prompt": "Given FEN: 8/1p5Q/5k2/p2p4/3q3P/4R1P1/8/6K1 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00929", "split": "rules", "task_type": "legality_check", "fen": "r2qkb1r/pppb1ppp/5n2/3Pp3/2P5/5Q2/PP1P1PPP/RNB1KB1R b KQkq -", "prompt": "FEN: r2qkb1r/pppb1ppp/5n2/3Pp3/2P5/5Q2/PP1P1PPP/RNB1KB1R b KQkq -\nIs the move b7b5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "b7b5", "_legality_check_reason_label": "legal", "move": "b7b5", "legality_reason_label": "legal"}}
{"example_id": "rules_00930", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/8/8/p4k2/7p/P6K/1P6/8 b - -", "prompt": "FEN: 8/8/8/p4k2/7p/P6K/1P6/8 b - -\nList pseudo-legal moves from a5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a5: a5a4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_00931", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn3rk1/4ppbp/Q2p1np1/2pP4/4P3/2N2N2/PP1B1PPP/R3K2R b KQ -", "prompt": "FEN: rn3rk1/4ppbp/Q2p1np1/2pP4/4P3/2N2N2/PP1B1PPP/R3K2R b KQ -\nFor the piece on c5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c5: c5c4.\nLegal: c5c4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_00932", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bq1rk1/1pp2pp1/p1np1n1p/2b1p3/P1B1P3/2PP1N1P/1P3PP1/RNBQR1K1 b - -", "prompt": "FEN: r1bq1rk1/1pp2pp1/p1np1n1p/2b1p3/P1B1P3/2PP1N1P/1P3PP1/RNBQR1K1 b - -\nFor move a6a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a6a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a6a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a6a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00933", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/8/8/1b1k4/2R5/2K5/8/8 w - - 1 67", "prompt": "FEN: 8/8/8/1b1k4/2R5/2K5/8/8 w - - 1 67\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c3 white king; c4 white rook.\nMoves by piece:\nc3 white king: c3b2 c3b3 c3b4 c3c2 c3d2 c3d3\nc4 white rook: c4a4 c4b4 c4c5 c4c6 c4c7 c4c8 c4d4 c4e4 c4f4 c4g4 c4h4\nAll legal moves: c3b2 c3b3 c3b4 c3c2 c3d2 c3d3 c4a4 c4b4 c4c5 c4c6 c4c7 c4c8 c4d4 c4e4 c4f4 c4g4 c4h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c3": ["c3b2", "c3b3", "c3b4", "c3c2", "c3d2", "c3d3"], "c4": ["c4a4", "c4b4", "c4c5", "c4c6", "c4c7", "c4c8", "c4d4", "c4e4", "c4f4", "c4g4", "c4h4"]}, "_legal_moves_by_piece_moves": "c3b2 c3b3 c3b4 c3c2 c3d2 c3d3 c4a4 c4b4 c4c5 c4c6 c4c7 c4c8 c4d4 c4e4 c4f4 c4g4 c4h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c3": ["c3b2", "c3b3", "c3b4", "c3c2", "c3d2", "c3d3"], "c4": ["c4a4", "c4b4", "c4c5", "c4c6", "c4c7", "c4c8", "c4d4", "c4e4", "c4f4", "c4g4", "c4h4"]}, "legal_moves": "c3b2 c3b3 c3b4 c3c2 c3d2 c3d3 c4a4 c4b4 c4c5 c4c6 c4c7 c4c8 c4d4 c4e4 c4f4 c4g4 c4h4"}}
{"example_id": "rules_00934", "split": "rules", "task_type": "legal_moves", "fen": "8/4kp2/p3p2p/1p1pP3/1r1P3K/8/7P/8 w - - 0 39", "prompt": "FEN: 8/4kp2/p3p2p/1p1pP3/1r1P3K/8/7P/8 w - - 0 39\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: h2h3 h4g3 h4g4 h4h3 h4h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": ""}}
{"example_id": "rules_00935", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/1p1nbppp/p2p1n2/P1pP3b/2N2B2/2NB1P2/1PP3PP/R2Q1RK1 b - - 2 14", "prompt": "FEN: r2q1rk1/1p1nbppp/p2p1n2/P1pP3b/2N2B2/2NB1P2/1PP3PP/R2Q1RK1 b - - 2 14\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a8a7 a8b8 a8c8 b7b5 b7b6 d7b6 d7b8 d7e5 d8a5 d8b6 d8b8 d8c7 d8c8 d8e8 f6d5 f6e4 f6e8 f6g4 f8e8 g7g5 g7g6 g8h8 h5f3 h5g4 h5g6 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00936", "split": "rules", "task_type": "legal_moves", "fen": "4B3/6k1/8/2B5/6K1/8/8/8 w - -", "prompt": "FEN: 4B3/6k1/8/2B5/6K1/8/8/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: c5a3 c5a7 c5b4 c5b6 c5d4 c5d6 c5e3 c5e7 c5f2 c5f8 c5g1 e8a4 e8b5 e8c6 e8d7 e8f7 e8g6 e8h5 g4f3 g4f4 g4f5 g4g3 g4g5 g4h3 g4h4 g4h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00937", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2k1b1r/pR2pppp/n4n2/3P4/Q7/5N2/P2B1PPP/4K2R w K -", "prompt": "FEN: r2k1b1r/pR2pppp/n4n2/3P4/Q7/5N2/P2B1PPP/4K2R w K -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: e1 white king; h1 white rook; a2 white pawn; d2 white bishop; f2 white pawn; g2 white pawn; h2 white pawn; f3 white knight; a4 white queen; d5 white pawn; b7 white rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "a4", "piece": "white queen"}, {"square": "d5", "piece": "white pawn"}, {"square": "b7", "piece": "white rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "a4", "piece": "white queen"}, {"square": "d5", "piece": "white pawn"}, {"square": "b7", "piece": "white rook"}]}}
{"example_id": "rules_00938", "split": "rules", "task_type": "piece_legal_moves", "fen": "2kr1bnr/pb2qppp/1pnpp3/1Pp5/8/2PP1PP1/PB2P1BP/RN1QK1NR b KQ - 0 10", "prompt": "FEN: 2kr1bnr/pb2qppp/1pnpp3/1Pp5/8/2PP1PP1/PB2P1BP/RN1QK1NR b KQ - 0 10\nWhat legal moves does the piece on a7 have?", "gold_answer": "a7a5 a7a6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a7", "piece": "pawn"}}
{"example_id": "rules_00939", "split": "rules", "task_type": "check_detection", "fen": "1nbqkbnr/1ppp1pp1/6r1/p3p2p/P3P3/3P1PP1/1PP1B2P/RNBQK1NR b KQk - 0 6", "prompt": "FEN: 1nbqkbnr/1ppp1pp1/6r1/p3p2p/P3P3/3P1PP1/1PP1B2P/RNBQK1NR b KQk - 0 6\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00940", "split": "rules", "task_type": "captures", "fen": "r4rk1/1p2qppp/p1b1p3/3P4/4R3/1PP2N2/P4PPP/R2Q2K1 b - - 0 20", "prompt": "FEN: r4rk1/1p2qppp/p1b1p3/3P4/4R3/1PP2N2/P4PPP/R2Q2K1 b - - 0 20\nList all capture moves available.", "gold_answer": "c6d5 e6d5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00941", "split": "rules", "task_type": "special_rules", "fen": "b2r1rk1/p4pp1/Pp1p3p/8/1pP5/2q1PP2/4B1PP/R2RQ1K1 w - -", "prompt": "Given FEN: b2r1rk1/p4pp1/Pp1p3p/8/1pP5/2q1PP2/4B1PP/R2RQ1K1 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00942", "split": "rules", "task_type": "legality_check", "fen": "8/2q4k/1P4p1/1b1P3p/4pP2/7P/6P1/6K1 w - - 0 41", "prompt": "FEN: 8/2q4k/1P4p1/1b1P3p/4pP2/7P/6P1/6K1 w - - 0 41\nIs the move b6b7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b6b7", "_legality_check_reason_label": "legal", "move": "b6b7", "legality_reason_label": "legal"}}
{"example_id": "rules_00943", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2q1rk1/4pp1p/p1npbbp1/1p1N4/4PP2/1N6/PPPQ2PP/1K1R1B1R b - -", "prompt": "FEN: r2q1rk1/4pp1p/p1npbbp1/1p1N4/4PP2/1N6/PPPQ2PP/1K1R1B1R b - -\nList pseudo-legal moves from b5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b5: b5b4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b5", "diagnostic": true, "hard_gate": false, "source_square": "b5"}}
{"example_id": "rules_00944", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2r2k1/p4ppp/2p1p3/1q6/NB3P2/1P1P1Q1P/P1P3P1/R4RK1 b - - 0 20", "prompt": "FEN: r2r2k1/p4ppp/2p1p3/1q6/NB3P2/1P1P1Q1P/P1P3P1/R4RK1 b - - 0 20\nFor the piece on g8, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g8: g8f8 g8h8.\nLegal: g8h8.\nRejected: g8f8 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g8", "diagnostic": true, "hard_gate": false, "source_square": "g8"}}
{"example_id": "rules_00945", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bkr3/pp1p2pp/8/5p2/8/2P2n2/P1Pn1PPP/R2Q1K1R w - -", "prompt": "FEN: r1bkr3/pp1p2pp/8/5p2/8/2P2n2/P1Pn1PPP/R2Q1K1R w - -\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_00946", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqkb1r/1p1n1pp1/p3p2p/3pP3/5B2/2N2Q2/PPP2PPP/R3KB1R b KQkq - 2 11", "prompt": "FEN: r1bqkb1r/1p1n1pp1/p3p2p/3pP3/5B2/2N2Q2/PPP2PPP/R3KB1R b KQkq - 2 11\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; a6 black pawn; e6 black pawn; h6 black pawn; b7 black pawn; d7 black knight; f7 black pawn; g7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; h8 black rook.\nMoves by piece:\nd5 black pawn: d5d4\na6 black pawn: a6a5\ne6 black pawn: no legal moves\nh6 black pawn: h6h5\nb7 black pawn: b7b5 b7b6\nd7 black knight: d7b6 d7b8 d7c5 d7e5 d7f6\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\na8 black rook: a8a7 a8b8\nc8 black bishop: no legal moves\nd8 black queen: d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4\ne8 black king: e8e7\nf8 black bishop: f8a3 f8b4 f8c5 f8d6 f8e7\nh8 black rook: h8g8 h8h7\nAll legal moves: a6a5 a8a7 a8b8 b7b5 b7b6 d5d4 d7b6 d7b8 d7c5 d7e5 d7f6 d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4 e8e7 f7f5 f7f6 f8a3 f8b4 f8c5 f8d6 f8e7 g7g5 g7g6 h6h5 h8g8 h8h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d5": ["d5d4"], "a6": ["a6a5"], "e6": [], "h6": ["h6h5"], "b7": ["b7b5", "b7b6"], "d7": ["d7b6", "d7b8", "d7c5", "d7e5", "d7f6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "a8": ["a8a7", "a8b8"], "c8": [], "d8": ["d8a5", "d8b6", "d8c7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8e7"], "f8": ["f8a3", "f8b4", "f8c5", "f8d6", "f8e7"], "h8": ["h8g8", "h8h7"]}, "_legal_moves_by_piece_moves": "a6a5 a8a7 a8b8 b7b5 b7b6 d5d4 d7b6 d7b8 d7c5 d7e5 d7f6 d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4 e8e7 f7f5 f7f6 f8a3 f8b4 f8c5 f8d6 f8e7 g7g5 g7g6 h6h5 h8g8 h8h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d5": ["d5d4"], "a6": ["a6a5"], "e6": [], "h6": ["h6h5"], "b7": ["b7b5", "b7b6"], "d7": ["d7b6", "d7b8", "d7c5", "d7e5", "d7f6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "a8": ["a8a7", "a8b8"], "c8": [], "d8": ["d8a5", "d8b6", "d8c7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8e7"], "f8": ["f8a3", "f8b4", "f8c5", "f8d6", "f8e7"], "h8": ["h8g8", "h8h7"]}, "legal_moves": "a6a5 a8a7 a8b8 b7b5 b7b6 d5d4 d7b6 d7b8 d7c5 d7e5 d7f6 d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4 e8e7 f7f5 f7f6 f8a3 f8b4 f8c5 f8d6 f8e7 g7g5 g7g6 h6h5 h8g8 h8h7"}}
{"example_id": "rules_00947", "split": "rules", "task_type": "ray_walk", "fen": "6r1/p4k2/2BQ4/1P6/P4p2/6qP/6P1/5K2 w - - 7 43", "prompt": "FEN: 6r1/p4k2/2BQ4/1P6/P4p2/6qP/6P1/5K2 w - - 7 43\nWalk each ray for the slider on c6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c6 white bishop.\nRay NE: d7 empty; e8 empty; edge.\nRay SE: d5 empty; e4 empty; f3 empty; g2 white pawn: own piece (stop, excluded).\nRay SW: b5 white pawn: own piece (stop, excluded).\nRay NW: b7 empty; a8 empty; edge.\nMoves from rays: c6a8 c6b7 c6d5 c6d7 c6e4 c6e8 c6f3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_00948", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/8/6p1/6P1/2b5/5rk1/8/7K b - - 21 83", "prompt": "FEN: 8/8/6p1/6P1/2b5/5rk1/8/7K b - - 21 83\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: f3 black rook; g3 black king; c4 black bishop; g6 black pawn.\nFilter by piece:\nf3 black rook: pseudo-legal f3a3 f3b3 f3c3 f3d3 f3e3 f3f1 f3f2 f3f4 f3f5 f3f6 f3f7 f3f8 | rejected none | legal f3a3 f3b3 f3c3 f3d3 f3e3 f3f1 f3f2 f3f4 f3f5 f3f6 f3f7 f3f8\ng3 black king: pseudo-legal g3f2 g3f4 g3g2 g3g4 g3h2 g3h3 g3h4 | rejected g3g2 king_would_be_in_check; g3h2 king_would_be_in_check | legal g3f2 g3f4 g3g4 g3h3 g3h4\nc4 black bishop: pseudo-legal c4a2 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 c4g8 | rejected none | legal c4a2 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 c4g8\ng6 black pawn: pseudo-legal none | rejected none | legal none\nAll legal moves: c4a2 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 c4g8 f3a3 f3b3 f3c3 f3d3 f3e3 f3f1 f3f2 f3f4 f3f5 f3f6 f3f7 f3f8 g3f2 g3f4 g3g4 g3h3 g3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_00949", "split": "rules", "task_type": "legal_moves", "fen": "8/2Pk1p2/p2r4/3P1K2/5N1p/8/8/8 w - - 0 54", "prompt": "FEN: 8/2Pk1p2/p2r4/3P1K2/5N1p/8/8/8 w - - 0 54\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: c7c8b c7c8n c7c8q c7c8r f4d3 f4e2 f4e6 f4g2 f4g6 f4h3 f4h5 f5e4 f5e5 f5g4 f5g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00950", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2q1rk1/pp1nbppp/2p1pnN1/8/4P1P1/7P/PPPN1PB1/R1BQ1RK1 b - -", "prompt": "FEN: r2q1rk1/pp1nbppp/2p1pnN1/8/4P1P1/7P/PPPN1PB1/R1BQ1RK1 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c6 black pawn; e6 black pawn; f6 black knight; a7 black pawn; b7 black pawn; d7 black knight; e7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; d8 black queen; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_00951", "split": "rules", "task_type": "piece_legal_moves", "fen": "rn2k1nr/pppbqpbp/3pp1p1/8/3PP3/2N1BN2/PPP1BPPP/R2QK2R w KQkq - 4 7", "prompt": "FEN: rn2k1nr/pppbqpbp/3pp1p1/8/3PP3/2N1BN2/PPP1BPPP/R2QK2R w KQkq - 4 7\nWhat legal moves does the piece on g2 have?", "gold_answer": "g2g3 g2g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "g2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g2", "piece": "pawn"}}
{"example_id": "rules_00952", "split": "rules", "task_type": "check_detection", "fen": "8/6k1/1RP4p/6p1/8/1p2K1PP/r7/8 w - -", "prompt": "FEN: 8/6k1/1RP4p/6p1/8/1p2K1PP/r7/8 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00953", "split": "rules", "task_type": "captures", "fen": "r2qkb1r/3n3p/p1b1p1p1/3pP2B/Np1Q4/4B3/PPP3PP/R3K2R w KQkq -", "prompt": "FEN: r2qkb1r/3n3p/p1b1p1p1/3pP2B/Np1Q4/4B3/PPP3PP/R3K2R w KQkq -\nList all capture moves available.", "gold_answer": "d4b4 d4d5 h5g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00954", "split": "rules", "task_type": "special_rules", "fen": "R7/6k1/3N2pp/8/1p6/1P3P1P/6PK/1rn5 w - - 5 43", "prompt": "Given FEN: R7/6k1/3N2pp/8/1p6/1P3P1P/6PK/1rn5 w - - 5 43\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00955", "split": "rules", "task_type": "legality_check", "fen": "3r2k1/ppq2ppp/4pn2/2n1Q1N1/3R4/2P3NP/PP3PP1/6K1 b - -", "prompt": "FEN: 3r2k1/ppq2ppp/4pn2/2n1Q1N1/3R4/2P3NP/PP3PP1/6K1 b - -\nIs the move a7b7 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "a7b7", "_legality_check_reason_label": "own_piece_destination", "move": "a7b7", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_00956", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "1k5r/pp2ppb1/3p2pp/3P4/Q4P1n/P3P3/1qr2P1P/R4K1R b - - 1 21", "prompt": "FEN: 1k5r/pp2ppb1/3p2pp/3P4/Q4P1n/P3P3/1qr2P1P/R4K1R b - - 1 21\nList pseudo-legal moves from b2.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b2: b2a1 b2a2 b2a3 b2b1 b2b3 b2b4 b2b5 b2b6 b2c1 b2c3 b2d4 b2e5 b2f6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b2", "diagnostic": true, "hard_gate": false, "source_square": "b2"}}
{"example_id": "rules_00957", "split": "rules", "task_type": "piece_legal_filter", "fen": "2kr4/pp6/2pqp3/3r4/3P2Q1/P5P1/1PR4P/5RK1 w - - 3 28", "prompt": "FEN: 2kr4/pp6/2pqp3/3r4/3P2Q1/P5P1/1PR4P/5RK1 w - - 3 28\nFor the piece on f1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f1: f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f1f4 f1f5 f1f6 f1f7 f1f8.\nLegal: f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f1f4 f1f5 f1f6 f1f7 f1f8.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "f1", "diagnostic": true, "hard_gate": false, "source_square": "f1"}}
{"example_id": "rules_00958", "split": "rules", "task_type": "king_safety_filter", "fen": "r7/pppnk3/3p4/3Pp2p/2P3pP/2N3P1/PP1q4/R4K1R b - - 3 21", "prompt": "FEN: r7/pppnk3/3p4/3Pp2p/2P3pP/2N3P1/PP1q4/R4K1R b - - 3 21\nFor move e7e6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e7e6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e7e6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e7e6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00959", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1b1kb1r/ppp1pppp/2n5/3q4/8/1P6/P1PP1PPP/R1BQKBNR w KQkq - 1 6", "prompt": "FEN: r1b1kb1r/ppp1pppp/2n5/3q4/8/1P6/P1PP1PPP/R1BQKBNR w KQkq - 1 6\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; e1 white king; f1 white bishop; g1 white knight; h1 white rook; a2 white pawn; c2 white pawn; d2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; b3 white pawn.\nMoves by piece:\na1 white rook: a1b1\nc1 white bishop: c1a3 c1b2\nd1 white queen: d1e2 d1f3 d1g4 d1h5\ne1 white king: e1e2\nf1 white bishop: f1a6 f1b5 f1c4 f1d3 f1e2\ng1 white knight: g1e2 g1f3 g1h3\nh1 white rook: no legal moves\na2 white pawn: a2a3 a2a4\nc2 white pawn: c2c3 c2c4\nd2 white pawn: d2d3 d2d4\nf2 white pawn: f2f3 f2f4\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nb3 white pawn: b3b4\nAll legal moves: a1b1 a2a3 a2a4 b3b4 c1a3 c1b2 c2c3 c2c4 d1e2 d1f3 d1g4 d1h5 d2d3 d2d4 e1e2 f1a6 f1b5 f1c4 f1d3 f1e2 f2f3 f2f4 g1e2 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1"], "c1": ["c1a3", "c1b2"], "d1": ["d1e2", "d1f3", "d1g4", "d1h5"], "e1": ["e1e2"], "f1": ["f1a6", "f1b5", "f1c4", "f1d3", "f1e2"], "g1": ["g1e2", "g1f3", "g1h3"], "h1": [], "a2": ["a2a3", "a2a4"], "c2": ["c2c3", "c2c4"], "d2": ["d2d3", "d2d4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "b3": ["b3b4"]}, "_legal_moves_by_piece_moves": "a1b1 a2a3 a2a4 b3b4 c1a3 c1b2 c2c3 c2c4 d1e2 d1f3 d1g4 d1h5 d2d3 d2d4 e1e2 f1a6 f1b5 f1c4 f1d3 f1e2 f2f3 f2f4 g1e2 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1"], "c1": ["c1a3", "c1b2"], "d1": ["d1e2", "d1f3", "d1g4", "d1h5"], "e1": ["e1e2"], "f1": ["f1a6", "f1b5", "f1c4", "f1d3", "f1e2"], "g1": ["g1e2", "g1f3", "g1h3"], "h1": [], "a2": ["a2a3", "a2a4"], "c2": ["c2c3", "c2c4"], "d2": ["d2d3", "d2d4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "b3": ["b3b4"]}, "legal_moves": "a1b1 a2a3 a2a4 b3b4 c1a3 c1b2 c2c3 c2c4 d1e2 d1f3 d1g4 d1h5 d2d3 d2d4 e1e2 f1a6 f1b5 f1c4 f1d3 f1e2 f2f3 f2f4 g1e2 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4"}}
{"example_id": "rules_00960", "split": "rules", "task_type": "ray_walk", "fen": "rn2k2r/p2p1p1p/1q2p1p1/1P2b3/3n4/4B3/BP2NPP1/R2Q1R1K b kq - 7 19", "prompt": "FEN: rn2k2r/p2p1p1p/1q2p1p1/1P2b3/3n4/4B3/BP2NPP1/R2Q1R1K b kq - 7 19\nWalk each ray for the slider on e5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e5 black bishop.\nRay NE: f6 empty; g7 empty; h8 black rook: own piece (stop, excluded).\nRay SE: f4 empty; g3 empty; h2 empty; edge.\nRay SW: d4 black knight: own piece (stop, excluded).\nRay NW: d6 empty; c7 empty; b8 black knight: own piece (stop, excluded).\nMoves from rays: e5c7 e5d6 e5f4 e5f6 e5g3 e5g7 e5h2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "e5", "diagnostic": true, "hard_gate": false, "source_square": "e5"}}
{"example_id": "rules_00961", "split": "rules", "task_type": "legal_moves", "fen": "r1bq3r/ppkn1p2/3p3p/2pPpPp1/2P5/2P5/P1B2PPP/1RBQ1RK1 w - -", "prompt": "FEN: r1bq3r/ppkn1p2/3p3p/2pPpPp1/2P5/2P5/P1B2PPP/1RBQ1RK1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a1 b1b2 b1b3 b1b4 b1b5 b1b6 b1b7 c1a3 c1b2 c1d2 c1e3 c1f4 c1g5 c2a4 c2b3 c2d3 c2e4 d1d2 d1d3 d1d4 d1e1 d1e2 d1f3 d1g4 d1h5 f1e1 f2f3 f2f4 f5f6 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00962", "split": "rules", "task_type": "legal_moves", "fen": "r1r3k1/5qp1/b4p1p/2p5/p1P1QpN1/P2P1N1P/5PP1/1R3RK1 b - - 2 24", "prompt": "FEN: r1r3k1/5qp1/b4p1p/2p5/p1P1QpN1/P2P1N1P/5PP1/1R3RK1 b - - 2 24\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6b5 a6b7 a6c4 a8a7 a8b8 c8b8 c8c6 c8c7 c8d8 c8e8 c8f8 f6f5 f7a7 f7b7 f7c4 f7c7 f7d5 f7d7 f7e6 f7e7 f7e8 f7f8 f7g6 f7h5 g7g5 g7g6 g8f8 g8h8 h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00963", "split": "rules", "task_type": "side_piece_inventory", "fen": "rn1qkbnr/p1p1pppp/8/2p5/1p1P4/4PN2/PP3PPP/R1BQ1K1R w kq - 0 9", "prompt": "FEN: rn1qkbnr/p1p1pppp/8/2p5/1p1P4/4PN2/PP3PPP/R1BQ1K1R w kq - 0 9\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; f1 white king; h1 white rook; a2 white pawn; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; e3 white pawn; f3 white knight; d4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "d4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "d4", "piece": "white pawn"}]}}
{"example_id": "rules_00964", "split": "rules", "task_type": "piece_legal_moves", "fen": "3rr1k1/1pp1npbp/p1n3p1/4pb2/2B5/PKP2NB1/1P1N1PPP/3R3R w - - 0 16", "prompt": "FEN: 3rr1k1/1pp1npbp/p1n3p1/4pb2/2B5/PKP2NB1/1P1N1PPP/3R3R w - - 0 16\nWhat legal moves does the piece on h1 have?", "gold_answer": "h1e1 h1f1 h1g1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h1", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "h1", "piece": "rook"}}
{"example_id": "rules_00965", "split": "rules", "task_type": "check_detection", "fen": "rnbqk1nr/1p2bppp/p2pp3/8/4P3/1N1BB3/PPP2PPP/RN1QK2R w KQkq -", "prompt": "FEN: rnbqk1nr/1p2bppp/p2pp3/8/4P3/1N1BB3/PPP2PPP/RN1QK2R w KQkq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00966", "split": "rules", "task_type": "captures", "fen": "8/8/8/p4k2/P7/6Kp/8/8 w - - 0 51", "prompt": "FEN: 8/8/8/p4k2/P7/6Kp/8/8 w - - 0 51\nList all capture moves available.", "gold_answer": "g3h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00967", "split": "rules", "task_type": "special_rules", "fen": "5rk1/2QR3p/2n1Ppp1/8/p1P5/2B4P/q4KP1/8 w - - 1 33", "prompt": "Given FEN: 5rk1/2QR3p/2n1Ppp1/8/p1P5/2B4P/q4KP1/8 w - - 1 33\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00968", "split": "rules", "task_type": "legality_check", "fen": "r5k1/5p2/4q1p1/4P3/8/6P1/pQ3P2/R5K1 w - -", "prompt": "FEN: r5k1/5p2/4q1p1/4P3/8/6P1/pQ3P2/R5K1 w - -\nIs the move g3f5 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "g3f5", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "g3f5", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_00969", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/qK2b3/8/6k1/8/5R2/8/r7 w - - 0 66", "prompt": "FEN: 8/qK2b3/8/6k1/8/5R2/8/r7 w - - 0 66\nList pseudo-legal moves from f3.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from f3: f3a3 f3b3 f3c3 f3d3 f3e3 f3f1 f3f2 f3f4 f3f5 f3f6 f3f7 f3f8 f3g3 f3h3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "f3", "diagnostic": true, "hard_gate": false, "source_square": "f3"}}
{"example_id": "rules_00970", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnb2rk1/ppp1ppbp/4q1p1/4P3/2PB4/5N2/PP2Q1PP/R3KB1R w KQ - 6 13", "prompt": "FEN: rnb2rk1/ppp1ppbp/4q1p1/4P3/2PB4/5N2/PP2Q1PP/R3KB1R w KQ - 6 13\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1 a1c1 a1d1.\nLegal: a1b1 a1c1 a1d1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00971", "split": "rules", "task_type": "king_safety_filter", "fen": "8/5pp1/3k3p/1r1p4/1P1K2PP/5P2/8/1R6 b - -", "prompt": "FEN: 8/5pp1/3k3p/1r1p4/1P1K2PP/5P2/8/1R6 b - -\nFor move d6c5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: d6c5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "d6c5", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "d6c5", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_00972", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r3k1nr/p1p2ppp/1pbb1q2/4p2Q/2B5/8/PPP2PPP/RNB1R1K1 w kq - 4 11", "prompt": "FEN: r3k1nr/p1p2ppp/1pbb1q2/4p2Q/2B5/8/PPP2PPP/RNB1R1K1 w kq - 4 11\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; e1 white rook; g1 white king; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c4 white bishop; h5 white queen.\nMoves by piece:\na1 white rook: no legal moves\nb1 white knight: b1a3 b1c3 b1d2\nc1 white bishop: c1d2 c1e3 c1f4 c1g5 c1h6\ne1 white rook: e1d1 e1e2 e1e3 e1e4 e1e5 e1f1\ng1 white king: g1f1 g1h1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: c2c3\nf2 white pawn: f2f3 f2f4\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nc4 white bishop: c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7\nh5 white queen: h5d1 h5e2 h5e5 h5f3 h5f5 h5f7 h5g4 h5g5 h5g6 h5h3 h5h4 h5h6 h5h7\nAll legal moves: a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 e1d1 e1e2 e1e3 e1e4 e1e5 e1f1 f2f3 f2f4 g1f1 g1h1 g2g3 g2g4 h2h3 h2h4 h5d1 h5e2 h5e5 h5f3 h5f5 h5f7 h5g4 h5g5 h5g6 h5h3 h5h4 h5h6 h5h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "b1": ["b1a3", "b1c3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "e1": ["e1d1", "e1e2", "e1e3", "e1e4", "e1e5", "e1f1"], "g1": ["g1f1", "g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c4": ["c4a6", "c4b3", "c4b5", "c4d3", "c4d5", "c4e2", "c4e6", "c4f1", "c4f7"], "h5": ["h5d1", "h5e2", "h5e5", "h5f3", "h5f5", "h5f7", "h5g4", "h5g5", "h5g6", "h5h3", "h5h4", "h5h6", "h5h7"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 e1d1 e1e2 e1e3 e1e4 e1e5 e1f1 f2f3 f2f4 g1f1 g1h1 g2g3 g2g4 h2h3 h2h4 h5d1 h5e2 h5e5 h5f3 h5f5 h5f7 h5g4 h5g5 h5g6 h5h3 h5h4 h5h6 h5h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "b1": ["b1a3", "b1c3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "e1": ["e1d1", "e1e2", "e1e3", "e1e4", "e1e5", "e1f1"], "g1": ["g1f1", "g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c4": ["c4a6", "c4b3", "c4b5", "c4d3", "c4d5", "c4e2", "c4e6", "c4f1", "c4f7"], "h5": ["h5d1", "h5e2", "h5e5", "h5f3", "h5f5", "h5f7", "h5g4", "h5g5", "h5g6", "h5h3", "h5h4", "h5h6", "h5h7"]}, "legal_moves": "a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 e1d1 e1e2 e1e3 e1e4 e1e5 e1f1 f2f3 f2f4 g1f1 g1h1 g2g3 g2g4 h2h3 h2h4 h5d1 h5e2 h5e5 h5f3 h5f5 h5f7 h5g4 h5g5 h5g6 h5h3 h5h4 h5h6 h5h7"}}
{"example_id": "rules_00973", "split": "rules", "task_type": "ray_walk", "fen": "r1bqkbnr/1pp2ppp/p1Bp4/4p3/4P3/5N2/PPPP1PPP/RNBQ1RK1 b kq - 0 5", "prompt": "FEN: r1bqkbnr/1pp2ppp/p1Bp4/4p3/4P3/5N2/PPPP1PPP/RNBQ1RK1 b kq - 0 5\nWalk each ray for the slider on a8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a8 black rook.\nRay N: edge.\nRay E: b8 empty; c8 black bishop: own piece (stop, excluded).\nRay S: a7 empty; a6 black pawn: own piece (stop, excluded).\nRay W: edge.\nMoves from rays: a8a7 a8b8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a8", "diagnostic": true, "hard_gate": false, "source_square": "a8"}}
{"example_id": "rules_00974", "split": "rules", "task_type": "legal_moves", "fen": "r1bqr1k1/pp1n1ppp/5n2/2b1p3/8/2NQ1BB1/PPP1NPPP/R3R1K1 b - -", "prompt": "FEN: r1bqr1k1/pp1n1ppp/5n2/2b1p3/8/2NQ1BB1/PPP1NPPP/R3R1K1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c5a3 c5b4 c5b6 c5d4 c5d6 c5e3 c5e7 c5f2 c5f8 d7b6 d7b8 d7f8 d8a5 d8b6 d8c7 d8e7 e5e4 e8e6 e8e7 e8f8 f6d5 f6e4 f6g4 f6h5 g7g5 g7g6 g8f8 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00975", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/pp2ppbp/2np1np1/8/2BPP1b1/2N2N2/PP3PPP/R1BQR1K1 w - -", "prompt": "FEN: r2q1rk1/pp2ppbp/2np1np1/8/2BPP1b1/2N2N2/PP3PPP/R1BQR1K1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d5 c3e2 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 d1a4 d1b3 d1c2 d1d2 d1d3 d1e2 d4d5 e1e2 e1e3 e1f1 e4e5 f3d2 f3e5 f3g5 f3h4 g1f1 g1h1 g2g3 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00976", "split": "rules", "task_type": "side_piece_inventory", "fen": "3r4/pr2N1kp/1p1P1p2/2p1p3/8/8/PP3Pb1/R2R2K1 w - - 0 26", "prompt": "FEN: 3r4/pr2N1kp/1p1P1p2/2p1p3/8/8/PP3Pb1/R2R2K1 w - - 0 26\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white rook; g1 white king; a2 white pawn; b2 white pawn; f2 white pawn; d6 white pawn; e7 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "d6", "piece": "white pawn"}, {"square": "e7", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "d6", "piece": "white pawn"}, {"square": "e7", "piece": "white knight"}]}}
{"example_id": "rules_00977", "split": "rules", "task_type": "piece_legal_moves", "fen": "r3k2r/1bq1b3/pp1p2pp/3Pp3/2Pp4/3P2P1/PP1B2BP/R2QR1K1 w kq - 0 21", "prompt": "FEN: r3k2r/1bq1b3/pp1p2pp/3Pp3/2Pp4/3P2P1/PP1B2BP/R2QR1K1 w kq - 0 21\nWhat legal moves does the piece on d2 have?", "gold_answer": "d2a5 d2b4 d2c1 d2c3 d2e3 d2f4 d2g5 d2h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "d2", "_piece_legal_moves_piece": "bishop", "diagnostic": true, "hard_gate": false, "source_square": "d2", "piece": "bishop"}}
{"example_id": "rules_00978", "split": "rules", "task_type": "check_detection", "fen": "2rq1rk1/1p2bppp/p1Npp3/6B1/5P2/2N3n1/PPP3PP/2KR3R w - -", "prompt": "FEN: 2rq1rk1/1p2bppp/p1Npp3/6B1/5P2/2N3n1/PPP3PP/2KR3R w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00979", "split": "rules", "task_type": "captures", "fen": "r1bq1rk1/pp2bppp/4pn2/2p1N3/2BP4/2P5/PP2QPPP/R1B1K2R w KQ -", "prompt": "FEN: r1bq1rk1/pp2bppp/4pn2/2p1N3/2BP4/2P5/PP2QPPP/R1B1K2R w KQ -\nList all capture moves available.", "gold_answer": "c4e6 d4c5 e5f7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00980", "split": "rules", "task_type": "special_rules", "fen": "3rkb1r/1pp2ppp/p1npq3/4p3/4P3/2P2Q1P/PP1PNPP1/R1B1K2R b KQk - 2 10", "prompt": "Given FEN: 3rkb1r/1pp2ppp/p1npq3/4p3/4P3/2P2Q1P/PP1PNPP1/R1B1K2R b KQk - 2 10\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00981", "split": "rules", "task_type": "legality_check", "fen": "rnbqkb1r/pp1p1ppp/2p2n2/4p3/2P1P3/3P3P/PP3PP1/RNBQKBNR b KQkq - 0 4", "prompt": "FEN: rnbqkb1r/pp1p1ppp/2p2n2/4p3/2P1P3/3P3P/PP3PP1/RNBQKBNR b KQkq - 0 4\nIs the move b7b8 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b7b8", "_legality_check_reason_label": "own_piece_destination", "move": "b7b8", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_00982", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r5rk/p5p1/n1p2p1p/1p1n4/3P3P/P1PB1NB1/2PK2R1/7R b - - 1 26", "prompt": "FEN: r5rk/p5p1/n1p2p1p/1p1n4/3P3P/P1PB1NB1/2PK2R1/7R b - - 1 26\nList pseudo-legal moves from b5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b5: b5b4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b5", "diagnostic": true, "hard_gate": false, "source_square": "b5"}}
{"example_id": "rules_00983", "split": "rules", "task_type": "piece_legal_filter", "fen": "2kr3r/1b2n2p/p1qbp1p1/3p1p2/p2P1P2/2PB2N1/1P2Q1PP/R1B2RK1 w - - 2 19", "prompt": "FEN: 2kr3r/1b2n2p/p1qbp1p1/3p1p2/p2P1P2/2PB2N1/1P2Q1PP/R1B2RK1 w - - 2 19\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1a2 a1a3 a1a4 a1b1.\nLegal: a1a2 a1a3 a1a4 a1b1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_00984", "split": "rules", "task_type": "king_safety_filter", "fen": "r2q1rk1/pp2bppp/1n6/2P4b/8/P1N1PN1P/4B1P1/R2Q1RK1 b - - 0 17", "prompt": "FEN: r2q1rk1/pp2bppp/1n6/2P4b/8/P1N1PN1P/4B1P1/R2Q1RK1 b - - 0 17\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00985", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r4rk1/pp4p1/2pp3p/8/2P5/1P4P1/P6P/1b2R1K1 w - - 0 30", "prompt": "FEN: r4rk1/pp4p1/2pp3p/8/2P5/1P4P1/P6P/1b2R1K1 w - - 0 30\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: e1 white rook; g1 white king; a2 white pawn; h2 white pawn; b3 white pawn; g3 white pawn; c4 white pawn.\nMoves by piece:\ne1 white rook: e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1e8 e1f1\ng1 white king: g1g2 g1h1\na2 white pawn: a2a3 a2a4\nh2 white pawn: h2h3 h2h4\nb3 white pawn: b3b4\ng3 white pawn: g3g4\nc4 white pawn: c4c5\nAll legal moves: a2a3 a2a4 b3b4 c4c5 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1e8 e1f1 g1g2 g1h1 g3g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e1": ["e1b1", "e1c1", "e1d1", "e1e2", "e1e3", "e1e4", "e1e5", "e1e6", "e1e7", "e1e8", "e1f1"], "g1": ["g1g2", "g1h1"], "a2": ["a2a3", "a2a4"], "h2": ["h2h3", "h2h4"], "b3": ["b3b4"], "g3": ["g3g4"], "c4": ["c4c5"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b3b4 c4c5 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1e8 e1f1 g1g2 g1h1 g3g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e1": ["e1b1", "e1c1", "e1d1", "e1e2", "e1e3", "e1e4", "e1e5", "e1e6", "e1e7", "e1e8", "e1f1"], "g1": ["g1g2", "g1h1"], "a2": ["a2a3", "a2a4"], "h2": ["h2h3", "h2h4"], "b3": ["b3b4"], "g3": ["g3g4"], "c4": ["c4c5"]}, "legal_moves": "a2a3 a2a4 b3b4 c4c5 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1e8 e1f1 g1g2 g1h1 g3g4 h2h3 h2h4"}}
{"example_id": "rules_00986", "split": "rules", "task_type": "ray_walk", "fen": "8/2p2kpp/Bpnrbp2/4p3/1P2P1PP/P1B5/2P2P2/5RK1 b - - 0 21", "prompt": "FEN: 8/2p2kpp/Bpnrbp2/4p3/1P2P1PP/P1B5/2P2P2/5RK1 b - - 0 21\nWalk each ray for the slider on d6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d6 black rook.\nRay N: d7 empty; d8 empty; edge.\nRay E: e6 black bishop: own piece (stop, excluded).\nRay S: d5 empty; d4 empty; d3 empty; d2 empty; d1 empty; edge.\nRay W: c6 black knight: own piece (stop, excluded).\nMoves from rays: d6d1 d6d2 d6d3 d6d4 d6d5 d6d7 d6d8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "d6", "diagnostic": true, "hard_gate": false, "source_square": "d6"}}
{"example_id": "rules_00987", "split": "rules", "task_type": "legal_moves", "fen": "r6r/pppb2k1/8/3P3p/P1P3pP/2NB1nP1/1P6/3R1RK1 w - - 1 25", "prompt": "FEN: r6r/pppb2k1/8/3P3p/P1P3pP/2NB1nP1/1P6/3R1RK1 w - - 1 25\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: f1f3 g1f2 g1g2 g1h1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00988", "split": "rules", "task_type": "legal_moves", "fen": "2b2qk1/p5b1/1p4B1/3pP3/8/1P4P1/PB1Q1PK1/8 b - - 0 30", "prompt": "FEN: 2b2qk1/p5b1/1p4B1/3pP3/8/1P4P1/PB1Q1PK1/8 b - - 0 30\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6b5 c8a6 c8b7 c8d7 c8e6 c8f5 c8g4 c8h3 d5d4 f8a3 f8b4 f8c5 f8d6 f8d8 f8e7 f8e8 f8f2 f8f3 f8f4 f8f5 f8f6 f8f7 g7e5 g7f6 g7h6 g7h8 g8h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00989", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2qk2r/pp2bpp1/5n1p/2pP3n/2b3P1/2N1B2P/PPPQNPB1/R3R1K1 b kq - 0 16", "prompt": "FEN: r2qk2r/pp2bpp1/5n1p/2pP3n/2b3P1/2N1B2P/PPPQNPB1/R3R1K1 b kq - 0 16\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c4 black bishop; c5 black pawn; h5 black knight; f6 black knight; h6 black pawn; a7 black pawn; b7 black pawn; e7 black bishop; f7 black pawn; g7 black pawn; a8 black rook; d8 black queen; e8 black king; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c4", "piece": "black bishop"}, {"square": "c5", "piece": "black pawn"}, {"square": "h5", "piece": "black knight"}, {"square": "f6", "piece": "black knight"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c4", "piece": "black bishop"}, {"square": "c5", "piece": "black pawn"}, {"square": "h5", "piece": "black knight"}, {"square": "f6", "piece": "black knight"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_00990", "split": "rules", "task_type": "piece_legal_moves", "fen": "r4rk1/1p3ppn/p2pb2p/2p3q1/4PR2/2PPQn1P/PPB3P1/RN4K1 w - - 0 18", "prompt": "FEN: r4rk1/1p3ppn/p2pb2p/2p3q1/4PR2/2PPQn1P/PPB3P1/RN4K1 w - - 0 18\nWhat legal moves does the piece on b1 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b1", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "b1", "piece": "knight"}}
{"example_id": "rules_00991", "split": "rules", "task_type": "check_detection", "fen": "r4k1r/pp1b1n1p/1b1p4/2pP1p2/4P2P/2P2P2/PP1KN1P1/RN5R w - - 1 18", "prompt": "FEN: r4k1r/pp1b1n1p/1b1p4/2pP1p2/4P2P/2P2P2/PP1KN1P1/RN5R w - - 1 18\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00992", "split": "rules", "task_type": "captures", "fen": "1rbq1rk1/p3bppp/2p1pn2/3p2B1/8/2P1PN1P/PP3PP1/1R1QKB1R b K - 4 11", "prompt": "FEN: 1rbq1rk1/p3bppp/2p1pn2/3p2B1/8/2P1PN1P/PP3PP1/1R1QKB1R b K - 4 11\nList all capture moves available.", "gold_answer": "b8b2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_00993", "split": "rules", "task_type": "special_rules", "fen": "1K1k4/R7/1P6/8/8/8/8/2r5 w - -", "prompt": "Given FEN: 1K1k4/R7/1P6/8/8/8/8/2r5 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_00994", "split": "rules", "task_type": "legality_check", "fen": "Q7/8/2pb4/6k1/8/1P4p1/4Q1K1/8 b - -", "prompt": "FEN: Q7/8/2pb4/6k1/8/1P4p1/4Q1K1/8 b - -\nIs the move g5c6 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "g5c6", "_legality_check_reason_label": "own_piece_destination", "move": "g5c6", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_00995", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1b2rk1/p2p1ppp/1p2pn2/8/3RP3/2N5/PPP1B1PP/5RK1 b - - 0 13", "prompt": "FEN: r1b2rk1/p2p1ppp/1p2pn2/8/3RP3/2N5/PPP1B1PP/5RK1 b - - 0 13\nList pseudo-legal moves from b6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b6: b6b5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b6", "diagnostic": true, "hard_gate": false, "source_square": "b6"}}
{"example_id": "rules_00996", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnbrk3/ppp2NR1/4p3/7p/3PP2q/2PB4/P3KP1P/R5Q1 b - - 0 16", "prompt": "FEN: rnbrk3/ppp2NR1/4p3/7p/3PP2q/2PB4/P3KP1P/R5Q1 b - - 0 16\nFor the piece on e8, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e8: e8d7 e8e7 e8f7 e8f8.\nLegal: e8d7 e8e7 e8f8.\nRejected: e8f7 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "e8", "diagnostic": true, "hard_gate": false, "source_square": "e8"}}
{"example_id": "rules_00997", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbq1rk1/1pp2ppp/p3pb2/8/3P4/3Q2P1/PPP2PBP/R1B1K1NR w KQ - 0 10", "prompt": "FEN: rnbq1rk1/1pp2ppp/p3pb2/8/3P4/3Q2P1/PPP2PBP/R1B1K1NR w KQ - 0 10\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_00998", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqkbnr/pp1p1ppp/n7/2pPp3/2P1PP2/P7/1P4PP/RNBQKBNR b KQkq - 0 6", "prompt": "FEN: r1bqkbnr/pp1p1ppp/n7/2pPp3/2P1PP2/P7/1P4PP/RNBQKBNR b KQkq - 0 6\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black pawn; e5 black pawn; a6 black knight; a7 black pawn; b7 black pawn; d7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\nc5 black pawn: no legal moves\ne5 black pawn: e5f4\na6 black knight: a6b4 a6b8 a6c7\na7 black pawn: no legal moves\nb7 black pawn: b7b5 b7b6\nd7 black pawn: d7d6\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8\nc8 black bishop: no legal moves\nd8 black queen: d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4\ne8 black king: e8e7\nf8 black bishop: f8d6 f8e7\ng8 black knight: g8e7 g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a6b4 a6b8 a6c7 a8b8 b7b5 b7b6 d7d6 d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4 e5f4 e8e7 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": [], "e5": ["e5f4"], "a6": ["a6b4", "a6b8", "a6c7"], "a7": [], "b7": ["b7b5", "b7b6"], "d7": ["d7d6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": [], "d8": ["d8a5", "d8b6", "d8c7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8e7"], "f8": ["f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a6b4 a6b8 a6c7 a8b8 b7b5 b7b6 d7d6 d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4 e5f4 e8e7 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": [], "e5": ["e5f4"], "a6": ["a6b4", "a6b8", "a6c7"], "a7": [], "b7": ["b7b5", "b7b6"], "d7": ["d7d6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": [], "d8": ["d8a5", "d8b6", "d8c7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8e7"], "f8": ["f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "legal_moves": "a6b4 a6b8 a6c7 a8b8 b7b5 b7b6 d7d6 d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4 e5f4 e8e7 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_00999", "split": "rules", "task_type": "ray_walk", "fen": "1r3r2/5pk1/1p1p1np1/p3p2p/7Q/4R2P/q1P2PP1/4R1K1 w - - 0 28", "prompt": "FEN: 1r3r2/5pk1/1p1p1np1/p3p2p/7Q/4R2P/q1P2PP1/4R1K1 w - - 0 28\nWalk each ray for the slider on e1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e1 white rook.\nRay N: e2 empty; e3 white rook: own piece (stop, excluded).\nRay E: f1 empty; g1 white king: own piece (stop, excluded).\nRay S: edge.\nRay W: d1 empty; c1 empty; b1 empty; a1 empty; edge.\nMoves from rays: e1a1 e1b1 e1c1 e1d1 e1e2 e1f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "e1", "diagnostic": true, "hard_gate": false, "source_square": "e1"}}
{"example_id": "rules_01000", "split": "rules", "task_type": "legal_moves", "fen": "r1bq1rk1/p1p2p2/2pp1n1p/2b1p1p1/4P3/2NP1NB1/PPP2PPP/R2Q1RK1 b - - 1 10", "prompt": "FEN: r1bq1rk1/p1p2p2/2pp1n1p/2b1p1p1/4P3/2NP1NB1/PPP2PPP/R2Q1RK1 b - - 1 10\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 c5a3 c5b4 c5b6 c5d4 c5e3 c5f2 c8a6 c8b7 c8d7 c8e6 c8f5 c8g4 c8h3 d6d5 d8d7 d8e7 d8e8 f6d5 f6d7 f6e4 f6e8 f6g4 f6h5 f6h7 f8e8 g5g4 g8g7 g8h7 g8h8 h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01001", "split": "rules", "task_type": "legal_moves", "fen": "1k3r2/ppb2B1R/2p2p2/4p1p1/3P4/P7/1PP2P2/1K6 w - - 0 37", "prompt": "FEN: 1k3r2/ppb2B1R/2p2p2/4p1p1/3P4/P7/1PP2P2/1K6 w - - 0 37\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 b1a1 b1a2 b1c1 b2b3 b2b4 c2c3 c2c4 d4d5 d4e5 f2f3 f2f4 f7a2 f7b3 f7c4 f7d5 f7e6 f7e8 f7g6 f7g8 f7h5 h7g7 h7h1 h7h2 h7h3 h7h4 h7h5 h7h6 h7h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01002", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2qk1r1/p1p5/1p1p1p1p/3PnPp1/1P3p2/8/P5PP/RNBQ1R1K b q - 0 15", "prompt": "FEN: r2qk1r1/p1p5/1p1p1p1p/3PnPp1/1P3p2/8/P5PP/RNBQ1R1K b q - 0 15\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: f4 black pawn; e5 black knight; g5 black pawn; b6 black pawn; d6 black pawn; f6 black pawn; h6 black pawn; a7 black pawn; c7 black pawn; a8 black rook; d8 black queen; e8 black king; g8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "f4", "piece": "black pawn"}, {"square": "e5", "piece": "black knight"}, {"square": "g5", "piece": "black pawn"}, {"square": "b6", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "g8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "f4", "piece": "black pawn"}, {"square": "e5", "piece": "black knight"}, {"square": "g5", "piece": "black pawn"}, {"square": "b6", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "g8", "piece": "black rook"}]}}
{"example_id": "rules_01003", "split": "rules", "task_type": "piece_legal_moves", "fen": "6k1/2p2p1p/p1P3p1/P2r4/3P4/2P5/4r1PP/R4K2 w - - 0 29", "prompt": "FEN: 6k1/2p2p1p/p1P3p1/P2r4/3P4/2P5/4r1PP/R4K2 w - - 0 29\nWhat legal moves does the piece on a1 have?", "gold_answer": "a1a2 a1a3 a1a4 a1b1 a1c1 a1d1 a1e1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a1", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "a1", "piece": "rook"}}
{"example_id": "rules_01004", "split": "rules", "task_type": "check_detection", "fen": "2Qq3r/p4k1p/3p4/8/8/8/PP4PP/4R2K w - - 3 31", "prompt": "FEN: 2Qq3r/p4k1p/3p4/8/8/8/PP4PP/4R2K w - - 3 31\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01005", "split": "rules", "task_type": "captures", "fen": "R1n5/2k4p/B5p1/2Prpp2/8/4P1PP/5P1K/8 b - - 3 35", "prompt": "FEN: R1n5/2k4p/B5p1/2Prpp2/8/4P1PP/5P1K/8 b - - 3 35\nList all capture moves available.", "gold_answer": "d5c5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01006", "split": "rules", "task_type": "special_rules", "fen": "r5k1/pp3ppp/4rq2/2p1n3/3pPB1P/P2P2Q1/1PP3P1/2KR3R b - - 3 18", "prompt": "Given FEN: r5k1/pp3ppp/4rq2/2p1n3/3pPB1P/P2P2Q1/1PP3P1/2KR3R b - - 3 18\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01007", "split": "rules", "task_type": "legality_check", "fen": "8/5pk1/3P1bp1/p1P4p/1PQ2p2/1B4PP/Pq6/3K4 b - -", "prompt": "FEN: 8/5pk1/3P1bp1/p1P4p/1PQ2p2/1B4PP/Pq6/3K4 b - -\nIs the move b2c2 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "b2c2", "_legality_check_reason_label": "legal", "move": "b2c2", "legality_reason_label": "legal"}}
{"example_id": "rules_01008", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5rk1/ppp1R1b1/6p1/2P4p/P2r4/1P3P2/4K3/1R6 b - - 1 29", "prompt": "FEN: 5rk1/ppp1R1b1/6p1/2P4p/P2r4/1P3P2/4K3/1R6 b - - 1 29\nList pseudo-legal moves from d4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d4: d4a4 d4b4 d4c4 d4d1 d4d2 d4d3 d4d5 d4d6 d4d7 d4d8 d4e4 d4f4 d4g4 d4h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_01009", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn2kb1r/ppp1pppp/5n2/q7/3P4/2N2b1P/PPP2PP1/R1BQKB1R w KQkq -", "prompt": "FEN: rn2kb1r/ppp1pppp/5n2/q7/3P4/2N2b1P/PPP2PP1/R1BQKB1R w KQkq -\nFor the piece on e1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e1: e1d2 e1e2.\nLegal: e1d2.\nRejected: e1e2 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "e1", "diagnostic": true, "hard_gate": false, "source_square": "e1"}}
{"example_id": "rules_01010", "split": "rules", "task_type": "king_safety_filter", "fen": "8/2b5/8/2kB4/6K1/8/8/8 w - -", "prompt": "FEN: 8/2b5/8/2kB4/6K1/8/8/8 w - -\nFor move g4f4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: g4f4.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "g4f4", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "g4f4", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01011", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "5k2/8/5P2/5K2/8/8/8/8 w - - 33 86", "prompt": "FEN: 5k2/8/5P2/5K2/8/8/8/8 w - - 33 86\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: f5 white king; f6 white pawn.\nMoves by piece:\nf5 white king: f5e4 f5e5 f5e6 f5f4 f5g4 f5g5 f5g6\nf6 white pawn: f6f7\nAll legal moves: f5e4 f5e5 f5e6 f5f4 f5g4 f5g5 f5g6 f6f7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"f5": ["f5e4", "f5e5", "f5e6", "f5f4", "f5g4", "f5g5", "f5g6"], "f6": ["f6f7"]}, "_legal_moves_by_piece_moves": "f5e4 f5e5 f5e6 f5f4 f5g4 f5g5 f5g6 f6f7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"f5": ["f5e4", "f5e5", "f5e6", "f5f4", "f5g4", "f5g5", "f5g6"], "f6": ["f6f7"]}, "legal_moves": "f5e4 f5e5 f5e6 f5f4 f5g4 f5g5 f5g6 f6f7"}}
{"example_id": "rules_01012", "split": "rules", "task_type": "ray_walk", "fen": "r1bq1rk1/ppppn1pp/3P4/2b1PpN1/2B5/2P5/P1Q2PPP/R1B1K2R b KQ -", "prompt": "FEN: r1bq1rk1/ppppn1pp/3P4/2b1PpN1/2B5/2P5/P1Q2PPP/R1B1K2R b KQ -\nWalk each ray for the slider on c5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c5 black bishop.\nRay NE: d6 white pawn: capture (stop, included).\nRay SE: d4 empty; e3 empty; f2 white pawn: capture (stop, included).\nRay SW: b4 empty; a3 empty; edge.\nRay NW: b6 empty; a7 black pawn: own piece (stop, excluded).\nMoves from rays: c5a3 c5b4 c5b6 c5d4 c5d6 c5e3 c5f2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_01013", "split": "rules", "task_type": "legal_moves", "fen": "r4rk1/ppp2qpp/3b1n2/8/4P3/1PR3PP/P2NRPK1/4Q3 w - - 1 21", "prompt": "FEN: r4rk1/ppp2qpp/3b1n2/8/4P3/1PR3PP/P2NRPK1/4Q3 w - - 1 21\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b3b4 c3c1 c3c2 c3c4 c3c5 c3c6 c3c7 c3d3 c3e3 c3f3 d2b1 d2c4 d2f1 d2f3 e1a1 e1b1 e1c1 e1d1 e1f1 e1g1 e1h1 e2e3 e4e5 f2f3 f2f4 g2f1 g2f3 g2g1 g2h1 g2h2 g3g4 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01014", "split": "rules", "task_type": "legal_moves", "fen": "r4rk1/pp1q2bp/2n1b1p1/3ppnP1/8/PBPP1N2/1P3P2/RNBQK2R w KQ - 2 14", "prompt": "FEN: r4rk1/pp1q2bp/2n1b1p1/3ppnP1/8/PBPP1N2/1P3P2/RNBQK2R w KQ - 2 14\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a3a4 b1d2 b3a2 b3a4 b3c2 b3c4 b3d5 c1d2 c1e3 c1f4 c3c4 d1c2 d1d2 d1e2 d3d4 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3h2 f3h4 h1f1 h1g1 h1h2 h1h3 h1h4 h1h5 h1h6 h1h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01015", "split": "rules", "task_type": "side_piece_inventory", "fen": "r5k1/6p1/8/3p3p/3R1P2/6P1/NK5P/7R b - - 0 35", "prompt": "FEN: r5k1/6p1/8/3p3p/3R1P2/6P1/NK5P/7R b - - 0 35\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; h5 black pawn; g7 black pawn; a8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "d5", "piece": "black pawn"}, {"square": "h5", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "d5", "piece": "black pawn"}, {"square": "h5", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01016", "split": "rules", "task_type": "piece_legal_moves", "fen": "r6k/pp3P1p/8/2p2nP1/2Pp4/8/PP3q2/3KR3 b - - 5 35", "prompt": "FEN: r6k/pp3P1p/8/2p2nP1/2Pp4/8/PP3q2/3KR3 b - - 5 35\nWhat legal moves does the piece on h8 have?", "gold_answer": "h8g7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h8", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "h8", "piece": "king"}}
{"example_id": "rules_01017", "split": "rules", "task_type": "check_detection", "fen": "r3kbnr/ppp2pp1/1q2p2p/8/4N3/3P1B2/PPPB1PPP/2KRR3 w kq - 0 13", "prompt": "FEN: r3kbnr/ppp2pp1/1q2p2p/8/4N3/3P1B2/PPPB1PPP/2KRR3 w kq - 0 13\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01018", "split": "rules", "task_type": "captures", "fen": "rnbqkb1r/pp3ppp/4pn2/2p5/2N5/6P1/PP1PPPBP/RNBQK2R b KQkq -", "prompt": "FEN: rnbqkb1r/pp3ppp/4pn2/2p5/2N5/6P1/PP1PPPBP/RNBQK2R b KQkq -\nList all capture moves available.", "gold_answer": "d8d2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01019", "split": "rules", "task_type": "special_rules", "fen": "r2qkbnr/ppp2pp1/2np3p/1B2p3/4P1b1/3P1N2/PPPN1PPP/R1BQ1RK1 b kq -", "prompt": "Given FEN: r2qkbnr/ppp2pp1/2np3p/1B2p3/4P1b1/3P1N2/PPPN1PPP/R1BQ1RK1 b kq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01020", "split": "rules", "task_type": "legality_check", "fen": "8/pp2k3/7r/2p1K2b/2P5/1P6/P5R1/8 b - - 11 54", "prompt": "FEN: 8/pp2k3/7r/2p1K2b/2P5/1P6/P5R1/8 b - - 11 54\nIs the move e7d6 legal?", "gold_answer": "No, illegal. Reason: king would be in check.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "e7d6", "_legality_check_reason_label": "king_would_be_in_check", "move": "e7d6", "legality_reason_label": "king_would_be_in_check"}}
{"example_id": "rules_01021", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "6rk/6pp/1Q3b2/1P3P2/P7/5N1P/2p2PK1/4R3 w - - 0 37", "prompt": "FEN: 6rk/6pp/1Q3b2/1P3P2/P7/5N1P/2p2PK1/4R3 w - - 0 37\nList pseudo-legal moves from e1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e1: e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1e8 e1f1 e1g1 e1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e1", "diagnostic": true, "hard_gate": false, "source_square": "e1"}}
{"example_id": "rules_01022", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2q1rk1/p3bpp1/2p1bn1p/2pp4/3P1B2/N1P2N2/PP2QPPP/R3R1K1 b - - 1 12", "prompt": "FEN: r2q1rk1/p3bpp1/2p1bn1p/2pp4/3P1B2/N1P2N2/PP2QPPP/R3R1K1 b - - 1 12\nFor the piece on c5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c5: c5c4 c5d4.\nLegal: c5c4 c5d4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_01023", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbqk1nr/p1p1bppp/1p1pp3/8/4P3/1P3P2/PBPP2PP/RN1QKBNR w KQkq - 2 5", "prompt": "FEN: rnbqk1nr/p1p1bppp/1p1pp3/8/4P3/1P3P2/PBPP2PP/RN1QKBNR w KQkq - 2 5\nFor move a2a3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a2a3.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a2a3", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a2a3", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01024", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/5p1p/4p1p1/3p4/6kP/6R1/2P4K/8 b - -", "prompt": "FEN: 8/5p1p/4p1p1/3p4/6kP/6R1/2P4K/8 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: g4 black king; d5 black pawn; e6 black pawn; g6 black pawn; f7 black pawn; h7 black pawn.\nMoves by piece:\ng4 black king: g4f4 g4f5 g4h4 g4h5\nd5 black pawn: no legal moves\ne6 black pawn: no legal moves\ng6 black pawn: no legal moves\nf7 black pawn: no legal moves\nh7 black pawn: no legal moves\nAll legal moves: g4f4 g4f5 g4h4 g4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"g4": ["g4f4", "g4f5", "g4h4", "g4h5"], "d5": [], "e6": [], "g6": [], "f7": [], "h7": []}, "_legal_moves_by_piece_moves": "g4f4 g4f5 g4h4 g4h5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"g4": ["g4f4", "g4f5", "g4h4", "g4h5"], "d5": [], "e6": [], "g6": [], "f7": [], "h7": []}, "legal_moves": "g4f4 g4f5 g4h4 g4h5"}}
{"example_id": "rules_01025", "split": "rules", "task_type": "ray_walk", "fen": "r2rb1k1/1p3ppp/1q2p3/1P2P3/N1pP4/b3PN2/2Q3PP/1R2R1K1 b - - 0 21", "prompt": "FEN: r2rb1k1/1p3ppp/1q2p3/1P2P3/N1pP4/b3PN2/2Q3PP/1R2R1K1 b - - 0 21\nWalk each ray for the slider on a3: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a3 black bishop.\nRay NE: b4 empty; c5 empty; d6 empty; e7 empty; f8 empty; edge.\nRay SE: b2 empty; c1 empty; edge.\nRay SW: edge.\nRay NW: edge.\nMoves from rays: a3b2 a3b4 a3c1 a3c5 a3d6 a3e7 a3f8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a3", "diagnostic": true, "hard_gate": false, "source_square": "a3"}}
{"example_id": "rules_01026", "split": "rules", "task_type": "legal_moves", "fen": "r6r/3nk2p/4p1p1/b1P2p2/1p1P4/3NPP2/P2B2PP/R2R2K1 b - - 3 27", "prompt": "FEN: r6r/3nk2p/4p1p1/b1P2p2/1p1P4/3NPP2/P2B2PP/R2R2K1 b - - 3 27\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a5b6 a5c7 a5d8 a8a6 a8a7 a8b8 a8c8 a8d8 a8e8 a8f8 a8g8 b4b3 d7b6 d7b8 d7c5 d7e5 d7f6 d7f8 e6e5 e7d8 e7e8 e7f6 e7f7 e7f8 f5f4 g6g5 h7h5 h7h6 h8b8 h8c8 h8d8 h8e8 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01027", "split": "rules", "task_type": "legal_moves", "fen": "r1bqk2r/pp1pppbp/2N2np1/8/2P1P3/2N5/PP3PPP/R1BQKB1R b KQkq -", "prompt": "FEN: r1bqk2r/pp1pppbp/2N2np1/8/2P1P3/2N5/PP3PPP/R1BQKB1R b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b7b5 b7b6 b7c6 d7c6 d7d5 d7d6 d8a5 d8b6 d8c7 e7e5 e7e6 e8f8 e8g8 f6d5 f6e4 f6g4 f6g8 f6h5 g6g5 g7f8 g7h6 h7h5 h7h6 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01028", "split": "rules", "task_type": "side_piece_inventory", "fen": "5r2/8/8/6K1/3k4/5r2/8/8 b - -", "prompt": "FEN: 5r2/8/8/6K1/3k4/5r2/8/8 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: f3 black rook; d4 black king; f8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "f3", "piece": "black rook"}, {"square": "d4", "piece": "black king"}, {"square": "f8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "f3", "piece": "black rook"}, {"square": "d4", "piece": "black king"}, {"square": "f8", "piece": "black rook"}]}}
{"example_id": "rules_01029", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bqk1nr/1ppp1ppp/1p4n1/8/4PP2/2P5/PP1N2PP/R2QKBNR w KQkq - 0 9", "prompt": "FEN: r1bqk1nr/1ppp1ppp/1p4n1/8/4PP2/2P5/PP1N2PP/R2QKBNR w KQkq - 0 9\nWhat legal moves does the piece on e4 have?", "gold_answer": "e4e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "e4", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "e4", "piece": "pawn"}}
{"example_id": "rules_01030", "split": "rules", "task_type": "check_detection", "fen": "6k1/1p2bp2/1p3p2/3p3p/3Pp2P/1PP3P1/rP3P2/1R3KN1 b - - 1 24", "prompt": "FEN: 6k1/1p2bp2/1p3p2/3p3p/3Pp2P/1PP3P1/rP3P2/1R3KN1 b - - 1 24\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01031", "split": "rules", "task_type": "captures", "fen": "r4rk1/ppp2pp1/1n3n1p/4NP2/2pPP2P/2P5/PP4P1/4RR1K b - - 4 24", "prompt": "FEN: r4rk1/ppp2pp1/1n3n1p/4NP2/2pPP2P/2P5/PP4P1/4RR1K b - - 4 24\nList all capture moves available.", "gold_answer": "f6e4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01032", "split": "rules", "task_type": "special_rules", "fen": "rn1qkbnr/ppp2ppp/8/3Np3/3pP1b1/2P2N2/PP1P1PPP/R1BQKB1R b KQkq -", "prompt": "Given FEN: rn1qkbnr/ppp2ppp/8/3Np3/3pP1b1/2P2N2/PP1P1PPP/R1BQKB1R b KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01033", "split": "rules", "task_type": "legality_check", "fen": "8/6pk/5p2/5P1P/1r3KR1/8/8/8 w - -", "prompt": "FEN: 8/6pk/5p2/5P1P/1r3KR1/8/8/8 w - -\nIs the move f4e3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f4e3", "_legality_check_reason_label": "legal", "move": "f4e3", "legality_reason_label": "legal"}}
{"example_id": "rules_01034", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r4rk1/1pq1npbp/p2p2p1/3Qp3/2P1P1bP/4BN2/P1P2PP1/1R2RBK1 w - -", "prompt": "FEN: r4rk1/1pq1npbp/p2p2p1/3Qp3/2P1P1bP/4BN2/P1P2PP1/1R2RBK1 w - -\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a1 b1b2 b1b3 b1b4 b1b5 b1b6 b1b7 b1c1 b1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01035", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1b1k2r/ppppqppp/5B2/4n3/1b2P3/2Q2N2/PPPN1PPP/R3KB1R b KQkq - 0 9", "prompt": "FEN: r1b1k2r/ppppqppp/5B2/4n3/1b2P3/2Q2N2/PPPN1PPP/R3KB1R b KQkq - 0 9\nFor the piece on b4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b4: b4a3 b4a5 b4c3 b4c5 b4d6.\nLegal: b4a3 b4a5 b4c3 b4c5 b4d6.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_01036", "split": "rules", "task_type": "king_safety_filter", "fen": "8/1r4kp/Q2p2p1/p1b2p2/1p1pbPn1/8/PP1BP3/K5R1 b - - 7 40", "prompt": "FEN: 8/1r4kp/Q2p2p1/p1b2p2/1p1pbPn1/8/PP1BP3/K5R1 b - - 7 40\nFor move a5a4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a5a4.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a5a4", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a5a4", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01037", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rn2kb1r/ppN2ppp/8/8/3p1Pb1/4PN1q/PP5P/R1BQKR2 b Qkq - 1 13", "prompt": "FEN: rn2kb1r/ppN2ppp/8/8/3p1Pb1/4PN1q/PP5P/R1BQKR2 b Qkq - 1 13\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: h3 black queen; d4 black pawn; g4 black bishop; a7 black pawn; b7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; e8 black king; f8 black bishop; h8 black rook.\nMoves by piece:\nh3 black queen: no legal moves\nd4 black pawn: no legal moves\ng4 black bishop: no legal moves\na7 black pawn: no legal moves\nb7 black pawn: no legal moves\nf7 black pawn: no legal moves\ng7 black pawn: no legal moves\nh7 black pawn: no legal moves\na8 black rook: no legal moves\nb8 black knight: no legal moves\ne8 black king: e8d7 e8d8 e8e7\nf8 black bishop: no legal moves\nh8 black rook: no legal moves\nAll legal moves: e8d7 e8d8 e8e7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"h3": [], "d4": [], "g4": [], "a7": [], "b7": [], "f7": [], "g7": [], "h7": [], "a8": [], "b8": [], "e8": ["e8d7", "e8d8", "e8e7"], "f8": [], "h8": []}, "_legal_moves_by_piece_moves": "e8d7 e8d8 e8e7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"h3": [], "d4": [], "g4": [], "a7": [], "b7": [], "f7": [], "g7": [], "h7": [], "a8": [], "b8": [], "e8": ["e8d7", "e8d8", "e8e7"], "f8": [], "h8": []}, "legal_moves": "e8d7 e8d8 e8e7"}}
{"example_id": "rules_01038", "split": "rules", "task_type": "ray_walk", "fen": "8/3kr3/6Q1/2K5/8/8/8/8 b - -", "prompt": "FEN: 8/3kr3/6Q1/2K5/8/8/8/8 b - -\nWalk each ray for the slider on e7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e7 black rook.\nRay N: e8 empty; edge.\nRay E: f7 empty; g7 empty; h7 empty; edge.\nRay S: e6 empty; e5 empty; e4 empty; e3 empty; e2 empty; e1 empty; edge.\nRay W: d7 black king: own piece (stop, excluded).\nMoves from rays: e7e1 e7e2 e7e3 e7e4 e7e5 e7e6 e7e8 e7f7 e7g7 e7h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "e7", "diagnostic": true, "hard_gate": false, "source_square": "e7"}}
{"example_id": "rules_01039", "split": "rules", "task_type": "legal_moves", "fen": "rn2kbnr/pp2pppp/2p5/3q4/3P4/3Q2N1/PPP2PPP/R1B1K1NR b KQkq -", "prompt": "FEN: rn2kbnr/pp2pppp/2p5/3q4/3P4/3Q2N1/PPP2PPP/R1B1K1NR b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8d7 c6c5 d5a2 d5a5 d5b3 d5b5 d5c4 d5c5 d5d4 d5d6 d5d7 d5d8 d5e4 d5e5 d5e6 d5f3 d5f5 d5g2 d5g5 d5h5 e7e5 e7e6 e8d7 e8d8 f7f5 f7f6 g7g5 g7g6 g8f6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01040", "split": "rules", "task_type": "legal_moves", "fen": "2rqr1k1/p4ppp/b4n2/2ppn3/8/P1P1PPN1/2B3PP/R1BQR1K1 w - -", "prompt": "FEN: 2rqr1k1/p4ppp/b4n2/2ppn3/8/P1P1PPN1/2B3PP/R1BQR1K1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1b1 a3a4 c1b2 c1d2 c2a4 c2b1 c2b3 c2d3 c2e4 c2f5 c2g6 c2h7 c3c4 d1d2 d1d3 d1d4 d1d5 d1e2 e1e2 e1f1 e3e4 f3f4 g1f2 g1h1 g3e2 g3e4 g3f1 g3f5 g3h1 g3h5 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01041", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqk2r/ppp1npbp/2np2p1/8/4PB2/3P2N1/PPP1B1PP/RN1Q1RK1 b kq - 0 8", "prompt": "FEN: r1bqk2r/ppp1npbp/2np2p1/8/4PB2/3P2N1/PPP1B1PP/RN1Q1RK1 b kq - 0 8\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c6 black knight; d6 black pawn; g6 black pawn; a7 black pawn; b7 black pawn; c7 black pawn; e7 black knight; f7 black pawn; g7 black bishop; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black king; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c6", "piece": "black knight"}, {"square": "d6", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "e7", "piece": "black knight"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black bishop"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c6", "piece": "black knight"}, {"square": "d6", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "e7", "piece": "black knight"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black bishop"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_01042", "split": "rules", "task_type": "piece_legal_moves", "fen": "1r6/3n4/p2k1pbp/K2P4/2P5/5P2/P6r/3R4 b - - 2 33", "prompt": "FEN: 1r6/3n4/p2k1pbp/K2P4/2P5/5P2/P6r/3R4 b - - 2 33\nWhat legal moves does the piece on a6 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a6", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a6", "piece": "pawn"}}
{"example_id": "rules_01043", "split": "rules", "task_type": "check_detection", "fen": "2kr3r/ppqb1ppp/2n1pn2/3p4/3P4/1BP2QPP/PP2N1P1/RN2K2R w KQ - 1 14", "prompt": "FEN: 2kr3r/ppqb1ppp/2n1pn2/3p4/3P4/1BP2QPP/PP2N1P1/RN2K2R w KQ - 1 14\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01044", "split": "rules", "task_type": "captures", "fen": "r1b2rk1/pppp1ppp/2N2q2/1Bb5/4Q3/8/PPPP1PPP/RNB2RK1 b - -", "prompt": "FEN: r1b2rk1/pppp1ppp/2N2q2/1Bb5/4Q3/8/PPPP1PPP/RNB2RK1 b - -\nList all capture moves available.", "gold_answer": "b7c6 c5f2 d7c6 f6b2 f6c6 f6f2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01045", "split": "rules", "task_type": "special_rules", "fen": "r1bqk1nr/ppppbppp/2n5/1B2p3/4P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4", "prompt": "Given FEN: r1bqk1nr/ppppbppp/2n5/1B2p3/4P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside.", "metric_type": "special_rules", "metadata": {"source": "lichess_openings", "is_chess960": false}}
{"example_id": "rules_01046", "split": "rules", "task_type": "legality_check", "fen": "8/8/3B4/p2kP3/1p6/P1P2K1R/1P6/8 w - - 0 45", "prompt": "FEN: 8/8/3B4/p2kP3/1p6/P1P2K1R/1P6/8 w - - 0 45\nIs the move f3g2 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f3g2", "_legality_check_reason_label": "legal", "move": "f3g2", "legality_reason_label": "legal"}}
{"example_id": "rules_01047", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1bq1rk1/1p1nb2p/p2p4/3P2p1/P4p2/N7/1PPBB1PP/R2Q1R1K b - -", "prompt": "FEN: r1bq1rk1/1p1nb2p/p2p4/3P2p1/P4p2/N7/1PPBB1PP/R2Q1R1K b - -\nList pseudo-legal moves from f4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from f4: f4f3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "f4", "diagnostic": true, "hard_gate": false, "source_square": "f4"}}
{"example_id": "rules_01048", "split": "rules", "task_type": "piece_legal_filter", "fen": "7R/kpK5/p7/3b4/8/P7/1P6/8 b - -", "prompt": "FEN: 7R/kpK5/p7/3b4/8/P7/1P6/8 b - -\nFor the piece on a7, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a7: a7a8 a7b6 a7b8.\nLegal: none.\nRejected: a7a8 king_would_be_in_check; a7b6 king_would_be_in_check; a7b8 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a7", "diagnostic": true, "hard_gate": false, "source_square": "a7"}}
{"example_id": "rules_01049", "split": "rules", "task_type": "king_safety_filter", "fen": "rnb1kbnr/pppp1p1p/4pq2/4P1p1/8/2N2N2/PPPP1PPP/R1BQKB1R b KQkq -", "prompt": "FEN: rnb1kbnr/pppp1p1p/4pq2/4P1p1/8/2N2N2/PPPP1PPP/R1BQKB1R b KQkq -\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01050", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1R1br3/3R4/k7/8/8/1KP5/P7/8 b - -", "prompt": "FEN: 1R1br3/3R4/k7/8/8/1KP5/P7/8 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a6 black king; d8 black bishop; e8 black rook.\nMoves by piece:\na6 black king: a6a5\nd8 black bishop: d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4\ne8 black rook: e8e1 e8e2 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 e8h8\nAll legal moves: a6a5 d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4 e8e1 e8e2 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 e8h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a6": ["a6a5"], "d8": ["d8a5", "d8b6", "d8c7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8e1", "e8e2", "e8e3", "e8e4", "e8e5", "e8e6", "e8e7", "e8f8", "e8g8", "e8h8"]}, "_legal_moves_by_piece_moves": "a6a5 d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4 e8e1 e8e2 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 e8h8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a6": ["a6a5"], "d8": ["d8a5", "d8b6", "d8c7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8e1", "e8e2", "e8e3", "e8e4", "e8e5", "e8e6", "e8e7", "e8f8", "e8g8", "e8h8"]}, "legal_moves": "a6a5 d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4 e8e1 e8e2 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 e8h8"}}
{"example_id": "rules_01051", "split": "rules", "task_type": "ray_walk", "fen": "rnbqk2r/pp3ppp/2p1pb2/3pP3/3P4/2N4P/PPP2PP1/R2QKBNR b KQkq - 0 7", "prompt": "FEN: rnbqk2r/pp3ppp/2p1pb2/3pP3/3P4/2N4P/PPP2PP1/R2QKBNR b KQkq - 0 7\nWalk each ray for the slider on f6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: f6 black bishop.\nRay NE: g7 black pawn: own piece (stop, excluded).\nRay SE: g5 empty; h4 empty; edge.\nRay SW: e5 white pawn: capture (stop, included).\nRay NW: e7 empty; d8 black queen: own piece (stop, excluded).\nMoves from rays: f6e5 f6e7 f6g5 f6h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "f6", "diagnostic": true, "hard_gate": false, "source_square": "f6"}}
{"example_id": "rules_01052", "split": "rules", "task_type": "legal_filter_trace", "fen": "2r3k1/p4pp1/1p2pb2/4q3/8/P7/3R1PPP/5K2 w - - 3 34", "prompt": "FEN: 2r3k1/p4pp1/1p2pb2/4q3/8/P7/3R1PPP/5K2 w - - 3 34\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: f1 white king; d2 white rook; f2 white pawn; g2 white pawn; h2 white pawn; a3 white pawn.\nFilter by piece:\nf1 white king: pseudo-legal f1e1 f1e2 f1g1 | rejected f1e1 king_would_be_in_check; f1e2 king_would_be_in_check | legal f1g1\nd2 white rook: pseudo-legal d2a2 d2b2 d2c2 d2d1 d2d3 d2d4 d2d5 d2d6 d2d7 d2d8 d2e2 | rejected none | legal d2a2 d2b2 d2c2 d2d1 d2d3 d2d4 d2d5 d2d6 d2d7 d2d8 d2e2\nf2 white pawn: pseudo-legal f2f3 f2f4 | rejected none | legal f2f3 f2f4\ng2 white pawn: pseudo-legal g2g3 g2g4 | rejected none | legal g2g3 g2g4\nh2 white pawn: pseudo-legal h2h3 h2h4 | rejected none | legal h2h3 h2h4\na3 white pawn: pseudo-legal a3a4 | rejected none | legal a3a4\nAll legal moves: a3a4 d2a2 d2b2 d2c2 d2d1 d2d3 d2d4 d2d5 d2d6 d2d7 d2d8 d2e2 f1g1 f2f3 f2f4 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01053", "split": "rules", "task_type": "legal_moves", "fen": "k3b3/8/5Kp1/1p6/P3q2p/8/8/8 w - - 0 61", "prompt": "FEN: k3b3/8/5Kp1/1p6/P3q2p/8/8/8 w - - 0 61\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a4a5 a4b5 f6g5 f6g7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01054", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqkbnr/p1pp1ppp/1pn1p3/8/2BPP3/2P5/PP3PPP/RNBQK1NR b KQkq - 0 4", "prompt": "FEN: r1bqkbnr/p1pp1ppp/1pn1p3/8/2BPP3/2P5/PP3PPP/RNBQK1NR b KQkq - 0 4\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: b6 black pawn; c6 black knight; e6 black pawn; a7 black pawn; c7 black pawn; d7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "b6", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "e6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "d7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "b6", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "e6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "d7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_01055", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnbq3r/ppp1bkpp/5n2/3p4/2BPP3/8/PPP2PPP/RNBQK2R w KQ -", "prompt": "FEN: rnbq3r/ppp1bkpp/5n2/3p4/2BPP3/8/PPP2PPP/RNBQK2R w KQ -\nWhat legal moves does the piece on g2 have?", "gold_answer": "g2g3 g2g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "g2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g2", "piece": "pawn"}}
{"example_id": "rules_01056", "split": "rules", "task_type": "check_detection", "fen": "4k3/5r2/2KQ4/8/8/8/8/8 w - -", "prompt": "FEN: 4k3/5r2/2KQ4/8/8/8/8/8 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01057", "split": "rules", "task_type": "captures", "fen": "r2qk2r/pp3ppp/2p5/b1P5/3PnP2/BP1QP3/P5PP/R4RK1 b kq - 0 16", "prompt": "FEN: r2qk2r/pp3ppp/2p5/b1P5/3PnP2/BP1QP3/P5PP/R4RK1 b kq - 0 16\nList all capture moves available.", "gold_answer": "d8d4 e4c5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01058", "split": "rules", "task_type": "special_rules", "fen": "r1bqk1nr/pp1pppbp/2n3p1/1B6/4P3/1N6/PPP2PPP/RNBQK2R b KQkq -", "prompt": "Given FEN: r1bqk1nr/pp1pppbp/2n3p1/1B6/4P3/1N6/PPP2PPP/RNBQK2R b KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01059", "split": "rules", "task_type": "legality_check", "fen": "r1bqkb1r/pp1p1ppp/2n1pn2/2p5/4P3/5N2/PPPPBPPP/RNBQ1RK1 w kq -", "prompt": "FEN: r1bqkb1r/pp1p1ppp/2n1pn2/2p5/4P3/5N2/PPPPBPPP/RNBQ1RK1 w kq -\nIs the move e4e5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "e4e5", "_legality_check_reason_label": "legal", "move": "e4e5", "legality_reason_label": "legal"}}
{"example_id": "rules_01060", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1bq1rk1/pp1n1pbp/3p2p1/6Pn/P2P1p2/1PP4P/4B3/RNBQK1NR b KQ - 1 12", "prompt": "FEN: r1bq1rk1/pp1n1pbp/3p2p1/6Pn/P2P1p2/1PP4P/4B3/RNBQK1NR b KQ - 1 12\nList pseudo-legal moves from f4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from f4: f4f3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "f4", "diagnostic": true, "hard_gate": false, "source_square": "f4"}}
{"example_id": "rules_01061", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/1kp5/8/8/4q2p/7P/6P1/5q1K w - - 0 51", "prompt": "FEN: 8/1kp5/8/8/4q2p/7P/6P1/5q1K w - - 0 51\nFor the piece on h1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from h1: h1g1 h1h2.\nLegal: h1h2.\nRejected: h1g1 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "h1", "diagnostic": true, "hard_gate": false, "source_square": "h1"}}
{"example_id": "rules_01062", "split": "rules", "task_type": "king_safety_filter", "fen": "5k2/8/5KQ1/8/8/8/8/8 w - -", "prompt": "FEN: 5k2/8/5KQ1/8/8/8/8/8 w - -\nFor move f6e7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: f6e7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "f6e7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "f6e7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01063", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1Q4k1/6pp/p3p3/6P1/2Pr1r1P/3p1BK1/8/8 b - - 1 44", "prompt": "FEN: 1Q4k1/6pp/p3p3/6P1/2Pr1r1P/3p1BK1/8/8 b - - 1 44\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d3 black pawn; d4 black rook; f4 black rook; a6 black pawn; e6 black pawn; g7 black pawn; h7 black pawn; g8 black king.\nMoves by piece:\nd3 black pawn: no legal moves\nd4 black rook: d4d8\nf4 black rook: f4f8\na6 black pawn: no legal moves\ne6 black pawn: no legal moves\ng7 black pawn: no legal moves\nh7 black pawn: no legal moves\ng8 black king: g8f7\nAll legal moves: d4d8 f4f8 g8f7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d3": [], "d4": ["d4d8"], "f4": ["f4f8"], "a6": [], "e6": [], "g7": [], "h7": [], "g8": ["g8f7"]}, "_legal_moves_by_piece_moves": "d4d8 f4f8 g8f7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d3": [], "d4": ["d4d8"], "f4": ["f4f8"], "a6": [], "e6": [], "g7": [], "h7": [], "g8": ["g8f7"]}, "legal_moves": "d4d8 f4f8 g8f7"}}
{"example_id": "rules_01064", "split": "rules", "task_type": "ray_walk", "fen": "8/p4R1p/7k/1p5P/3p2P1/3b4/PPr1r1B1/3R2K1 w - -", "prompt": "FEN: 8/p4R1p/7k/1p5P/3p2P1/3b4/PPr1r1B1/3R2K1 w - -\nWalk each ray for the slider on d1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d1 white rook.\nRay N: d2 empty; d3 black bishop: capture (stop, included).\nRay E: e1 empty; f1 empty; g1 white king: own piece (stop, excluded).\nRay S: edge.\nRay W: c1 empty; b1 empty; a1 empty; edge.\nMoves from rays: d1a1 d1b1 d1c1 d1d2 d1d3 d1e1 d1f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_01065", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/1k4p1/4N1N1/2K5/8/8/8/8 b - -", "prompt": "FEN: 8/1k4p1/4N1N1/2K5/8/8/8/8 b - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b7 black king; g7 black pawn.\nFilter by piece:\nb7 black king: pseudo-legal b7a6 b7a7 b7a8 b7b6 b7b8 b7c6 b7c7 b7c8 | rejected b7b6 king_would_be_in_check; b7c6 king_would_be_in_check; b7c7 king_would_be_in_check | legal b7a6 b7a7 b7a8 b7b8 b7c8\ng7 black pawn: pseudo-legal none | rejected none | legal none\nAll legal moves: b7a6 b7a7 b7a8 b7b8 b7c8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01066", "split": "rules", "task_type": "legal_moves", "fen": "r2qk2r/1p2ppb1/p3b1pp/n2nN3/P1pP1B2/2N2B2/1P3PPP/R2Q1RK1 w kq -", "prompt": "FEN: r2qk2r/1p2ppb1/p3b1pp/n2nN3/P1pP1B2/2N2B2/1P3PPP/R2Q1RK1 w kq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 a1b1 a1c1 b2b3 b2b4 c3a2 c3b1 c3b5 c3d5 c3e2 c3e4 d1b1 d1b3 d1c1 d1c2 d1d2 d1d3 d1e1 d1e2 e5c4 e5c6 e5d3 e5d7 e5f7 e5g4 e5g6 f1e1 f3d5 f3e2 f3e4 f3g4 f3h5 f4c1 f4d2 f4e3 f4g3 f4g5 f4h6 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01067", "split": "rules", "task_type": "side_piece_inventory", "fen": "r3q1k1/ppp2rp1/2npb3/4p1Bp/4P2P/P1P1NP2/1PPKB3/R5R1 b - - 11 20", "prompt": "FEN: r3q1k1/ppp2rp1/2npb3/4p1Bp/4P2P/P1P1NP2/1PPKB3/R5R1 b - - 11 20\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: e5 black pawn; h5 black pawn; c6 black knight; d6 black pawn; e6 black bishop; a7 black pawn; b7 black pawn; c7 black pawn; f7 black rook; g7 black pawn; a8 black rook; e8 black queen; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "h5", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "d6", "piece": "black pawn"}, {"square": "e6", "piece": "black bishop"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black rook"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "e8", "piece": "black queen"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "h5", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "d6", "piece": "black pawn"}, {"square": "e6", "piece": "black bishop"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black rook"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "e8", "piece": "black queen"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01068", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnbqkb1r/pppppppp/8/2nPP3/2P5/4B3/PP3PPP/RN1QKBNR b KQkq - 2 6", "prompt": "FEN: rnbqkb1r/pppppppp/8/2nPP3/2P5/4B3/PP3PPP/RN1QKBNR b KQkq - 2 6\nWhat legal moves does the piece on c8 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c8", "_piece_legal_moves_piece": "bishop", "diagnostic": true, "hard_gate": false, "source_square": "c8", "piece": "bishop"}}
{"example_id": "rules_01069", "split": "rules", "task_type": "check_detection", "fen": "rn2kb1r/ppp3q1/3p1p2/4Pn2/2P4p/5B2/PP3PPP/RNBQ1RK1 b kq - 0 13", "prompt": "FEN: rn2kb1r/ppp3q1/3p1p2/4Pn2/2P4p/5B2/PP3PPP/RNBQ1RK1 b kq - 0 13\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01070", "split": "rules", "task_type": "captures", "fen": "6r1/k2b1p2/Pp1p4/3PpP2/2P1P1pr/1N2b1N1/4KnBP/RR6 b - - 13 36", "prompt": "FEN: 6r1/k2b1p2/Pp1p4/3PpP2/2P1P1pr/1N2b1N1/4KnBP/RR6 b - - 13 36\nList all capture moves available.", "gold_answer": "d7f5 f2e4 h4h2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01071", "split": "rules", "task_type": "special_rules", "fen": "r4rk1/pp1n4/2q3B1/3pP3/3B1P2/2P5/PPQ4P/6RK b - -", "prompt": "Given FEN: r4rk1/pp1n4/2q3B1/3pP3/3B1P2/2P5/PPQ4P/6RK b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01072", "split": "rules", "task_type": "legality_check", "fen": "2r5/8/5p2/1P2p3/1K2k2P/6P1/3p4/1R6 w - - 0 64", "prompt": "FEN: 2r5/8/5p2/1P2p3/1K2k2P/6P1/3p4/1R6 w - - 0 64\nIs the move b1b2 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b1b2", "_legality_check_reason_label": "legal", "move": "b1b2", "legality_reason_label": "legal"}}
{"example_id": "rules_01073", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r6Q/1kp2p1p/pb1p4/1p1P4/1P6/1B3N2/1P3PPP/RN4K1 w - - 1 23", "prompt": "FEN: r6Q/1kp2p1p/pb1p4/1p1P4/1P6/1B3N2/1P3PPP/RN4K1 w - - 1 23\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1a2 a1a3 a1a4 a1a5 a1a6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01074", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/p1k5/3r4/4r2p/pK6/1P6/8/8 w - - 0 53", "prompt": "FEN: 8/p1k5/3r4/4r2p/pK6/1P6/8/8 w - - 0 53\nFor the piece on b4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b4: b4a3 b4a4 b4a5 b4b5 b4c3 b4c4 b4c5.\nLegal: b4a3 b4a4 b4c3 b4c4.\nRejected: b4a5 king_would_be_in_check; b4b5 king_would_be_in_check; b4c5 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_01075", "split": "rules", "task_type": "king_safety_filter", "fen": "r2qk2r/pb1nbppp/1pp1pn2/P2p4/3N4/1P2P1P1/1BPPQPBP/RN2K2R b KQkq - 0 10", "prompt": "FEN: r2qk2r/pb1nbppp/1pp1pn2/P2p4/3N4/1P2P1P1/1BPPQPBP/RN2K2R b KQkq - 0 10\nFor move a7a6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a6.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a6", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a6", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01076", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnbq1rk1/1pp1ppbp/1n1p2p1/p3P3/P2P4/1B3N1P/1PPN1PP1/R1BQK2R b KQ -", "prompt": "FEN: rnbq1rk1/1pp1ppbp/1n1p2p1/p3P3/P2P4/1B3N1P/1PPN1PP1/R1BQK2R b KQ -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a5 black pawn; b6 black knight; d6 black pawn; g6 black pawn; b7 black pawn; c7 black pawn; e7 black pawn; f7 black pawn; g7 black bishop; h7 black pawn; a8 black rook; b8 black knight; c8 black bishop; d8 black queen; f8 black rook; g8 black king.\nMoves by piece:\na5 black pawn: no legal moves\nb6 black knight: b6a4 b6c4 b6d5 b6d7\nd6 black pawn: d6d5 d6e5\ng6 black pawn: g6g5\nb7 black pawn: no legal moves\nc7 black pawn: c7c5 c7c6\ne7 black pawn: e7e6\nf7 black pawn: no legal moves\ng7 black bishop: g7e5 g7f6 g7h6 g7h8\nh7 black pawn: h7h5 h7h6\na8 black rook: a8a6 a8a7\nb8 black knight: b8a6 b8c6 b8d7\nc8 black bishop: c8d7 c8e6 c8f5 c8g4 c8h3\nd8 black queen: d8d7 d8e8\nf8 black rook: f8e8\ng8 black king: g8h8\nAll legal moves: a8a6 a8a7 b6a4 b6c4 b6d5 b6d7 b8a6 b8c6 b8d7 c7c5 c7c6 c8d7 c8e6 c8f5 c8g4 c8h3 d6d5 d6e5 d8d7 d8e8 e7e6 f8e8 g6g5 g7e5 g7f6 g7h6 g7h8 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a5": [], "b6": ["b6a4", "b6c4", "b6d5", "b6d7"], "d6": ["d6d5", "d6e5"], "g6": ["g6g5"], "b7": [], "c7": ["c7c5", "c7c6"], "e7": ["e7e6"], "f7": [], "g7": ["g7e5", "g7f6", "g7h6", "g7h8"], "h7": ["h7h5", "h7h6"], "a8": ["a8a6", "a8a7"], "b8": ["b8a6", "b8c6", "b8d7"], "c8": ["c8d7", "c8e6", "c8f5", "c8g4", "c8h3"], "d8": ["d8d7", "d8e8"], "f8": ["f8e8"], "g8": ["g8h8"]}, "_legal_moves_by_piece_moves": "a8a6 a8a7 b6a4 b6c4 b6d5 b6d7 b8a6 b8c6 b8d7 c7c5 c7c6 c8d7 c8e6 c8f5 c8g4 c8h3 d6d5 d6e5 d8d7 d8e8 e7e6 f8e8 g6g5 g7e5 g7f6 g7h6 g7h8 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a5": [], "b6": ["b6a4", "b6c4", "b6d5", "b6d7"], "d6": ["d6d5", "d6e5"], "g6": ["g6g5"], "b7": [], "c7": ["c7c5", "c7c6"], "e7": ["e7e6"], "f7": [], "g7": ["g7e5", "g7f6", "g7h6", "g7h8"], "h7": ["h7h5", "h7h6"], "a8": ["a8a6", "a8a7"], "b8": ["b8a6", "b8c6", "b8d7"], "c8": ["c8d7", "c8e6", "c8f5", "c8g4", "c8h3"], "d8": ["d8d7", "d8e8"], "f8": ["f8e8"], "g8": ["g8h8"]}, "legal_moves": "a8a6 a8a7 b6a4 b6c4 b6d5 b6d7 b8a6 b8c6 b8d7 c7c5 c7c6 c8d7 c8e6 c8f5 c8g4 c8h3 d6d5 d6e5 d8d7 d8e8 e7e6 f8e8 g6g5 g7e5 g7f6 g7h6 g7h8 g8h8 h7h5 h7h6"}}
{"example_id": "rules_01077", "split": "rules", "task_type": "ray_walk", "fen": "8/3r3p/R5pk/5p2/4p2P/6P1/4KP2/8 b - -", "prompt": "FEN: 8/3r3p/R5pk/5p2/4p2P/6P1/4KP2/8 b - -\nWalk each ray for the slider on d7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d7 black rook.\nRay N: d8 empty; edge.\nRay E: e7 empty; f7 empty; g7 empty; h7 black pawn: own piece (stop, excluded).\nRay S: d6 empty; d5 empty; d4 empty; d3 empty; d2 empty; d1 empty; edge.\nRay W: c7 empty; b7 empty; a7 empty; edge.\nMoves from rays: d7a7 d7b7 d7c7 d7d1 d7d2 d7d3 d7d4 d7d5 d7d6 d7d8 d7e7 d7f7 d7g7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "d7", "diagnostic": true, "hard_gate": false, "source_square": "d7"}}
{"example_id": "rules_01078", "split": "rules", "task_type": "legal_filter_trace", "fen": "6R1/8/8/P1p1n3/2P2k2/2K3p1/8/8 w - - 0 43", "prompt": "FEN: 6R1/8/8/P1p1n3/2P2k2/2K3p1/8/8 w - - 0 43\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c3 white king; c4 white pawn; a5 white pawn; g8 white rook.\nFilter by piece:\nc3 white king: pseudo-legal c3b2 c3b3 c3b4 c3c2 c3d2 c3d3 c3d4 | rejected c3b4 king_would_be_in_check; c3d3 king_would_be_in_check; c3d4 king_would_be_in_check | legal c3b2 c3b3 c3c2 c3d2\nc4 white pawn: pseudo-legal none | rejected none | legal none\na5 white pawn: pseudo-legal a5a6 | rejected none | legal a5a6\ng8 white rook: pseudo-legal g8a8 g8b8 g8c8 g8d8 g8e8 g8f8 g8g3 g8g4 g8g5 g8g6 g8g7 g8h8 | rejected none | legal g8a8 g8b8 g8c8 g8d8 g8e8 g8f8 g8g3 g8g4 g8g5 g8g6 g8g7 g8h8\nAll legal moves: a5a6 c3b2 c3b3 c3c2 c3d2 g8a8 g8b8 g8c8 g8d8 g8e8 g8f8 g8g3 g8g4 g8g5 g8g6 g8g7 g8h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01079", "split": "rules", "task_type": "legal_moves", "fen": "5R2/pppkp2p/6p1/4n3/N5P1/1P6/P1r3P1/R5K1 b - - 1 22", "prompt": "FEN: 5R2/pppkp2p/6p1/4n3/N5P1/1P6/P1r3P1/R5K1 b - - 1 22\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 c2a2 c2b2 c2c1 c2c3 c2c4 c2c5 c2c6 c2d2 c2e2 c2f2 c2g2 c7c5 c7c6 d7c6 d7d6 d7e6 e5c4 e5c6 e5d3 e5f3 e5f7 e5g4 e7e6 g6g5 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01080", "split": "rules", "task_type": "side_piece_inventory", "fen": "1k1r3r/1bq2p2/p4p2/3NpP2/7p/1B1Q2P1/PPP4P/1K2R3 b - -", "prompt": "FEN: 1k1r3r/1bq2p2/p4p2/3NpP2/7p/1B1Q2P1/PPP4P/1K2R3 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: h4 black pawn; e5 black pawn; a6 black pawn; f6 black pawn; b7 black bishop; c7 black queen; f7 black pawn; b8 black king; d8 black rook; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "h4", "piece": "black pawn"}, {"square": "e5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "b7", "piece": "black bishop"}, {"square": "c7", "piece": "black queen"}, {"square": "f7", "piece": "black pawn"}, {"square": "b8", "piece": "black king"}, {"square": "d8", "piece": "black rook"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "h4", "piece": "black pawn"}, {"square": "e5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "b7", "piece": "black bishop"}, {"square": "c7", "piece": "black queen"}, {"square": "f7", "piece": "black pawn"}, {"square": "b8", "piece": "black king"}, {"square": "d8", "piece": "black rook"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_01081", "split": "rules", "task_type": "piece_legal_moves", "fen": "r2q1rk1/2p2pp1/p1p2n1p/3p1P2/1b4PB/2N4P/PPP2P2/R2Q1RK1 w - - 1 15", "prompt": "FEN: r2q1rk1/2p2pp1/p1p2n1p/3p1P2/1b4PB/2N4P/PPP2P2/R2Q1RK1 w - - 1 15\nWhat legal moves does the piece on b2 have?", "gold_answer": "b2b3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "b2", "piece": "pawn"}}
{"example_id": "rules_01082", "split": "rules", "task_type": "check_detection", "fen": "4r2k/1p3qpp/8/p1QPr1b1/3Rp3/1P3P2/1P3P1P/3R2NK b - -", "prompt": "FEN: 4r2k/1p3qpp/8/p1QPr1b1/3Rp3/1P3P2/1P3P1P/3R2NK b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01083", "split": "rules", "task_type": "captures", "fen": "rn3rk1/1b3ppp/p3pn2/1pb5/8/2N1PN2/PP3PPP/R1BBK2R b KQ - 3 12", "prompt": "FEN: rn3rk1/1b3ppp/p3pn2/1pb5/8/2N1PN2/PP3PPP/R1BBK2R b KQ - 3 12\nList all capture moves available.", "gold_answer": "b7f3 c5e3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01084", "split": "rules", "task_type": "special_rules", "fen": "2R2rk1/1p1b1ppp/p3p3/3pP2B/1b1P4/1P2P1P1/1P1N3P/5RK1 b - - 0 20", "prompt": "Given FEN: 2R2rk1/1p1b1ppp/p3p3/3pP2B/1b1P4/1P2P1P1/1P1N3P/5RK1 b - - 0 20\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01085", "split": "rules", "task_type": "legality_check", "fen": "1r6/p3k1pp/3p4/bP2pb1n/P1Pp1pP1/B2P1P2/2RNP2P/4R1K1 b - - 0 23", "prompt": "FEN: 1r6/p3k1pp/3p4/bP2pb1n/P1Pp1pP1/B2P1P2/2RNP2P/4R1K1 b - - 0 23\nIs the move b8a8 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b8a8", "_legality_check_reason_label": "legal", "move": "b8a8", "legality_reason_label": "legal"}}
{"example_id": "rules_01086", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1b1kb1r/1p1n1p1p/2p1p1p1/3p4/qp1P4/N1PBP3/PB1Q1PPP/R3K2R w KQkq - 0 13", "prompt": "FEN: r1b1kb1r/1p1n1p1p/2p1p1p1/3p4/qp1P4/N1PBP3/PB1Q1PPP/R3K2R w KQkq - 0 13\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1 a1c1 a1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01087", "split": "rules", "task_type": "piece_legal_filter", "fen": "r4rk1/p3Rppp/3P1n2/1pp5/2Bp4/3P2Pb/PPPN1P1P/4R1K1 w - - 0 19", "prompt": "FEN: r4rk1/p3Rppp/3P1n2/1pp5/2Bp4/3P2Pb/PPPN1P1P/4R1K1 w - - 0 19\nFor the piece on g1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g1: g1f1 g1g2 g1h1.\nLegal: g1h1.\nRejected: g1f1 king_would_be_in_check; g1g2 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g1", "diagnostic": true, "hard_gate": false, "source_square": "g1"}}
{"example_id": "rules_01088", "split": "rules", "task_type": "king_safety_filter", "fen": "r3kb1r/pp1npppp/2p5/8/P3P1b1/3P1N2/1PP3PP/R1B1KB1R w KQkq -", "prompt": "FEN: r3kb1r/pp1npppp/2p5/8/P3P1b1/3P1N2/1PP3PP/R1B1KB1R w KQkq -\nFor move a1a2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1a2.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a1a2", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1a2", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01089", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r3k2r/pppbq1pp/2np1p1n/4p3/1b3P2/2NPP1P1/PPPBQ1BP/2KR2NR b kq - 6 9", "prompt": "FEN: r3k2r/pppbq1pp/2np1p1n/4p3/1b3P2/2NPP1P1/PPPBQ1BP/2KR2NR b kq - 6 9\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b4 black bishop; e5 black pawn; c6 black knight; d6 black pawn; f6 black pawn; h6 black knight; a7 black pawn; b7 black pawn; c7 black pawn; d7 black bishop; e7 black queen; g7 black pawn; h7 black pawn; a8 black rook; e8 black king; h8 black rook.\nMoves by piece:\nb4 black bishop: b4a3 b4a5 b4c3 b4c5\ne5 black pawn: e5e4 e5f4\nc6 black knight: c6a5 c6b8 c6d4 c6d8\nd6 black pawn: d6d5\nf6 black pawn: f6f5\nh6 black knight: h6f5 h6f7 h6g4 h6g8\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nc7 black pawn: no legal moves\nd7 black bishop: d7c8 d7e6 d7f5 d7g4 d7h3\ne7 black queen: e7d8 e7e6 e7f7 e7f8\ng7 black pawn: g7g5 g7g6\nh7 black pawn: no legal moves\na8 black rook: a8b8 a8c8 a8d8\ne8 black king: e8c8 e8d8 e8f7 e8f8 e8g8\nh8 black rook: h8f8 h8g8\nAll legal moves: a7a5 a7a6 a8b8 a8c8 a8d8 b4a3 b4a5 b4c3 b4c5 b7b5 b7b6 c6a5 c6b8 c6d4 c6d8 d6d5 d7c8 d7e6 d7f5 d7g4 d7h3 e5e4 e5f4 e7d8 e7e6 e7f7 e7f8 e8c8 e8d8 e8f7 e8f8 e8g8 f6f5 g7g5 g7g6 h6f5 h6f7 h6g4 h6g8 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b4": ["b4a3", "b4a5", "b4c3", "b4c5"], "e5": ["e5e4", "e5f4"], "c6": ["c6a5", "c6b8", "c6d4", "c6d8"], "d6": ["d6d5"], "f6": ["f6f5"], "h6": ["h6f5", "h6f7", "h6g4", "h6g8"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": [], "d7": ["d7c8", "d7e6", "d7f5", "d7g4", "d7h3"], "e7": ["e7d8", "e7e6", "e7f7", "e7f8"], "g7": ["g7g5", "g7g6"], "h7": [], "a8": ["a8b8", "a8c8", "a8d8"], "e8": ["e8c8", "e8d8", "e8f7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 a8c8 a8d8 b4a3 b4a5 b4c3 b4c5 b7b5 b7b6 c6a5 c6b8 c6d4 c6d8 d6d5 d7c8 d7e6 d7f5 d7g4 d7h3 e5e4 e5f4 e7d8 e7e6 e7f7 e7f8 e8c8 e8d8 e8f7 e8f8 e8g8 f6f5 g7g5 g7g6 h6f5 h6f7 h6g4 h6g8 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b4": ["b4a3", "b4a5", "b4c3", "b4c5"], "e5": ["e5e4", "e5f4"], "c6": ["c6a5", "c6b8", "c6d4", "c6d8"], "d6": ["d6d5"], "f6": ["f6f5"], "h6": ["h6f5", "h6f7", "h6g4", "h6g8"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": [], "d7": ["d7c8", "d7e6", "d7f5", "d7g4", "d7h3"], "e7": ["e7d8", "e7e6", "e7f7", "e7f8"], "g7": ["g7g5", "g7g6"], "h7": [], "a8": ["a8b8", "a8c8", "a8d8"], "e8": ["e8c8", "e8d8", "e8f7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "legal_moves": "a7a5 a7a6 a8b8 a8c8 a8d8 b4a3 b4a5 b4c3 b4c5 b7b5 b7b6 c6a5 c6b8 c6d4 c6d8 d6d5 d7c8 d7e6 d7f5 d7g4 d7h3 e5e4 e5f4 e7d8 e7e6 e7f7 e7f8 e8c8 e8d8 e8f7 e8f8 e8g8 f6f5 g7g5 g7g6 h6f5 h6f7 h6g4 h6g8 h8f8 h8g8"}}
{"example_id": "rules_01090", "split": "rules", "task_type": "ray_walk", "fen": "r1bq1rk1/p2nb1pp/2n1p3/1p1pP3/2pP4/2N1BN2/PPPQ2PP/2KR1B1R w - -", "prompt": "FEN: r1bq1rk1/p2nb1pp/2n1p3/1p1pP3/2pP4/2N1BN2/PPPQ2PP/2KR1B1R w - -\nWalk each ray for the slider on d1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d1 white rook.\nRay N: d2 white queen: own piece (stop, excluded).\nRay E: e1 empty; f1 white bishop: own piece (stop, excluded).\nRay S: edge.\nRay W: c1 white king: own piece (stop, excluded).\nMoves from rays: d1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_01091", "split": "rules", "task_type": "legal_moves", "fen": "rnbqkbnr/pp1p1ppp/3Pp3/2p5/8/8/PPP1PPPP/RNBQKBNR b KQkq - 0 3", "prompt": "FEN: rnbqkbnr/pp1p1ppp/3Pp3/2p5/8/8/PPP1PPPP/RNBQKBNR b KQkq - 0 3\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 c5c4 d8a5 d8b6 d8c7 d8e7 d8f6 d8g5 d8h4 e6e5 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01092", "split": "rules", "task_type": "legal_moves", "fen": "r1bqkb1r/pp1np1p1/2p1pn1p/7Q/3P4/3B4/PPP2PPP/R1B1K1NR b KQkq -", "prompt": "FEN: r1bqkb1r/pp1np1p1/2p1pn1p/7Q/3P4/3B4/PPP2PPP/R1B1K1NR b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: f6h5 g7g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01093", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/8/3k1p2/3pp1p1/3Pn1P1/4R2P/r3N3/5K2 b - -", "prompt": "FEN: 8/8/3k1p2/3pp1p1/3Pn1P1/4R2P/r3N3/5K2 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: a2 black rook; e4 black knight; d5 black pawn; e5 black pawn; g5 black pawn; d6 black king; f6 black pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "a2", "piece": "black rook"}, {"square": "e4", "piece": "black knight"}, {"square": "d5", "piece": "black pawn"}, {"square": "e5", "piece": "black pawn"}, {"square": "g5", "piece": "black pawn"}, {"square": "d6", "piece": "black king"}, {"square": "f6", "piece": "black pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "a2", "piece": "black rook"}, {"square": "e4", "piece": "black knight"}, {"square": "d5", "piece": "black pawn"}, {"square": "e5", "piece": "black pawn"}, {"square": "g5", "piece": "black pawn"}, {"square": "d6", "piece": "black king"}, {"square": "f6", "piece": "black pawn"}]}}
{"example_id": "rules_01094", "split": "rules", "task_type": "piece_legal_moves", "fen": "3rk2r/5ppp/1q2pn2/1pb5/2p5/2N2QP1/1P2PP1P/R1B2RK1 w k -", "prompt": "FEN: 3rk2r/5ppp/1q2pn2/1pb5/2p5/2N2QP1/1P2PP1P/R1B2RK1 w k -\nWhat legal moves does the piece on f3 have?", "gold_answer": "f3a8 f3b7 f3c6 f3d3 f3d5 f3e3 f3e4 f3f4 f3f5 f3f6 f3g2 f3g4 f3h1 f3h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f3", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "f3", "piece": "queen"}}
{"example_id": "rules_01095", "split": "rules", "task_type": "check_detection", "fen": "r2r2k1/p4ppp/2p2b2/2Pp1Q2/q7/7P/3B1PP1/2R1R1K1 b - - 6 24", "prompt": "FEN: r2r2k1/p4ppp/2p2b2/2Pp1Q2/q7/7P/3B1PP1/2R1R1K1 b - - 6 24\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01096", "split": "rules", "task_type": "captures", "fen": "r2qkb1r/pp2np1p/2n1b1p1/3N4/2B5/5N2/PP3PPP/R1BQ1RK1 w kq -", "prompt": "FEN: r2qkb1r/pp2np1p/2n1b1p1/3N4/2B5/5N2/PP3PPP/R1BQ1RK1 w kq -\nList all capture moves available.", "gold_answer": "d5e7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01097", "split": "rules", "task_type": "special_rules", "fen": "4k3/1p6/1P4R1/1r6/7P/6P1/5PK1/8 b - - 0 54", "prompt": "Given FEN: 4k3/1p6/1P4R1/1r6/7P/6P1/5PK1/8 b - - 0 54\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01098", "split": "rules", "task_type": "legality_check", "fen": "3Q4/8/8/2B5/2K1Q3/8/8/2k5 w - - 5 65", "prompt": "FEN: 3Q4/8/8/2B5/2K1Q3/8/8/2k5 w - - 5 65\nIs the move c5d8 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c5d8", "_legality_check_reason_label": "own_piece_destination", "move": "c5d8", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_01099", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r3kb1r/pb1n1ppp/1qp1pn2/1p4N1/P1pP4/2N3P1/1P2PPBP/R1BQ1RK1 w kq -", "prompt": "FEN: r3kb1r/pb1n1ppp/1qp1pn2/1p4N1/P1pP4/2N3P1/1P2PPBP/R1BQ1RK1 w kq -\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1a2 a1a3 a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01100", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn1qr1k1/pp3ppp/2p2n2/8/1b3P2/1NN3Q1/PPPP2PP/R1BK3R b - - 2 13", "prompt": "FEN: rn1qr1k1/pp3ppp/2p2n2/8/1b3P2/1NN3Q1/PPPP2PP/R1BK3R b - - 2 13\nFor the piece on b4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b4: b4a3 b4a5 b4c3 b4c5 b4d6 b4e7 b4f8.\nLegal: b4a3 b4a5 b4c3 b4c5 b4d6 b4e7 b4f8.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_01101", "split": "rules", "task_type": "king_safety_filter", "fen": "r2qkb1r/ppp2pp1/3pB2p/4P2n/3n1B2/2N2N2/PP3PPP/R3K2R b KQkq - 0 11", "prompt": "FEN: r2qkb1r/ppp2pp1/3pB2p/4P2n/3n1B2/2N2N2/PP3PPP/R3K2R b KQkq - 0 11\nFor move e8d7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e8d7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e8d7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e8d7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01102", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r3kbnr/p1pq1pp1/np2p3/3pP2p/3P3P/2N2N1Q/PPP2PP1/R1B1K2R w KQkq -", "prompt": "FEN: r3kbnr/p1pq1pp1/np2p3/3pP2p/3P3P/2N2N1Q/PPP2PP1/R1B1K2R w KQkq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; e1 white king; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; c3 white knight; f3 white knight; h3 white queen; d4 white pawn; h4 white pawn; e5 white pawn.\nMoves by piece:\na1 white rook: a1b1\nc1 white bishop: c1d2 c1e3 c1f4 c1g5 c1h6\ne1 white king: e1d1 e1d2 e1e2 e1f1 e1g1\nh1 white rook: h1f1 h1g1 h1h2\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: no legal moves\nf2 white pawn: no legal moves\ng2 white pawn: g2g3 g2g4\nc3 white knight: c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4\nf3 white knight: f3d2 f3g1 f3g5 f3h2\nh3 white queen: h3e6 h3f5 h3g3 h3g4 h3h2\nd4 white pawn: no legal moves\nh4 white pawn: no legal moves\ne5 white pawn: no legal moves\nAll legal moves: a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 e1d1 e1d2 e1e2 e1f1 e1g1 f3d2 f3g1 f3g5 f3h2 g2g3 g2g4 h1f1 h1g1 h1h2 h3e6 h3f5 h3g3 h3g4 h3h2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "e1": ["e1d1", "e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1", "h1h2"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": [], "f2": [], "g2": ["g2g3", "g2g4"], "c3": ["c3a4", "c3b1", "c3b5", "c3d1", "c3d5", "c3e2", "c3e4"], "f3": ["f3d2", "f3g1", "f3g5", "f3h2"], "h3": ["h3e6", "h3f5", "h3g3", "h3g4", "h3h2"], "d4": [], "h4": [], "e5": []}, "_legal_moves_by_piece_moves": "a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 e1d1 e1d2 e1e2 e1f1 e1g1 f3d2 f3g1 f3g5 f3h2 g2g3 g2g4 h1f1 h1g1 h1h2 h3e6 h3f5 h3g3 h3g4 h3h2", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "e1": ["e1d1", "e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1", "h1h2"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": [], "f2": [], "g2": ["g2g3", "g2g4"], "c3": ["c3a4", "c3b1", "c3b5", "c3d1", "c3d5", "c3e2", "c3e4"], "f3": ["f3d2", "f3g1", "f3g5", "f3h2"], "h3": ["h3e6", "h3f5", "h3g3", "h3g4", "h3h2"], "d4": [], "h4": [], "e5": []}, "legal_moves": "a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 e1d1 e1d2 e1e2 e1f1 e1g1 f3d2 f3g1 f3g5 f3h2 g2g3 g2g4 h1f1 h1g1 h1h2 h3e6 h3f5 h3g3 h3g4 h3h2"}}
{"example_id": "rules_01103", "split": "rules", "task_type": "ray_walk", "fen": "r1b2rk1/pp2b2p/2q1p1p1/2p2p2/2P1PPPn/2P3N1/P1P1Q3/R1BR1K2 w - - 0 21", "prompt": "FEN: r1b2rk1/pp2b2p/2q1p1p1/2p2p2/2P1PPPn/2P3N1/P1P1Q3/R1BR1K2 w - - 0 21\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 white bishop: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01104", "split": "rules", "task_type": "legal_filter_trace", "fen": "1Q1R4/p4p1k/4rPp1/6Pp/4p3/4P1KP/8/1q6 b - - 3 38", "prompt": "FEN: 1Q1R4/p4p1k/4rPp1/6Pp/4p3/4P1KP/8/1q6 b - - 3 38\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b1 black queen; e4 black pawn; h5 black pawn; e6 black rook; g6 black pawn; a7 black pawn; f7 black pawn; h7 black king.\nFilter by piece:\nb1 black queen: pseudo-legal b1a1 b1a2 b1b2 b1b3 b1b4 b1b5 b1b6 b1b7 b1b8 b1c1 b1c2 b1d1 b1d3 b1e1 b1f1 b1g1 b1h1 | rejected none | legal b1a1 b1a2 b1b2 b1b3 b1b4 b1b5 b1b6 b1b7 b1b8 b1c1 b1c2 b1d1 b1d3 b1e1 b1f1 b1g1 b1h1\ne4 black pawn: pseudo-legal none | rejected none | legal none\nh5 black pawn: pseudo-legal h5h4 | rejected none | legal h5h4\ne6 black rook: pseudo-legal e6a6 e6b6 e6c6 e6d6 e6e5 e6e7 e6e8 e6f6 | rejected none | legal e6a6 e6b6 e6c6 e6d6 e6e5 e6e7 e6e8 e6f6\ng6 black pawn: pseudo-legal none | rejected none | legal none\na7 black pawn: pseudo-legal a7a5 a7a6 | rejected none | legal a7a5 a7a6\nf7 black pawn: pseudo-legal none | rejected none | legal none\nh7 black king: pseudo-legal h7g7 h7g8 h7h6 h7h8 | rejected h7g7 king_would_be_in_check; h7g8 king_would_be_in_check; h7h6 king_would_be_in_check; h7h8 king_would_be_in_check | legal none\nAll legal moves: a7a5 a7a6 b1a1 b1a2 b1b2 b1b3 b1b4 b1b5 b1b6 b1b7 b1b8 b1c1 b1c2 b1d1 b1d3 b1e1 b1f1 b1g1 b1h1 e6a6 e6b6 e6c6 e6d6 e6e5 e6e7 e6e8 e6f6 h5h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01105", "split": "rules", "task_type": "legal_moves", "fen": "r2qr1k1/1b3pbp/2p1p1p1/2BpP3/1P3P2/4P1P1/2Q3BP/R4RK1 b - - 0 25", "prompt": "FEN: r2qr1k1/1b3pbp/2p1p1p1/2BpP3/1P3P2/4P1P1/2Q3BP/R4RK1 b - - 0 25\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a8a1 a8a2 a8a3 a8a4 a8a5 a8a6 a8a7 a8b8 a8c8 b7a6 b7c8 d5d4 d8a5 d8b6 d8b8 d8c7 d8c8 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e8e7 e8f8 f7f5 f7f6 g6g5 g7e5 g7f6 g7f8 g7h6 g7h8 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01106", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/8/8/5k2/2Q2p2/4b3/4K3/8 w - -", "prompt": "FEN: 8/8/8/5k2/2Q2p2/4b3/4K3/8 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: e2 white king; c4 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "e2", "piece": "white king"}, {"square": "c4", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "e2", "piece": "white king"}, {"square": "c4", "piece": "white queen"}]}}
{"example_id": "rules_01107", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/3k4/8/3KP3/8/8/8/B7 b - -", "prompt": "FEN: 8/3k4/8/3KP3/8/8/8/B7 b - -\nWhat legal moves does the piece on d7 have?", "gold_answer": "d7c7 d7c8 d7d8 d7e7 d7e8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "d7", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "d7", "piece": "king"}}
{"example_id": "rules_01108", "split": "rules", "task_type": "check_detection", "fen": "r2r3k/7p/3b1p2/p3p2b/n1B1P3/6P1/3N1PKP/B1R5 b - - 1 37", "prompt": "FEN: r2r3k/7p/3b1p2/p3p2b/n1B1P3/6P1/3N1PKP/B1R5 b - - 1 37\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01109", "split": "rules", "task_type": "captures", "fen": "8/5K2/2k4r/4P3/3R4/8/8/8 b - -", "prompt": "FEN: 8/5K2/2k4r/4P3/3R4/8/8/8 b - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01110", "split": "rules", "task_type": "special_rules", "fen": "b7/p5r1/1p6/2k1pB2/P7/2N5/1P4PP/3R2K1 w - - 4 32", "prompt": "Given FEN: b7/p5r1/1p6/2k1pB2/P7/2N5/1P4PP/3R2K1 w - - 4 32\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01111", "split": "rules", "task_type": "legality_check", "fen": "8/pp1k4/2q2bQ1/8/7P/5R1P/PP3PK1/8 b - -", "prompt": "FEN: 8/pp1k4/2q2bQ1/8/7P/5R1P/PP3PK1/8 b - -\nIs the move f6e7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f6e7", "_legality_check_reason_label": "legal", "move": "f6e7", "legality_reason_label": "legal"}}
{"example_id": "rules_01112", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "N2k1b1r/pQ3ppp/8/3pp3/4nqbK/5N2/P5PP/R4B1R b - -", "prompt": "FEN: N2k1b1r/pQ3ppp/8/3pp3/4nqbK/5N2/P5PP/R4B1R b - -\nList pseudo-legal moves from e4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e4: e4c3 e4c5 e4d2 e4d6 e4f2 e4f6 e4g3 e4g5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e4", "diagnostic": true, "hard_gate": false, "source_square": "e4"}}
{"example_id": "rules_01113", "split": "rules", "task_type": "piece_legal_filter", "fen": "2kr3r/1ppq1ppp/pb1pb1n1/6N1/1P2PpP1/N1PP1P1P/P3Q1B1/R3K2R w KQ - 2 16", "prompt": "FEN: 2kr3r/1ppq1ppp/pb1pb1n1/6N1/1P2PpP1/N1PP1P1P/P3Q1B1/R3K2R w KQ - 2 16\nFor the piece on e1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e1: e1c1 e1d1 e1d2 e1f1 e1f2.\nLegal: e1c1 e1d1 e1d2 e1f1.\nRejected: e1f2 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "e1", "diagnostic": true, "hard_gate": false, "source_square": "e1"}}
{"example_id": "rules_01114", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbq1rk1/pp2ppbp/3p1np1/2P5/4P3/2N2N2/PPP1BPPP/R1BQ1RK1 b - - 0 7", "prompt": "FEN: rnbq1rk1/pp2ppbp/3p1np1/2P5/4P3/2N2N2/PPP1BPPP/R1BQ1RK1 b - - 0 7\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01115", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/6p1/p5Pp/P1p4P/2p5/2Pk4/PK6/8 w - -", "prompt": "FEN: 8/6p1/p5Pp/P1p4P/2p5/2Pk4/PK6/8 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a2 white pawn; b2 white king; c3 white pawn; a5 white pawn; h5 white pawn; g6 white pawn.\nMoves by piece:\na2 white pawn: a2a3 a2a4\nb2 white king: b2a1 b2a3 b2b1 b2c1\nc3 white pawn: no legal moves\na5 white pawn: no legal moves\nh5 white pawn: no legal moves\ng6 white pawn: no legal moves\nAll legal moves: a2a3 a2a4 b2a1 b2a3 b2b1 b2c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a2": ["a2a3", "a2a4"], "b2": ["b2a1", "b2a3", "b2b1", "b2c1"], "c3": [], "a5": [], "h5": [], "g6": []}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b2a1 b2a3 b2b1 b2c1", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a2": ["a2a3", "a2a4"], "b2": ["b2a1", "b2a3", "b2b1", "b2c1"], "c3": [], "a5": [], "h5": [], "g6": []}, "legal_moves": "a2a3 a2a4 b2a1 b2a3 b2b1 b2c1"}}
{"example_id": "rules_01116", "split": "rules", "task_type": "legal_moves", "fen": "1k6/3B1N2/1K6/8/8/8/8/8 b - -", "prompt": "FEN: 1k6/3B1N2/1K6/8/8/8/8/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b8a8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": ""}}
{"example_id": "rules_01117", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/1p1nbpp1/2p1pn1p/p2p1b2/2PP4/1P3NPP/PB1NPPB1/R2QR1K1 b - -", "prompt": "FEN: r2q1rk1/1p1nbpp1/2p1pn1p/p2p1b2/2PP4/1P3NPP/PB1NPPB1/R2QR1K1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a5a4 a8a6 a8a7 a8b8 a8c8 b7b5 b7b6 c6c5 d5c4 d7b6 d7b8 d7c5 d7e5 d8b6 d8b8 d8c7 d8c8 d8e8 e6e5 e7a3 e7b4 e7c5 e7d6 f5b1 f5c2 f5d3 f5e4 f5g4 f5g6 f5h3 f5h7 f6e4 f6e8 f6g4 f6h5 f6h7 f8e8 g7g5 g7g6 g8h7 g8h8 h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01118", "split": "rules", "task_type": "legal_moves", "fen": "5nk1/q1rr1pbp/p3p1p1/1p1pP3/3P3B/2P5/PP1Q1RPP/4NRK1 w - - 0 27", "prompt": "FEN: 5nk1/q1rr1pbp/p3p1p1/1p1pP3/3P3B/2P5/PP1Q1RPP/4NRK1 w - - 0 27\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 b2b4 c3c4 d2c1 d2c2 d2d1 d2d3 d2e2 d2e3 d2f4 d2g5 d2h6 e1c2 e1d3 e1f3 f2e2 f2f3 f2f4 f2f5 f2f6 f2f7 g1h1 g2g3 g2g4 h2h3 h4d8 h4e7 h4f6 h4g3 h4g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01119", "split": "rules", "task_type": "side_piece_inventory", "fen": "4r1k1/1p2nppp/1pn1P3/5P1q/P1B1Q3/2P4P/1P4P1/5K2 b - - 0 27", "prompt": "FEN: 4r1k1/1p2nppp/1pn1P3/5P1q/P1B1Q3/2P4P/1P4P1/5K2 b - - 0 27\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: h5 black queen; b6 black pawn; c6 black knight; b7 black pawn; e7 black knight; f7 black pawn; g7 black pawn; h7 black pawn; e8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "h5", "piece": "black queen"}, {"square": "b6", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "b7", "piece": "black pawn"}, {"square": "e7", "piece": "black knight"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "e8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "h5", "piece": "black queen"}, {"square": "b6", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "b7", "piece": "black pawn"}, {"square": "e7", "piece": "black knight"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "e8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01120", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/6p1/7p/2K5/5k2/7P/8/8 b - - 3 54", "prompt": "FEN: 8/6p1/7p/2K5/5k2/7P/8/8 b - - 3 54\nWhat legal moves does the piece on f4 have?", "gold_answer": "f4e3 f4e4 f4e5 f4f3 f4f5 f4g3 f4g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f4", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "f4", "piece": "king"}}
{"example_id": "rules_01121", "split": "rules", "task_type": "check_detection", "fen": "r5k1/p2pn3/1p2pp1Q/6p1/2q5/6BP/P4PP1/4RK2 w - -", "prompt": "FEN: r5k1/p2pn3/1p2pp1Q/6p1/2q5/6BP/P4PP1/4RK2 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01122", "split": "rules", "task_type": "captures", "fen": "3r4/pp4k1/2p1r3/5pp1/8/2P4P/P1P2PP1/R4RK1 b - - 0 20", "prompt": "FEN: 3r4/pp4k1/2p1r3/5pp1/8/2P4P/P1P2PP1/R4RK1 b - - 0 20\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01123", "split": "rules", "task_type": "special_rules", "fen": "r1bq1rk1/1pp2pp1/2np4/p5B1/2B1P1n1/P1P2N2/5PPP/R1Q1K2R b KQ - 2 14", "prompt": "Given FEN: r1bq1rk1/1pp2pp1/2np4/p5B1/2B1P1n1/P1P2N2/5PPP/R1Q1K2R b KQ - 2 14\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01124", "split": "rules", "task_type": "legality_check", "fen": "8/5p2/6kp/5Qp1/6P1/2p3KP/1q6/8 b - -", "prompt": "FEN: 8/5p2/6kp/5Qp1/6P1/2p3KP/1q6/8 b - -\nIs the move f7c3 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f7c3", "_legality_check_reason_label": "own_piece_destination", "move": "f7c3", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_01125", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "3r4/8/8/5k2/2PK4/8/4R3/8 w - -", "prompt": "FEN: 3r4/8/8/5k2/2PK4/8/4R3/8 w - -\nList pseudo-legal moves from e2.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e2: e2a2 e2b2 e2c2 e2d2 e2e1 e2e3 e2e4 e2e5 e2e6 e2e7 e2e8 e2f2 e2g2 e2h2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e2", "diagnostic": true, "hard_gate": false, "source_square": "e2"}}
{"example_id": "rules_01126", "split": "rules", "task_type": "piece_legal_filter", "fen": "r3r1k1/pp3p2/2pBpP1p/q1PpP1pn/3P4/P1P5/3QnP1P/R4RK1 w - - 0 21", "prompt": "FEN: r3r1k1/pp3p2/2pBpP1p/q1PpP1pn/3P4/P1P5/3QnP1P/R4RK1 w - - 0 21\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1a2 a1b1 a1c1 a1d1 a1e1.\nLegal: none.\nRejected: a1a2 does_not_resolve_check; a1b1 does_not_resolve_check; a1c1 does_not_resolve_check; a1d1 does_not_resolve_check; a1e1 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01127", "split": "rules", "task_type": "king_safety_filter", "fen": "2r2rk1/1p4p1/p4p1p/7R/4pP1B/8/PPn1PN2/2K1R3 w - - 0 23", "prompt": "FEN: 2r2rk1/1p4p1/p4p1p/7R/4pP1B/8/PPn1PN2/2K1R3 w - - 0 23\nFor move c1c2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c1c2.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "c1c2", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "c1c2", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01128", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1rb1k3/7Q/p1p1pp2/2p5/7P/1P1P1N2/P1P2P2/2K3R1 w - - 2 27", "prompt": "FEN: 1rb1k3/7Q/p1p1pp2/2p5/7P/1P1P1N2/P1P2P2/2K3R1 w - - 2 27\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c1 white king; g1 white rook; a2 white pawn; c2 white pawn; f2 white pawn; b3 white pawn; d3 white pawn; f3 white knight; h4 white pawn; h7 white queen.\nMoves by piece:\nc1 white king: c1b1 c1b2 c1d1 c1d2\ng1 white rook: g1d1 g1e1 g1f1 g1g2 g1g3 g1g4 g1g5 g1g6 g1g7 g1g8 g1h1\na2 white pawn: a2a3 a2a4\nc2 white pawn: c2c3 c2c4\nf2 white pawn: no legal moves\nb3 white pawn: b3b4\nd3 white pawn: d3d4\nf3 white knight: f3d2 f3d4 f3e1 f3e5 f3g5 f3h2\nh4 white pawn: h4h5\nh7 white queen: h7a7 h7b7 h7c7 h7d7 h7e4 h7e7 h7f5 h7f7 h7g6 h7g7 h7g8 h7h5 h7h6 h7h8\nAll legal moves: a2a3 a2a4 b3b4 c1b1 c1b2 c1d1 c1d2 c2c3 c2c4 d3d4 f3d2 f3d4 f3e1 f3e5 f3g5 f3h2 g1d1 g1e1 g1f1 g1g2 g1g3 g1g4 g1g5 g1g6 g1g7 g1g8 g1h1 h4h5 h7a7 h7b7 h7c7 h7d7 h7e4 h7e7 h7f5 h7f7 h7g6 h7g7 h7g8 h7h5 h7h6 h7h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c1": ["c1b1", "c1b2", "c1d1", "c1d2"], "g1": ["g1d1", "g1e1", "g1f1", "g1g2", "g1g3", "g1g4", "g1g5", "g1g6", "g1g7", "g1g8", "g1h1"], "a2": ["a2a3", "a2a4"], "c2": ["c2c3", "c2c4"], "f2": [], "b3": ["b3b4"], "d3": ["d3d4"], "f3": ["f3d2", "f3d4", "f3e1", "f3e5", "f3g5", "f3h2"], "h4": ["h4h5"], "h7": ["h7a7", "h7b7", "h7c7", "h7d7", "h7e4", "h7e7", "h7f5", "h7f7", "h7g6", "h7g7", "h7g8", "h7h5", "h7h6", "h7h8"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b3b4 c1b1 c1b2 c1d1 c1d2 c2c3 c2c4 d3d4 f3d2 f3d4 f3e1 f3e5 f3g5 f3h2 g1d1 g1e1 g1f1 g1g2 g1g3 g1g4 g1g5 g1g6 g1g7 g1g8 g1h1 h4h5 h7a7 h7b7 h7c7 h7d7 h7e4 h7e7 h7f5 h7f7 h7g6 h7g7 h7g8 h7h5 h7h6 h7h8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c1": ["c1b1", "c1b2", "c1d1", "c1d2"], "g1": ["g1d1", "g1e1", "g1f1", "g1g2", "g1g3", "g1g4", "g1g5", "g1g6", "g1g7", "g1g8", "g1h1"], "a2": ["a2a3", "a2a4"], "c2": ["c2c3", "c2c4"], "f2": [], "b3": ["b3b4"], "d3": ["d3d4"], "f3": ["f3d2", "f3d4", "f3e1", "f3e5", "f3g5", "f3h2"], "h4": ["h4h5"], "h7": ["h7a7", "h7b7", "h7c7", "h7d7", "h7e4", "h7e7", "h7f5", "h7f7", "h7g6", "h7g7", "h7g8", "h7h5", "h7h6", "h7h8"]}, "legal_moves": "a2a3 a2a4 b3b4 c1b1 c1b2 c1d1 c1d2 c2c3 c2c4 d3d4 f3d2 f3d4 f3e1 f3e5 f3g5 f3h2 g1d1 g1e1 g1f1 g1g2 g1g3 g1g4 g1g5 g1g6 g1g7 g1g8 g1h1 h4h5 h7a7 h7b7 h7c7 h7d7 h7e4 h7e7 h7f5 h7f7 h7g6 h7g7 h7g8 h7h5 h7h6 h7h8"}}
{"example_id": "rules_01129", "split": "rules", "task_type": "ray_walk", "fen": "4r3/P7/2p3p1/8/3P1k2/4p3/6KP/5R2 b - - 1 50", "prompt": "FEN: 4r3/P7/2p3p1/8/3P1k2/4p3/6KP/5R2 b - - 1 50\nWalk each ray for the slider on e8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e8 black rook.\nRay N: edge.\nRay E: f8 empty; g8 empty; h8 empty; edge.\nRay S: e7 empty; e6 empty; e5 empty; e4 empty; e3 black pawn: own piece (stop, excluded).\nRay W: d8 empty; c8 empty; b8 empty; a8 empty; edge.\nMoves from rays: e8a8 e8b8 e8c8 e8d8 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 e8h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "e8", "diagnostic": true, "hard_gate": false, "source_square": "e8"}}
{"example_id": "rules_01130", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/1p6/p3p3/3p1pk1/3P4/2P2K1P/PP6/8 w - -", "prompt": "FEN: 8/1p6/p3p3/3p1pk1/3P4/2P2K1P/PP6/8 w - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a2 white pawn; b2 white pawn; c3 white pawn; f3 white king; h3 white pawn; d4 white pawn.\nFilter by piece:\na2 white pawn: pseudo-legal a2a3 a2a4 | rejected none | legal a2a3 a2a4\nb2 white pawn: pseudo-legal b2b3 b2b4 | rejected none | legal b2b3 b2b4\nc3 white pawn: pseudo-legal c3c4 | rejected none | legal c3c4\nf3 white king: pseudo-legal f3e2 f3e3 f3e4 f3f2 f3f4 f3g2 f3g3 f3g4 | rejected f3e4 king_would_be_in_check; f3f4 king_would_be_in_check; f3g4 king_would_be_in_check | legal f3e2 f3e3 f3f2 f3g2 f3g3\nh3 white pawn: pseudo-legal h3h4 | rejected none | legal h3h4\nd4 white pawn: pseudo-legal none | rejected none | legal none\nAll legal moves: a2a3 a2a4 b2b3 b2b4 c3c4 f3e2 f3e3 f3f2 f3g2 f3g3 h3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01131", "split": "rules", "task_type": "legal_moves", "fen": "8/8/5K2/8/8/4k3/5p2/3Q4 b - -", "prompt": "FEN: 8/8/5K2/8/8/4k3/5p2/3Q4 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: e3e4 e3f4 f2f1b f2f1n f2f1q f2f1r", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01132", "split": "rules", "task_type": "side_piece_inventory", "fen": "2kr1r2/1pp3p1/p4n1p/4b1B1/1PB5/2P2P2/P1K3PP/3R3R w - - 0 22", "prompt": "FEN: 2kr1r2/1pp3p1/p4n1p/4b1B1/1PB5/2P2P2/P1K3PP/3R3R w - - 0 22\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: d1 white rook; h1 white rook; a2 white pawn; c2 white king; g2 white pawn; h2 white pawn; c3 white pawn; f3 white pawn; b4 white pawn; c4 white bishop; g5 white bishop.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "d1", "piece": "white rook"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "c2", "piece": "white king"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "f3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "c4", "piece": "white bishop"}, {"square": "g5", "piece": "white bishop"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "d1", "piece": "white rook"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "c2", "piece": "white king"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "f3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "c4", "piece": "white bishop"}, {"square": "g5", "piece": "white bishop"}]}}
{"example_id": "rules_01133", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b2rk1/ppq2ppp/2n2n2/2p5/5B2/1P1P1N2/P1P3BP/RN1QR2K b - - 0 15", "prompt": "FEN: r1b2rk1/ppq2ppp/2n2n2/2p5/5B2/1P1P1N2/P1P3BP/RN1QR2K b - - 0 15\nWhat legal moves does the piece on c6 have?", "gold_answer": "c6a5 c6b4 c6b8 c6d4 c6d8 c6e5 c6e7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c6", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "c6", "piece": "knight"}}
{"example_id": "rules_01134", "split": "rules", "task_type": "check_detection", "fen": "8/6k1/4K3/8/2R3p1/7p/8/8 b - -", "prompt": "FEN: 8/6k1/4K3/8/2R3p1/7p/8/8 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01135", "split": "rules", "task_type": "captures", "fen": "8/8/8/ppp2p1p/4kBpP/PbK3P1/8/8 b - - 3 47", "prompt": "FEN: 8/8/8/ppp2p1p/4kBpP/PbK3P1/8/8 b - - 3 47\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01136", "split": "rules", "task_type": "special_rules", "fen": "rnb1k2r/ppp2pp1/3b1p1p/7q/3P4/2N2N2/PPP2PPP/R2QKB1R w KQkq -", "prompt": "Given FEN: rnb1k2r/ppp2pp1/3b1p1p/7q/3P4/2N2N2/PPP2PPP/R2QKB1R w KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01137", "split": "rules", "task_type": "legality_check", "fen": "3r4/pp3k1p/6p1/2P1q3/4p1K1/4B3/PP2P2r/R3R2B w - -", "prompt": "FEN: 3r4/pp3k1p/6p1/2P1q3/4p1K1/4B3/PP2P2r/R3R2B w - -\nIs the move a2e1 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "a2e1", "_legality_check_reason_label": "own_piece_destination", "move": "a2e1", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_01138", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2kr3r/ppp5/7p/3npp2/b5p1/1NP1P3/P1K2PPP/3R1B1R b - - 0 19", "prompt": "FEN: 2kr3r/ppp5/7p/3npp2/b5p1/1NP1P3/P1K2PPP/3R1B1R b - - 0 19\nList pseudo-legal moves from a4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a4: a4b3 a4b5 a4c6 a4d7 a4e8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a4", "diagnostic": true, "hard_gate": false, "source_square": "a4"}}
{"example_id": "rules_01139", "split": "rules", "task_type": "piece_legal_filter", "fen": "1kr4r/4bpp1/p1p1p3/Np1qPn2/PP1Pb2p/R1Q2N1P/3B1PP1/2R3K1 w - -", "prompt": "FEN: 1kr4r/4bpp1/p1p1p3/Np1qPn2/PP1Pb2p/R1Q2N1P/3B1PP1/2R3K1 w - -\nFor the piece on c1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c1: c1a1 c1b1 c1c2 c1d1 c1e1 c1f1.\nLegal: c1a1 c1b1 c1c2 c1d1 c1e1 c1f1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_01140", "split": "rules", "task_type": "king_safety_filter", "fen": "8/8/2k5/6Q1/3K4/8/8/8 b - -", "prompt": "FEN: 8/8/2k5/6Q1/3K4/8/8/8 b - -\nFor move c6b5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c6b5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "c6b5", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "c6b5", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01141", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rn1qkbnr/pb3ppp/1pppp3/3P4/2P1P3/P7/1P3PPP/RNBQKBNR w KQkq - 0 6", "prompt": "FEN: rn1qkbnr/pb3ppp/1pppp3/3P4/2P1P3/P7/1P3PPP/RNBQKBNR w KQkq - 0 6\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; d1 white queen; e1 white king; f1 white bishop; g1 white knight; h1 white rook; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; a3 white pawn; c4 white pawn; e4 white pawn; d5 white pawn.\nMoves by piece:\na1 white rook: a1a2\nb1 white knight: b1c3 b1d2\nc1 white bishop: c1d2 c1e3 c1f4 c1g5 c1h6\nd1 white queen: d1a4 d1b3 d1c2 d1d2 d1d3 d1d4 d1e2 d1f3 d1g4 d1h5\ne1 white king: e1d2 e1e2\nf1 white bishop: f1d3 f1e2\ng1 white knight: g1e2 g1f3 g1h3\nh1 white rook: no legal moves\nb2 white pawn: b2b3 b2b4\nf2 white pawn: f2f3 f2f4\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\na3 white pawn: a3a4\nc4 white pawn: c4c5\ne4 white pawn: e4e5\nd5 white pawn: d5c6 d5e6\nAll legal moves: a1a2 a3a4 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c4c5 d1a4 d1b3 d1c2 d1d2 d1d3 d1d4 d1e2 d1f3 d1g4 d1h5 d5c6 d5e6 e1d2 e1e2 e4e5 f1d3 f1e2 f2f3 f2f4 g1e2 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1a2"], "b1": ["b1c3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1a4", "d1b3", "d1c2", "d1d2", "d1d3", "d1d4", "d1e2", "d1f3", "d1g4", "d1h5"], "e1": ["e1d2", "e1e2"], "f1": ["f1d3", "f1e2"], "g1": ["g1e2", "g1f3", "g1h3"], "h1": [], "b2": ["b2b3", "b2b4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "a3": ["a3a4"], "c4": ["c4c5"], "e4": ["e4e5"], "d5": ["d5c6", "d5e6"]}, "_legal_moves_by_piece_moves": "a1a2 a3a4 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c4c5 d1a4 d1b3 d1c2 d1d2 d1d3 d1d4 d1e2 d1f3 d1g4 d1h5 d5c6 d5e6 e1d2 e1e2 e4e5 f1d3 f1e2 f2f3 f2f4 g1e2 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1a2"], "b1": ["b1c3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1a4", "d1b3", "d1c2", "d1d2", "d1d3", "d1d4", "d1e2", "d1f3", "d1g4", "d1h5"], "e1": ["e1d2", "e1e2"], "f1": ["f1d3", "f1e2"], "g1": ["g1e2", "g1f3", "g1h3"], "h1": [], "b2": ["b2b3", "b2b4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "a3": ["a3a4"], "c4": ["c4c5"], "e4": ["e4e5"], "d5": ["d5c6", "d5e6"]}, "legal_moves": "a1a2 a3a4 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c4c5 d1a4 d1b3 d1c2 d1d2 d1d3 d1d4 d1e2 d1f3 d1g4 d1h5 d5c6 d5e6 e1d2 e1e2 e4e5 f1d3 f1e2 f2f3 f2f4 g1e2 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4"}}
{"example_id": "rules_01142", "split": "rules", "task_type": "ray_walk", "fen": "2kr3r/1pq4p/p1n2p2/3p2p1/PPpP4/2P5/B2NQPPb/R1B2R1K b - - 1 19", "prompt": "FEN: 2kr3r/1pq4p/p1n2p2/3p2p1/PPpP4/2P5/B2NQPPb/R1B2R1K b - - 1 19\nWalk each ray for the slider on h2: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: h2 black bishop.\nRay NE: edge.\nRay SE: edge.\nRay SW: g1 empty; edge.\nRay NW: g3 empty; f4 empty; e5 empty; d6 empty; c7 black queen: own piece (stop, excluded).\nMoves from rays: h2d6 h2e5 h2f4 h2g1 h2g3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "h2", "diagnostic": true, "hard_gate": false, "source_square": "h2"}}
{"example_id": "rules_01143", "split": "rules", "task_type": "legal_moves", "fen": "r5k1/1b4pp/pp2p1r1/8/P2p3q/1B1Q2P1/1PP2P1P/4RRK1 b - -", "prompt": "FEN: r5k1/1b4pp/pp2p1r1/8/P2p3q/1B1Q2P1/1PP2P1P/4RRK1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 a8b8 a8c8 a8d8 a8e8 a8f8 b6b5 b7c6 b7c8 b7d5 b7e4 b7f3 b7g2 b7h1 g6f6 g6g3 g6g4 g6g5 g6h6 g8f7 g8f8 g8h8 h4d8 h4e4 h4e7 h4f4 h4f6 h4g3 h4g4 h4g5 h4h2 h4h3 h4h5 h4h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01144", "split": "rules", "task_type": "legal_moves", "fen": "r3r1k1/5bbp/6p1/2B1pp2/pP2p3/6P1/2RN1PKP/R7 w - -", "prompt": "FEN: r3r1k1/5bbp/6p1/2B1pp2/pP2p3/6P1/2RN1PKP/R7 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 a1a4 a1b1 a1c1 a1d1 a1e1 a1f1 a1g1 a1h1 b4b5 c2a2 c2b2 c2c1 c2c3 c2c4 c5a7 c5b6 c5d4 c5d6 c5e3 c5e7 c5f8 d2b1 d2b3 d2c4 d2e4 d2f1 d2f3 f2f3 f2f4 g2f1 g2g1 g2h1 g2h3 g3g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01145", "split": "rules", "task_type": "side_piece_inventory", "fen": "r4rk1/pb2b1p1/1p2pn1p/8/3PN3/3B2qP/PP4P1/R1B2RK1 w - - 0 20", "prompt": "FEN: r4rk1/pb2b1p1/1p2pn1p/8/3PN3/3B2qP/PP4P1/R1B2RK1 w - - 0 20\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; g2 white pawn; d3 white bishop; h3 white pawn; d4 white pawn; e4 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "h3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "e4", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "h3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "e4", "piece": "white knight"}]}}
{"example_id": "rules_01146", "split": "rules", "task_type": "piece_legal_moves", "fen": "1k3r2/pp4p1/3bpn2/5qp1/3P2p1/1P2B3/P4P2/2R1N1KQ b - - 1 31", "prompt": "FEN: 1k3r2/pp4p1/3bpn2/5qp1/3P2p1/1P2B3/P4P2/2R1N1KQ b - - 1 31\nWhat legal moves does the piece on g4 have?", "gold_answer": "g4g3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "g4", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g4", "piece": "pawn"}}
{"example_id": "rules_01147", "split": "rules", "task_type": "check_detection", "fen": "r2qn2r/1b1k4/3p2QB/2pP4/p3P2p/P6P/BbP2PP1/R3K2R w KQ - 0 23", "prompt": "FEN: r2qn2r/1b1k4/3p2QB/2pP4/p3P2p/P6P/BbP2PP1/R3K2R w KQ - 0 23\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01148", "split": "rules", "task_type": "captures", "fen": "rn1qkb1r/pp2pppp/2p2nb1/3p4/3P3N/5PP1/PPP1P1BP/RNBQK2R w KQkq -", "prompt": "FEN: rn1qkb1r/pp2pppp/2p2nb1/3p4/3P3N/5PP1/PPP1P1BP/RNBQK2R w KQkq -\nList all capture moves available.", "gold_answer": "h4g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01149", "split": "rules", "task_type": "special_rules", "fen": "r1b1k1r1/pp2np1Q/2n1pq2/3p4/8/P1p1BN2/2P1BPPP/R3K2R w KQq -", "prompt": "Given FEN: r1b1k1r1/pp2np1Q/2n1pq2/3p4/8/P1p1BN2/2P1BPPP/R3K2R w KQq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside, queenside.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01150", "split": "rules", "task_type": "legality_check", "fen": "2rqr1k1/Q4pbp/P3p1p1/3n4/2pP4/4PB1P/1P3PPB/R4RK1 w - - 1 20", "prompt": "FEN: 2rqr1k1/Q4pbp/P3p1p1/3n4/2pP4/4PB1P/1P3PPB/R4RK1 w - - 1 20\nIs the move h2e5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "h2e5", "_legality_check_reason_label": "legal", "move": "h2e5", "legality_reason_label": "legal"}}
{"example_id": "rules_01151", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "3r1rk1/p4ppp/1p3q2/1Qp5/8/5N1P/PPP2PP1/4R1K1 b - - 3 19", "prompt": "FEN: 3r1rk1/p4ppp/1p3q2/1Qp5/8/5N1P/PPP2PP1/4R1K1 b - - 3 19\nList pseudo-legal moves from c5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c5: c5c4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_01152", "split": "rules", "task_type": "piece_legal_filter", "fen": "3r1kr1/pp2p1bp/1n4p1/4np2/2P2P2/1P1BQqPP/PB3K2/N1R3R1 w - -", "prompt": "FEN: 3r1kr1/pp2p1bp/1n4p1/4np2/2P2P2/1P1BQqPP/PB3K2/N1R3R1 w - -\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1c2.\nLegal: none.\nRejected: a1c2 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01153", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbqkbnr/pp1p1ppp/2p5/8/2PPN3/8/PP2PPPP/R1BQKBNR b KQkq - 0 4", "prompt": "FEN: rnbqkbnr/pp1p1ppp/2p5/8/2PPN3/8/PP2PPPP/R1BQKBNR b KQkq - 0 4\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01154", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "4r1r1/pp2b3/2p1P2k/4R2p/6Pq/PP1Q1p1P/1B3P2/3R2K1 b - - 4 34", "prompt": "FEN: 4r1r1/pp2b3/2p1P2k/4R2p/6Pq/PP1Q1p1P/1B3P2/3R2K1 b - - 4 34\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: f3 black pawn; h4 black queen; h5 black pawn; c6 black pawn; h6 black king; a7 black pawn; b7 black pawn; e7 black bishop; e8 black rook; g8 black rook.\nMoves by piece:\nf3 black pawn: no legal moves\nh4 black queen: h4f2 h4f6 h4g3 h4g4 h4g5 h4h3\nh5 black pawn: h5g4\nc6 black pawn: c6c5\nh6 black king: h6g7\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\ne7 black bishop: e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7f8 e7g5\ne8 black rook: e8a8 e8b8 e8c8 e8d8 e8f8\ng8 black rook: g8f8 g8g4 g8g5 g8g6 g8g7 g8h8\nAll legal moves: a7a5 a7a6 b7b5 b7b6 c6c5 e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7f8 e7g5 e8a8 e8b8 e8c8 e8d8 e8f8 g8f8 g8g4 g8g5 g8g6 g8g7 g8h8 h4f2 h4f6 h4g3 h4g4 h4g5 h4h3 h5g4 h6g7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"f3": [], "h4": ["h4f2", "h4f6", "h4g3", "h4g4", "h4g5", "h4h3"], "h5": ["h5g4"], "c6": ["c6c5"], "h6": ["h6g7"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6", "e7d8", "e7f6", "e7f8", "e7g5"], "e8": ["e8a8", "e8b8", "e8c8", "e8d8", "e8f8"], "g8": ["g8f8", "g8g4", "g8g5", "g8g6", "g8g7", "g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7b5 b7b6 c6c5 e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7f8 e7g5 e8a8 e8b8 e8c8 e8d8 e8f8 g8f8 g8g4 g8g5 g8g6 g8g7 g8h8 h4f2 h4f6 h4g3 h4g4 h4g5 h4h3 h5g4 h6g7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"f3": [], "h4": ["h4f2", "h4f6", "h4g3", "h4g4", "h4g5", "h4h3"], "h5": ["h5g4"], "c6": ["c6c5"], "h6": ["h6g7"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6", "e7d8", "e7f6", "e7f8", "e7g5"], "e8": ["e8a8", "e8b8", "e8c8", "e8d8", "e8f8"], "g8": ["g8f8", "g8g4", "g8g5", "g8g6", "g8g7", "g8h8"]}, "legal_moves": "a7a5 a7a6 b7b5 b7b6 c6c5 e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7f8 e7g5 e8a8 e8b8 e8c8 e8d8 e8f8 g8f8 g8g4 g8g5 g8g6 g8g7 g8h8 h4f2 h4f6 h4g3 h4g4 h4g5 h4h3 h5g4 h6g7"}}
{"example_id": "rules_01155", "split": "rules", "task_type": "ray_walk", "fen": "6k1/p1q2p1p/1p2p1p1/8/8/P3Q1RP/1P3PPK/3r4 b - - 3 28", "prompt": "FEN: 6k1/p1q2p1p/1p2p1p1/8/8/P3Q1RP/1P3PPK/3r4 b - - 3 28\nWalk each ray for the slider on d1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d1 black rook.\nRay N: d2 empty; d3 empty; d4 empty; d5 empty; d6 empty; d7 empty; d8 empty; edge.\nRay E: e1 empty; f1 empty; g1 empty; h1 empty; edge.\nRay S: edge.\nRay W: c1 empty; b1 empty; a1 empty; edge.\nMoves from rays: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 d1g1 d1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_01156", "split": "rules", "task_type": "legal_moves", "fen": "rn2kb1r/ppp1qppp/3p1n2/8/6b1/2NBBN2/PPP2PPP/R2QK2R w KQkq - 4 9", "prompt": "FEN: rn2kb1r/ppp1qppp/3p1n2/8/6b1/2NBBN2/PPP2PPP/R2QK2R w KQkq - 4 9\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a2a3 a2a4 b2b3 b2b4 c3a4 c3b1 c3b5 c3d5 c3e2 c3e4 d1b1 d1c1 d1d2 d1e2 d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 d3g6 d3h7 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01157", "split": "rules", "task_type": "legal_moves", "fen": "5rk1/5pq1/Q3b3/2ppp2B/3b2P1/P6P/1PP5/3K1R2 w - - 0 25", "prompt": "FEN: 5rk1/5pq1/Q3b3/2ppp2B/3b2P1/P6P/1PP5/3K1R2 w - - 0 25\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 a6a4 a6a5 a6a7 a6a8 a6b5 a6b6 a6b7 a6c4 a6c6 a6c8 a6d3 a6d6 a6e2 a6e6 b2b3 b2b4 c2c3 c2c4 d1c1 d1d2 d1e1 d1e2 f1e1 f1f2 f1f3 f1f4 f1f5 f1f6 f1f7 f1g1 f1h1 g4g5 h3h4 h5f7 h5g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01158", "split": "rules", "task_type": "side_piece_inventory", "fen": "r4rk1/1p1qb1pp/p1nppn2/4p1N1/N3P3/4B2P/PP2QPP1/2RR2K1 b - -", "prompt": "FEN: r4rk1/1p1qb1pp/p1nppn2/4p1N1/N3P3/4B2P/PP2QPP1/2RR2K1 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: e5 black pawn; a6 black pawn; c6 black knight; d6 black pawn; e6 black pawn; f6 black knight; b7 black pawn; d7 black queen; e7 black bishop; g7 black pawn; h7 black pawn; a8 black rook; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "d6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black queen"}, {"square": "e7", "piece": "black bishop"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "d6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black queen"}, {"square": "e7", "piece": "black bishop"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01159", "split": "rules", "task_type": "piece_legal_moves", "fen": "r5k1/1r2b1pp/5p2/3pB3/3N2b1/4P3/p4PPP/R1R3K1 w - - 0 26", "prompt": "FEN: r5k1/1r2b1pp/5p2/3pB3/3N2b1/4P3/p4PPP/R1R3K1 w - - 0 26\nWhat legal moves does the piece on g2 have?", "gold_answer": "g2g3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "g2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g2", "piece": "pawn"}}
{"example_id": "rules_01160", "split": "rules", "task_type": "check_detection", "fen": "3n2k1/ppp3p1/4p1p1/4P3/8/P1B2N1P/1PP1n1PK/8 w - - 0 23", "prompt": "FEN: 3n2k1/ppp3p1/4p1p1/4P3/8/P1B2N1P/1PP1n1PK/8 w - - 0 23\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01161", "split": "rules", "task_type": "captures", "fen": "rnbqk1nr/pp1pppbp/6p1/2p5/4P3/6P1/PPPPNPBP/RNBQK2R b KQkq -", "prompt": "FEN: rnbqk1nr/pp1pppbp/6p1/2p5/4P3/6P1/PPPPNPBP/RNBQK2R b KQkq -\nList all capture moves available.", "gold_answer": "g7b2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01162", "split": "rules", "task_type": "special_rules", "fen": "rnbq1rk1/pp2npbp/3pp1p1/2p5/3P4/1P2PN2/PBP2PPP/RN1QKB1R w KQ - 0 8", "prompt": "Given FEN: rnbq1rk1/pp2npbp/3pp1p1/2p5/3P4/1P2PN2/PBP2PPP/RN1QKB1R w KQ - 0 8\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01163", "split": "rules", "task_type": "legality_check", "fen": "6k1/p4pp1/1p3n1p/1b1p1P2/P2P4/1P3NqP/3Qr1P1/1BR4K w - - 1 31", "prompt": "FEN: 6k1/p4pp1/1p3n1p/1b1p1P2/P2P4/1P3NqP/3Qr1P1/1BR4K w - - 1 31\nIs the move f6b1 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f6b1", "_legality_check_reason_label": "wrong_side_piece", "move": "f6b1", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01164", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1bq1rk1/ppp1bppp/3p1n2/8/1n2P3/3Q1N2/PPP1BPPP/RNB1R1K1 w - - 5 11", "prompt": "FEN: r1bq1rk1/ppp1bppp/3p1n2/8/1n2P3/3Q1N2/PPP1BPPP/RNB1R1K1 w - - 5 11\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a3 b1c3 b1d2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01165", "split": "rules", "task_type": "piece_legal_filter", "fen": "2B5/P1R5/5k1p/3b4/1P3K1P/8/5r2/8 w - -", "prompt": "FEN: 2B5/P1R5/5k1p/3b4/1P3K1P/8/5r2/8 w - -\nFor the piece on b4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b4: b4b5.\nLegal: none.\nRejected: b4b5 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_01166", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbqk1nr/pppp1p1p/4p1p1/8/1P1P4/P1P1P3/5PPP/bNBQKBNR b Kkq - 0 5", "prompt": "FEN: rnbqk1nr/pppp1p1p/4p1p1/8/1P1P4/P1P1P3/5PPP/bNBQKBNR b Kkq - 0 5\nFor move a1b2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b2.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b2", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b2", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01167", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "5k2/4n1p1/2pQp3/3pPp2/PP6/1KP5/5q2/R4B2 b - - 3 42", "prompt": "FEN: 5k2/4n1p1/2pQp3/3pPp2/PP6/1KP5/5q2/R4B2 b - - 3 42\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: f2 black queen; d5 black pawn; f5 black pawn; c6 black pawn; e6 black pawn; e7 black knight; g7 black pawn; f8 black king.\nMoves by piece:\nf2 black queen: f2a2 f2a7 f2b2 f2b6 f2c2 f2c5 f2d2 f2d4 f2e1 f2e2 f2e3 f2f1 f2f3 f2f4 f2g1 f2g2 f2g3 f2h2 f2h4\nd5 black pawn: d5d4\nf5 black pawn: f5f4\nc6 black pawn: c6c5\ne6 black pawn: no legal moves\ne7 black knight: no legal moves\ng7 black pawn: g7g5 g7g6\nf8 black king: f8e8 f8f7 f8g8\nAll legal moves: c6c5 d5d4 f2a2 f2a7 f2b2 f2b6 f2c2 f2c5 f2d2 f2d4 f2e1 f2e2 f2e3 f2f1 f2f3 f2f4 f2g1 f2g2 f2g3 f2h2 f2h4 f5f4 f8e8 f8f7 f8g8 g7g5 g7g6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"f2": ["f2a2", "f2a7", "f2b2", "f2b6", "f2c2", "f2c5", "f2d2", "f2d4", "f2e1", "f2e2", "f2e3", "f2f1", "f2f3", "f2f4", "f2g1", "f2g2", "f2g3", "f2h2", "f2h4"], "d5": ["d5d4"], "f5": ["f5f4"], "c6": ["c6c5"], "e6": [], "e7": [], "g7": ["g7g5", "g7g6"], "f8": ["f8e8", "f8f7", "f8g8"]}, "_legal_moves_by_piece_moves": "c6c5 d5d4 f2a2 f2a7 f2b2 f2b6 f2c2 f2c5 f2d2 f2d4 f2e1 f2e2 f2e3 f2f1 f2f3 f2f4 f2g1 f2g2 f2g3 f2h2 f2h4 f5f4 f8e8 f8f7 f8g8 g7g5 g7g6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"f2": ["f2a2", "f2a7", "f2b2", "f2b6", "f2c2", "f2c5", "f2d2", "f2d4", "f2e1", "f2e2", "f2e3", "f2f1", "f2f3", "f2f4", "f2g1", "f2g2", "f2g3", "f2h2", "f2h4"], "d5": ["d5d4"], "f5": ["f5f4"], "c6": ["c6c5"], "e6": [], "e7": [], "g7": ["g7g5", "g7g6"], "f8": ["f8e8", "f8f7", "f8g8"]}, "legal_moves": "c6c5 d5d4 f2a2 f2a7 f2b2 f2b6 f2c2 f2c5 f2d2 f2d4 f2e1 f2e2 f2e3 f2f1 f2f3 f2f4 f2g1 f2g2 f2g3 f2h2 f2h4 f5f4 f8e8 f8f7 f8g8 g7g5 g7g6"}}
{"example_id": "rules_01168", "split": "rules", "task_type": "ray_walk", "fen": "2rr4/pp3pkp/5np1/1N2pb2/P1Pp4/7P/1P2PPP1/2R1KB1R b K c3 0 16", "prompt": "FEN: 2rr4/pp3pkp/5np1/1N2pb2/P1Pp4/7P/1P2PPP1/2R1KB1R b K c3 0 16\nWalk each ray for the slider on f5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: f5 black bishop.\nRay NE: g6 black pawn: own piece (stop, excluded).\nRay SE: g4 empty; h3 white pawn: capture (stop, included).\nRay SW: e4 empty; d3 empty; c2 empty; b1 empty; edge.\nRay NW: e6 empty; d7 empty; c8 black rook: own piece (stop, excluded).\nMoves from rays: f5b1 f5c2 f5d3 f5d7 f5e4 f5e6 f5g4 f5h3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "f5", "diagnostic": true, "hard_gate": false, "source_square": "f5"}}
{"example_id": "rules_01169", "split": "rules", "task_type": "legal_moves", "fen": "8/p5bk/1pn1q1pp/2pQ1p1n/P4P1N/2P1N1P1/1P5P/2B3K1 b - - 3 26", "prompt": "FEN: 8/p5bk/1pn1q1pp/2pQ1p1n/P4P1N/2P1N1P1/1P5P/2B3K1 b - - 3 26\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6b5 c5c4 c6a5 c6b4 c6b8 c6d4 c6d8 c6e5 c6e7 e6c8 e6d5 e6d6 e6d7 e6e3 e6e4 e6e5 e6e7 e6e8 e6f6 e6f7 e6g8 g6g5 g7c3 g7d4 g7e5 g7f6 g7f8 g7h8 h5f4 h5f6 h5g3 h7g8 h7h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01170", "split": "rules", "task_type": "legal_moves", "fen": "3r1rk1/p2P3p/b1p3p1/4pn2/2P1N2q/1P6/P2Q2PP/3RR2K w - -", "prompt": "FEN: 3r1rk1/p2P3p/b1p3p1/4pn2/2P1N2q/1P6/P2Q2PP/3RR2K w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b3b4 c4c5 d1a1 d1b1 d1c1 d2a5 d2b2 d2b4 d2c1 d2c2 d2c3 d2d3 d2d4 d2d5 d2d6 d2e2 d2e3 d2f2 d2f4 d2g5 d2h6 e1e2 e1e3 e1f1 e1g1 e4c3 e4c5 e4d6 e4f2 e4f6 e4g3 e4g5 g2g3 g2g4 h1g1 h2h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01171", "split": "rules", "task_type": "side_piece_inventory", "fen": "2r5/8/5N1k/5K2/7R/7P/8/8 b - -", "prompt": "FEN: 2r5/8/5N1k/5K2/7R/7P/8/8 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: h6 black king; c8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "h6", "piece": "black king"}, {"square": "c8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "h6", "piece": "black king"}, {"square": "c8", "piece": "black rook"}]}}
{"example_id": "rules_01172", "split": "rules", "task_type": "piece_legal_moves", "fen": "r3r1k1/ppp2pp1/2p1b2p/2q5/3p1B2/5N1P/PPP2PP1/R2QR1K1 b - - 1 15", "prompt": "FEN: r3r1k1/ppp2pp1/2p1b2p/2q5/3p1B2/5N1P/PPP2PP1/R2QR1K1 b - - 1 15\nWhat legal moves does the piece on c5 have?", "gold_answer": "c5a3 c5a5 c5b4 c5b5 c5b6 c5c2 c5c3 c5c4 c5d5 c5d6 c5e5 c5e7 c5f5 c5f8 c5g5 c5h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c5", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "c5", "piece": "queen"}}
{"example_id": "rules_01173", "split": "rules", "task_type": "check_detection", "fen": "rn1R3k/6np/b3Brp1/6N1/p1P4P/5P2/P5P1/2K1R3 b - - 1 28", "prompt": "FEN: rn1R3k/6np/b3Brp1/6N1/p1P4P/5P2/P5P1/2K1R3 b - - 1 28\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01174", "split": "rules", "task_type": "captures", "fen": "r2q1r2/pp2bp1k/3p2pp/n1pNp3/2B1P3/2PP1Q1P/PP3P1P/2KR2R1 w - - 6 15", "prompt": "FEN: r2q1r2/pp2bp1k/3p2pp/n1pNp3/2B1P3/2PP1Q1P/PP3P1P/2KR2R1 w - - 6 15\nList all capture moves available.", "gold_answer": "d5e7 f3f7 g1g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01175", "split": "rules", "task_type": "special_rules", "fen": "8/6p1/3pk1p1/r7/p4R2/3K4/PP6/8 b - - 8 40", "prompt": "Given FEN: 8/6p1/3pk1p1/r7/p4R2/3K4/PP6/8 b - - 8 40\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01176", "split": "rules", "task_type": "legality_check", "fen": "r4rk1/ppp2ppp/6q1/4p3/1PPn4/P2P2Pb/1B3P1P/RN1QR1K1 b - - 0 14", "prompt": "FEN: r4rk1/ppp2ppp/6q1/4p3/1PPn4/P2P2Pb/1B3P1P/RN1QR1K1 b - - 0 14\nIs the move b7b6 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b7b6", "_legality_check_reason_label": "legal", "move": "b7b6", "legality_reason_label": "legal"}}
{"example_id": "rules_01177", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2kr3r/1pp1bppp/p1p2n2/4B3/q1N1P3/3P1Q2/P4PPP/R1R3K1 b - -", "prompt": "FEN: 2kr3r/1pp1bppp/p1p2n2/4B3/q1N1P3/3P1Q2/P4PPP/R1R3K1 b - -\nList pseudo-legal moves from a4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a4: a4a2 a4a3 a4a5 a4b3 a4b4 a4b5 a4c2 a4c4 a4d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a4", "diagnostic": true, "hard_gate": false, "source_square": "a4"}}
{"example_id": "rules_01178", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/1P2k1p1/8/p2RPp1p/1p1K1P1P/1P4r1/P7/8 b - -", "prompt": "FEN: 8/1P2k1p1/8/p2RPp1p/1p1K1P1P/1P4r1/P7/8 b - -\nFor the piece on e7, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e7: e7d6 e7d7 e7d8 e7e6 e7e8 e7f6 e7f7 e7f8.\nLegal: e7e6 e7e8 e7f7 e7f8.\nRejected: e7d6 king_would_be_in_check; e7d7 king_would_be_in_check; e7d8 king_would_be_in_check; e7f6 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "e7", "diagnostic": true, "hard_gate": false, "source_square": "e7"}}
{"example_id": "rules_01179", "split": "rules", "task_type": "king_safety_filter", "fen": "2kr1bnr/p2p4/bpp2pp1/8/3P1B2/2P2N1P/PP1N2P1/R3R1K1 b - - 1 18", "prompt": "FEN: 2kr1bnr/p2p4/bpp2pp1/8/3P1B2/2P2N1P/PP1N2P1/R3R1K1 b - - 1 18\nFor move c8b8, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c8b8.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "c8b8", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "c8b8", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01180", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r2kr3/pq2b1Qp/1p4p1/1b6/5P2/8/PPP3PP/R1BR2K1 b - - 4 22", "prompt": "FEN: r2kr3/pq2b1Qp/1p4p1/1b6/5P2/8/PPP3PP/R1BR2K1 b - - 4 22\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b5 black bishop; b6 black pawn; g6 black pawn; a7 black pawn; b7 black queen; e7 black bishop; h7 black pawn; a8 black rook; d8 black king; e8 black rook.\nMoves by piece:\nb5 black bishop: b5d3 b5d7\nb6 black pawn: no legal moves\ng6 black pawn: no legal moves\na7 black pawn: no legal moves\nb7 black queen: b7d5 b7d7\ne7 black bishop: e7d6\nh7 black pawn: no legal moves\na8 black rook: no legal moves\nd8 black king: d8c7 d8c8\ne8 black rook: no legal moves\nAll legal moves: b5d3 b5d7 b7d5 b7d7 d8c7 d8c8 e7d6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b5": ["b5d3", "b5d7"], "b6": [], "g6": [], "a7": [], "b7": ["b7d5", "b7d7"], "e7": ["e7d6"], "h7": [], "a8": [], "d8": ["d8c7", "d8c8"], "e8": []}, "_legal_moves_by_piece_moves": "b5d3 b5d7 b7d5 b7d7 d8c7 d8c8 e7d6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b5": ["b5d3", "b5d7"], "b6": [], "g6": [], "a7": [], "b7": ["b7d5", "b7d7"], "e7": ["e7d6"], "h7": [], "a8": [], "d8": ["d8c7", "d8c8"], "e8": []}, "legal_moves": "b5d3 b5d7 b7d5 b7d7 d8c7 d8c8 e7d6"}}
{"example_id": "rules_01181", "split": "rules", "task_type": "ray_walk", "fen": "5bnr/1k1r1bpp/p2p1p2/B2Pp3/4P3/3B1N1P/5PP1/RNR3K1 w - - 3 22", "prompt": "FEN: 5bnr/1k1r1bpp/p2p1p2/B2Pp3/4P3/3B1N1P/5PP1/RNR3K1 w - - 3 22\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 empty; a3 empty; a4 empty; a5 white bishop: own piece (stop, excluded).\nRay E: b1 white knight: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1a2 a1a3 a1a4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01182", "split": "rules", "task_type": "legal_moves", "fen": "4k2r/p1p1nppp/1p1pp3/2b5/P1N1P3/1P1R1N2/5PPP/3R2K1 b k - 5 20", "prompt": "FEN: 4k2r/p1p1nppp/1p1pp3/2b5/P1N1P3/1P1R1N2/5PPP/3R2K1 b k - 5 20\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6b5 c5a3 c5b4 c5d4 c5e3 c5f2 c7c6 d6d5 e6e5 e7c6 e7c8 e7d5 e7f5 e7g6 e7g8 e8d7 e8d8 e8f8 e8g8 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01183", "split": "rules", "task_type": "legal_moves", "fen": "8/p7/6p1/3Q2P1/2P2p2/1PkPRB1P/n7/6K1 w - - 0 40", "prompt": "FEN: 8/p7/6p1/3Q2P1/2P2p2/1PkPRB1P/n7/6K1 w - - 0 40\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b3b4 c4c5 d3d4 d5a5 d5a8 d5b5 d5b7 d5c5 d5c6 d5d4 d5d6 d5d7 d5d8 d5e4 d5e5 d5e6 d5f5 d5f7 d5g8 e3e1 e3e2 e3e4 e3e5 e3e6 e3e7 e3e8 f3d1 f3e2 f3e4 f3g2 f3g4 f3h1 f3h5 g1f1 g1f2 g1g2 g1h1 g1h2 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01184", "split": "rules", "task_type": "side_piece_inventory", "fen": "r5k1/pp1bpp1p/3p2pQ/4n1PR/4P3/1B2qP2/P1P5/1K1R4 b - -", "prompt": "FEN: r5k1/pp1bpp1p/3p2pQ/4n1PR/4P3/1B2qP2/P1P5/1K1R4 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: e3 black queen; e5 black knight; d6 black pawn; g6 black pawn; a7 black pawn; b7 black pawn; d7 black bishop; e7 black pawn; f7 black pawn; h7 black pawn; a8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "e3", "piece": "black queen"}, {"square": "e5", "piece": "black knight"}, {"square": "d6", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black bishop"}, {"square": "e7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "e3", "piece": "black queen"}, {"square": "e5", "piece": "black knight"}, {"square": "d6", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black bishop"}, {"square": "e7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01185", "split": "rules", "task_type": "piece_legal_moves", "fen": "rn2kbnr/1p2qpp1/p5bp/2pN4/3pP1PP/N4P2/PPP1B3/R1BQK2R b KQkq - 1 14", "prompt": "FEN: rn2kbnr/1p2qpp1/p5bp/2pN4/3pP1PP/N4P2/PPP1B3/R1BQK2R b KQkq - 1 14\nWhat legal moves does the piece on f7 have?", "gold_answer": "f7f5 f7f6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f7", "piece": "pawn"}}
{"example_id": "rules_01186", "split": "rules", "task_type": "check_detection", "fen": "r3k2r/1pp1bppp/p1p1bn2/4N2Q/4P3/3PB3/PPqN1PPP/R4RK1 w kq -", "prompt": "FEN: r3k2r/1pp1bppp/p1p1bn2/4N2Q/4P3/3PB3/PPqN1PPP/R4RK1 w kq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01187", "split": "rules", "task_type": "captures", "fen": "8/8/p5K1/1p6/1P2n3/P4k2/8/8 w - - 3 49", "prompt": "FEN: 8/8/p5K1/1p6/1P2n3/P4k2/8/8 w - - 3 49\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01188", "split": "rules", "task_type": "special_rules", "fen": "2kr3r/pp3pbp/2pp2p1/6P1/4P3/1PNP4/1P1KBP2/7R w - - 1 21", "prompt": "Given FEN: 2kr3r/pp3pbp/2pp2p1/6P1/4P3/1PNP4/1P1KBP2/7R w - - 1 21\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01189", "split": "rules", "task_type": "legality_check", "fen": "rnbq1rk1/pp3ppp/4pn2/2p5/1bpP4/2NBPN2/PP3PPP/R1BQ1RK1 w - -", "prompt": "FEN: rnbq1rk1/pp3ppp/4pn2/2p5/1bpP4/2NBPN2/PP3PPP/R1BQ1RK1 w - -\nIs the move d3a7 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "d3a7", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "d3a7", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_01190", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/8/6p1/4Kp1p/6k1/8/8/6R1 b - -", "prompt": "FEN: 8/8/6p1/4Kp1p/6k1/8/8/6R1 b - -\nList pseudo-legal moves from g4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g4: g4f3 g4f4 g4g3 g4g5 g4h3 g4h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g4", "diagnostic": true, "hard_gate": false, "source_square": "g4"}}
{"example_id": "rules_01191", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2q1rk1/3nbppp/p1bp4/2p5/2P1PR2/P2PN3/4Q1PP/RBB3K1 w - - 1 18", "prompt": "FEN: r2q1rk1/3nbppp/p1bp4/2p5/2P1PR2/P2PN3/4Q1PP/RBB3K1 w - - 1 18\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1a2.\nLegal: a1a2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01192", "split": "rules", "task_type": "king_safety_filter", "fen": "4rrk1/1p1b2pp/p2bpqp1/3p4/2P5/6P1/PP1NQP1P/R1B2RK1 w - - 1 18", "prompt": "FEN: 4rrk1/1p1b2pp/p2bpqp1/3p4/2P5/6P1/PP1NQP1P/R1B2RK1 w - - 1 18\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01193", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/2pkn1N1/7p/pp2KP2/1P4P1/P3P2P/8/8 b - - 0 35", "prompt": "FEN: 8/2pkn1N1/7p/pp2KP2/1P4P1/P3P2P/8/8 b - - 0 35\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a5 black pawn; b5 black pawn; h6 black pawn; c7 black pawn; d7 black king; e7 black knight.\nMoves by piece:\na5 black pawn: a5a4 a5b4\nb5 black pawn: no legal moves\nh6 black pawn: h6h5\nc7 black pawn: c7c5 c7c6\nd7 black king: d7c6 d7c8 d7d8\ne7 black knight: e7c6 e7c8 e7d5 e7f5 e7g6 e7g8\nAll legal moves: a5a4 a5b4 c7c5 c7c6 d7c6 d7c8 d7d8 e7c6 e7c8 e7d5 e7f5 e7g6 e7g8 h6h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a5": ["a5a4", "a5b4"], "b5": [], "h6": ["h6h5"], "c7": ["c7c5", "c7c6"], "d7": ["d7c6", "d7c8", "d7d8"], "e7": ["e7c6", "e7c8", "e7d5", "e7f5", "e7g6", "e7g8"]}, "_legal_moves_by_piece_moves": "a5a4 a5b4 c7c5 c7c6 d7c6 d7c8 d7d8 e7c6 e7c8 e7d5 e7f5 e7g6 e7g8 h6h5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a5": ["a5a4", "a5b4"], "b5": [], "h6": ["h6h5"], "c7": ["c7c5", "c7c6"], "d7": ["d7c6", "d7c8", "d7d8"], "e7": ["e7c6", "e7c8", "e7d5", "e7f5", "e7g6", "e7g8"]}, "legal_moves": "a5a4 a5b4 c7c5 c7c6 d7c6 d7c8 d7d8 e7c6 e7c8 e7d5 e7f5 e7g6 e7g8 h6h5"}}
{"example_id": "rules_01194", "split": "rules", "task_type": "ray_walk", "fen": "r3r1k1/pp1q1ppp/n1pb1n2/3p4/3P4/2N1PNP1/PPQB1PKP/R3R3 w - -", "prompt": "FEN: r3r1k1/pp1q1ppp/n1pb1n2/3p4/3P4/2N1PNP1/PPQB1PKP/R3R3 w - -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 empty; e1 white rook: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1 a1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01195", "split": "rules", "task_type": "legal_moves", "fen": "r5k1/1p3ppp/5q2/p1nQ4/P1P1r3/8/2P2PPP/R3R1K1 w - - 0 20", "prompt": "FEN: r5k1/1p3ppp/5q2/p1nQ4/P1P1r3/8/2P2PPP/R3R1K1 w - - 0 20\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 a1b1 a1c1 a1d1 c2c3 d5b7 d5c5 d5c6 d5d1 d5d2 d5d3 d5d4 d5d6 d5d7 d5d8 d5e4 d5e5 d5e6 d5f5 d5f7 d5g5 d5h5 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1f1 f2f3 f2f4 g1f1 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01196", "split": "rules", "task_type": "legal_moves", "fen": "r1b2rk1/pp2ppbp/4n1p1/q7/3BP3/2P1QN2/P3BPPP/R4RK1 w - -", "prompt": "FEN: r1b2rk1/pp2ppbp/4n1p1/q7/3BP3/2P1QN2/P3BPPP/R4RK1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a1d1 a1e1 a2a3 a2a4 c3c4 d4a7 d4b6 d4c5 d4e5 d4f6 d4g7 e2a6 e2b5 e2c4 e2d1 e2d3 e3c1 e3d2 e3d3 e3f4 e3g5 e3h6 e4e5 f1b1 f1c1 f1d1 f1e1 f3d2 f3e1 f3e5 f3g5 f3h4 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01197", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bq1rk1/3n1pbp/pp2pnp1/3p4/3P4/2NN4/PPP2PPP/R1BQRBK1 w - -", "prompt": "FEN: r1bq1rk1/3n1pbp/pp2pnp1/3p4/3P4/2NN4/PPP2PPP/R1BQRBK1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; e1 white rook; f1 white bishop; g1 white king; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white knight; d3 white knight; d4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white rook"}, {"square": "f1", "piece": "white bishop"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d3", "piece": "white knight"}, {"square": "d4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white rook"}, {"square": "f1", "piece": "white bishop"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "d3", "piece": "white knight"}, {"square": "d4", "piece": "white pawn"}]}}
{"example_id": "rules_01198", "split": "rules", "task_type": "piece_legal_moves", "fen": "2r5/kb6/1p2P3/pB1p4/3P4/Q4N2/2PN2P1/2K3R1 b - - 0 34", "prompt": "FEN: 2r5/kb6/1p2P3/pB1p4/3P4/Q4N2/2PN2P1/2K3R1 b - - 0 34\nWhat legal moves does the piece on c8 have?", "gold_answer": "c8a8 c8b8 c8c2 c8c3 c8c4 c8c5 c8c6 c8c7 c8d8 c8e8 c8f8 c8g8 c8h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c8", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "c8", "piece": "rook"}}
{"example_id": "rules_01199", "split": "rules", "task_type": "check_detection", "fen": "2r2rk1/3nqpb1/3p1np1/p5Bp/Pp1NP1PP/3Q4/1P3P1N/R3K2R b KQ - 0 20", "prompt": "FEN: 2r2rk1/3nqpb1/3p1np1/p5Bp/Pp1NP1PP/3Q4/1P3P1N/R3K2R b KQ - 0 20\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01200", "split": "rules", "task_type": "captures", "fen": "rn3rk1/pp3p2/b1p2qpQ/5NR1/3P4/2P5/PPB3PP/R5K1 w - - 2 28", "prompt": "FEN: rn3rk1/pp3p2/b1p2qpQ/5NR1/3P4/2P5/PPB3PP/R5K1 w - - 2 28\nList all capture moves available.", "gold_answer": "g5g6 h6f8 h6g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01201", "split": "rules", "task_type": "special_rules", "fen": "r3k2r/p1p3p1/2p1p3/2p1P3/4P3/2P2QK1/PP1q3p/R6R w kq - 0 21", "prompt": "Given FEN: r3k2r/p1p3p1/2p1p3/2p1P3/4P3/2P2QK1/PP1q3p/R6R w kq - 0 21\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01202", "split": "rules", "task_type": "legality_check", "fen": "r1b2rk1/1p3p1p/p3q1p1/2p4Q/2Pb4/2NB4/PP4PP/R4R1K w - - 0 17", "prompt": "FEN: r1b2rk1/1p3p1p/p3q1p1/2p4Q/2Pb4/2NB4/PP4PP/R4R1K w - - 0 17\nIs the move b2b7 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b2b7", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "b2b7", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_01203", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rn1qk1nr/pbpp1pbp/1p2p1p1/8/3PPP2/2NBB3/PPP3PP/R2QK1NR b KQkq - 1 6", "prompt": "FEN: rn1qk1nr/pbpp1pbp/1p2p1p1/8/3PPP2/2NBB3/PPP3PP/R2QK1NR b KQkq - 1 6\nList pseudo-legal moves from b6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b6: b6b5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b6", "diagnostic": true, "hard_gate": false, "source_square": "b6"}}
{"example_id": "rules_01204", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1bBr1k1/pp1p1p1p/3p2p1/8/8/3P2n1/PP2NPPP/RN2K2R w KQ - 0 16", "prompt": "FEN: r1bBr1k1/pp1p1p1p/3p2p1/8/8/3P2n1/PP2NPPP/RN2K2R w KQ - 0 16\nFor the piece on e1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e1: e1d1 e1d2 e1f1.\nLegal: e1d1 e1d2.\nRejected: e1f1 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "e1", "diagnostic": true, "hard_gate": false, "source_square": "e1"}}
{"example_id": "rules_01205", "split": "rules", "task_type": "king_safety_filter", "fen": "4k3/2Q5/4K3/6n1/8/8/8/8 w - -", "prompt": "FEN: 4k3/2Q5/4K3/6n1/8/8/8/8 w - -\nFor move c7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c7a5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "c7a5", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "c7a5", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_01206", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bq1rk1/pp1nbppp/4pn2/1NPp4/8/PP2PP2/1BP3PP/R2QKBNR b KQ - 0 9", "prompt": "FEN: r1bq1rk1/pp1nbppp/4pn2/1NPp4/8/PP2PP2/1BP3PP/R2QKBNR b KQ - 0 9\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; e6 black pawn; f6 black knight; a7 black pawn; b7 black pawn; d7 black knight; e7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; f8 black rook; g8 black king.\nMoves by piece:\nd5 black pawn: d5d4\ne6 black pawn: e6e5\nf6 black knight: f6e4 f6e8 f6g4 f6h5\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b6\nd7 black knight: d7b6 d7b8 d7c5 d7e5\ne7 black bishop: e7c5 e7d6\nf7 black pawn: no legal moves\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8\nc8 black bishop: no legal moves\nd8 black queen: d8a5 d8b6 d8c7 d8e8\nf8 black rook: f8e8\ng8 black king: g8h8\nAll legal moves: a7a5 a7a6 a8b8 b7b6 d5d4 d7b6 d7b8 d7c5 d7e5 d8a5 d8b6 d8c7 d8e8 e6e5 e7c5 e7d6 f6e4 f6e8 f6g4 f6h5 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d5": ["d5d4"], "e6": ["e6e5"], "f6": ["f6e4", "f6e8", "f6g4", "f6h5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b6"], "d7": ["d7b6", "d7b8", "d7c5", "d7e5"], "e7": ["e7c5", "e7d6"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": [], "d8": ["d8a5", "d8b6", "d8c7", "d8e8"], "f8": ["f8e8"], "g8": ["g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 b7b6 d5d4 d7b6 d7b8 d7c5 d7e5 d8a5 d8b6 d8c7 d8e8 e6e5 e7c5 e7d6 f6e4 f6e8 f6g4 f6h5 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d5": ["d5d4"], "e6": ["e6e5"], "f6": ["f6e4", "f6e8", "f6g4", "f6h5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b6"], "d7": ["d7b6", "d7b8", "d7c5", "d7e5"], "e7": ["e7c5", "e7d6"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": [], "d8": ["d8a5", "d8b6", "d8c7", "d8e8"], "f8": ["f8e8"], "g8": ["g8h8"]}, "legal_moves": "a7a5 a7a6 a8b8 b7b6 d5d4 d7b6 d7b8 d7c5 d7e5 d8a5 d8b6 d8c7 d8e8 e6e5 e7c5 e7d6 f6e4 f6e8 f6g4 f6h5 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6"}}
{"example_id": "rules_01207", "split": "rules", "task_type": "ray_walk", "fen": "5n2/4r1k1/p1R1pq2/2P3pp/1P2Qp2/5P2/P5PP/4R1K1 b - - 0 36", "prompt": "FEN: 5n2/4r1k1/p1R1pq2/2P3pp/1P2Qp2/5P2/P5PP/4R1K1 b - - 0 36\nWalk each ray for the slider on f6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: f6 black queen.\nRay N: f7 empty; f8 black knight: own piece (stop, excluded).\nRay NE: g7 black king: own piece (stop, excluded).\nRay E: g6 empty; h6 empty; edge.\nRay SE: g5 black pawn: own piece (stop, excluded).\nRay S: f5 empty; f4 black pawn: own piece (stop, excluded).\nRay SW: e5 empty; d4 empty; c3 empty; b2 empty; a1 empty; edge.\nRay W: e6 black pawn: own piece (stop, excluded).\nRay NW: e7 black rook: own piece (stop, excluded).\nMoves from rays: f6a1 f6b2 f6c3 f6d4 f6e5 f6f5 f6f7 f6g6 f6h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "f6", "diagnostic": true, "hard_gate": false, "source_square": "f6"}}
{"example_id": "rules_01208", "split": "rules", "task_type": "legal_moves", "fen": "r1b2knr/ppNp1ppp/2n5/8/1q2P3/2N1P3/P1P3PP/R2QKB1R w KQ -", "prompt": "FEN: r1b2knr/ppNp1ppp/2n5/8/1q2P3/2N1P3/P1P3PP/R2QKB1R w KQ -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a2a3 a2a4 c7a6 c7a8 c7b5 c7d5 c7e6 c7e8 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1e2 d1f3 d1g4 d1h5 e1d2 e1e2 e1f2 e4e5 f1a6 f1b5 f1c4 f1d3 f1e2 g2g3 g2g4 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01209", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/pp2bpp1/3pbn1p/4p3/4P3/2NQBP2/PPP3PP/2KR1B1R w - - 2 12", "prompt": "FEN: r2q1rk1/pp2bpp1/3pbn1p/4p3/4P3/2NQBP2/PPP3PP/2KR1B1R w - - 2 12\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 b2b4 c1b1 c1d2 c3a4 c3b1 c3b5 c3d5 c3e2 d1d2 d1e1 d3a6 d3b5 d3c4 d3d2 d3d4 d3d5 d3d6 d3e2 e3a7 e3b6 e3c5 e3d2 e3d4 e3f2 e3f4 e3g1 e3g5 e3h6 f1e2 f3f4 g2g3 g2g4 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01210", "split": "rules", "task_type": "side_piece_inventory", "fen": "3r1rk1/pp1qbppp/2n1bn2/2ppp3/8/1P1PP1PP/PBPNNPBK/R2Q1R2 w - - 7 12", "prompt": "FEN: 3r1rk1/pp1qbppp/2n1bn2/2ppp3/8/1P1PP1PP/PBPNNPBK/R2Q1R2 w - - 7 12\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white queen; f1 white rook; a2 white pawn; b2 white bishop; c2 white pawn; d2 white knight; e2 white knight; f2 white pawn; g2 white bishop; h2 white king; b3 white pawn; d3 white pawn; e3 white pawn; g3 white pawn; h3 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white bishop"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white knight"}, {"square": "e2", "piece": "white knight"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white bishop"}, {"square": "h2", "piece": "white king"}, {"square": "b3", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white bishop"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white knight"}, {"square": "e2", "piece": "white knight"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white bishop"}, {"square": "h2", "piece": "white king"}, {"square": "b3", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}]}}
{"example_id": "rules_01211", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b3R1/p2p3p/5Rnk/bp6/2BpP3/3P1N2/PP4PP/6K1 w - -", "prompt": "FEN: r1b3R1/p2p3p/5Rnk/bp6/2BpP3/3P1N2/PP4PP/6K1 w - -\nWhat legal moves does the piece on h2 have?", "gold_answer": "h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "h2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "h2", "piece": "pawn"}}
{"example_id": "rules_01212", "split": "rules", "task_type": "check_detection", "fen": "r5k1/1b2qpp1/2p1p2p/1pP1P2P/1P3PP1/p1B5/2B1Q3/K2R4 w - - 1 31", "prompt": "FEN: r5k1/1b2qpp1/2p1p2p/1pP1P2P/1P3PP1/p1B5/2B1Q3/K2R4 w - - 1 31\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01213", "split": "rules", "task_type": "captures", "fen": "rn1qk2r/pp1bbpp1/2pp1n1p/8/3PP3/P1N2N1P/1P3PP1/R1BQKB1R w KQkq - 1 9", "prompt": "FEN: rn1qk2r/pp1bbpp1/2pp1n1p/8/3PP3/P1N2N1P/1P3PP1/R1BQKB1R w KQkq - 1 9\nList all capture moves available.", "gold_answer": "c1h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01214", "split": "rules", "task_type": "special_rules", "fen": "2kr3r/pbpnq3/1p2p1p1/6pp/2PP4/4QPB1/P1P1B1PP/1R3RK1 w - - 1 20", "prompt": "Given FEN: 2kr3r/pbpnq3/1p2p1p1/6pp/2PP4/4QPB1/P1P1B1PP/1R3RK1 w - - 1 20\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01215", "split": "rules", "task_type": "legality_check", "fen": "1rb2rk1/pp2qpp1/3p3p/2pB4/3pP3/3P3P/PPPQ1PP1/2KR3R w - - 2 16", "prompt": "FEN: 1rb2rk1/pp2qpp1/3p3p/2pB4/3pP3/3P3P/PPPQ1PP1/2KR3R w - - 2 16\nIs the move g2h3 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g2h3", "_legality_check_reason_label": "own_piece_destination", "move": "g2h3", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_01216", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1bqk2r/pp1pnppp/2n1p3/2b5/4P3/2N2N2/PPP2PPP/R1BQKB1R w KQkq - 6 7", "prompt": "FEN: r1bqk2r/pp1pnppp/2n1p3/2b5/4P3/2N2N2/PPP2PPP/R1BQKB1R w KQkq - 6 7\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01217", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2qkb1r/ppp1pppp/5n2/3p1b2/3P1P2/2NPPN2/PP4PP/R1BQK2R b KQkq - 0 7", "prompt": "FEN: r2qkb1r/ppp1pppp/5n2/3p1b2/3P1P2/2NPPN2/PP4PP/R1BQK2R b KQkq - 0 7\nFor the piece on f5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f5: f5c8 f5d3 f5d7 f5e4 f5e6 f5g4 f5g6 f5h3.\nLegal: f5c8 f5d3 f5d7 f5e4 f5e6 f5g4 f5g6 f5h3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "f5", "diagnostic": true, "hard_gate": false, "source_square": "f5"}}
{"example_id": "rules_01218", "split": "rules", "task_type": "king_safety_filter", "fen": "8/8/2p1k3/1p6/1P1PK3/2P5/8/8 b - -", "prompt": "FEN: 8/8/2p1k3/1p6/1P1PK3/2P5/8/8 b - -\nFor move e6d5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e6d5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "e6d5", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e6d5", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01219", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1b2rk1/ppq3pp/2nbp3/5p2/Q1N2n2/2P2N2/PP3PPP/R1B1KB1R b KQ -", "prompt": "FEN: r1b2rk1/ppq3pp/2nbp3/5p2/Q1N2n2/2P2N2/PP3PPP/R1B1KB1R b KQ -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: f4 black knight; f5 black pawn; c6 black knight; d6 black bishop; e6 black pawn; a7 black pawn; b7 black pawn; c7 black queen; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; f8 black rook; g8 black king.\nMoves by piece:\nf4 black knight: f4d3 f4d5 f4e2 f4g2 f4g6 f4h3 f4h5\nf5 black pawn: no legal moves\nc6 black knight: c6a5 c6b4 c6b8 c6d4 c6d8 c6e5 c6e7\nd6 black bishop: d6a3 d6b4 d6c5 d6e5 d6e7\ne6 black pawn: e6e5\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nc7 black queen: c7a5 c7b6 c7b8 c7d7 c7d8 c7e7 c7f7\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8\nc8 black bishop: c8d7\nf8 black rook: f8d8 f8e8 f8f6 f8f7\ng8 black king: g8f7 g8h8\nAll legal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6d8 c6e5 c6e7 c7a5 c7b6 c7b8 c7d7 c7d8 c7e7 c7f7 c8d7 d6a3 d6b4 d6c5 d6e5 d6e7 e6e5 f4d3 f4d5 f4e2 f4g2 f4g6 f4h3 f4h5 f8d8 f8e8 f8f6 f8f7 g7g5 g7g6 g8f7 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"f4": ["f4d3", "f4d5", "f4e2", "f4g2", "f4g6", "f4h3", "f4h5"], "f5": [], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6d8", "c6e5", "c6e7"], "d6": ["d6a3", "d6b4", "d6c5", "d6e5", "d6e7"], "e6": ["e6e5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7a5", "c7b6", "c7b8", "c7d7", "c7d8", "c7e7", "c7f7"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7"], "f8": ["f8d8", "f8e8", "f8f6", "f8f7"], "g8": ["g8f7", "g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6d8 c6e5 c6e7 c7a5 c7b6 c7b8 c7d7 c7d8 c7e7 c7f7 c8d7 d6a3 d6b4 d6c5 d6e5 d6e7 e6e5 f4d3 f4d5 f4e2 f4g2 f4g6 f4h3 f4h5 f8d8 f8e8 f8f6 f8f7 g7g5 g7g6 g8f7 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"f4": ["f4d3", "f4d5", "f4e2", "f4g2", "f4g6", "f4h3", "f4h5"], "f5": [], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6d8", "c6e5", "c6e7"], "d6": ["d6a3", "d6b4", "d6c5", "d6e5", "d6e7"], "e6": ["e6e5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7a5", "c7b6", "c7b8", "c7d7", "c7d8", "c7e7", "c7f7"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7"], "f8": ["f8d8", "f8e8", "f8f6", "f8f7"], "g8": ["g8f7", "g8h8"]}, "legal_moves": "a7a5 a7a6 a8b8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6d8 c6e5 c6e7 c7a5 c7b6 c7b8 c7d7 c7d8 c7e7 c7f7 c8d7 d6a3 d6b4 d6c5 d6e5 d6e7 e6e5 f4d3 f4d5 f4e2 f4g2 f4g6 f4h3 f4h5 f8d8 f8e8 f8f6 f8f7 g7g5 g7g6 g8f7 g8h8 h7h5 h7h6"}}
{"example_id": "rules_01220", "split": "rules", "task_type": "ray_walk", "fen": "2r2rk1/1p1nb1p1/q3pP1p/p2p4/3P4/PP3NP1/1B1Q1P1P/2R1R1K1 b - -", "prompt": "FEN: 2r2rk1/1p1nb1p1/q3pP1p/p2p4/3P4/PP3NP1/1B1Q1P1P/2R1R1K1 b - -\nWalk each ray for the slider on a6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a6 black queen.\nRay N: a7 empty; a8 empty; edge.\nRay NE: b7 black pawn: own piece (stop, excluded).\nRay E: b6 empty; c6 empty; d6 empty; e6 black pawn: own piece (stop, excluded).\nRay SE: b5 empty; c4 empty; d3 empty; e2 empty; f1 empty; edge.\nRay S: a5 black pawn: own piece (stop, excluded).\nRay SW: edge.\nRay W: edge.\nRay NW: edge.\nMoves from rays: a6a7 a6a8 a6b5 a6b6 a6c4 a6c6 a6d3 a6d6 a6e2 a6f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a6", "diagnostic": true, "hard_gate": false, "source_square": "a6"}}
{"example_id": "rules_01221", "split": "rules", "task_type": "legal_moves", "fen": "r4rk1/2pR2bp/p4pp1/3pp3/8/P4PBP/1PP2PP1/4R1K1 w - - 0 18", "prompt": "FEN: r4rk1/2pR2bp/p4pp1/3pp3/8/P4PBP/1PP2PP1/4R1K1 w - - 0 18\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 b2b3 b2b4 c2c3 c2c4 d7c7 d7d5 d7d6 d7d8 d7e7 d7f7 d7g7 e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1f1 f3f4 g1f1 g1h1 g1h2 g3e5 g3f4 g3h2 g3h4 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01222", "split": "rules", "task_type": "legal_moves", "fen": "r1bqkb1r/3npppp/p2p1n2/1p6/P1p1P3/2PB1N2/1P1P1PPP/RNBQ1RK1 w kq -", "prompt": "FEN: r1bqkb1r/3npppp/p2p1n2/1p6/P1p1P3/2PB1N2/1P1P1PPP/RNBQ1RK1 w kq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 a4a5 a4b5 b1a3 b2b3 b2b4 d1b3 d1c2 d1e1 d1e2 d3c2 d3c4 d3e2 e4e5 f1e1 f3d4 f3e1 f3e5 f3g5 f3h4 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01223", "split": "rules", "task_type": "side_piece_inventory", "fen": "1k6/2B5/2K5/8/6Bb/8/8/8 b - -", "prompt": "FEN: 1k6/2B5/2K5/8/6Bb/8/8/8 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: h4 black bishop; b8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "h4", "piece": "black bishop"}, {"square": "b8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "h4", "piece": "black bishop"}, {"square": "b8", "piece": "black king"}]}}
{"example_id": "rules_01224", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/8/8/8/8/2K5/2N5/1k3B2 b - -", "prompt": "FEN: 8/8/8/8/8/2K5/2N5/1k3B2 b - -\nWhat legal moves does the piece on b1 have?", "gold_answer": "b1a2 b1c1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "b1", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "b1", "piece": "king"}}
{"example_id": "rules_01225", "split": "rules", "task_type": "check_detection", "fen": "5rk1/p5pp/8/1p6/5qQ1/2P4P/R6K/8 w - - 0 48", "prompt": "FEN: 5rk1/p5pp/8/1p6/5qQ1/2P4P/R6K/8 w - - 0 48\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01226", "split": "rules", "task_type": "captures", "fen": "rn1q1rk1/pbpp2pp/1p2p3/5p2/2PPnB2/2bBPN2/PPQ2PPP/R4RK1 w - -", "prompt": "FEN: rn1q1rk1/pbpp2pp/1p2p3/5p2/2PPnB2/2bBPN2/PPQ2PPP/R4RK1 w - -\nList all capture moves available.", "gold_answer": "b2c3 c2c3 d3e4 f4c7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01227", "split": "rules", "task_type": "special_rules", "fen": "2kr2nr/pppb1ppp/2n1p3/8/4P3/1PN2P2/PKPB2PP/R4B1R b - - 0 12", "prompt": "Given FEN: 2kr2nr/pppb1ppp/2n1p3/8/4P3/1PN2P2/PKPB2PP/R4B1R b - - 0 12\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01228", "split": "rules", "task_type": "legality_check", "fen": "8/8/8/3K4/8/2k5/1p3p2/5Q2 w - -", "prompt": "FEN: 8/8/8/3K4/8/2k5/1p3p2/5Q2 w - -\nIs the move f1f2 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f1f2", "_legality_check_reason_label": "legal", "move": "f1f2", "legality_reason_label": "legal"}}
{"example_id": "rules_01229", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r3k2r/pbp2ppp/2qb1n2/4p1N1/2p5/1PN5/P1PPQPPP/R1B2RK1 w kq -", "prompt": "FEN: r3k2r/pbp2ppp/2qb1n2/4p1N1/2p5/1PN5/P1PPQPPP/R1B2RK1 w kq -\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01230", "split": "rules", "task_type": "piece_legal_filter", "fen": "2R2Q2/4k3/8/8/7K/8/7P/8 b - -", "prompt": "FEN: 2R2Q2/4k3/8/8/7K/8/7P/8 b - -\nFor the piece on e7, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e7: e7d6 e7d7 e7d8 e7e6 e7e8 e7f6 e7f7 e7f8.\nLegal: e7d7 e7e6.\nRejected: e7d6 does_not_resolve_check; e7d8 does_not_resolve_check; e7e8 does_not_resolve_check; e7f6 does_not_resolve_check; e7f7 does_not_resolve_check; e7f8 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "e7", "diagnostic": true, "hard_gate": false, "source_square": "e7"}}
{"example_id": "rules_01231", "split": "rules", "task_type": "king_safety_filter", "fen": "r1br4/ppqnk1Q1/2n1p3/2ppP1N1/5B2/2P1P3/PP3PPP/R3K2R b KQ -", "prompt": "FEN: r1br4/ppqnk1Q1/2n1p3/2ppP1N1/5B2/2P1P3/PP3PPP/R3K2R b KQ -\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_01232", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "3r1rk1/1np3pp/p2q4/1p1ppb2/8/1BP1BN2/PP3QPP/R4NK1 w - -", "prompt": "FEN: 3r1rk1/1np3pp/p2q4/1p1ppb2/8/1BP1BN2/PP3QPP/R4NK1 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; f1 white knight; g1 white king; a2 white pawn; b2 white pawn; f2 white queen; g2 white pawn; h2 white pawn; b3 white bishop; c3 white pawn; e3 white bishop; f3 white knight.\nMoves by piece:\na1 white rook: a1b1 a1c1 a1d1 a1e1\nf1 white knight: f1d2 f1g3\ng1 white king: g1h1\na2 white pawn: a2a3 a2a4\nb2 white pawn: no legal moves\nf2 white queen: f2c2 f2d2 f2e1 f2e2 f2g3 f2h4\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nb3 white bishop: b3a4 b3c2 b3c4 b3d1 b3d5\nc3 white pawn: c3c4\ne3 white bishop: e3a7 e3b6 e3c1 e3c5 e3d2 e3d4 e3f4 e3g5 e3h6\nf3 white knight: f3d2 f3d4 f3e1 f3e5 f3g5 f3h4\nAll legal moves: a1b1 a1c1 a1d1 a1e1 a2a3 a2a4 b3a4 b3c2 b3c4 b3d1 b3d5 c3c4 e3a7 e3b6 e3c1 e3c5 e3d2 e3d4 e3f4 e3g5 e3h6 f1d2 f1g3 f2c2 f2d2 f2e1 f2e2 f2g3 f2h4 f3d2 f3d4 f3e1 f3e5 f3g5 f3h4 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1", "a1c1", "a1d1", "a1e1"], "f1": ["f1d2", "f1g3"], "g1": ["g1h1"], "a2": ["a2a3", "a2a4"], "b2": [], "f2": ["f2c2", "f2d2", "f2e1", "f2e2", "f2g3", "f2h4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "b3": ["b3a4", "b3c2", "b3c4", "b3d1", "b3d5"], "c3": ["c3c4"], "e3": ["e3a7", "e3b6", "e3c1", "e3c5", "e3d2", "e3d4", "e3f4", "e3g5", "e3h6"], "f3": ["f3d2", "f3d4", "f3e1", "f3e5", "f3g5", "f3h4"]}, "_legal_moves_by_piece_moves": "a1b1 a1c1 a1d1 a1e1 a2a3 a2a4 b3a4 b3c2 b3c4 b3d1 b3d5 c3c4 e3a7 e3b6 e3c1 e3c5 e3d2 e3d4 e3f4 e3g5 e3h6 f1d2 f1g3 f2c2 f2d2 f2e1 f2e2 f2g3 f2h4 f3d2 f3d4 f3e1 f3e5 f3g5 f3h4 g1h1 g2g3 g2g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1", "a1c1", "a1d1", "a1e1"], "f1": ["f1d2", "f1g3"], "g1": ["g1h1"], "a2": ["a2a3", "a2a4"], "b2": [], "f2": ["f2c2", "f2d2", "f2e1", "f2e2", "f2g3", "f2h4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "b3": ["b3a4", "b3c2", "b3c4", "b3d1", "b3d5"], "c3": ["c3c4"], "e3": ["e3a7", "e3b6", "e3c1", "e3c5", "e3d2", "e3d4", "e3f4", "e3g5", "e3h6"], "f3": ["f3d2", "f3d4", "f3e1", "f3e5", "f3g5", "f3h4"]}, "legal_moves": "a1b1 a1c1 a1d1 a1e1 a2a3 a2a4 b3a4 b3c2 b3c4 b3d1 b3d5 c3c4 e3a7 e3b6 e3c1 e3c5 e3d2 e3d4 e3f4 e3g5 e3h6 f1d2 f1g3 f2c2 f2d2 f2e1 f2e2 f2g3 f2h4 f3d2 f3d4 f3e1 f3e5 f3g5 f3h4 g1h1 g2g3 g2g4 h2h3 h2h4"}}
{"example_id": "rules_01233", "split": "rules", "task_type": "ray_walk", "fen": "4n3/B1pkPR2/8/8/8/2N5/4K3/8 w - - 3 40", "prompt": "FEN: 4n3/B1pkPR2/8/8/8/2N5/4K3/8 w - - 3 40\nWalk each ray for the slider on a7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a7 white bishop.\nRay NE: b8 empty; edge.\nRay SE: b6 empty; c5 empty; d4 empty; e3 empty; f2 empty; g1 empty; edge.\nRay SW: edge.\nRay NW: edge.\nMoves from rays: a7b6 a7b8 a7c5 a7d4 a7e3 a7f2 a7g1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a7", "diagnostic": true, "hard_gate": false, "source_square": "a7"}}
{"example_id": "rules_01234", "split": "rules", "task_type": "legal_moves", "fen": "2r1rk2/p6R/1p2P1p1/3P1p2/8/2K4P/PP4P1/5R2 w - - 1 32", "prompt": "FEN: 2r1rk2/p6R/1p2P1p1/3P1p2/8/2K4P/PP4P1/5R2 w - - 1 32\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: c3b3 c3b4 c3d2 c3d3 c3d4 h7c7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01235", "split": "rules", "task_type": "legal_moves", "fen": "8/1B3p2/K2k1n2/1p5p/1P4p1/8/6PP/8 b - -", "prompt": "FEN: 8/1B3p2/K2k1n2/1p5p/1P4p1/8/6PP/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: d6c7 d6d7 d6e5 d6e6 d6e7 f6d5 f6d7 f6e4 f6e8 f6g8 f6h7 g4g3 h5h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01236", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2qk1nr/ppp1bppp/2n1p3/3p4/2PP4/P3PN2/1P3PPP/1RBQKB1R w Kkq - 2 7", "prompt": "FEN: r2qk1nr/ppp1bppp/2n1p3/3p4/2PP4/P3PN2/1P3PPP/1RBQKB1R w Kkq - 2 7\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: b1 white rook; c1 white bishop; d1 white queen; e1 white king; f1 white bishop; h1 white rook; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; a3 white pawn; e3 white pawn; f3 white knight; c4 white pawn; d4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "f1", "piece": "white bishop"}, {"square": "h1", "piece": "white rook"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "c4", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "f1", "piece": "white bishop"}, {"square": "h1", "piece": "white rook"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "c4", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}]}}
{"example_id": "rules_01237", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b1k2r/ppq2ppp/3p1n2/2P1n3/4PB2/2Q5/PP3PPP/RN3RK1 w kq - 0 13", "prompt": "FEN: r1b1k2r/ppq2ppp/3p1n2/2P1n3/4PB2/2Q5/PP3PPP/RN3RK1 w kq - 0 13\nWhat legal moves does the piece on b2 have?", "gold_answer": "b2b3 b2b4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "b2", "piece": "pawn"}}
{"example_id": "rules_01238", "split": "rules", "task_type": "check_detection", "fen": "8/2p5/1k6/5QP1/N1P5/4P3/PPP3P1/R5K1 b - - 0 28", "prompt": "FEN: 8/2p5/1k6/5QP1/N1P5/4P3/PPP3P1/R5K1 b - - 0 28\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01239", "split": "rules", "task_type": "captures", "fen": "3N1k2/6p1/r1n1Pp2/7p/p1r5/2P2P2/R5PP/R5K1 w - - 3 40", "prompt": "FEN: 3N1k2/6p1/r1n1Pp2/7p/p1r5/2P2P2/R5PP/R5K1 w - - 3 40\nList all capture moves available.", "gold_answer": "a2a4 d8c6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01240", "split": "rules", "task_type": "special_rules", "fen": "8/8/8/8/8/4K1k1/8/7q w - - 2 69", "prompt": "Given FEN: 8/8/8/8/8/4K1k1/8/7q w - - 2 69\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01241", "split": "rules", "task_type": "legality_check", "fen": "5r2/2R1k3/p2p1n1r/Pp2pB2/1P2P2p/3PPP2/5K1R/8 b - - 5 30", "prompt": "FEN: 5r2/2R1k3/p2p1n1r/Pp2pB2/1P2P2p/3PPP2/5K1R/8 b - - 5 30\nIs the move e7e8 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "e7e8", "_legality_check_reason_label": "legal", "move": "e7e8", "legality_reason_label": "legal"}}
{"example_id": "rules_01242", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2q1rk1/pp3ppp/1np1pn2/8/2PP2b1/1PB2N2/P3BPPP/R2QR1K1 w - - 3 13", "prompt": "FEN: r2q1rk1/pp3ppp/1np1pn2/8/2PP2b1/1PB2N2/P3BPPP/R2QR1K1 w - - 3 13\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1 a1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01243", "split": "rules", "task_type": "piece_legal_filter", "fen": "3qrk1R/p1r3p1/1p2pbQ1/nP6/3Pb3/P7/5PPP/R5K1 b - -", "prompt": "FEN: 3qrk1R/p1r3p1/1p2pbQ1/nP6/3Pb3/P7/5PPP/R5K1 b - -\nFor the piece on e4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e4: e4a8 e4b1 e4b7 e4c2 e4c6 e4d3 e4d5 e4f3 e4f5 e4g2 e4g6.\nLegal: none.\nRejected: e4a8 does_not_resolve_check; e4b1 does_not_resolve_check; e4b7 does_not_resolve_check; e4c2 does_not_resolve_check; e4c6 does_not_resolve_check; e4d3 does_not_resolve_check; e4d5 does_not_resolve_check; e4f3 does_not_resolve_check; e4f5 does_not_resolve_check; e4g2 does_not_resolve_check; e4g6 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "e4", "diagnostic": true, "hard_gate": false, "source_square": "e4"}}
{"example_id": "rules_01244", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bq1rk1/1pp1nppp/p1n1p3/8/2pP4/2N1PN1P/PP3PP1/R2QKB1R w KQ -", "prompt": "FEN: r1bq1rk1/1pp1nppp/p1n1p3/8/2pP4/2N1PN1P/PP3PP1/R2QKB1R w KQ -\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01245", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1b1k2r/pp3ppp/1qn1pn2/3p4/1bPP4/2N1BN2/PP2BPPP/R2Q1RK1 b kq - 2 9", "prompt": "FEN: r1b1k2r/pp3ppp/1qn1pn2/3p4/1bPP4/2N1BN2/PP2BPPP/R2Q1RK1 b kq - 2 9\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b4 black bishop; d5 black pawn; b6 black queen; c6 black knight; e6 black pawn; f6 black knight; a7 black pawn; b7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; e8 black king; h8 black rook.\nMoves by piece:\nb4 black bishop: b4a3 b4a5 b4c3 b4c5 b4d6 b4e7 b4f8\nd5 black pawn: d5c4\nb6 black queen: b6a5 b6a6 b6b5 b6c5 b6c7 b6d4 b6d8\nc6 black knight: c6a5 c6b8 c6d4 c6d8 c6e5 c6e7\ne6 black pawn: e6e5\nf6 black knight: f6d7 f6e4 f6g4 f6g8 f6h5\na7 black pawn: a7a5 a7a6\nb7 black pawn: no legal moves\nf7 black pawn: no legal moves\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8\nc8 black bishop: c8d7\ne8 black king: e8d7 e8d8 e8e7 e8f8 e8g8\nh8 black rook: h8f8 h8g8\nAll legal moves: a7a5 a7a6 a8b8 b4a3 b4a5 b4c3 b4c5 b4d6 b4e7 b4f8 b6a5 b6a6 b6b5 b6c5 b6c7 b6d4 b6d8 c6a5 c6b8 c6d4 c6d8 c6e5 c6e7 c8d7 d5c4 e6e5 e8d7 e8d8 e8e7 e8f8 e8g8 f6d7 f6e4 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b4": ["b4a3", "b4a5", "b4c3", "b4c5", "b4d6", "b4e7", "b4f8"], "d5": ["d5c4"], "b6": ["b6a5", "b6a6", "b6b5", "b6c5", "b6c7", "b6d4", "b6d8"], "c6": ["c6a5", "c6b8", "c6d4", "c6d8", "c6e5", "c6e7"], "e6": ["e6e5"], "f6": ["f6d7", "f6e4", "f6g4", "f6g8", "f6h5"], "a7": ["a7a5", "a7a6"], "b7": [], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7"], "e8": ["e8d7", "e8d8", "e8e7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 b4a3 b4a5 b4c3 b4c5 b4d6 b4e7 b4f8 b6a5 b6a6 b6b5 b6c5 b6c7 b6d4 b6d8 c6a5 c6b8 c6d4 c6d8 c6e5 c6e7 c8d7 d5c4 e6e5 e8d7 e8d8 e8e7 e8f8 e8g8 f6d7 f6e4 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b4": ["b4a3", "b4a5", "b4c3", "b4c5", "b4d6", "b4e7", "b4f8"], "d5": ["d5c4"], "b6": ["b6a5", "b6a6", "b6b5", "b6c5", "b6c7", "b6d4", "b6d8"], "c6": ["c6a5", "c6b8", "c6d4", "c6d8", "c6e5", "c6e7"], "e6": ["e6e5"], "f6": ["f6d7", "f6e4", "f6g4", "f6g8", "f6h5"], "a7": ["a7a5", "a7a6"], "b7": [], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7"], "e8": ["e8d7", "e8d8", "e8e7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "legal_moves": "a7a5 a7a6 a8b8 b4a3 b4a5 b4c3 b4c5 b4d6 b4e7 b4f8 b6a5 b6a6 b6b5 b6c5 b6c7 b6d4 b6d8 c6a5 c6b8 c6d4 c6d8 c6e5 c6e7 c8d7 d5c4 e6e5 e8d7 e8d8 e8e7 e8f8 e8g8 f6d7 f6e4 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8"}}
{"example_id": "rules_01246", "split": "rules", "task_type": "ray_walk", "fen": "5k2/1R6/p5p1/8/6p1/4N3/PPr5/1K1r4 w - -", "prompt": "FEN: 5k2/1R6/p5p1/8/6p1/4N3/PPr5/1K1r4 w - -\nWalk each ray for the slider on b7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b7 white rook.\nRay N: b8 empty; edge.\nRay E: c7 empty; d7 empty; e7 empty; f7 empty; g7 empty; h7 empty; edge.\nRay S: b6 empty; b5 empty; b4 empty; b3 empty; b2 white pawn: own piece (stop, excluded).\nRay W: a7 empty; edge.\nMoves from rays: b7a7 b7b3 b7b4 b7b5 b7b6 b7b8 b7c7 b7d7 b7e7 b7f7 b7g7 b7h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "b7", "diagnostic": true, "hard_gate": false, "source_square": "b7"}}
{"example_id": "rules_01247", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/6pp/p2p1b1k/5Qp1/6P1/8/P1P1pP1P/1R4K1 b - - 3 41", "prompt": "FEN: 8/6pp/p2p1b1k/5Qp1/6P1/8/P1P1pP1P/1R4K1 b - - 3 41\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e2 black pawn; g5 black pawn; a6 black pawn; d6 black pawn; f6 black bishop; h6 black king; g7 black pawn; h7 black pawn.\nFilter by piece:\ne2 black pawn: pseudo-legal e2e1b e2e1n e2e1q e2e1r | rejected none | legal e2e1b e2e1n e2e1q e2e1r\ng5 black pawn: pseudo-legal none | rejected none | legal none\na6 black pawn: pseudo-legal a6a5 | rejected none | legal a6a5\nd6 black pawn: pseudo-legal d6d5 | rejected none | legal d6d5\nf6 black bishop: pseudo-legal f6a1 f6b2 f6c3 f6d4 f6d8 f6e5 f6e7 | rejected none | legal f6a1 f6b2 f6c3 f6d4 f6d8 f6e5 f6e7\nh6 black king: pseudo-legal h6g6 h6h5 | rejected h6g6 king_would_be_in_check; h6h5 king_would_be_in_check | legal none\ng7 black pawn: pseudo-legal g7g6 | rejected none | legal g7g6\nh7 black pawn: pseudo-legal none | rejected none | legal none\nAll legal moves: a6a5 d6d5 e2e1b e2e1n e2e1q e2e1r f6a1 f6b2 f6c3 f6d4 f6d8 f6e5 f6e7 g7g6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01248", "split": "rules", "task_type": "legal_moves", "fen": "1Q6/6pk/P5qp/7r/5p2/4P1P1/5PQP/1R4K1 b - - 0 46", "prompt": "FEN: 1Q6/6pk/P5qp/7r/5p2/4P1P1/5PQP/1R4K1 b - - 0 46\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: f4e3 f4f3 f4g3 g6a6 g6b1 g6b6 g6c2 g6c6 g6d3 g6d6 g6e4 g6e6 g6e8 g6f5 g6f6 g6f7 g6g3 g6g4 g6g5 h5a5 h5b5 h5c5 h5d5 h5e5 h5f5 h5g5 h5h2 h5h3 h5h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01249", "split": "rules", "task_type": "side_piece_inventory", "fen": "rn2kb1r/ppq1pppp/2p2n2/5b2/P1B3P1/2NP1P2/1PPB3P/R2QK1NR b KQkq -", "prompt": "FEN: rn2kb1r/ppq1pppp/2p2n2/5b2/P1B3P1/2NP1P2/1PPB3P/R2QK1NR b KQkq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: f5 black bishop; c6 black pawn; f6 black knight; a7 black pawn; b7 black pawn; c7 black queen; e7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; e8 black king; f8 black bishop; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "f5", "piece": "black bishop"}, {"square": "c6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black queen"}, {"square": "e7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "f5", "piece": "black bishop"}, {"square": "c6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black queen"}, {"square": "e7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_01250", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/5k1p/6pK/5p2/1ppB4/7P/P5P1/8 b - - 1 38", "prompt": "FEN: 8/5k1p/6pK/5p2/1ppB4/7P/P5P1/8 b - - 1 38\nWhat legal moves does the piece on f5 have?", "gold_answer": "f5f4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f5", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f5", "piece": "pawn"}}
{"example_id": "rules_01251", "split": "rules", "task_type": "check_detection", "fen": "rn2k1nr/pbppqpb1/1p2p1p1/7p/2PP4/1PNBPN2/P4PPP/R1BQ1RK1 b kq - 0 8", "prompt": "FEN: rn2k1nr/pbppqpb1/1p2p1p1/7p/2PP4/1PNBPN2/P4PPP/R1BQ1RK1 b kq - 0 8\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01252", "split": "rules", "task_type": "captures", "fen": "3b1Qk1/3P2p1/4P3/1P5p/8/4q3/1P4PP/5R1K b - -", "prompt": "FEN: 3b1Qk1/3P2p1/4P3/1P5p/8/4q3/1P4PP/5R1K b - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01253", "split": "rules", "task_type": "special_rules", "fen": "r1bqr1k1/ppp1nppp/5b2/3p4/8/2P2NP1/PP2PPBP/R1BQR1K1 b - - 6 11", "prompt": "Given FEN: r1bqr1k1/ppp1nppp/5b2/3p4/8/2P2NP1/PP2PPBP/R1BQR1K1 b - - 6 11\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01254", "split": "rules", "task_type": "legality_check", "fen": "r1r3k1/Bnn1qbb1/3p1p1p/1p1PpPpB/1Pp1P3/2P3NP/R2Q2PN/R5K1 b - -", "prompt": "FEN: r1r3k1/Bnn1qbb1/3p1p1p/1p1PpPpB/1Pp1P3/2P3NP/R2Q2PN/R5K1 b - -\nIs the move a8a7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "a8a7", "_legality_check_reason_label": "legal", "move": "a8a7", "legality_reason_label": "legal"}}
{"example_id": "rules_01255", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5r2/ppp3kp/3p1qp1/Q7/2P1rP2/P7/1P4PP/3R1RK1 b - -", "prompt": "FEN: 5r2/ppp3kp/3p1qp1/Q7/2P1rP2/P7/1P4PP/3R1RK1 b - -\nList pseudo-legal moves from e4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e4: e4c4 e4d4 e4e1 e4e2 e4e3 e4e5 e4e6 e4e7 e4e8 e4f4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e4", "diagnostic": true, "hard_gate": false, "source_square": "e4"}}
{"example_id": "rules_01256", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/p1p1k1p1/2p1p2p/8/1r6/1P6/P4PPP/3R2K1 w - - 1 21", "prompt": "FEN: 8/p1p1k1p1/2p1p2p/8/1r6/1P6/P4PPP/3R2K1 w - - 1 21\nFor the piece on d1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d1: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1.\nLegal: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_01257", "split": "rules", "task_type": "king_safety_filter", "fen": "r2q1rk1/1bppnpp1/p6p/1p2N3/3Pn3/1BP5/PP3PPP/RN1Q1RK1 b - - 0 13", "prompt": "FEN: r2q1rk1/1bppnpp1/p6p/1p2N3/3Pn3/1BP5/PP3PPP/RN1Q1RK1 b - - 0 13\nFor move f7f5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: f7f5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "f7f5", "_king_safety_filter_reason_label": "pinned_piece_exposes_king", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "f7f5", "legality_reason_label": "pinned_piece_exposes_king", "expected_is_legal": false}}
{"example_id": "rules_01258", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1rbk3r/pp1p3p/4qbp1/P1pNPn2/2P1Q3/3B4/1P3PPP/R4RK1 w - - 0 17", "prompt": "FEN: 1rbk3r/pp1p3p/4qbp1/P1pNPn2/2P1Q3/3B4/1P3PPP/R4RK1 w - - 0 17\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; f1 white rook; g1 white king; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; d3 white bishop; c4 white pawn; e4 white queen; a5 white pawn; d5 white knight; e5 white pawn.\nMoves by piece:\na1 white rook: a1a2 a1a3 a1a4 a1b1 a1c1 a1d1 a1e1\nf1 white rook: f1b1 f1c1 f1d1 f1e1\ng1 white king: g1h1\nb2 white pawn: b2b3 b2b4\nf2 white pawn: f2f3 f2f4\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nd3 white bishop: d3b1 d3c2 d3e2\nc4 white pawn: no legal moves\ne4 white queen: e4d4 e4e1 e4e2 e4e3 e4f3 e4f4 e4f5 e4g4 e4h4\na5 white pawn: a5a6\nd5 white knight: d5b4 d5b6 d5c3 d5c7 d5e3 d5e7 d5f4 d5f6\ne5 white pawn: e5f6\nAll legal moves: a1a2 a1a3 a1a4 a1b1 a1c1 a1d1 a1e1 a5a6 b2b3 b2b4 d3b1 d3c2 d3e2 d5b4 d5b6 d5c3 d5c7 d5e3 d5e7 d5f4 d5f6 e4d4 e4e1 e4e2 e4e3 e4f3 e4f4 e4f5 e4g4 e4h4 e5f6 f1b1 f1c1 f1d1 f1e1 f2f3 f2f4 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1a2", "a1a3", "a1a4", "a1b1", "a1c1", "a1d1", "a1e1"], "f1": ["f1b1", "f1c1", "f1d1", "f1e1"], "g1": ["g1h1"], "b2": ["b2b3", "b2b4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "d3": ["d3b1", "d3c2", "d3e2"], "c4": [], "e4": ["e4d4", "e4e1", "e4e2", "e4e3", "e4f3", "e4f4", "e4f5", "e4g4", "e4h4"], "a5": ["a5a6"], "d5": ["d5b4", "d5b6", "d5c3", "d5c7", "d5e3", "d5e7", "d5f4", "d5f6"], "e5": ["e5f6"]}, "_legal_moves_by_piece_moves": "a1a2 a1a3 a1a4 a1b1 a1c1 a1d1 a1e1 a5a6 b2b3 b2b4 d3b1 d3c2 d3e2 d5b4 d5b6 d5c3 d5c7 d5e3 d5e7 d5f4 d5f6 e4d4 e4e1 e4e2 e4e3 e4f3 e4f4 e4f5 e4g4 e4h4 e5f6 f1b1 f1c1 f1d1 f1e1 f2f3 f2f4 g1h1 g2g3 g2g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1a2", "a1a3", "a1a4", "a1b1", "a1c1", "a1d1", "a1e1"], "f1": ["f1b1", "f1c1", "f1d1", "f1e1"], "g1": ["g1h1"], "b2": ["b2b3", "b2b4"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "d3": ["d3b1", "d3c2", "d3e2"], "c4": [], "e4": ["e4d4", "e4e1", "e4e2", "e4e3", "e4f3", "e4f4", "e4f5", "e4g4", "e4h4"], "a5": ["a5a6"], "d5": ["d5b4", "d5b6", "d5c3", "d5c7", "d5e3", "d5e7", "d5f4", "d5f6"], "e5": ["e5f6"]}, "legal_moves": "a1a2 a1a3 a1a4 a1b1 a1c1 a1d1 a1e1 a5a6 b2b3 b2b4 d3b1 d3c2 d3e2 d5b4 d5b6 d5c3 d5c7 d5e3 d5e7 d5f4 d5f6 e4d4 e4e1 e4e2 e4e3 e4f3 e4f4 e4f5 e4g4 e4h4 e5f6 f1b1 f1c1 f1d1 f1e1 f2f3 f2f4 g1h1 g2g3 g2g4 h2h3 h2h4"}}
{"example_id": "rules_01259", "split": "rules", "task_type": "ray_walk", "fen": "rn2kb1r/pp2qppp/2p5/3P3n/8/1P5P/PBPPBP2/R2QK1R1 b Qkq - 0 12", "prompt": "FEN: rn2kb1r/pp2qppp/2p5/3P3n/8/1P5P/PBPPBP2/R2QK1R1 b Qkq - 0 12\nWalk each ray for the slider on e7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e7 black queen.\nRay N: e8 black king: own piece (stop, excluded).\nRay NE: f8 black bishop: own piece (stop, excluded).\nRay E: f7 black pawn: own piece (stop, excluded).\nRay SE: f6 empty; g5 empty; h4 empty; edge.\nRay S: e6 empty; e5 empty; e4 empty; e3 empty; e2 white bishop: capture (stop, included).\nRay SW: d6 empty; c5 empty; b4 empty; a3 empty; edge.\nRay W: d7 empty; c7 empty; b7 black pawn: own piece (stop, excluded).\nRay NW: d8 empty; edge.\nMoves from rays: e7a3 e7b4 e7c5 e7c7 e7d6 e7d7 e7d8 e7e2 e7e3 e7e4 e7e5 e7e6 e7f6 e7g5 e7h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "e7", "diagnostic": true, "hard_gate": false, "source_square": "e7"}}
{"example_id": "rules_01260", "split": "rules", "task_type": "legal_moves", "fen": "rn1qk2r/p3bppp/1pppp3/3PP3/5P2/3P2P1/PP4QP/RNB1K1NR b KQkq - 0 10", "prompt": "FEN: rn1qk2r/p3bppp/1pppp3/3PP3/5P2/3P2P1/PP4QP/RNB1K1NR b KQkq - 0 10\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6b5 b8a6 b8d7 c6c5 c6d5 d6e5 d8c7 d8c8 d8d7 e6d5 e7f6 e7f8 e7g5 e7h4 e8d7 e8f8 e8g8 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01261", "split": "rules", "task_type": "legal_moves", "fen": "rnb4r/p4Bp1/k2BPn1p/1p6/2q1P2P/8/2P1QPP1/R2R2K1 b - - 1 21", "prompt": "FEN: rnb4r/p4Bp1/k2BPn1p/1p6/2q1P2P/8/2P1QPP1/R2R2K1 b - - 1 21\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6b6 a6b7 c4a2 c4a4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01262", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/3r4/p2N1pk1/1p4p1/1PbP3p/2P4P/P4PP1/R3R1K1 w - - 1 39", "prompt": "FEN: 8/3r4/p2N1pk1/1p4p1/1PbP3p/2P4P/P4PP1/R3R1K1 w - - 1 39\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; e1 white rook; g1 white king; a2 white pawn; f2 white pawn; g2 white pawn; c3 white pawn; h3 white pawn; b4 white pawn; d4 white pawn; d6 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "d6", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "d6", "piece": "white knight"}]}}
{"example_id": "rules_01263", "split": "rules", "task_type": "piece_legal_moves", "fen": "1r6/8/p7/P1Bk4/3Pb3/5p1P/5K1R/8 w - - 1 55", "prompt": "FEN: 1r6/8/p7/P1Bk4/3Pb3/5p1P/5K1R/8 w - - 1 55\nWhat legal moves does the piece on h2 have?", "gold_answer": "h2g2 h2h1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h2", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "h2", "piece": "rook"}}
{"example_id": "rules_01264", "split": "rules", "task_type": "check_detection", "fen": "r1b1k2r/pp2nppp/2p2n2/3p4/3P1N2/2PB1N2/PP3PPP/R4RK1 b kq -", "prompt": "FEN: r1b1k2r/pp2nppp/2p2n2/3p4/3P1N2/2PB1N2/PP3PPP/R4RK1 b kq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01265", "split": "rules", "task_type": "captures", "fen": "8/3n4/Q2k4/1P5P/2Bp4/2b3q1/2K5/8 b - - 2 46", "prompt": "FEN: 8/3n4/Q2k4/1P5P/2Bp4/2b3q1/2K5/8 b - - 2 46\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01266", "split": "rules", "task_type": "special_rules", "fen": "2r5/4p1k1/p2p2p1/2r5/K1P4Q/1P6/q7/8 w - - 0 43", "prompt": "Given FEN: 2r5/4p1k1/p2p2p1/2r5/K1P4Q/1P6/q7/8 w - - 0 43\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01267", "split": "rules", "task_type": "legality_check", "fen": "6k1/1R3pp1/p3p2p/P3P3/1n6/3r4/1P2N1PP/6K1 b - - 0 25", "prompt": "FEN: 6k1/1R3pp1/p3p2p/P3P3/1n6/3r4/1P2N1PP/6K1 b - - 0 25\nIs the move g7e2 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g7e2", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "g7e2", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_01268", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2q1rk1/pb3ppp/1pnbpn2/3pN3/3P1P2/P2BP3/1P1N2PP/R1BQ1RK1 b - -", "prompt": "FEN: r2q1rk1/pb3ppp/1pnbpn2/3pN3/3P1P2/P2BP3/1P1N2PP/R1BQ1RK1 b - -\nList pseudo-legal moves from b6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b6: b6b5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b6", "diagnostic": true, "hard_gate": false, "source_square": "b6"}}
{"example_id": "rules_01269", "split": "rules", "task_type": "piece_legal_filter", "fen": "r4rk1/5pp1/2np1P2/1p4R1/1p1pP3/1B1P4/2P3PP/4R1K1 b - - 0 25", "prompt": "FEN: r4rk1/5pp1/2np1P2/1p4R1/1p1pP3/1B1P4/2P3PP/4R1K1 b - - 0 25\nFor the piece on g7, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g7: g7f6 g7g6.\nLegal: g7g6.\nRejected: g7f6 pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g7", "diagnostic": true, "hard_gate": false, "source_square": "g7"}}
{"example_id": "rules_01270", "split": "rules", "task_type": "king_safety_filter", "fen": "8/3b1p1k/2p3q1/3Pp2p/p3P2r/8/4K3/2R2R2 w - - 0 41", "prompt": "FEN: 8/3b1p1k/2p3q1/3Pp2p/p3P2r/8/4K3/2R2R2 w - - 0 41\nFor move c1a1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c1a1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "c1a1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "c1a1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01271", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnb1k2r/pppp1ppp/5n2/8/8/2PN1B2/PPP2PqP/R1BQK2R b KQkq -", "prompt": "FEN: rnb1k2r/pppp1ppp/5n2/8/8/2PN1B2/PPP2PqP/R1BQK2R b KQkq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: g2 black queen; f6 black knight; a7 black pawn; b7 black pawn; c7 black pawn; d7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; c8 black bishop; e8 black king; h8 black rook.\nMoves by piece:\ng2 black queen: g2f1 g2f2 g2f3 g2g1 g2g3 g2g4 g2g5 g2g6 g2h1 g2h2 g2h3\nf6 black knight: f6d5 f6e4 f6g4 f6g8 f6h5\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nc7 black pawn: c7c5 c7c6\nd7 black pawn: d7d5 d7d6\nf7 black pawn: no legal moves\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: no legal moves\nb8 black knight: b8a6 b8c6\nc8 black bishop: no legal moves\ne8 black king: e8d8 e8e7 e8f8 e8g8\nh8 black rook: h8f8 h8g8\nAll legal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 c7c5 c7c6 d7d5 d7d6 e8d8 e8e7 e8f8 e8g8 f6d5 f6e4 f6g4 f6g8 f6h5 g2f1 g2f2 g2f3 g2g1 g2g3 g2g4 g2g5 g2g6 g2h1 g2h2 g2h3 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"g2": ["g2f1", "g2f2", "g2f3", "g2g1", "g2g3", "g2g4", "g2g5", "g2g6", "g2h1", "g2h2", "g2h3"], "f6": ["f6d5", "f6e4", "f6g4", "f6g8", "f6h5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7c5", "c7c6"], "d7": ["d7d5", "d7d6"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8c6"], "c8": [], "e8": ["e8d8", "e8e7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 c7c5 c7c6 d7d5 d7d6 e8d8 e8e7 e8f8 e8g8 f6d5 f6e4 f6g4 f6g8 f6h5 g2f1 g2f2 g2f3 g2g1 g2g3 g2g4 g2g5 g2g6 g2h1 g2h2 g2h3 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"g2": ["g2f1", "g2f2", "g2f3", "g2g1", "g2g3", "g2g4", "g2g5", "g2g6", "g2h1", "g2h2", "g2h3"], "f6": ["f6d5", "f6e4", "f6g4", "f6g8", "f6h5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7c5", "c7c6"], "d7": ["d7d5", "d7d6"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8c6"], "c8": [], "e8": ["e8d8", "e8e7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "legal_moves": "a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 c7c5 c7c6 d7d5 d7d6 e8d8 e8e7 e8f8 e8g8 f6d5 f6e4 f6g4 f6g8 f6h5 g2f1 g2f2 g2f3 g2g1 g2g3 g2g4 g2g5 g2g6 g2h1 g2h2 g2h3 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8"}}
{"example_id": "rules_01272", "split": "rules", "task_type": "ray_walk", "fen": "r1b1qrk1/p3bp1p/2R1p1p1/3pN3/3P4/1Q3N2/PP3PPP/R5K1 w - -", "prompt": "FEN: r1b1qrk1/p3bp1p/2R1p1p1/3pN3/3P4/1Q3N2/PP3PPP/R5K1 w - -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 empty; e1 empty; f1 empty; g1 white king: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1 a1d1 a1e1 a1f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01273", "split": "rules", "task_type": "legal_moves", "fen": "r2qkb1r/3p1ppp/n3pn2/P7/3PP3/2P2Q2/5PPP/RNB1K1NR b KQkq - 0 10", "prompt": "FEN: r2qkb1r/3p1ppp/n3pn2/P7/3PP3/2P2Q2/5PPP/RNB1K1NR b KQkq - 0 10\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6b4 a6b8 a6c5 a6c7 a8a7 a8b8 a8c8 d7d5 d7d6 d8a5 d8b6 d8b8 d8c7 d8c8 d8e7 e6e5 e8e7 f6d5 f6e4 f6g4 f6g8 f6h5 f8a3 f8b4 f8c5 f8d6 f8e7 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01274", "split": "rules", "task_type": "legal_moves", "fen": "4k1r1/pp3p1p/3rp3/8/4p3/BP2PnPp/P4P1P/3R3K w - - 0 26", "prompt": "FEN: 4k1r1/pp3p1p/3rp3/8/4p3/BP2PnPp/P4P1P/3R3K w - - 0 26\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3b2 a3b4 a3c1 a3c5 a3d6 b3b4 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1e1 d1f1 d1g1 g3g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01275", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1b4k/pp1nq2p/2p5/2Pp1rp1/3PpPQ1/2P3P1/P2N1P1P/1BR2RK1 w - - 2 18", "prompt": "FEN: r1b4k/pp1nq2p/2p5/2Pp1rp1/3PpPQ1/2P3P1/P2N1P1P/1BR2RK1 w - - 2 18\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: b1 white bishop; c1 white rook; f1 white rook; g1 white king; a2 white pawn; d2 white knight; f2 white pawn; h2 white pawn; c3 white pawn; g3 white pawn; d4 white pawn; f4 white pawn; g4 white queen; c5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "b1", "piece": "white bishop"}, {"square": "c1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "d2", "piece": "white knight"}, {"square": "f2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "g4", "piece": "white queen"}, {"square": "c5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "b1", "piece": "white bishop"}, {"square": "c1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "d2", "piece": "white knight"}, {"square": "f2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "g4", "piece": "white queen"}, {"square": "c5", "piece": "white pawn"}]}}
{"example_id": "rules_01276", "split": "rules", "task_type": "piece_legal_moves", "fen": "3r3r/pk1n1pp1/2pq3p/1p1p2P1/3P1n1P/2NQ4/PPP1N3/1K2R2R w - -", "prompt": "FEN: 3r3r/pk1n1pp1/2pq3p/1p1p2P1/3P1n1P/2NQ4/PPP1N3/1K2R2R w - -\nWhat legal moves does the piece on e1 have?", "gold_answer": "e1c1 e1d1 e1f1 e1g1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "e1", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "e1", "piece": "rook"}}
{"example_id": "rules_01277", "split": "rules", "task_type": "check_detection", "fen": "8/7p/7p/4kPP1/8/8/2K5/8 w - -", "prompt": "FEN: 8/7p/7p/4kPP1/8/8/2K5/8 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01278", "split": "rules", "task_type": "captures", "fen": "r2q1bnr/ppp1kBpp/3p4/3NN3/4P3/8/PP3PPP/R1Bb1RK1 b - - 2 10", "prompt": "FEN: r2q1bnr/ppp1kBpp/3p4/3NN3/4P3/8/PP3PPP/R1Bb1RK1 b - - 2 10\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_openings", "is_chess960": false}}
{"example_id": "rules_01279", "split": "rules", "task_type": "special_rules", "fen": "4rrk1/ppp2ppp/3p4/2b2P2/1nP1B3/2R2PP1/PP2N1qP/3QKR2 b - - 8 19", "prompt": "Given FEN: 4rrk1/ppp2ppp/3p4/2b2P2/1nP1B3/2R2PP1/PP2N1qP/3QKR2 b - - 8 19\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01280", "split": "rules", "task_type": "legality_check", "fen": "4k2r/pp1r1ppp/4p3/4N3/Q2q4/8/PP3bPP/R1B2K2 w k -", "prompt": "FEN: 4k2r/pp1r1ppp/4p3/4N3/Q2q4/8/PP3bPP/R1B2K2 w k -\nIs the move h2h4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "h2h4", "_legality_check_reason_label": "legal", "move": "h2h4", "legality_reason_label": "legal"}}
{"example_id": "rules_01281", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5r2/1pp1p1kp/2n3p1/r4p2/8/P3PN2/2PP1PPP/R2R2K1 b - - 0 17", "prompt": "FEN: 5r2/1pp1p1kp/2n3p1/r4p2/8/P3PN2/2PP1PPP/R2R2K1 b - - 0 17\nList pseudo-legal moves from a5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a5: a5a3 a5a4 a5a6 a5a7 a5a8 a5b5 a5c5 a5d5 a5e5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_01282", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn2k1nr/ppp2ppp/3p4/2b5/4P1b1/8/PPPP1NPP/RNB1KB1R w KQkq - 0 7", "prompt": "FEN: rn2k1nr/ppp2ppp/3p4/2b5/4P1b1/8/PPPP1NPP/RNB1KB1R w KQkq - 0 7\nFor the piece on e1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e1: e1d1 e1e2.\nLegal: none.\nRejected: e1d1 king_would_be_in_check; e1e2 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "e1", "diagnostic": true, "hard_gate": false, "source_square": "e1"}}
{"example_id": "rules_01283", "split": "rules", "task_type": "king_safety_filter", "fen": "r5k1/pR6/3p1R2/2p5/2PpqP2/1P6/P1P5/1K6 b - - 0 28", "prompt": "FEN: r5k1/pR6/3p1R2/2p5/2PpqP2/1P6/P1P5/1K6 b - - 0 28\nFor move g8f7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: g8f7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "g8f7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "g8f7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01284", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/2R5/2P1k3/5p1p/r4K1P/5PP1/4r3/2R5 w - -", "prompt": "FEN: 8/2R5/2P1k3/5p1p/r4K1P/5PP1/4r3/2R5 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c1 white rook; f3 white pawn; g3 white pawn; f4 white king; h4 white pawn; c6 white pawn; c7 white rook.\nMoves by piece:\nc1 white rook: c1c4\nf3 white pawn: no legal moves\ng3 white pawn: no legal moves\nf4 white king: f4g5\nh4 white pawn: no legal moves\nc6 white pawn: no legal moves\nc7 white rook: no legal moves\nAll legal moves: c1c4 f4g5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c1": ["c1c4"], "f3": [], "g3": [], "f4": ["f4g5"], "h4": [], "c6": [], "c7": []}, "_legal_moves_by_piece_moves": "c1c4 f4g5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c1": ["c1c4"], "f3": [], "g3": [], "f4": ["f4g5"], "h4": [], "c6": [], "c7": []}, "legal_moves": "c1c4 f4g5"}}
{"example_id": "rules_01285", "split": "rules", "task_type": "legal_moves", "fen": "2Q5/8/8/3k4/8/8/5K2/8 b - -", "prompt": "FEN: 2Q5/8/8/3k4/8/8/5K2/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: d5d4 d5d6 d5e4 d5e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": ""}}
{"example_id": "rules_01286", "split": "rules", "task_type": "legal_filter_trace", "fen": "6k1/8/6P1/5BK1/8/6r1/8/8 w - - 7 62", "prompt": "FEN: 6k1/8/6P1/5BK1/8/6r1/8/8 w - - 7 62\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: f5 white bishop; g5 white king; g6 white pawn.\nFilter by piece:\nf5 white bishop: pseudo-legal f5b1 f5c2 f5c8 f5d3 f5d7 f5e4 f5e6 f5g4 f5h3 | rejected f5b1 does_not_resolve_check; f5c2 does_not_resolve_check; f5c8 does_not_resolve_check; f5d3 does_not_resolve_check; f5d7 does_not_resolve_check; f5e4 does_not_resolve_check; f5e6 does_not_resolve_check; f5h3 does_not_resolve_check | legal f5g4\ng5 white king: pseudo-legal g5f4 g5f6 g5g4 g5h4 g5h5 g5h6 | rejected g5g4 does_not_resolve_check | legal g5f4 g5f6 g5h4 g5h5 g5h6\ng6 white pawn: pseudo-legal g6g7 | rejected g6g7 does_not_resolve_check | legal none\nAll legal moves: f5g4 g5f4 g5f6 g5h4 g5h5 g5h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01287", "split": "rules", "task_type": "legal_moves", "fen": "r1b1r1k1/1p3p1p/2ppn1p1/8/n1P1P3/2NN1P2/Pp1Q1BPP/5BK1 b - -", "prompt": "FEN: r1b1r1k1/1p3p1p/2ppn1p1/8/n1P1P3/2NN1P2/Pp1Q1BPP/5BK1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a4b6 a4c3 a4c5 a8a5 a8a6 a8a7 a8b8 b2b1b b2b1n b2b1q b2b1r b7b5 b7b6 c6c5 c8d7 d6d5 e6c5 e6c7 e6d4 e6d8 e6f4 e6f8 e6g5 e6g7 e8d8 e8e7 e8f8 f7f5 f7f6 g6g5 g8f8 g8g7 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01288", "split": "rules", "task_type": "side_piece_inventory", "fen": "4r2k/ppp3p1/3b3p/8/6b1/3B4/PPP2RPP/RN5K w - - 5 22", "prompt": "FEN: 4r2k/ppp3p1/3b3p/8/6b1/3B4/PPP2RPP/RN5K w - - 5 22\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; h1 white king; a2 white pawn; b2 white pawn; c2 white pawn; f2 white rook; g2 white pawn; h2 white pawn; d3 white bishop.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "h1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white rook"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "h1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white rook"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}]}}
{"example_id": "rules_01289", "split": "rules", "task_type": "piece_legal_moves", "fen": "r3kbnr/pp3ppp/2n1pq2/1BPp4/2P5/4BQ2/PP3PPP/RN2K2R w KQkq -", "prompt": "FEN: r3kbnr/pp3ppp/2n1pq2/1BPp4/2P5/4BQ2/PP3PPP/RN2K2R w KQkq -\nWhat legal moves does the piece on f2 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f2", "piece": "pawn"}}
{"example_id": "rules_01290", "split": "rules", "task_type": "check_detection", "fen": "rnbq1rk1/1pp2pb1/3p3p/p2Pp3/2P1P1pP/2N2NP1/PP2B1P1/R2QK2R w KQ -", "prompt": "FEN: rnbq1rk1/1pp2pb1/3p3p/p2Pp3/2P1P1pP/2N2NP1/PP2B1P1/R2QK2R w KQ -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01291", "split": "rules", "task_type": "captures", "fen": "r1b2r2/5pkp/1q1p2p1/p1nN4/4PP2/P6P/BPP1Q1P1/2KR3R b - - 2 23", "prompt": "FEN: r1b2r2/5pkp/1q1p2p1/p1nN4/4PP2/P6P/BPP1Q1P1/2KR3R b - - 2 23\nList all capture moves available.", "gold_answer": "b6b2 c5e4 c8h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01292", "split": "rules", "task_type": "special_rules", "fen": "r4rk1/p4ppp/1p2n3/1P1PQ3/8/5N2/2q2PPP/RR4K1 b - - 0 23", "prompt": "Given FEN: r4rk1/p4ppp/1p2n3/1P1PQ3/8/5N2/2q2PPP/RR4K1 b - - 0 23\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01293", "split": "rules", "task_type": "legality_check", "fen": "3q1rk1/1p2b1pp/p3pn2/2pp2B1/6Q1/3P3P/PPP3P1/RN4K1 w - - 2 18", "prompt": "FEN: 3q1rk1/1p2b1pp/p3pn2/2pp2B1/6Q1/3P3P/PPP3P1/RN4K1 w - - 2 18\nIs the move a2a3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "a2a3", "_legality_check_reason_label": "legal", "move": "a2a3", "legality_reason_label": "legal"}}
{"example_id": "rules_01294", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5rk1/pp4bp/5qp1/3Pp3/1PPp4/7P/PB2Q1P1/R5K1 b - - 5 22", "prompt": "FEN: 5rk1/pp4bp/5qp1/3Pp3/1PPp4/7P/PB2Q1P1/R5K1 b - - 5 22\nList pseudo-legal moves from d4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d4: d4d3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_01295", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn3rk1/1b3p1p/pq1p1bp1/1p1P4/8/2N2N2/PPQ1BPPP/R2R2K1 b - - 1 16", "prompt": "FEN: rn3rk1/1b3p1p/pq1p1bp1/1p1P4/8/2N2N2/PPQ1BPPP/R2R2K1 b - - 1 16\nFor the piece on b5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b5: b5b4.\nLegal: b5b4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b5", "diagnostic": true, "hard_gate": false, "source_square": "b5"}}
{"example_id": "rules_01296", "split": "rules", "task_type": "king_safety_filter", "fen": "4r1k1/pp1n4/2p1q2p/2P2ppb/2PP4/P3pP2/3Q1BPP/R4RK1 w - - 0 24", "prompt": "FEN: 4r1k1/pp1n4/2p1q2p/2P2ppb/2PP4/P3pP2/3Q1BPP/R4RK1 w - - 0 24\nFor move a1a2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1a2.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1a2", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1a2", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01297", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r2qr1k1/pp3ppp/2nbpn2/3p3b/2PP4/1P1B1N1P/PB1N1PP1/R2QR1K1 b - -", "prompt": "FEN: r2qr1k1/pp3ppp/2nbpn2/3p3b/2PP4/1P1B1N1P/PB1N1PP1/R2QR1K1 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; h5 black bishop; c6 black knight; d6 black bishop; e6 black pawn; f6 black knight; a7 black pawn; b7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; d8 black queen; e8 black rook; g8 black king.\nMoves by piece:\nd5 black pawn: d5c4\nh5 black bishop: h5f3 h5g4 h5g6\nc6 black knight: c6a5 c6b4 c6b8 c6d4 c6e5 c6e7\nd6 black bishop: d6a3 d6b4 d6b8 d6c5 d6c7 d6e5 d6e7 d6f4 d6f8 d6g3 d6h2\ne6 black pawn: e6e5\nf6 black knight: f6d7 f6e4 f6g4\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nf7 black pawn: no legal moves\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h6\na8 black rook: a8b8 a8c8\nd8 black queen: d8a5 d8b6 d8b8 d8c7 d8c8 d8d7 d8e7\ne8 black rook: e8e7 e8f8\ng8 black king: g8f8 g8h8\nAll legal moves: a7a5 a7a6 a8b8 a8c8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 d5c4 d6a3 d6b4 d6b8 d6c5 d6c7 d6e5 d6e7 d6f4 d6f8 d6g3 d6h2 d8a5 d8b6 d8b8 d8c7 d8c8 d8d7 d8e7 e6e5 e8e7 e8f8 f6d7 f6e4 f6g4 g7g5 g7g6 g8f8 g8h8 h5f3 h5g4 h5g6 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d5": ["d5c4"], "h5": ["h5f3", "h5g4", "h5g6"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5", "c6e7"], "d6": ["d6a3", "d6b4", "d6b8", "d6c5", "d6c7", "d6e5", "d6e7", "d6f4", "d6f8", "d6g3", "d6h2"], "e6": ["e6e5"], "f6": ["f6d7", "f6e4", "f6g4"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h6"], "a8": ["a8b8", "a8c8"], "d8": ["d8a5", "d8b6", "d8b8", "d8c7", "d8c8", "d8d7", "d8e7"], "e8": ["e8e7", "e8f8"], "g8": ["g8f8", "g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 a8c8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 d5c4 d6a3 d6b4 d6b8 d6c5 d6c7 d6e5 d6e7 d6f4 d6f8 d6g3 d6h2 d8a5 d8b6 d8b8 d8c7 d8c8 d8d7 d8e7 e6e5 e8e7 e8f8 f6d7 f6e4 f6g4 g7g5 g7g6 g8f8 g8h8 h5f3 h5g4 h5g6 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d5": ["d5c4"], "h5": ["h5f3", "h5g4", "h5g6"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5", "c6e7"], "d6": ["d6a3", "d6b4", "d6b8", "d6c5", "d6c7", "d6e5", "d6e7", "d6f4", "d6f8", "d6g3", "d6h2"], "e6": ["e6e5"], "f6": ["f6d7", "f6e4", "f6g4"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h6"], "a8": ["a8b8", "a8c8"], "d8": ["d8a5", "d8b6", "d8b8", "d8c7", "d8c8", "d8d7", "d8e7"], "e8": ["e8e7", "e8f8"], "g8": ["g8f8", "g8h8"]}, "legal_moves": "a7a5 a7a6 a8b8 a8c8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 d5c4 d6a3 d6b4 d6b8 d6c5 d6c7 d6e5 d6e7 d6f4 d6f8 d6g3 d6h2 d8a5 d8b6 d8b8 d8c7 d8c8 d8d7 d8e7 e6e5 e8e7 e8f8 f6d7 f6e4 f6g4 g7g5 g7g6 g8f8 g8h8 h5f3 h5g4 h5g6 h7h6"}}
{"example_id": "rules_01298", "split": "rules", "task_type": "ray_walk", "fen": "2n2rk1/2q2pbp/2p1p1p1/3pP3/1PP5/8/1B1NQPPP/R5K1 b - -", "prompt": "FEN: 2n2rk1/2q2pbp/2p1p1p1/3pP3/1PP5/8/1B1NQPPP/R5K1 b - -\nWalk each ray for the slider on c7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c7 black queen.\nRay N: c8 black knight: own piece (stop, excluded).\nRay NE: d8 empty; edge.\nRay E: d7 empty; e7 empty; f7 black pawn: own piece (stop, excluded).\nRay SE: d6 empty; e5 white pawn: capture (stop, included).\nRay S: c6 black pawn: own piece (stop, excluded).\nRay SW: b6 empty; a5 empty; edge.\nRay W: b7 empty; a7 empty; edge.\nRay NW: b8 empty; edge.\nMoves from rays: c7a5 c7a7 c7b6 c7b7 c7b8 c7d6 c7d7 c7d8 c7e5 c7e7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c7", "diagnostic": true, "hard_gate": false, "source_square": "c7"}}
{"example_id": "rules_01299", "split": "rules", "task_type": "legal_moves", "fen": "r3kb1r/ppp2ppp/q4n2/4p3/8/1QP5/PP1P1PPP/RNB1K2R w KQkq -", "prompt": "FEN: r3kb1r/ppp2ppp/q4n2/4p3/8/1QP5/PP1P1PPP/RNB1K2R w KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a3 b3a3 b3a4 b3b4 b3b5 b3b6 b3b7 b3c2 b3c4 b3d1 b3d5 b3e6 b3f7 c3c4 d2d3 d2d4 e1d1 f2f3 f2f4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01300", "split": "rules", "task_type": "legal_moves", "fen": "2r2rk1/1p2qpbp/pBbp1np1/2P1p3/4P1P1/2N1Q2P/PP2BP2/3RK2R b K -", "prompt": "FEN: 2r2rk1/1p2qpbp/pBbp1np1/2P1p3/4P1P1/2N1Q2P/PP2BP2/3RK2R b K -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 c6a4 c6b5 c6d5 c6d7 c6e4 c6e8 c8a8 c8b8 c8c7 c8d8 c8e8 d6c5 d6d5 e7c7 e7d7 e7d8 e7e6 e7e8 f6d5 f6d7 f6e4 f6e8 f6g4 f6h5 f8d8 f8e8 g6g5 g7h6 g7h8 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01301", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2qkbnr/pppnpppp/8/3p4/5Pb1/4PN2/PPPP2PP/RNBQKB1R w KQkq -", "prompt": "FEN: r2qkbnr/pppnpppp/8/3p4/5Pb1/4PN2/PPPP2PP/RNBQKB1R w KQkq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; d1 white queen; e1 white king; f1 white bishop; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; d2 white pawn; g2 white pawn; h2 white pawn; e3 white pawn; f3 white knight; f4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "f1", "piece": "white bishop"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "f4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "f1", "piece": "white bishop"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "f4", "piece": "white pawn"}]}}
{"example_id": "rules_01302", "split": "rules", "task_type": "piece_legal_moves", "fen": "b5rk/p5r1/3p2q1/PPp1p2p/2Pp2P1/3P1P2/3Q1NP1/1R3RK1 b - - 0 33", "prompt": "FEN: b5rk/p5r1/3p2q1/PPp1p2p/2Pp2P1/3P1P2/3Q1NP1/1R3RK1 b - - 0 33\nWhat legal moves does the piece on g8 have?", "gold_answer": "g8b8 g8c8 g8d8 g8e8 g8f8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "g8", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "g8", "piece": "rook"}}
{"example_id": "rules_01303", "split": "rules", "task_type": "check_detection", "fen": "r1bq1rk1/pppnbppp/3ppn2/8/2PPP3/2N2N2/PP2BPPP/R1BQ1RK1 b - -", "prompt": "FEN: r1bq1rk1/pppnbppp/3ppn2/8/2PPP3/2N2N2/PP2BPPP/R1BQ1RK1 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01304", "split": "rules", "task_type": "captures", "fen": "1r2r1k1/3q1pb1/3p1n1p/1NnPp1p1/2P4B/1p3N1P/1P1Q1PP1/3RR1K1 w - - 0 25", "prompt": "FEN: 1r2r1k1/3q1pb1/3p1n1p/1NnPp1p1/2P4B/1p3N1P/1P1Q1PP1/3RR1K1 w - - 0 25\nList all capture moves available.", "gold_answer": "b5d6 d2g5 e1e5 f3e5 f3g5 h4g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01305", "split": "rules", "task_type": "special_rules", "fen": "8/6pk/7p/3pp1r1/5q2/7P/PR2QPP1/3r3K w - -", "prompt": "Given FEN: 8/6pk/7p/3pp1r1/5q2/7P/PR2QPP1/3r3K w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01306", "split": "rules", "task_type": "legality_check", "fen": "8/7k/p7/1p3pQp/4N3/P3P3/1P3PPP/5RK1 w - - 1 32", "prompt": "FEN: 8/7k/p7/1p3pQp/4N3/P3P3/1P3PPP/5RK1 w - - 1 32\nIs the move g5g3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g5g3", "_legality_check_reason_label": "legal", "move": "g5g3", "legality_reason_label": "legal"}}
{"example_id": "rules_01307", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "4r1k1/2R2ppp/pp3r2/3R4/1P6/P3P3/5P1P/6K1 w - - 0 30", "prompt": "FEN: 4r1k1/2R2ppp/pp3r2/3R4/1P6/P3P3/5P1P/6K1 w - - 0 30\nList pseudo-legal moves from g1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g1: g1f1 g1g2 g1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g1", "diagnostic": true, "hard_gate": false, "source_square": "g1"}}
{"example_id": "rules_01308", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1b1k2r/pp2ppbp/2n2np1/2p5/3Pq3/N1P2N2/PP2BPPP/R1BQ1RK1 b kq -", "prompt": "FEN: r1b1k2r/pp2ppbp/2n2np1/2p5/3Pq3/N1P2N2/PP2BPPP/R1BQ1RK1 b kq -\nFor the piece on e4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e4: e4b1 e4c2 e4d3 e4d4 e4d5 e4e2 e4e3 e4e5 e4e6 e4f3 e4f4 e4f5 e4g4 e4h4.\nLegal: e4b1 e4c2 e4d3 e4d4 e4d5 e4e2 e4e3 e4e5 e4e6 e4f3 e4f4 e4f5 e4g4 e4h4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "e4", "diagnostic": true, "hard_gate": false, "source_square": "e4"}}
{"example_id": "rules_01309", "split": "rules", "task_type": "king_safety_filter", "fen": "5r2/P2P4/8/8/7P/8/4K2P/7k w - -", "prompt": "FEN: 5r2/P2P4/8/8/7P/8/4K2P/7k w - -\nFor move e2f1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e2f1.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "e2f1", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e2f1", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01310", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2kr1bnr/ppqb2pp/2n1p3/2ppP3/5B2/2P2N2/PP2BPPP/RN1QR1K1 b - -", "prompt": "FEN: 2kr1bnr/ppqb2pp/2n1p3/2ppP3/5B2/2P2N2/PP2BPPP/RN1QR1K1 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black pawn; d5 black pawn; c6 black knight; e6 black pawn; a7 black pawn; b7 black pawn; c7 black queen; d7 black bishop; g7 black pawn; h7 black pawn; c8 black king; d8 black rook; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\nc5 black pawn: c5c4\nd5 black pawn: d5d4\nc6 black knight: c6a5 c6b4 c6b8 c6d4 c6e5 c6e7\ne6 black pawn: no legal moves\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nc7 black queen: c7a5 c7b6 c7b8 c7d6 c7e5\nd7 black bishop: d7e8\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\nc8 black king: c8b8\nd8 black rook: d8e8\nf8 black bishop: f8d6 f8e7\ng8 black knight: g8e7 g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a7a5 a7a6 b7b5 b7b6 c5c4 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 c7a5 c7b6 c7b8 c7d6 c7e5 c8b8 d5d4 d7e8 d8e8 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": ["c5c4"], "d5": ["d5d4"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5", "c6e7"], "e6": [], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7a5", "c7b6", "c7b8", "c7d6", "c7e5"], "d7": ["d7e8"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8b8"], "d8": ["d8e8"], "f8": ["f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7b5 b7b6 c5c4 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 c7a5 c7b6 c7b8 c7d6 c7e5 c8b8 d5d4 d7e8 d8e8 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": ["c5c4"], "d5": ["d5d4"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5", "c6e7"], "e6": [], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7a5", "c7b6", "c7b8", "c7d6", "c7e5"], "d7": ["d7e8"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8b8"], "d8": ["d8e8"], "f8": ["f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "legal_moves": "a7a5 a7a6 b7b5 b7b6 c5c4 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 c7a5 c7b6 c7b8 c7d6 c7e5 c8b8 d5d4 d7e8 d8e8 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_01311", "split": "rules", "task_type": "ray_walk", "fen": "3qk2r/1rp1bpp1/3p1n1p/p1pPp3/4P3/P1N1BQ2/1PP2PPP/1K1R3R b k - 7 16", "prompt": "FEN: 3qk2r/1rp1bpp1/3p1n1p/p1pPp3/4P3/P1N1BQ2/1PP2PPP/1K1R3R b k - 7 16\nWalk each ray for the slider on b7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b7 black rook.\nRay N: b8 empty; edge.\nRay E: c7 black pawn: own piece (stop, excluded).\nRay S: b6 empty; b5 empty; b4 empty; b3 empty; b2 white pawn: capture (stop, included).\nRay W: a7 empty; edge.\nMoves from rays: b7a7 b7b2 b7b3 b7b4 b7b5 b7b6 b7b8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "b7", "diagnostic": true, "hard_gate": false, "source_square": "b7"}}
{"example_id": "rules_01312", "split": "rules", "task_type": "legal_moves", "fen": "rnbqkb1r/1p1p1ppp/p3pn2/2P5/8/2N1BN2/PPP1PPPP/R2QKB1R b KQkq - 1 5", "prompt": "FEN: rnbqkb1r/1p1p1ppp/p3pn2/2P5/8/2N1BN2/PPP1PPPP/R2QKB1R b KQkq - 1 5\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 b7b5 b7b6 b8c6 d7d5 d7d6 d8a5 d8b6 d8c7 d8e7 e6e5 e8e7 f6d5 f6e4 f6g4 f6g8 f6h5 f8c5 f8d6 f8e7 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01313", "split": "rules", "task_type": "legal_moves", "fen": "3r4/2p2kPp/p1b2p1B/1p2p2P/3R4/1PPr1P2/P4KP1/4R3 w - -", "prompt": "FEN: 3r4/2p2kPp/p1b2p1B/1p2p2P/3R4/1PPr1P2/P4KP1/4R3 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b3b4 c3c4 d4a4 d4b4 d4c4 d4d3 d4d5 d4d6 d4d7 d4d8 d4e4 d4f4 d4g4 d4h4 e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1f1 e1g1 e1h1 f2e2 f2f1 f2g1 f2g3 f3f4 g2g3 g2g4 g7g8b g7g8n g7g8q g7g8r h6c1 h6d2 h6e3 h6f4 h6g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01314", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/8/4K3/2B5/2B1k3/8/8/8 w - -", "prompt": "FEN: 8/8/4K3/2B5/2B1k3/8/8/8 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: c4 white bishop; c5 white bishop; e6 white king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "c4", "piece": "white bishop"}, {"square": "c5", "piece": "white bishop"}, {"square": "e6", "piece": "white king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "c4", "piece": "white bishop"}, {"square": "c5", "piece": "white bishop"}, {"square": "e6", "piece": "white king"}]}}
{"example_id": "rules_01315", "split": "rules", "task_type": "piece_legal_moves", "fen": "5k2/7Q/4K3/8/8/8/8/8 b - -", "prompt": "FEN: 5k2/7Q/4K3/8/8/8/8/8 b - -\nWhat legal moves does the piece on f8 have?", "gold_answer": "f8e8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f8", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "f8", "piece": "king"}}
{"example_id": "rules_01316", "split": "rules", "task_type": "check_detection", "fen": "k1r5/P7/3K2p1/5p1p/5P1P/R5P1/8/8 w - -", "prompt": "FEN: k1r5/P7/3K2p1/5p1p/5P1P/R5P1/8/8 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01317", "split": "rules", "task_type": "captures", "fen": "2r1r1k1/6b1/5p2/p1Pp1N1p/N3p3/4P3/1PR2PPP/6K1 w - - 0 27", "prompt": "FEN: 2r1r1k1/6b1/5p2/p1Pp1N1p/N3p3/4P3/1PR2PPP/6K1 w - - 0 27\nList all capture moves available.", "gold_answer": "f5g7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01318", "split": "rules", "task_type": "special_rules", "fen": "r3k2r/p2qbpp1/5n1p/2p5/4p3/1P6/1PPPQPPP/RNB2RK1 b kq - 0 15", "prompt": "Given FEN: r3k2r/p2qbpp1/5n1p/2p5/4p3/1P6/1PPPQPPP/RNB2RK1 b kq - 0 15\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside, queenside.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01319", "split": "rules", "task_type": "legality_check", "fen": "4r2k/2p3pp/p1Pb1r2/1p1P3q/P7/1BPR3P/KPN1np2/5Q1R w - - 4 34", "prompt": "FEN: 4r2k/2p3pp/p1Pb1r2/1p1P3q/P7/1BPR3P/KPN1np2/5Q1R w - - 4 34\nIs the move h5g8 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "h5g8", "_legality_check_reason_label": "wrong_side_piece", "move": "h5g8", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01320", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rn1q1bnr/ppp1k3/4b2p/4Q3/2B1Pp1P/8/PPPP2P1/RNB1K2R w KQ -", "prompt": "FEN: rn1q1bnr/ppp1k3/4b2p/4Q3/2B1Pp1P/8/PPPP2P1/RNB1K2R w KQ -\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a3 b1c3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01321", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1b1kb1r/pp2pppp/2n5/q1pp4/3P3B/2P1PN2/P1PQBPPP/R3K2R b KQkq -", "prompt": "FEN: r1b1kb1r/pp2pppp/2n5/q1pp4/3P3B/2P1PN2/P1PQBPPP/R3K2R b KQkq -\nFor the piece on a5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a5: a5a2 a5a3 a5a4 a5a6 a5b4 a5b5 a5b6 a5c3 a5c7 a5d8.\nLegal: a5a2 a5a3 a5a4 a5a6 a5b4 a5b5 a5b6 a5c3 a5c7 a5d8.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_01322", "split": "rules", "task_type": "king_safety_filter", "fen": "8/8/8/8/8/1P1R1p2/P5k1/K7 w - - 1 39", "prompt": "FEN: 8/8/8/8/8/1P1R1p2/P5k1/K7 w - - 1 39\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01323", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r2qk1nr/1b5p/2nbp1p1/p2pNp1Q/1ppP1P2/2P1P3/PPBN2PP/R1B2RK1 w kq - 0 13", "prompt": "FEN: r2qk1nr/1b5p/2nbp1p1/p2pNp1Q/1ppP1P2/2P1P3/PPBN2PP/R1B2RK1 w kq - 0 13\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; c2 white bishop; d2 white knight; g2 white pawn; h2 white pawn; c3 white pawn; e3 white pawn; d4 white pawn; f4 white pawn; e5 white knight; h5 white queen.\nMoves by piece:\na1 white rook: a1b1\nc1 white bishop: no legal moves\nf1 white rook: f1d1 f1e1 f1f2 f1f3\ng1 white king: g1f2 g1h1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3\nc2 white bishop: c2a4 c2b1 c2b3 c2d1 c2d3 c2e4 c2f5\nd2 white knight: d2b1 d2b3 d2c4 d2e4 d2f3\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nc3 white pawn: c3b4\ne3 white pawn: e3e4\nd4 white pawn: no legal moves\nf4 white pawn: no legal moves\ne5 white knight: e5c4 e5c6 e5d3 e5d7 e5f3 e5f7 e5g4 e5g6\nh5 white queen: h5d1 h5e2 h5f3 h5f5 h5g4 h5g5 h5g6 h5h3 h5h4 h5h6 h5h7\nAll legal moves: a1b1 a2a3 a2a4 b2b3 c2a4 c2b1 c2b3 c2d1 c2d3 c2e4 c2f5 c3b4 d2b1 d2b3 d2c4 d2e4 d2f3 e3e4 e5c4 e5c6 e5d3 e5d7 e5f3 e5f7 e5g4 e5g6 f1d1 f1e1 f1f2 f1f3 g1f2 g1h1 g2g3 g2g4 h2h3 h2h4 h5d1 h5e2 h5f3 h5f5 h5g4 h5g5 h5g6 h5h3 h5h4 h5h6 h5h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1"], "c1": [], "f1": ["f1d1", "f1e1", "f1f2", "f1f3"], "g1": ["g1f2", "g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3"], "c2": ["c2a4", "c2b1", "c2b3", "c2d1", "c2d3", "c2e4", "c2f5"], "d2": ["d2b1", "d2b3", "d2c4", "d2e4", "d2f3"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c3": ["c3b4"], "e3": ["e3e4"], "d4": [], "f4": [], "e5": ["e5c4", "e5c6", "e5d3", "e5d7", "e5f3", "e5f7", "e5g4", "e5g6"], "h5": ["h5d1", "h5e2", "h5f3", "h5f5", "h5g4", "h5g5", "h5g6", "h5h3", "h5h4", "h5h6", "h5h7"]}, "_legal_moves_by_piece_moves": "a1b1 a2a3 a2a4 b2b3 c2a4 c2b1 c2b3 c2d1 c2d3 c2e4 c2f5 c3b4 d2b1 d2b3 d2c4 d2e4 d2f3 e3e4 e5c4 e5c6 e5d3 e5d7 e5f3 e5f7 e5g4 e5g6 f1d1 f1e1 f1f2 f1f3 g1f2 g1h1 g2g3 g2g4 h2h3 h2h4 h5d1 h5e2 h5f3 h5f5 h5g4 h5g5 h5g6 h5h3 h5h4 h5h6 h5h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1"], "c1": [], "f1": ["f1d1", "f1e1", "f1f2", "f1f3"], "g1": ["g1f2", "g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3"], "c2": ["c2a4", "c2b1", "c2b3", "c2d1", "c2d3", "c2e4", "c2f5"], "d2": ["d2b1", "d2b3", "d2c4", "d2e4", "d2f3"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c3": ["c3b4"], "e3": ["e3e4"], "d4": [], "f4": [], "e5": ["e5c4", "e5c6", "e5d3", "e5d7", "e5f3", "e5f7", "e5g4", "e5g6"], "h5": ["h5d1", "h5e2", "h5f3", "h5f5", "h5g4", "h5g5", "h5g6", "h5h3", "h5h4", "h5h6", "h5h7"]}, "legal_moves": "a1b1 a2a3 a2a4 b2b3 c2a4 c2b1 c2b3 c2d1 c2d3 c2e4 c2f5 c3b4 d2b1 d2b3 d2c4 d2e4 d2f3 e3e4 e5c4 e5c6 e5d3 e5d7 e5f3 e5f7 e5g4 e5g6 f1d1 f1e1 f1f2 f1f3 g1f2 g1h1 g2g3 g2g4 h2h3 h2h4 h5d1 h5e2 h5f3 h5f5 h5g4 h5g5 h5g6 h5h3 h5h4 h5h6 h5h7"}}
{"example_id": "rules_01324", "split": "rules", "task_type": "ray_walk", "fen": "1r1qkb1r/3b1ppp/p1n2n2/1p1Np3/4P3/1B2BN2/PP3PPP/R2QR1K1 b k -", "prompt": "FEN: 1r1qkb1r/3b1ppp/p1n2n2/1p1Np3/4P3/1B2BN2/PP3PPP/R2QR1K1 b k -\nWalk each ray for the slider on d7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d7 black bishop.\nRay NE: e8 black king: own piece (stop, excluded).\nRay SE: e6 empty; f5 empty; g4 empty; h3 empty; edge.\nRay SW: c6 black knight: own piece (stop, excluded).\nRay NW: c8 empty; edge.\nMoves from rays: d7c8 d7e6 d7f5 d7g4 d7h3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "d7", "diagnostic": true, "hard_gate": false, "source_square": "d7"}}
{"example_id": "rules_01325", "split": "rules", "task_type": "legal_moves", "fen": "2r2rk1/3bqpp1/1np4p/p2pN3/1p1P1Pn1/1P1BPR2/P1Q1N1PP/2R3K1 b - -", "prompt": "FEN: 2r2rk1/3bqpp1/1np4p/p2pN3/1p1P1Pn1/1P1BPR2/P1Q1N1PP/2R3K1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a5a4 b6a4 b6a8 b6c4 c6c5 c8a8 c8b8 c8c7 c8d8 c8e8 d7e6 d7e8 d7f5 e7c5 e7d6 e7d8 e7e5 e7e6 e7e8 e7f6 e7g5 e7h4 f7f5 f7f6 f8d8 f8e8 g4e3 g4e5 g4f2 g4f6 g4h2 g7g5 g7g6 g8h8 h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01326", "split": "rules", "task_type": "legal_moves", "fen": "r2q4/pp3r2/4bnkp/2Pp1p2/P2Pp3/B3P3/2Q1BPP1/R3K2R b KQ - 0 20", "prompt": "FEN: r2q4/pp3r2/4bnkp/2Pp1p2/P2Pp3/B3P3/2Q1BPP1/R3K2R b KQ - 0 20\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 a8c8 b7b5 b7b6 d8a5 d8b6 d8b8 d8c7 d8c8 d8d6 d8d7 d8e7 d8e8 d8f8 d8g8 d8h8 e6c8 e6d7 f5f4 f6d7 f6e8 f6g4 f6g8 f6h5 f6h7 f7c7 f7d7 f7e7 f7f8 f7g7 f7h7 g6g5 g6g7 g6h7 h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01327", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqk2r/ppp2pp1/3b1n2/3p3p/3np3/1PN1P3/PBPPBPPP/R2Q1RK1 w kq - 0 9", "prompt": "FEN: r1bqk2r/ppp2pp1/3b1n2/3p3p/3np3/1PN1P3/PBPPBPPP/R2Q1RK1 w kq - 0 9\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white queen; f1 white rook; g1 white king; a2 white pawn; b2 white bishop; c2 white pawn; d2 white pawn; e2 white bishop; f2 white pawn; g2 white pawn; h2 white pawn; b3 white pawn; c3 white knight; e3 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white bishop"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white pawn"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "b3", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "e3", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white bishop"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white pawn"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "b3", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "e3", "piece": "white pawn"}]}}
{"example_id": "rules_01328", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/3k4/8/3BK3/2N5/8/8/8 b - -", "prompt": "FEN: 8/3k4/8/3BK3/2N5/8/8/8 b - -\nWhat legal moves does the piece on d7 have?", "gold_answer": "d7c7 d7c8 d7d8 d7e7 d7e8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "d7", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "d7", "piece": "king"}}
{"example_id": "rules_01329", "split": "rules", "task_type": "check_detection", "fen": "2rq1r1k/p5pp/2p1Q3/1p3p2/1P1P4/P3P2P/5PP1/2R2RK1 b - - 3 21", "prompt": "FEN: 2rq1r1k/p5pp/2p1Q3/1p3p2/1P1P4/P3P2P/5PP1/2R2RK1 b - - 3 21\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01330", "split": "rules", "task_type": "captures", "fen": "2r1k2Q/pp1bqr2/7p/3p2pn/8/P4RBP/1P3PP1/4R1K1 b - -", "prompt": "FEN: 2r1k2Q/pp1bqr2/7p/3p2pn/8/P4RBP/1P3PP1/4R1K1 b - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01331", "split": "rules", "task_type": "special_rules", "fen": "1r4k1/5p1p/2n1b3/2qpN3/8/2B1P3/PP3PPP/1K1R1B1R w - - 5 20", "prompt": "Given FEN: 1r4k1/5p1p/2n1b3/2qpN3/8/2B1P3/PP3PPP/1K1R1B1R w - - 5 20\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01332", "split": "rules", "task_type": "legality_check", "fen": "r2qk2r/ppp2ppp/2np1n2/2b5/3pPPb1/3B1N1P/PPPN2P1/R1BQ1RK1 b kq -", "prompt": "FEN: r2qk2r/ppp2ppp/2np1n2/2b5/3pPPb1/3B1N1P/PPPN2P1/R1BQ1RK1 b kq -\nIs the move f6d5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f6d5", "_legality_check_reason_label": "legal", "move": "f6d5", "legality_reason_label": "legal"}}
{"example_id": "rules_01333", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5r2/4r2p/p4p2/1ppp1P2/4pkPR/3P4/PPP3KP/5R2 b - - 1 31", "prompt": "FEN: 5r2/4r2p/p4p2/1ppp1P2/4pkPR/3P4/PPP3KP/5R2 b - - 1 31\nList pseudo-legal moves from e4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e4: e4d3 e4e3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e4", "diagnostic": true, "hard_gate": false, "source_square": "e4"}}
{"example_id": "rules_01334", "split": "rules", "task_type": "piece_legal_filter", "fen": "r4rk1/1ppnbppp/p1nq4/3p3b/1P1PpP2/P1N1P2P/2PQ4/R1B1KBNR w KQ - 1 13", "prompt": "FEN: r4rk1/1ppnbppp/p1nq4/3p3b/1P1PpP2/P1N1P2P/2PQ4/R1B1KBNR w KQ - 1 13\nFor the piece on e1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e1: e1d1 e1e2 e1f2.\nLegal: e1f2.\nRejected: e1d1 king_would_be_in_check; e1e2 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "e1", "diagnostic": true, "hard_gate": false, "source_square": "e1"}}
{"example_id": "rules_01335", "split": "rules", "task_type": "king_safety_filter", "fen": "r1br2k1/pp3ppp/4p3/n2pP3/8/1B3N2/PPP2PPP/R2R2K1 w - - 0 15", "prompt": "FEN: r1br2k1/pp3ppp/4p3/n2pP3/8/1B3N2/PPP2PPP/R2R2K1 w - - 0 15\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01336", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r3k2r/pppqb1p1/2n1p3/3pPppn/3P4/2P2PP1/PP1NQBBP/R3K2R b KQkq -", "prompt": "FEN: r3k2r/pppqb1p1/2n1p3/3pPppn/3P4/2P2PP1/PP1NQBBP/R3K2R b KQkq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; f5 black pawn; g5 black pawn; h5 black knight; c6 black knight; e6 black pawn; a7 black pawn; b7 black pawn; c7 black pawn; d7 black queen; e7 black bishop; g7 black pawn; a8 black rook; e8 black king; h8 black rook.\nMoves by piece:\nd5 black pawn: no legal moves\nf5 black pawn: f5f4\ng5 black pawn: g5g4\nh5 black knight: h5f4 h5f6 h5g3\nc6 black knight: c6a5 c6b4 c6b8 c6d4 c6d8 c6e5\ne6 black pawn: no legal moves\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nc7 black pawn: no legal moves\nd7 black queen: d7c8 d7d6 d7d8\ne7 black bishop: e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7f8\ng7 black pawn: g7g6\na8 black rook: a8b8 a8c8 a8d8\ne8 black king: e8c8 e8d8 e8f7 e8f8 e8g8\nh8 black rook: h8f8 h8g8 h8h6 h8h7\nAll legal moves: a7a5 a7a6 a8b8 a8c8 a8d8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6d8 c6e5 d7c8 d7d6 d7d8 e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7f8 e8c8 e8d8 e8f7 e8f8 e8g8 f5f4 g5g4 g7g6 h5f4 h5f6 h5g3 h8f8 h8g8 h8h6 h8h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d5": [], "f5": ["f5f4"], "g5": ["g5g4"], "h5": ["h5f4", "h5f6", "h5g3"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6d8", "c6e5"], "e6": [], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": [], "d7": ["d7c8", "d7d6", "d7d8"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6", "e7d8", "e7f6", "e7f8"], "g7": ["g7g6"], "a8": ["a8b8", "a8c8", "a8d8"], "e8": ["e8c8", "e8d8", "e8f7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8", "h8h6", "h8h7"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 a8c8 a8d8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6d8 c6e5 d7c8 d7d6 d7d8 e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7f8 e8c8 e8d8 e8f7 e8f8 e8g8 f5f4 g5g4 g7g6 h5f4 h5f6 h5g3 h8f8 h8g8 h8h6 h8h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d5": [], "f5": ["f5f4"], "g5": ["g5g4"], "h5": ["h5f4", "h5f6", "h5g3"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6d8", "c6e5"], "e6": [], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": [], "d7": ["d7c8", "d7d6", "d7d8"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6", "e7d8", "e7f6", "e7f8"], "g7": ["g7g6"], "a8": ["a8b8", "a8c8", "a8d8"], "e8": ["e8c8", "e8d8", "e8f7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8", "h8h6", "h8h7"]}, "legal_moves": "a7a5 a7a6 a8b8 a8c8 a8d8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6d8 c6e5 d7c8 d7d6 d7d8 e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7f8 e8c8 e8d8 e8f7 e8f8 e8g8 f5f4 g5g4 g7g6 h5f4 h5f6 h5g3 h8f8 h8g8 h8h6 h8h7"}}
{"example_id": "rules_01337", "split": "rules", "task_type": "ray_walk", "fen": "2kr3r/pppq1p2/2nbbn1p/3p4/1P1P2pN/1NP1B1P1/P4PBP/R2Q1RK1 b - - 1 13", "prompt": "FEN: 2kr3r/pppq1p2/2nbbn1p/3p4/1P1P2pN/1NP1B1P1/P4PBP/R2Q1RK1 b - - 1 13\nWalk each ray for the slider on d6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d6 black bishop.\nRay NE: e7 empty; f8 empty; edge.\nRay SE: e5 empty; f4 empty; g3 white pawn: capture (stop, included).\nRay SW: c5 empty; b4 white pawn: capture (stop, included).\nRay NW: c7 black pawn: own piece (stop, excluded).\nMoves from rays: d6b4 d6c5 d6e5 d6e7 d6f4 d6f8 d6g3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "d6", "diagnostic": true, "hard_gate": false, "source_square": "d6"}}
{"example_id": "rules_01338", "split": "rules", "task_type": "legal_moves", "fen": "5rk1/5rp1/1n2p2p/1p2p1q1/p2pP1P1/3p1P1P/PPPN1RQ1/6RK w - - 0 29", "prompt": "FEN: 5rk1/5rp1/1n2p2p/1p2p1q1/p2pP1P1/3p1P1P/PPPN1RQ1/6RK w - - 0 29\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 b2b3 b2b4 c2c3 c2c4 c2d3 d2b1 d2b3 d2c4 d2f1 f2e2 f2f1 f3f4 g1a1 g1b1 g1c1 g1d1 g1e1 g1f1 g2f1 g2g3 g2h2 h1h2 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01339", "split": "rules", "task_type": "legal_moves", "fen": "r2qr1k1/1b2bppp/p4n2/1p1p4/1PnP4/2Q1P1P1/1N2NPBP/R1B2RK1 w - - 0 18", "prompt": "FEN: r2qr1k1/1b2bppp/p4n2/1p1p4/1PnP4/2Q1P1P1/1N2NPBP/R1B2RK1 w - - 0 18\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 a1a4 a1a5 a1a6 a1b1 b2a4 b2c4 b2d1 b2d3 c1d2 c3a3 c3b3 c3c2 c3c4 c3d2 c3d3 c3e1 e2f4 e3e4 f1d1 f1e1 f2f3 f2f4 g1h1 g2d5 g2e4 g2f3 g2h1 g2h3 g3g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01340", "split": "rules", "task_type": "side_piece_inventory", "fen": "5r2/1R3ppp/4p3/2k5/2p5/2P2PKP/r5P1/8 b - - 6 30", "prompt": "FEN: 5r2/1R3ppp/4p3/2k5/2p5/2P2PKP/r5P1/8 b - - 6 30\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: a2 black rook; c4 black pawn; c5 black king; e6 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; f8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "a2", "piece": "black rook"}, {"square": "c4", "piece": "black pawn"}, {"square": "c5", "piece": "black king"}, {"square": "e6", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "f8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "a2", "piece": "black rook"}, {"square": "c4", "piece": "black pawn"}, {"square": "c5", "piece": "black king"}, {"square": "e6", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "f8", "piece": "black rook"}]}}
{"example_id": "rules_01341", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bqk1nr/pp2nppp/2Pp4/b3p3/Q1B1P3/2P2N2/P4PPP/RNB1K2R b KQkq -", "prompt": "FEN: r1bqk1nr/pp2nppp/2Pp4/b3p3/Q1B1P3/2P2N2/P4PPP/RNB1K2R b KQkq -\nWhat legal moves does the piece on d8 have?", "gold_answer": "d8b6 d8c7 d8d7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "d8", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "d8", "piece": "queen"}}
{"example_id": "rules_01342", "split": "rules", "task_type": "check_detection", "fen": "1R6/4p3/N1k1p2K/pN2P3/2B1pPP1/2n5/4Ppb1/8 b - -", "prompt": "FEN: 1R6/4p3/N1k1p2K/pN2P3/2B1pPP1/2n5/4Ppb1/8 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01343", "split": "rules", "task_type": "captures", "fen": "3r3r/pppk1p2/3p1npp/1Pb1p3/P3P3/2PBNP1P/3P1P2/2R1K2R b K - 1 19", "prompt": "FEN: 3r3r/pppk1p2/3p1npp/1Pb1p3/P3P3/2PBNP1P/3P1P2/2R1K2R b K - 1 19\nList all capture moves available.", "gold_answer": "c5e3 f6e4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01344", "split": "rules", "task_type": "special_rules", "fen": "8/8/8/8/8/4K1k1/r6p/7R w - - 6 66", "prompt": "Given FEN: 8/8/8/8/8/4K1k1/r6p/7R w - - 6 66\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01345", "split": "rules", "task_type": "legality_check", "fen": "r2q1rk1/1p2ppb1/2npbnpp/p1pN4/2P1P3/P2P1NP1/1P1B1PBP/R2Q1RK1 b - - 3 11", "prompt": "FEN: r2q1rk1/1p2ppb1/2npbnpp/p1pN4/2P1P3/P2P1NP1/1P1B1PBP/R2Q1RK1 b - - 3 11\nIs the move a7b4 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "a7b4", "_legality_check_reason_label": "empty_source", "move": "a7b4", "legality_reason_label": "empty_source"}}
{"example_id": "rules_01346", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2kr1b1r/pp2q2p/n1p1pn2/3p2p1/3P4/1BP5/PP3PPP/RNBQR1K1 w - - 1 12", "prompt": "FEN: 2kr1b1r/pp2q2p/n1p1pn2/3p2p1/3P4/1BP5/PP3PPP/RNBQR1K1 w - - 1 12\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a3 b1d2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01347", "split": "rules", "task_type": "piece_legal_filter", "fen": "r4rk1/3b2b1/p2ppq1p/1p1P3Q/6p1/3BB1P1/P6P/1R2R1K1 w - - 0 23", "prompt": "FEN: r4rk1/3b2b1/p2ppq1p/1p1P3Q/6p1/3BB1P1/P6P/1R2R1K1 w - - 0 23\nFor the piece on g1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g1: g1f1 g1f2 g1g2 g1h1.\nLegal: g1g2 g1h1.\nRejected: g1f1 king_would_be_in_check; g1f2 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g1", "diagnostic": true, "hard_gate": false, "source_square": "g1"}}
{"example_id": "rules_01348", "split": "rules", "task_type": "king_safety_filter", "fen": "rn5r/pb2bkq1/1pppNn2/7p/3P4/2NB2B1/PPPQ1PPP/R3K2R w KQ - 1 14", "prompt": "FEN: rn5r/pb2bkq1/1pppNn2/7p/3P4/2NB2B1/PPPQ1PPP/R3K2R w KQ - 1 14\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01349", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "6k1/5pp1/5np1/3p1P2/8/6PP/1pq2nRK/8 b - -", "prompt": "FEN: 6k1/5pp1/5np1/3p1P2/8/6PP/1pq2nRK/8 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b2 black pawn; c2 black queen; f2 black knight; d5 black pawn; f6 black knight; g6 black pawn; f7 black pawn; g7 black pawn; g8 black king.\nMoves by piece:\nb2 black pawn: b2b1b b2b1n b2b1q b2b1r\nc2 black queen: c2a4 c2b1 c2b3 c2c1 c2c3 c2c4 c2c5 c2c6 c2c7 c2c8 c2d1 c2d2 c2d3 c2e2 c2e4 c2f5\nf2 black knight: f2d1 f2d3 f2e4 f2g4 f2h1 f2h3\nd5 black pawn: d5d4\nf6 black knight: f6d7 f6e4 f6e8 f6g4 f6h5 f6h7\ng6 black pawn: g6f5 g6g5\nf7 black pawn: no legal moves\ng7 black pawn: no legal moves\ng8 black king: g8f8 g8h7 g8h8\nAll legal moves: b2b1b b2b1n b2b1q b2b1r c2a4 c2b1 c2b3 c2c1 c2c3 c2c4 c2c5 c2c6 c2c7 c2c8 c2d1 c2d2 c2d3 c2e2 c2e4 c2f5 d5d4 f2d1 f2d3 f2e4 f2g4 f2h1 f2h3 f6d7 f6e4 f6e8 f6g4 f6h5 f6h7 g6f5 g6g5 g8f8 g8h7 g8h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b2": ["b2b1b", "b2b1n", "b2b1q", "b2b1r"], "c2": ["c2a4", "c2b1", "c2b3", "c2c1", "c2c3", "c2c4", "c2c5", "c2c6", "c2c7", "c2c8", "c2d1", "c2d2", "c2d3", "c2e2", "c2e4", "c2f5"], "f2": ["f2d1", "f2d3", "f2e4", "f2g4", "f2h1", "f2h3"], "d5": ["d5d4"], "f6": ["f6d7", "f6e4", "f6e8", "f6g4", "f6h5", "f6h7"], "g6": ["g6f5", "g6g5"], "f7": [], "g7": [], "g8": ["g8f8", "g8h7", "g8h8"]}, "_legal_moves_by_piece_moves": "b2b1b b2b1n b2b1q b2b1r c2a4 c2b1 c2b3 c2c1 c2c3 c2c4 c2c5 c2c6 c2c7 c2c8 c2d1 c2d2 c2d3 c2e2 c2e4 c2f5 d5d4 f2d1 f2d3 f2e4 f2g4 f2h1 f2h3 f6d7 f6e4 f6e8 f6g4 f6h5 f6h7 g6f5 g6g5 g8f8 g8h7 g8h8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b2": ["b2b1b", "b2b1n", "b2b1q", "b2b1r"], "c2": ["c2a4", "c2b1", "c2b3", "c2c1", "c2c3", "c2c4", "c2c5", "c2c6", "c2c7", "c2c8", "c2d1", "c2d2", "c2d3", "c2e2", "c2e4", "c2f5"], "f2": ["f2d1", "f2d3", "f2e4", "f2g4", "f2h1", "f2h3"], "d5": ["d5d4"], "f6": ["f6d7", "f6e4", "f6e8", "f6g4", "f6h5", "f6h7"], "g6": ["g6f5", "g6g5"], "f7": [], "g7": [], "g8": ["g8f8", "g8h7", "g8h8"]}, "legal_moves": "b2b1b b2b1n b2b1q b2b1r c2a4 c2b1 c2b3 c2c1 c2c3 c2c4 c2c5 c2c6 c2c7 c2c8 c2d1 c2d2 c2d3 c2e2 c2e4 c2f5 d5d4 f2d1 f2d3 f2e4 f2g4 f2h1 f2h3 f6d7 f6e4 f6e8 f6g4 f6h5 f6h7 g6f5 g6g5 g8f8 g8h7 g8h8"}}
{"example_id": "rules_01350", "split": "rules", "task_type": "ray_walk", "fen": "rn1q1rk1/p3nppp/1p2p3/2ppP1B1/3P4/P1PP1N2/5PPP/R2Q1RK1 b - -", "prompt": "FEN: rn1q1rk1/p3nppp/1p2p3/2ppP1B1/3P4/P1PP1N2/5PPP/R2Q1RK1 b - -\nWalk each ray for the slider on a8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a8 black rook.\nRay N: edge.\nRay E: b8 black knight: own piece (stop, excluded).\nRay S: a7 black pawn: own piece (stop, excluded).\nRay W: edge.\nMoves from rays: none", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a8", "diagnostic": true, "hard_gate": false, "source_square": "a8"}}
{"example_id": "rules_01351", "split": "rules", "task_type": "legal_moves", "fen": "5rk1/4qpb1/2pr4/p3p3/1p2P1QP/6P1/P5PN/1B3R1K b - - 0 30", "prompt": "FEN: 5rk1/4qpb1/2pr4/p3p3/1p2P1QP/6P1/P5PN/1B3R1K b - - 0 30\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a5a4 b4b3 c6c5 d6d1 d6d2 d6d3 d6d4 d6d5 d6d7 d6d8 d6e6 d6f6 d6g6 d6h6 e7a7 e7b7 e7c7 e7d7 e7d8 e7e6 e7e8 e7f6 e7g5 e7h4 f7f5 f7f6 f8a8 f8b8 f8c8 f8d8 f8e8 g8h7 g8h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01352", "split": "rules", "task_type": "legal_moves", "fen": "7r/pbqnbk2/2pr1nRp/1p2p3/4PP1N/2N1B3/PPP4P/2K1RQ2 w - -", "prompt": "FEN: 7r/pbqnbk2/2pr1nRp/1p2p3/4PP1N/2N1B3/PPP4P/2K1RQ2 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 b2b4 c1b1 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 e1d1 e1e2 e3a7 e3b6 e3c5 e3d2 e3d4 e3f2 e3g1 f1b5 f1c4 f1d3 f1e2 f1f2 f1f3 f1g1 f1g2 f1h1 f1h3 f4e5 f4f5 g6f6 g6g1 g6g2 g6g3 g6g4 g6g5 g6g7 g6g8 g6h6 h2h3 h4f3 h4f5 h4g2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01353", "split": "rules", "task_type": "side_piece_inventory", "fen": "4r3/2P5/4kp2/1K1N1R2/1P1b1P2/8/8/8 w - - 1 53", "prompt": "FEN: 4r3/2P5/4kp2/1K1N1R2/1P1b1P2/8/8/8 w - - 1 53\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: b4 white pawn; f4 white pawn; b5 white king; d5 white knight; f5 white rook; c7 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "b4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "b5", "piece": "white king"}, {"square": "d5", "piece": "white knight"}, {"square": "f5", "piece": "white rook"}, {"square": "c7", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "b4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "b5", "piece": "white king"}, {"square": "d5", "piece": "white knight"}, {"square": "f5", "piece": "white rook"}, {"square": "c7", "piece": "white pawn"}]}}
{"example_id": "rules_01354", "split": "rules", "task_type": "piece_legal_moves", "fen": "r3kb1r/p1q2ppp/2p2n2/4p3/2B1P1b1/2N2Q2/PPP2PPP/3RK2R w Kkq - 6 13", "prompt": "FEN: r3kb1r/p1q2ppp/2p2n2/4p3/2B1P1b1/2N2Q2/PPP2PPP/3RK2R w Kkq - 6 13\nWhat legal moves does the piece on f3 have?", "gold_answer": "f3d3 f3e2 f3e3 f3f4 f3f5 f3f6 f3g3 f3g4 f3h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f3", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "f3", "piece": "queen"}}
{"example_id": "rules_01355", "split": "rules", "task_type": "check_detection", "fen": "3r2k1/pp2n1pp/8/1N1pP3/1P1K4/6P1/P6P/2R5 w - -", "prompt": "FEN: 3r2k1/pp2n1pp/8/1N1pP3/1P1K4/6P1/P6P/2R5 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01356", "split": "rules", "task_type": "captures", "fen": "r1bqk2r/1ppp1ppp/p1n2n2/2b1p3/4P3/2N2N2/PPPP1PPP/R1BQKB1R w KQkq -", "prompt": "FEN: r1bqk2r/1ppp1ppp/p1n2n2/2b1p3/4P3/2N2N2/PPPP1PPP/R1BQKB1R w KQkq -\nList all capture moves available.", "gold_answer": "f1a6 f3e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01357", "split": "rules", "task_type": "special_rules", "fen": "r1bqkb1r/pp3ppp/4n3/3pN2P/4p3/2N3P1/PPP2P2/R1BQK2R w KQkq -", "prompt": "Given FEN: r1bqkb1r/pp3ppp/4n3/3pN2P/4p3/2N3P1/PPP2P2/R1BQK2R w KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01358", "split": "rules", "task_type": "legality_check", "fen": "8/6p1/8/7p/pk5P/6P1/P7/1K6 w - - 2 49", "prompt": "FEN: 8/6p1/8/7p/pk5P/6P1/P7/1K6 w - - 2 49\nIs the move b1c2 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b1c2", "_legality_check_reason_label": "legal", "move": "b1c2", "legality_reason_label": "legal"}}
{"example_id": "rules_01359", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5rk1/p4ppp/2qp4/2nN4/1RP1p3/P1PP2P1/4PP1P/2Q2RK1 w - -", "prompt": "FEN: 5rk1/p4ppp/2qp4/2nN4/1RP1p3/P1PP2P1/4PP1P/2Q2RK1 w - -\nList pseudo-legal moves from c1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c1: c1a1 c1b1 c1b2 c1c2 c1d1 c1d2 c1e1 c1e3 c1f4 c1g5 c1h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_01360", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnbqk2r/ppp1bpp1/3p1n1p/8/2BNP3/8/PPP1QPPP/RNB1K2R w KQkq -", "prompt": "FEN: rnbqk2r/ppp1bpp1/3p1n1p/8/2BNP3/8/PPP1QPPP/RNB1K2R w KQkq -\nFor the piece on b1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b1: b1a3 b1c3 b1d2.\nLegal: b1a3 b1c3 b1d2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01361", "split": "rules", "task_type": "king_safety_filter", "fen": "1r6/p4pk1/2Q5/2n1q1pp/1b4bP/2N1P3/PP3PP1/2R1KB1R w K -", "prompt": "FEN: 1r6/p4pk1/2Q5/2n1q1pp/1b4bP/2N1P3/PP3PP1/2R1KB1R w K -\nFor move c3a4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c3a4.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "c3a4", "_king_safety_filter_reason_label": "pinned_piece_exposes_king", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "c3a4", "legality_reason_label": "pinned_piece_exposes_king", "expected_is_legal": false}}
{"example_id": "rules_01362", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2kr3r/ppp3pp/2nb4/3qpp2/2P5/P2P4/1P2QPPP/R1B1R1K1 b - - 0 18", "prompt": "FEN: 2kr3r/ppp3pp/2nb4/3qpp2/2P5/P2P4/1P2QPPP/R1B1R1K1 b - - 0 18\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d5 black queen; e5 black pawn; f5 black pawn; c6 black knight; d6 black bishop; a7 black pawn; b7 black pawn; c7 black pawn; g7 black pawn; h7 black pawn; c8 black king; d8 black rook; h8 black rook.\nMoves by piece:\nd5 black queen: d5a5 d5b5 d5c4 d5c5 d5d3 d5d4 d5e4 d5e6 d5f3 d5f7 d5g2 d5g8\ne5 black pawn: e5e4\nf5 black pawn: f5f4\nc6 black knight: c6a5 c6b4 c6b8 c6d4 c6e7\nd6 black bishop: d6a3 d6b4 d6c5 d6e7 d6f8\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nc7 black pawn: no legal moves\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\nc8 black king: c8b8 c8d7\nd8 black rook: d8d7 d8e8 d8f8 d8g8\nh8 black rook: h8e8 h8f8 h8g8\nAll legal moves: a7a5 a7a6 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e7 c8b8 c8d7 d5a5 d5b5 d5c4 d5c5 d5d3 d5d4 d5e4 d5e6 d5f3 d5f7 d5g2 d5g8 d6a3 d6b4 d6c5 d6e7 d6f8 d8d7 d8e8 d8f8 d8g8 e5e4 f5f4 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d5": ["d5a5", "d5b5", "d5c4", "d5c5", "d5d3", "d5d4", "d5e4", "d5e6", "d5f3", "d5f7", "d5g2", "d5g8"], "e5": ["e5e4"], "f5": ["f5f4"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e7"], "d6": ["d6a3", "d6b4", "d6c5", "d6e7", "d6f8"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8b8", "c8d7"], "d8": ["d8d7", "d8e8", "d8f8", "d8g8"], "h8": ["h8e8", "h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e7 c8b8 c8d7 d5a5 d5b5 d5c4 d5c5 d5d3 d5d4 d5e4 d5e6 d5f3 d5f7 d5g2 d5g8 d6a3 d6b4 d6c5 d6e7 d6f8 d8d7 d8e8 d8f8 d8g8 e5e4 f5f4 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d5": ["d5a5", "d5b5", "d5c4", "d5c5", "d5d3", "d5d4", "d5e4", "d5e6", "d5f3", "d5f7", "d5g2", "d5g8"], "e5": ["e5e4"], "f5": ["f5f4"], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e7"], "d6": ["d6a3", "d6b4", "d6c5", "d6e7", "d6f8"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8b8", "c8d7"], "d8": ["d8d7", "d8e8", "d8f8", "d8g8"], "h8": ["h8e8", "h8f8", "h8g8"]}, "legal_moves": "a7a5 a7a6 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e7 c8b8 c8d7 d5a5 d5b5 d5c4 d5c5 d5d3 d5d4 d5e4 d5e6 d5f3 d5f7 d5g2 d5g8 d6a3 d6b4 d6c5 d6e7 d6f8 d8d7 d8e8 d8f8 d8g8 e5e4 f5f4 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8"}}
{"example_id": "rules_01363", "split": "rules", "task_type": "ray_walk", "fen": "rn2r2k/ppp1q2n/3b3Q/5BB1/8/8/PPP2PPP/RN3RK1 b - -", "prompt": "FEN: rn2r2k/ppp1q2n/3b3Q/5BB1/8/8/PPP2PPP/RN3RK1 b - -\nWalk each ray for the slider on d6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d6 black bishop.\nRay NE: e7 black queen: own piece (stop, excluded).\nRay SE: e5 empty; f4 empty; g3 empty; h2 white pawn: capture (stop, included).\nRay SW: c5 empty; b4 empty; a3 empty; edge.\nRay NW: c7 black pawn: own piece (stop, excluded).\nMoves from rays: d6a3 d6b4 d6c5 d6e5 d6f4 d6g3 d6h2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "d6", "diagnostic": true, "hard_gate": false, "source_square": "d6"}}
{"example_id": "rules_01364", "split": "rules", "task_type": "legal_moves", "fen": "6k1/p4pnQ/1p3qp1/3p2N1/6P1/2P4P/P4PK1/8 b - - 6 31", "prompt": "FEN: 6k1/p4pnQ/1p3qp1/3p2N1/6P1/2P4P/P4PK1/8 b - - 6 31\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: g8f8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01365", "split": "rules", "task_type": "legal_moves", "fen": "8/4k3/1p2P3/p7/2P1K1Bp/PP5P/8/5r2 w - - 1 55", "prompt": "FEN: 8/4k3/1p2P3/p7/2P1K1Bp/PP5P/8/5r2 w - - 1 55\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 b3b4 c4c5 e4d3 e4d4 e4d5 e4e3 e4e5 g4d1 g4e2 g4f3 g4f5 g4h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01366", "split": "rules", "task_type": "side_piece_inventory", "fen": "3q2k1/5p2/5Q1p/1p2p3/1Pp4P/2P5/2B2P2/6K1 w - -", "prompt": "FEN: 3q2k1/5p2/5Q1p/1p2p3/1Pp4P/2P5/2B2P2/6K1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: g1 white king; c2 white bishop; f2 white pawn; c3 white pawn; b4 white pawn; h4 white pawn; f6 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "g1", "piece": "white king"}, {"square": "c2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "h4", "piece": "white pawn"}, {"square": "f6", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "g1", "piece": "white king"}, {"square": "c2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "b4", "piece": "white pawn"}, {"square": "h4", "piece": "white pawn"}, {"square": "f6", "piece": "white queen"}]}}
{"example_id": "rules_01367", "split": "rules", "task_type": "piece_legal_moves", "fen": "2rqk1nr/1b2pp1p/3p2p1/pN6/n1P1PB2/P4P2/K2Q2PP/3R1BNR b k - 0 15", "prompt": "FEN: 2rqk1nr/1b2pp1p/3p2p1/pN6/n1P1PB2/P4P2/K2Q2PP/3R1BNR b k - 0 15\nWhat legal moves does the piece on a4 have?", "gold_answer": "a4b2 a4b6 a4c3 a4c5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a4", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "a4", "piece": "knight"}}
{"example_id": "rules_01368", "split": "rules", "task_type": "check_detection", "fen": "r2qkb1r/pp1nppp1/2p2n1p/3p2N1/3P4/3QP2P/PPP2PP1/RNB1K2R w KQkq - 0 8", "prompt": "FEN: r2qkb1r/pp1nppp1/2p2n1p/3p2N1/3P4/3QP2P/PPP2PP1/RNB1K2R w KQkq - 0 8\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01369", "split": "rules", "task_type": "captures", "fen": "3rr1k1/2q2ppp/2np1bb1/1p2p3/4P3/2P2NNP/1PB2PP1/R2QR1K1 w - -", "prompt": "FEN: 3rr1k1/2q2ppp/2np1bb1/1p2p3/4P3/2P2NNP/1PB2PP1/R2QR1K1 w - -\nList all capture moves available.", "gold_answer": "d1d6 f3e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01370", "split": "rules", "task_type": "special_rules", "fen": "2b1k2r/1p1n1ppp/2p1pn2/b2p4/2PP4/2N1PN2/1B2BPPP/4K2R w Kk - 0 13", "prompt": "Given FEN: 2b1k2r/1p1n1ppp/2p1pn2/b2p4/2PP4/2N1PN2/1B2BPPP/4K2R w Kk - 0 13\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01371", "split": "rules", "task_type": "legality_check", "fen": "r4r1k/1p3p2/p1p2P2/8/3p2bP/2B5/PPP2PB1/2K4R w - - 0 24", "prompt": "FEN: r4r1k/1p3p2/p1p2P2/8/3p2bP/2B5/PPP2PB1/2K4R w - - 0 24\nIs the move b7e1 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b7e1", "_legality_check_reason_label": "wrong_side_piece", "move": "b7e1", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01372", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "3r4/3rb3/2kNb1p1/4P2p/p1pR3P/B4P2/1P1K2P1/3R4 b - -", "prompt": "FEN: 3r4/3rb3/2kNb1p1/4P2p/p1pR3P/B4P2/1P1K2P1/3R4 b - -\nList pseudo-legal moves from c4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c4: c4c3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c4", "diagnostic": true, "hard_gate": false, "source_square": "c4"}}
{"example_id": "rules_01373", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/8/2b5/3k4/1Q6/4K3/8/8 w - -", "prompt": "FEN: 8/8/2b5/3k4/1Q6/4K3/8/8 w - -\nFor the piece on e3, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e3: e3d2 e3d3 e3d4 e3e2 e3e4 e3f2 e3f3 e3f4.\nLegal: e3d2 e3d3 e3e2 e3f2 e3f3 e3f4.\nRejected: e3d4 king_would_be_in_check; e3e4 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "e3", "diagnostic": true, "hard_gate": false, "source_square": "e3"}}
{"example_id": "rules_01374", "split": "rules", "task_type": "king_safety_filter", "fen": "7r/pQ1bq1kp/5np1/2p1Np2/2P2P2/PP2b3/2K1N1PP/5B1R b - - 1 25", "prompt": "FEN: 7r/pQ1bq1kp/5np1/2p1Np2/2P2P2/PP2b3/2K1N1PP/5B1R b - - 1 25\nFor move g7f7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: g7f7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "g7f7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "g7f7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01375", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqkb1r/ppp2ppp/2n2n2/4p3/4P3/3P4/PPP1B1PP/RNBQK1NR w KQkq -", "prompt": "FEN: r1bqkb1r/ppp2ppp/2n2n2/4p3/4P3/3P4/PPP1B1PP/RNBQK1NR w KQkq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; d1 white queen; e1 white king; g1 white knight; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; e2 white bishop; g2 white pawn; h2 white pawn; d3 white pawn; e4 white pawn.\nMoves by piece:\na1 white rook: no legal moves\nb1 white knight: b1a3 b1c3 b1d2\nc1 white bishop: c1d2 c1e3 c1f4 c1g5 c1h6\nd1 white queen: d1d2\ne1 white king: e1d2 e1f1 e1f2\ng1 white knight: g1f3 g1h3\nh1 white rook: no legal moves\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: c2c3 c2c4\ne2 white bishop: e2f1 e2f3 e2g4 e2h5\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nd3 white pawn: d3d4\ne4 white pawn: no legal moves\nAll legal moves: a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c2c4 d1d2 d3d4 e1d2 e1f1 e1f2 e2f1 e2f3 e2g4 e2h5 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "b1": ["b1a3", "b1c3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1d2"], "e1": ["e1d2", "e1f1", "e1f2"], "g1": ["g1f3", "g1h3"], "h1": [], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "e2": ["e2f1", "e2f3", "e2g4", "e2h5"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "d3": ["d3d4"], "e4": []}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c2c4 d1d2 d3d4 e1d2 e1f1 e1f2 e2f1 e2f3 e2g4 e2h5 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "b1": ["b1a3", "b1c3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1d2"], "e1": ["e1d2", "e1f1", "e1f2"], "g1": ["g1f3", "g1h3"], "h1": [], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "e2": ["e2f1", "e2f3", "e2g4", "e2h5"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "d3": ["d3d4"], "e4": []}, "legal_moves": "a2a3 a2a4 b1a3 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c2c4 d1d2 d3d4 e1d2 e1f1 e1f2 e2f1 e2f3 e2g4 e2h5 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4"}}
{"example_id": "rules_01376", "split": "rules", "task_type": "ray_walk", "fen": "3r2r1/kpQ2p2/qN2b2p/p7/5p2/P5P1/5P1P/R3R1K1 w - - 7 25", "prompt": "FEN: 3r2r1/kpQ2p2/qN2b2p/p7/5p2/P5P1/5P1P/R3R1K1 w - - 7 25\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 empty; a3 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 empty; e1 white rook: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1a2 a1b1 a1c1 a1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01377", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/k1K5/8/2N5/4B3/8/8/8 w - -", "prompt": "FEN: 8/k1K5/8/2N5/4B3/8/8/8 w - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: e4 white bishop; c5 white knight; c7 white king.\nFilter by piece:\ne4 white bishop: pseudo-legal e4a8 e4b1 e4b7 e4c2 e4c6 e4d3 e4d5 e4f3 e4f5 e4g2 e4g6 e4h1 e4h7 | rejected none | legal e4a8 e4b1 e4b7 e4c2 e4c6 e4d3 e4d5 e4f3 e4f5 e4g2 e4g6 e4h1 e4h7\nc5 white knight: pseudo-legal c5a4 c5a6 c5b3 c5b7 c5d3 c5d7 c5e6 | rejected none | legal c5a4 c5a6 c5b3 c5b7 c5d3 c5d7 c5e6\nc7 white king: pseudo-legal c7b6 c7b7 c7b8 c7c6 c7c8 c7d6 c7d7 c7d8 | rejected c7b6 king_would_be_in_check; c7b7 king_would_be_in_check; c7b8 king_would_be_in_check | legal c7c6 c7c8 c7d6 c7d7 c7d8\nAll legal moves: c5a4 c5a6 c5b3 c5b7 c5d3 c5d7 c5e6 c7c6 c7c8 c7d6 c7d7 c7d8 e4a8 e4b1 e4b7 e4c2 e4c6 e4d3 e4d5 e4f3 e4f5 e4g2 e4g6 e4h1 e4h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01378", "split": "rules", "task_type": "legal_moves", "fen": "r3k2r/pppq1ppp/2npbn2/4p3/2B1P3/2PPP1QP/PP4P1/RN2K1NR w KQkq - 1 10", "prompt": "FEN: r3k2r/pppq1ppp/2npbn2/4p3/2B1P3/2PPP1QP/PP4P1/RN2K1NR w KQkq - 1 10\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a3 b1d2 b2b3 b2b4 c4a6 c4b3 c4b5 c4d5 c4e6 d3d4 e1d1 e1d2 e1e2 e1f1 e1f2 g1e2 g1f3 g3e5 g3f2 g3f3 g3f4 g3g4 g3g5 g3g6 g3g7 g3h2 g3h4 h1h2 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01379", "split": "rules", "task_type": "side_piece_inventory", "fen": "5R2/8/7p/5p2/P4P2/6kP/2r3P1/6K1 w - -", "prompt": "FEN: 5R2/8/7p/5p2/P4P2/6kP/2r3P1/6K1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: g1 white king; g2 white pawn; h3 white pawn; a4 white pawn; f4 white pawn; f8 white rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "g1", "piece": "white king"}, {"square": "g2", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}, {"square": "a4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "f8", "piece": "white rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "g1", "piece": "white king"}, {"square": "g2", "piece": "white pawn"}, {"square": "h3", "piece": "white pawn"}, {"square": "a4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "f8", "piece": "white rook"}]}}
{"example_id": "rules_01380", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/8/2N5/k1K5/8/1B6/8/8 b - -", "prompt": "FEN: 8/8/2N5/k1K5/8/1B6/8/8 b - -\nWhat legal moves does the piece on a5 have?", "gold_answer": "a5a6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "a5", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "a5", "piece": "king"}}
{"example_id": "rules_01381", "split": "rules", "task_type": "check_detection", "fen": "rr6/3q1pkp/3ppnp1/1N6/PQ6/3PP3/1P3P1P/R3K1N1 b Q - 0 23", "prompt": "FEN: rr6/3q1pkp/3ppnp1/1N6/PQ6/3PP3/1P3P1P/R3K1N1 b Q - 0 23\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01382", "split": "rules", "task_type": "captures", "fen": "r6k/1bp3p1/p2b2qp/1p2B3/1P6/P3P3/B3Q1PP/5RK1 w - - 1 24", "prompt": "FEN: r6k/1bp3p1/p2b2qp/1p2B3/1P6/P3P3/B3Q1PP/5RK1 w - - 1 24\nList all capture moves available.", "gold_answer": "e2b5 e5d6 e5g7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01383", "split": "rules", "task_type": "special_rules", "fen": "8/pp2k3/2p5/3brpp1/1P1N4/P1P3KP/3R1P2/8 w - - 2 35", "prompt": "Given FEN: 8/pp2k3/2p5/3brpp1/1P1N4/P1P3KP/3R1P2/8 w - - 2 35\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01384", "split": "rules", "task_type": "legality_check", "fen": "3r1k1r/R4ppp/8/4p3/8/2K1Pb2/5PPP/7R w - - 0 22", "prompt": "FEN: 3r1k1r/R4ppp/8/4p3/8/2K1Pb2/5PPP/7R w - - 0 22\nIs the move c3b4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c3b4", "_legality_check_reason_label": "legal", "move": "c3b4", "legality_reason_label": "legal"}}
{"example_id": "rules_01385", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2q1rk1/ppp2ppp/2n5/3n3b/2BP4/5N1P/PP1N1PP1/R2QR1K1 w - - 1 13", "prompt": "FEN: r2q1rk1/ppp2ppp/2n5/3n3b/2BP4/5N1P/PP1N1PP1/R2QR1K1 w - - 1 13\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1 a1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01386", "split": "rules", "task_type": "piece_legal_filter", "fen": "1k6/8/1K2B3/4B3/8/8/8/8 b - -", "prompt": "FEN: 1k6/8/1K2B3/4B3/8/8/8/8 b - -\nFor the piece on b8, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b8: b8a7 b8a8 b8b7 b8c7 b8c8.\nLegal: b8a8.\nRejected: b8a7 does_not_resolve_check; b8b7 does_not_resolve_check; b8c7 does_not_resolve_check; b8c8 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "b8", "diagnostic": true, "hard_gate": false, "source_square": "b8"}}
{"example_id": "rules_01387", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bqr1k1/pp3ppp/2n1p3/8/2PbN3/BQ6/P3B1PP/3R1R1K w - -", "prompt": "FEN: r1bqr1k1/pp3ppp/2n1p3/8/2PbN3/BQ6/P3B1PP/3R1R1K w - -\nFor move h1g1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: h1g1.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "h1g1", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "h1g1", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01388", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r2qk2r/ppp1bpp1/2n3bp/3np3/2B3P1/P2P1N1P/1PP2P2/RNBQK2R w KQkq - 2 11", "prompt": "FEN: r2qk2r/ppp1bpp1/2n3bp/3np3/2B3P1/P2P1N1P/1PP2P2/RNBQK2R w KQkq - 2 11\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; d1 white queen; e1 white king; h1 white rook; b2 white pawn; c2 white pawn; f2 white pawn; a3 white pawn; d3 white pawn; f3 white knight; h3 white pawn; c4 white bishop; g4 white pawn.\nMoves by piece:\na1 white rook: a1a2\nb1 white knight: b1c3 b1d2\nc1 white bishop: c1d2 c1e3 c1f4 c1g5 c1h6\nd1 white queen: d1d2 d1e2\ne1 white king: e1d2 e1e2 e1f1 e1g1\nh1 white rook: h1f1 h1g1 h1h2\nb2 white pawn: b2b3 b2b4\nc2 white pawn: c2c3\nf2 white pawn: no legal moves\na3 white pawn: a3a4\nd3 white pawn: d3d4\nf3 white knight: f3d2 f3d4 f3e5 f3g1 f3g5 f3h2 f3h4\nh3 white pawn: h3h4\nc4 white bishop: c4a2 c4a6 c4b3 c4b5 c4d5\ng4 white pawn: g4g5\nAll legal moves: a1a2 a3a4 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c4a2 c4a6 c4b3 c4b5 c4d5 d1d2 d1e2 d3d4 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3g5 f3h2 f3h4 g4g5 h1f1 h1g1 h1h2 h3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1a2"], "b1": ["b1c3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1d2", "d1e2"], "e1": ["e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1", "h1h2"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3"], "f2": [], "a3": ["a3a4"], "d3": ["d3d4"], "f3": ["f3d2", "f3d4", "f3e5", "f3g1", "f3g5", "f3h2", "f3h4"], "h3": ["h3h4"], "c4": ["c4a2", "c4a6", "c4b3", "c4b5", "c4d5"], "g4": ["g4g5"]}, "_legal_moves_by_piece_moves": "a1a2 a3a4 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c4a2 c4a6 c4b3 c4b5 c4d5 d1d2 d1e2 d3d4 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3g5 f3h2 f3h4 g4g5 h1f1 h1g1 h1h2 h3h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1a2"], "b1": ["b1c3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1d2", "d1e2"], "e1": ["e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1", "h1h2"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3"], "f2": [], "a3": ["a3a4"], "d3": ["d3d4"], "f3": ["f3d2", "f3d4", "f3e5", "f3g1", "f3g5", "f3h2", "f3h4"], "h3": ["h3h4"], "c4": ["c4a2", "c4a6", "c4b3", "c4b5", "c4d5"], "g4": ["g4g5"]}, "legal_moves": "a1a2 a3a4 b1c3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c4a2 c4a6 c4b3 c4b5 c4d5 d1d2 d1e2 d3d4 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3g5 f3h2 f3h4 g4g5 h1f1 h1g1 h1h2 h3h4"}}
{"example_id": "rules_01389", "split": "rules", "task_type": "ray_walk", "fen": "r1bqkb1r/pp1ppppp/1nn5/2p1P3/8/2P2N2/PP1PBPPP/RNBQK2R b KQkq -", "prompt": "FEN: r1bqkb1r/pp1ppppp/1nn5/2p1P3/8/2P2N2/PP1PBPPP/RNBQK2R b KQkq -\nWalk each ray for the slider on a8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a8 black rook.\nRay N: edge.\nRay E: b8 empty; c8 black bishop: own piece (stop, excluded).\nRay S: a7 black pawn: own piece (stop, excluded).\nRay W: edge.\nMoves from rays: a8b8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a8", "diagnostic": true, "hard_gate": false, "source_square": "a8"}}
{"example_id": "rules_01390", "split": "rules", "task_type": "legal_moves", "fen": "rnbqkbnr/p3pppp/1ppp4/8/8/1P1PP3/PBP2PPP/RN1QKBNR b KQkq - 0 4", "prompt": "FEN: rnbqkbnr/p3pppp/1ppp4/8/8/1P1PP3/PBP2PPP/RN1QKBNR b KQkq - 0 4\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6b5 b8a6 b8d7 c6c5 c8a6 c8b7 c8d7 c8e6 c8f5 c8g4 c8h3 d6d5 d8c7 d8d7 e7e5 e7e6 e8d7 f7f5 f7f6 g7g5 g7g6 g8f6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01391", "split": "rules", "task_type": "legal_moves", "fen": "r1b1k2r/pp3pbp/4p1p1/3pPn2/1p1q1P2/P7/2P1B1PP/RNBQ1R1K w kq - 0 13", "prompt": "FEN: r1b1k2r/pp3pbp/4p1p1/3pPn2/1p1q1P2/P7/2P1B1PP/RNBQ1R1K w kq - 0 13\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a3a4 a3b4 b1c3 b1d2 c1b2 c1d2 c1e3 c2c3 c2c4 d1d2 d1d3 d1d4 d1e1 e2a6 e2b5 e2c4 e2d3 e2f3 e2g4 e2h5 f1e1 f1f2 f1f3 f1g1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01392", "split": "rules", "task_type": "side_piece_inventory", "fen": "6k1/4q2p/1p2ppp1/p2b4/Pn1Pp3/BP2PN2/5PPP/1Q4K1 b - - 1 27", "prompt": "FEN: 6k1/4q2p/1p2ppp1/p2b4/Pn1Pp3/BP2PN2/5PPP/1Q4K1 b - - 1 27\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: b4 black knight; e4 black pawn; a5 black pawn; d5 black bishop; b6 black pawn; e6 black pawn; f6 black pawn; g6 black pawn; e7 black queen; h7 black pawn; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "b4", "piece": "black knight"}, {"square": "e4", "piece": "black pawn"}, {"square": "a5", "piece": "black pawn"}, {"square": "d5", "piece": "black bishop"}, {"square": "b6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "e7", "piece": "black queen"}, {"square": "h7", "piece": "black pawn"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "b4", "piece": "black knight"}, {"square": "e4", "piece": "black pawn"}, {"square": "a5", "piece": "black pawn"}, {"square": "d5", "piece": "black bishop"}, {"square": "b6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "e7", "piece": "black queen"}, {"square": "h7", "piece": "black pawn"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01393", "split": "rules", "task_type": "piece_legal_moves", "fen": "3N4/k1K5/8/8/2B5/8/8/8 b - -", "prompt": "FEN: 3N4/k1K5/8/8/2B5/8/8/8 b - -\nWhat legal moves does the piece on a7 have?", "gold_answer": "a7a8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "a7", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "a7", "piece": "king"}}
{"example_id": "rules_01394", "split": "rules", "task_type": "check_detection", "fen": "1k1rr3/2p3pp/1pQb4/8/R7/P2q4/5PP1/2B3K1 b - - 7 31", "prompt": "FEN: 1k1rr3/2p3pp/1pQb4/8/R7/P2q4/5PP1/2B3K1 b - - 7 31\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01395", "split": "rules", "task_type": "captures", "fen": "2rk1b1r/7p/p1np1N1n/1p6/3P2pN/1Q1PP3/PP3PPP/R4RK1 w - - 1 19", "prompt": "FEN: 2rk1b1r/7p/p1np1N1n/1p6/3P2pN/1Q1PP3/PP3PPP/R4RK1 w - - 1 19\nList all capture moves available.", "gold_answer": "b3b5 f6g4 f6h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01396", "split": "rules", "task_type": "special_rules", "fen": "rnbqk2r/p4ppp/4pn2/1pp3B1/PbpPP3/2N2N2/1P3PPP/R2QKB1R w KQkq -", "prompt": "Given FEN: rnbqk2r/p4ppp/4pn2/1pp3B1/PbpPP3/2N2N2/1P3PPP/R2QKB1R w KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01397", "split": "rules", "task_type": "legality_check", "fen": "8/8/8/3B4/5k2/2NK4/8/8 w - -", "prompt": "FEN: 8/8/8/3B4/5k2/2NK4/8/8 w - -\nIs the move f4a8 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f4a8", "_legality_check_reason_label": "wrong_side_piece", "move": "f4a8", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01398", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnbqk2r/pp3ppp/2pbpn2/3p4/3P1B2/P1N1PQ2/1PP2PPP/R3KBNR b KQkq -", "prompt": "FEN: rnbqk2r/pp3ppp/2pbpn2/3p4/3P1B2/P1N1PQ2/1PP2PPP/R3KBNR b KQkq -\nList pseudo-legal moves from c6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c6: c6c5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_01399", "split": "rules", "task_type": "piece_legal_filter", "fen": "3Q4/8/8/1k6/8/4K3/8/8 w - -", "prompt": "FEN: 3Q4/8/8/1k6/8/4K3/8/8 w - -\nFor the piece on e3, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e3: e3d2 e3d3 e3d4 e3e2 e3e4 e3f2 e3f3 e3f4.\nLegal: e3d2 e3d3 e3d4 e3e2 e3e4 e3f2 e3f3 e3f4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "e3", "diagnostic": true, "hard_gate": false, "source_square": "e3"}}
{"example_id": "rules_01400", "split": "rules", "task_type": "king_safety_filter", "fen": "3k4/3b2p1/8/5n2/1p5r/5P2/rP1R1K2/8 b - - 1 47", "prompt": "FEN: 3k4/3b2p1/8/5n2/1p5r/5P2/rP1R1K2/8 b - - 1 47\nFor move d7a4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: d7a4.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "d7a4", "_king_safety_filter_reason_label": "pinned_piece_exposes_king", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "d7a4", "legality_reason_label": "pinned_piece_exposes_king", "expected_is_legal": false}}
{"example_id": "rules_01401", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1n1q1rk1/r1p1bppp/p1B1pn2/8/PpNP1P2/1Q2P3/1P3P1P/R1B1K2R w KQ -", "prompt": "FEN: 1n1q1rk1/r1p1bppp/p1B1pn2/8/PpNP1P2/1Q2P3/1P3P1P/R1B1K2R w KQ -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; e1 white king; h1 white rook; b2 white pawn; f2 white pawn; h2 white pawn; b3 white queen; e3 white pawn; a4 white pawn; c4 white knight; d4 white pawn; f4 white pawn; c6 white bishop.\nMoves by piece:\na1 white rook: a1a2 a1a3 a1b1\nc1 white bishop: c1d2\ne1 white king: e1d1 e1d2 e1e2 e1f1 e1g1\nh1 white rook: h1f1 h1g1\nb2 white pawn: no legal moves\nf2 white pawn: f2f3\nh2 white pawn: h2h3 h2h4\nb3 white queen: b3a2 b3a3 b3b4 b3c2 b3c3 b3d1 b3d3\ne3 white pawn: e3e4\na4 white pawn: a4a5\nc4 white knight: c4a3 c4a5 c4b6 c4d2 c4d6 c4e5\nd4 white pawn: d4d5\nf4 white pawn: f4f5\nc6 white bishop: c6a8 c6b5 c6b7 c6d5 c6d7 c6e4 c6e8 c6f3 c6g2\nAll legal moves: a1a2 a1a3 a1b1 a4a5 b3a2 b3a3 b3b4 b3c2 b3c3 b3d1 b3d3 c1d2 c4a3 c4a5 c4b6 c4d2 c4d6 c4e5 c6a8 c6b5 c6b7 c6d5 c6d7 c6e4 c6e8 c6f3 c6g2 d4d5 e1d1 e1d2 e1e2 e1f1 e1g1 e3e4 f2f3 f4f5 h1f1 h1g1 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1a2", "a1a3", "a1b1"], "c1": ["c1d2"], "e1": ["e1d1", "e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1"], "b2": [], "f2": ["f2f3"], "h2": ["h2h3", "h2h4"], "b3": ["b3a2", "b3a3", "b3b4", "b3c2", "b3c3", "b3d1", "b3d3"], "e3": ["e3e4"], "a4": ["a4a5"], "c4": ["c4a3", "c4a5", "c4b6", "c4d2", "c4d6", "c4e5"], "d4": ["d4d5"], "f4": ["f4f5"], "c6": ["c6a8", "c6b5", "c6b7", "c6d5", "c6d7", "c6e4", "c6e8", "c6f3", "c6g2"]}, "_legal_moves_by_piece_moves": "a1a2 a1a3 a1b1 a4a5 b3a2 b3a3 b3b4 b3c2 b3c3 b3d1 b3d3 c1d2 c4a3 c4a5 c4b6 c4d2 c4d6 c4e5 c6a8 c6b5 c6b7 c6d5 c6d7 c6e4 c6e8 c6f3 c6g2 d4d5 e1d1 e1d2 e1e2 e1f1 e1g1 e3e4 f2f3 f4f5 h1f1 h1g1 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1a2", "a1a3", "a1b1"], "c1": ["c1d2"], "e1": ["e1d1", "e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1"], "b2": [], "f2": ["f2f3"], "h2": ["h2h3", "h2h4"], "b3": ["b3a2", "b3a3", "b3b4", "b3c2", "b3c3", "b3d1", "b3d3"], "e3": ["e3e4"], "a4": ["a4a5"], "c4": ["c4a3", "c4a5", "c4b6", "c4d2", "c4d6", "c4e5"], "d4": ["d4d5"], "f4": ["f4f5"], "c6": ["c6a8", "c6b5", "c6b7", "c6d5", "c6d7", "c6e4", "c6e8", "c6f3", "c6g2"]}, "legal_moves": "a1a2 a1a3 a1b1 a4a5 b3a2 b3a3 b3b4 b3c2 b3c3 b3d1 b3d3 c1d2 c4a3 c4a5 c4b6 c4d2 c4d6 c4e5 c6a8 c6b5 c6b7 c6d5 c6d7 c6e4 c6e8 c6f3 c6g2 d4d5 e1d1 e1d2 e1e2 e1f1 e1g1 e3e4 f2f3 f4f5 h1f1 h1g1 h2h3 h2h4"}}
{"example_id": "rules_01402", "split": "rules", "task_type": "ray_walk", "fen": "r1bqk1nr/ppp2pQp/2np4/4p3/1bB1P3/2N5/PPPP1PPP/R1B1K1NR b KQkq -", "prompt": "FEN: r1bqk1nr/ppp2pQp/2np4/4p3/1bB1P3/2N5/PPPP1PPP/R1B1K1NR b KQkq -\nWalk each ray for the slider on b4: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b4 black bishop.\nRay NE: c5 empty; d6 black pawn: own piece (stop, excluded).\nRay SE: c3 white knight: capture (stop, included).\nRay SW: a3 empty; edge.\nRay NW: a5 empty; edge.\nMoves from rays: b4a3 b4a5 b4c3 b4c5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_01403", "split": "rules", "task_type": "legal_moves", "fen": "5knr/pb3p1p/1p2p1p1/1N2n3/5B2/2P5/PP2BP1P/R3K1R1 b Q - 1 18", "prompt": "FEN: 5knr/pb3p1p/1p2p1p1/1N2n3/5B2/2P5/PP2BP1P/R3K1R1 b Q - 1 18\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7a6 b7a8 b7c6 b7c8 b7d5 b7e4 b7f3 b7g2 b7h1 e5c4 e5c6 e5d3 e5d7 e5f3 e5g4 f7f5 f7f6 f8e7 f8e8 f8g7 g6g5 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01404", "split": "rules", "task_type": "legal_moves", "fen": "r2rb1k1/pp2Rp1p/3p2p1/1P1P4/P2b1PP1/B2B3P/3P2K1/8 b - - 4 24", "prompt": "FEN: r2rb1k1/pp2Rp1p/3p2p1/1P1P4/P2b1PP1/B2B3P/3P2K1/8 b - - 4 24\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 a8c8 b7b6 d4a1 d4b2 d4b6 d4c3 d4c5 d4e3 d4e5 d4f2 d4f6 d4g1 d4g7 d4h8 d8b8 d8c8 d8d7 e8b5 e8c6 e8d7 f7f5 f7f6 g6g5 g8f8 g8g7 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01405", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2qkb1r/1b1nn1p1/p2p1p1p/1ppPp3/4P3/PBN1BN2/1PP2PPP/R2Q1RK1 w kq - 4 11", "prompt": "FEN: r2qkb1r/1b1nn1p1/p2p1p1p/1ppPp3/4P3/PBN1BN2/1PP2PPP/R2Q1RK1 w kq - 4 11\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white queen; f1 white rook; g1 white king; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; a3 white pawn; b3 white bishop; c3 white knight; e3 white bishop; f3 white knight; e4 white pawn; d5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "b3", "piece": "white bishop"}, {"square": "c3", "piece": "white knight"}, {"square": "e3", "piece": "white bishop"}, {"square": "f3", "piece": "white knight"}, {"square": "e4", "piece": "white pawn"}, {"square": "d5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "b3", "piece": "white bishop"}, {"square": "c3", "piece": "white knight"}, {"square": "e3", "piece": "white bishop"}, {"square": "f3", "piece": "white knight"}, {"square": "e4", "piece": "white pawn"}, {"square": "d5", "piece": "white pawn"}]}}
{"example_id": "rules_01406", "split": "rules", "task_type": "piece_legal_moves", "fen": "6k1/p4qpp/P3p3/2BpP3/3Pp3/8/1r3QPP/4K3 b - - 6 32", "prompt": "FEN: 6k1/p4qpp/P3p3/2BpP3/3Pp3/8/1r3QPP/4K3 b - - 6 32\nWhat legal moves does the piece on g8 have?", "gold_answer": "g8h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "g8", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "g8", "piece": "king"}}
{"example_id": "rules_01407", "split": "rules", "task_type": "check_detection", "fen": "8/p3P3/8/8/5QB1/1P4P1/Pk6/6K1 b - - 0 44", "prompt": "FEN: 8/p3P3/8/8/5QB1/1P4P1/Pk6/6K1 b - - 0 44\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01408", "split": "rules", "task_type": "captures", "fen": "r3kbnr/pppb1ppp/2nq4/4p3/2P3P1/3PpP2/PP1B2BP/RN1QK1NR w KQkq - 0 10", "prompt": "FEN: r3kbnr/pppb1ppp/2nq4/4p3/2P3P1/3PpP2/PP1B2BP/RN1QK1NR w KQkq - 0 10\nList all capture moves available.", "gold_answer": "d2e3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01409", "split": "rules", "task_type": "special_rules", "fen": "r1br2k1/1p3ppp/p1n1p3/3q4/8/1Q2PN2/PP1N1PPP/2R2RK1 b - - 1 14", "prompt": "Given FEN: r1br2k1/1p3ppp/p1n1p3/3q4/8/1Q2PN2/PP1N1PPP/2R2RK1 b - - 1 14\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01410", "split": "rules", "task_type": "legality_check", "fen": "4rrk1/1pp2ppn/p1p2qbp/8/4P1R1/2NP2QP/PPP3P1/5RK1 b - - 8 20", "prompt": "FEN: 4rrk1/1pp2ppn/p1p2qbp/8/4P1R1/2NP2QP/PPP3P1/5RK1 b - - 8 20\nIs the move b7b6 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b7b6", "_legality_check_reason_label": "legal", "move": "b7b6", "legality_reason_label": "legal"}}
{"example_id": "rules_01411", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/8/3k1p2/3p2p1/1P3PP1/4K3/8/8 b - -", "prompt": "FEN: 8/8/3k1p2/3p2p1/1P3PP1/4K3/8/8 b - -\nList pseudo-legal moves from d5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d5: d5d4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_01412", "split": "rules", "task_type": "piece_legal_filter", "fen": "1r4k1/6P1/2N4K/8/1P1RP3/3P4/8/8 b - - 2 49", "prompt": "FEN: 1r4k1/6P1/2N4K/8/1P1RP3/3P4/8/8 b - - 2 49\nFor the piece on g8, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g8: g8f7 g8f8 g8g7 g8h7 g8h8.\nLegal: g8f7.\nRejected: g8f8 king_would_be_in_check; g8g7 king_would_be_in_check; g8h7 king_would_be_in_check; g8h8 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g8", "diagnostic": true, "hard_gate": false, "source_square": "g8"}}
{"example_id": "rules_01413", "split": "rules", "task_type": "king_safety_filter", "fen": "3k3r/4bppp/p1p5/2n1n3/PP3P2/7P/1P3PB1/RNB3K1 b - -", "prompt": "FEN: 3k3r/4bppp/p1p5/2n1n3/PP3P2/7P/1P3PB1/RNB3K1 b - -\nFor move a6a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a6a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a6a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a6a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01414", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "5rk1/p6p/1q6/1p4p1/1Pp1RbQ1/P1Pr1P1P/1B4P1/5K1R b - - 1 34", "prompt": "FEN: 5rk1/p6p/1q6/1p4p1/1Pp1RbQ1/P1Pr1P1P/1B4P1/5K1R b - - 1 34\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d3 black rook; c4 black pawn; f4 black bishop; b5 black pawn; g5 black pawn; b6 black queen; a7 black pawn; h7 black pawn; f8 black rook; g8 black king.\nMoves by piece:\nd3 black rook: d3c3 d3d1 d3d2 d3d4 d3d5 d3d6 d3d7 d3d8 d3e3 d3f3\nc4 black pawn: no legal moves\nf4 black bishop: f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4h2\nb5 black pawn: no legal moves\ng5 black pawn: no legal moves\nb6 black queen: b6a5 b6a6 b6b7 b6b8 b6c5 b6c6 b6c7 b6d4 b6d6 b6d8 b6e3 b6e6 b6f2 b6f6 b6g1 b6g6 b6h6\na7 black pawn: a7a5 a7a6\nh7 black pawn: h7h5 h7h6\nf8 black rook: f8a8 f8b8 f8c8 f8d8 f8e8 f8f5 f8f6 f8f7\ng8 black king: g8f7 g8g7 g8h8\nAll legal moves: a7a5 a7a6 b6a5 b6a6 b6b7 b6b8 b6c5 b6c6 b6c7 b6d4 b6d6 b6d8 b6e3 b6e6 b6f2 b6f6 b6g1 b6g6 b6h6 d3c3 d3d1 d3d2 d3d4 d3d5 d3d6 d3d7 d3d8 d3e3 d3f3 f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4h2 f8a8 f8b8 f8c8 f8d8 f8e8 f8f5 f8f6 f8f7 g8f7 g8g7 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d3": ["d3c3", "d3d1", "d3d2", "d3d4", "d3d5", "d3d6", "d3d7", "d3d8", "d3e3", "d3f3"], "c4": [], "f4": ["f4b8", "f4c1", "f4c7", "f4d2", "f4d6", "f4e3", "f4e5", "f4g3", "f4h2"], "b5": [], "g5": [], "b6": ["b6a5", "b6a6", "b6b7", "b6b8", "b6c5", "b6c6", "b6c7", "b6d4", "b6d6", "b6d8", "b6e3", "b6e6", "b6f2", "b6f6", "b6g1", "b6g6", "b6h6"], "a7": ["a7a5", "a7a6"], "h7": ["h7h5", "h7h6"], "f8": ["f8a8", "f8b8", "f8c8", "f8d8", "f8e8", "f8f5", "f8f6", "f8f7"], "g8": ["g8f7", "g8g7", "g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b6a5 b6a6 b6b7 b6b8 b6c5 b6c6 b6c7 b6d4 b6d6 b6d8 b6e3 b6e6 b6f2 b6f6 b6g1 b6g6 b6h6 d3c3 d3d1 d3d2 d3d4 d3d5 d3d6 d3d7 d3d8 d3e3 d3f3 f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4h2 f8a8 f8b8 f8c8 f8d8 f8e8 f8f5 f8f6 f8f7 g8f7 g8g7 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d3": ["d3c3", "d3d1", "d3d2", "d3d4", "d3d5", "d3d6", "d3d7", "d3d8", "d3e3", "d3f3"], "c4": [], "f4": ["f4b8", "f4c1", "f4c7", "f4d2", "f4d6", "f4e3", "f4e5", "f4g3", "f4h2"], "b5": [], "g5": [], "b6": ["b6a5", "b6a6", "b6b7", "b6b8", "b6c5", "b6c6", "b6c7", "b6d4", "b6d6", "b6d8", "b6e3", "b6e6", "b6f2", "b6f6", "b6g1", "b6g6", "b6h6"], "a7": ["a7a5", "a7a6"], "h7": ["h7h5", "h7h6"], "f8": ["f8a8", "f8b8", "f8c8", "f8d8", "f8e8", "f8f5", "f8f6", "f8f7"], "g8": ["g8f7", "g8g7", "g8h8"]}, "legal_moves": "a7a5 a7a6 b6a5 b6a6 b6b7 b6b8 b6c5 b6c6 b6c7 b6d4 b6d6 b6d8 b6e3 b6e6 b6f2 b6f6 b6g1 b6g6 b6h6 d3c3 d3d1 d3d2 d3d4 d3d5 d3d6 d3d7 d3d8 d3e3 d3f3 f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4h2 f8a8 f8b8 f8c8 f8d8 f8e8 f8f5 f8f6 f8f7 g8f7 g8g7 g8h8 h7h5 h7h6"}}
{"example_id": "rules_01415", "split": "rules", "task_type": "ray_walk", "fen": "rnbqkb1r/pp3ppp/5n2/3p4/3P4/1pN1PN2/P4PPP/R1BQKB1R w KQkq -", "prompt": "FEN: rnbqkb1r/pp3ppp/5n2/3p4/3P4/1pN1PN2/P4PPP/R1BQKB1R w KQkq -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 white bishop: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01416", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/8/6K1/8/8/8/1kp5/5Q2 w - -", "prompt": "FEN: 8/8/6K1/8/8/8/1kp5/5Q2 w - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: f1 white queen; g6 white king.\nFilter by piece:\nf1 white queen: pseudo-legal f1a1 f1a6 f1b1 f1b5 f1c1 f1c4 f1d1 f1d3 f1e1 f1e2 f1f2 f1f3 f1f4 f1f5 f1f6 f1f7 f1f8 f1g1 f1g2 f1h1 f1h3 | rejected none | legal f1a1 f1a6 f1b1 f1b5 f1c1 f1c4 f1d1 f1d3 f1e1 f1e2 f1f2 f1f3 f1f4 f1f5 f1f6 f1f7 f1f8 f1g1 f1g2 f1h1 f1h3\ng6 white king: pseudo-legal g6f5 g6f6 g6f7 g6g5 g6g7 g6h5 g6h6 g6h7 | rejected none | legal g6f5 g6f6 g6f7 g6g5 g6g7 g6h5 g6h6 g6h7\nAll legal moves: f1a1 f1a6 f1b1 f1b5 f1c1 f1c4 f1d1 f1d3 f1e1 f1e2 f1f2 f1f3 f1f4 f1f5 f1f6 f1f7 f1f8 f1g1 f1g2 f1h1 f1h3 g6f5 g6f6 g6f7 g6g5 g6g7 g6h5 g6h6 g6h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01417", "split": "rules", "task_type": "legal_moves", "fen": "4r3/p5pk/6bp/8/1p3NPP/2Pp1P2/P2R1K2/8 b - - 0 34", "prompt": "FEN: 4r3/p5pk/6bp/8/1p3NPP/2Pp1P2/P2R1K2/8 b - - 0 34\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b4b3 b4c3 e8a8 e8b8 e8c8 e8d8 e8e1 e8e2 e8e3 e8e4 e8e5 e8e6 e8e7 e8f8 e8g8 e8h8 g6e4 g6f5 g6f7 g6h5 h6h5 h7g8 h7h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01418", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/pp4r1/2p5/7p/2k4P/P7/7K/8 b - - 3 49", "prompt": "FEN: 8/pp4r1/2p5/7p/2k4P/P7/7K/8 b - - 3 49\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c4 black king; h5 black pawn; c6 black pawn; a7 black pawn; b7 black pawn; g7 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c4", "piece": "black king"}, {"square": "h5", "piece": "black pawn"}, {"square": "c6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "g7", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c4", "piece": "black king"}, {"square": "h5", "piece": "black pawn"}, {"square": "c6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "g7", "piece": "black rook"}]}}
{"example_id": "rules_01419", "split": "rules", "task_type": "piece_legal_moves", "fen": "2kr4/2ppbp2/p5p1/1p4Pp/3Pb3/1P6/PPN5/R1B1K3 b - - 2 23", "prompt": "FEN: 2kr4/2ppbp2/p5p1/1p4Pp/3Pb3/1P6/PPN5/R1B1K3 b - - 2 23\nWhat legal moves does the piece on e4 have?", "gold_answer": "e4a8 e4b7 e4c2 e4c6 e4d3 e4d5 e4f3 e4f5 e4g2 e4h1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "e4", "_piece_legal_moves_piece": "bishop", "diagnostic": true, "hard_gate": false, "source_square": "e4", "piece": "bishop"}}
{"example_id": "rules_01420", "split": "rules", "task_type": "check_detection", "fen": "5r2/p1p2p1p/1qP2nk1/5R2/1pPN4/1P1Br2P/PQ4P1/R5K1 w - - 3 25", "prompt": "FEN: 5r2/p1p2p1p/1qP2nk1/5R2/1pPN4/1P1Br2P/PQ4P1/R5K1 w - - 3 25\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01421", "split": "rules", "task_type": "captures", "fen": "4b3/8/3k4/3P4/1B1KP3/8/8/8 b - -", "prompt": "FEN: 4b3/8/3k4/3P4/1B1KP3/8/8/8 b - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01422", "split": "rules", "task_type": "special_rules", "fen": "8/8/p1p5/P1P5/5k1P/1KP1p3/1N5r/8 b - - 3 56", "prompt": "Given FEN: 8/8/p1p5/P1P5/5k1P/1KP1p3/1N5r/8 b - - 3 56\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01423", "split": "rules", "task_type": "legality_check", "fen": "rnb1r1k1/1p3pbp/p2p2p1/2pP2B1/Pq2B3/R1N2N2/1P1Q1PPP/4K2R b K -", "prompt": "FEN: rnb1r1k1/1p3pbp/p2p2p1/2pP2B1/Pq2B3/R1N2N2/1P1Q1PPP/4K2R b K -\nIs the move d6f7 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "d6f7", "_legality_check_reason_label": "own_piece_destination", "move": "d6f7", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_01424", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rn1q1rk1/pp3ppp/2pb2b1/8/3PpP1P/2P1P1R1/PP1N2Q1/R1B1K1N1 b Q - 1 16", "prompt": "FEN: rn1q1rk1/pp3ppp/2pb2b1/8/3PpP1P/2P1P1R1/PP1N2Q1/R1B1K1N1 b Q - 1 16\nList pseudo-legal moves from c6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c6: c6c5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c6", "diagnostic": true, "hard_gate": false, "source_square": "c6"}}
{"example_id": "rules_01425", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2qkb1r/pp5p/2n1bnp1/2pp1p2/8/2PPP1P1/PPK1BP1P/RNBQ3R b kq - 1 11", "prompt": "FEN: r2qkb1r/pp5p/2n1bnp1/2pp1p2/8/2PPP1P1/PPK1BP1P/RNBQ3R b kq - 1 11\nFor the piece on c5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c5: c5c4.\nLegal: c5c4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_01426", "split": "rules", "task_type": "king_safety_filter", "fen": "r5k1/6p1/bp2p3/p2pBr2/3P4/2P1P1P1/P5K1/R6R b - - 0 27", "prompt": "FEN: r5k1/6p1/bp2p3/p2pBr2/3P4/2P1P1P1/P5K1/R6R b - - 0 27\nFor move g8h7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: g8h7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "g8h7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "g8h7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01427", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnb1kbnr/ppp1q1pp/5p2/3pp3/8/3P2P1/PPPBPPBP/RN1QK1NR w KQkq - 0 7", "prompt": "FEN: rnb1kbnr/ppp1q1pp/5p2/3pp3/8/3P2P1/PPPBPPBP/RN1QK1NR w KQkq - 0 7\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; d1 white queen; e1 white king; g1 white knight; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; d2 white bishop; e2 white pawn; f2 white pawn; g2 white bishop; h2 white pawn; d3 white pawn; g3 white pawn.\nMoves by piece:\na1 white rook: no legal moves\nb1 white knight: b1a3 b1c3\nd1 white queen: d1c1\ne1 white king: e1f1\ng1 white knight: g1f3 g1h3\nh1 white rook: no legal moves\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: c2c3 c2c4\nd2 white bishop: d2a5 d2b4 d2c1 d2c3 d2e3 d2f4 d2g5 d2h6\ne2 white pawn: e2e3 e2e4\nf2 white pawn: f2f3 f2f4\ng2 white bishop: g2d5 g2e4 g2f1 g2f3 g2h3\nh2 white pawn: h2h3 h2h4\nd3 white pawn: d3d4\ng3 white pawn: g3g4\nAll legal moves: a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c2c3 c2c4 d1c1 d2a5 d2b4 d2c1 d2c3 d2e3 d2f4 d2g5 d2h6 d3d4 e1f1 e2e3 e2e4 f2f3 f2f4 g1f3 g1h3 g2d5 g2e4 g2f1 g2f3 g2h3 g3g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "b1": ["b1a3", "b1c3"], "d1": ["d1c1"], "e1": ["e1f1"], "g1": ["g1f3", "g1h3"], "h1": [], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "d2": ["d2a5", "d2b4", "d2c1", "d2c3", "d2e3", "d2f4", "d2g5", "d2h6"], "e2": ["e2e3", "e2e4"], "f2": ["f2f3", "f2f4"], "g2": ["g2d5", "g2e4", "g2f1", "g2f3", "g2h3"], "h2": ["h2h3", "h2h4"], "d3": ["d3d4"], "g3": ["g3g4"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c2c3 c2c4 d1c1 d2a5 d2b4 d2c1 d2c3 d2e3 d2f4 d2g5 d2h6 d3d4 e1f1 e2e3 e2e4 f2f3 f2f4 g1f3 g1h3 g2d5 g2e4 g2f1 g2f3 g2h3 g3g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "b1": ["b1a3", "b1c3"], "d1": ["d1c1"], "e1": ["e1f1"], "g1": ["g1f3", "g1h3"], "h1": [], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "d2": ["d2a5", "d2b4", "d2c1", "d2c3", "d2e3", "d2f4", "d2g5", "d2h6"], "e2": ["e2e3", "e2e4"], "f2": ["f2f3", "f2f4"], "g2": ["g2d5", "g2e4", "g2f1", "g2f3", "g2h3"], "h2": ["h2h3", "h2h4"], "d3": ["d3d4"], "g3": ["g3g4"]}, "legal_moves": "a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c2c3 c2c4 d1c1 d2a5 d2b4 d2c1 d2c3 d2e3 d2f4 d2g5 d2h6 d3d4 e1f1 e2e3 e2e4 f2f3 f2f4 g1f3 g1h3 g2d5 g2e4 g2f1 g2f3 g2h3 g3g4 h2h3 h2h4"}}
{"example_id": "rules_01428", "split": "rules", "task_type": "ray_walk", "fen": "rnbqkbnr/p4ppp/1pppp3/8/8/1PP1P3/P1QP1PPP/RNB1KBNR w KQkq - 0 5", "prompt": "FEN: rnbqkbnr/p4ppp/1pppp3/8/8/1PP1P3/P1QP1PPP/RNB1KBNR w KQkq - 0 5\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 white knight: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: none", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01429", "split": "rules", "task_type": "legal_moves", "fen": "r1bq1rk1/p2p1pp1/2p2n1p/4p3/2B1P2B/2P5/P1P2PPP/R2Q1RK1 b - - 1 11", "prompt": "FEN: r1bq1rk1/p2p1pp1/2p2n1p/4p3/2B1P2B/2P5/P1P2PPP/R2Q1RK1 b - - 1 11\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 c6c5 c8a6 c8b7 d7d5 d7d6 d8a5 d8b6 d8c7 d8e7 d8e8 f6d5 f6e4 f6e8 f6g4 f6h5 f6h7 f8e8 g7g5 g7g6 g8h7 g8h8 h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01430", "split": "rules", "task_type": "legal_moves", "fen": "r3k1nr/1bp3bp/p2pP3/1p4B1/8/1P6/1PP1QPqP/RN2K2R w KQkq -", "prompt": "FEN: r3k1nr/1bp3bp/p2pP3/1p4B1/8/1P6/1PP1QPqP/RN2K2R w KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 a1a4 a1a5 a1a6 b1a3 b1c3 b1d2 b3b4 c2c3 c2c4 e1d1 e1d2 e2b5 e2c4 e2d1 e2d2 e2d3 e2e3 e2e4 e2e5 e2f1 e2f3 e2g4 e2h5 e6e7 f2f3 f2f4 g5c1 g5d2 g5d8 g5e3 g5e7 g5f4 g5f6 g5h4 g5h6 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01431", "split": "rules", "task_type": "side_piece_inventory", "fen": "r3kbnr/ppqb2pp/2n1p3/3pP3/P2p3P/2P2N2/1P4P1/RNBQKB1R w KQkq - 0 10", "prompt": "FEN: r3kbnr/ppqb2pp/2n1p3/3pP3/P2p3P/2P2N2/1P4P1/RNBQKB1R w KQkq - 0 10\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; d1 white queen; e1 white king; f1 white bishop; h1 white rook; b2 white pawn; g2 white pawn; c3 white pawn; f3 white knight; a4 white pawn; h4 white pawn; e5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "f1", "piece": "white bishop"}, {"square": "h1", "piece": "white rook"}, {"square": "b2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "a4", "piece": "white pawn"}, {"square": "h4", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "f1", "piece": "white bishop"}, {"square": "h1", "piece": "white rook"}, {"square": "b2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "a4", "piece": "white pawn"}, {"square": "h4", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}]}}
{"example_id": "rules_01432", "split": "rules", "task_type": "piece_legal_moves", "fen": "2Q2N2/ppp4p/2kp2p1/2bPp3/5P2/3P4/PP1K1nPP/n1B4R b - -", "prompt": "FEN: 2Q2N2/ppp4p/2kp2p1/2bPp3/5P2/3P4/PP1K1nPP/n1B4R b - -\nWhat legal moves does the piece on f2 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f2", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "f2", "piece": "knight"}}
{"example_id": "rules_01433", "split": "rules", "task_type": "check_detection", "fen": "r1b1kb1r/pp2pppp/6q1/2p5/8/2Q4P/PPP2P2/R1B1K1NR b KQkq - 3 13", "prompt": "FEN: r1b1kb1r/pp2pppp/6q1/2p5/8/2Q4P/PPP2P2/R1B1K1NR b KQkq - 3 13\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01434", "split": "rules", "task_type": "captures", "fen": "8/4k3/N6p/2P5/P1bp1P2/6K1/7P/8 w - - 1 48", "prompt": "FEN: 8/4k3/N6p/2P5/P1bp1P2/6K1/7P/8 w - - 1 48\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01435", "split": "rules", "task_type": "special_rules", "fen": "k7/8/2p5/r6p/1K6/1P1p4/2q4P/8 b - - 2 42", "prompt": "Given FEN: k7/8/2p5/r6p/1K6/1P1p4/2q4P/8 b - - 2 42\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01436", "split": "rules", "task_type": "legality_check", "fen": "8/4q3/2p5/2P4k/3p1p1P/5P1K/5Q2/8 w - - 0 50", "prompt": "FEN: 8/4q3/2p5/2P4k/3p1p1P/5P1K/5Q2/8 w - - 0 50\nIs the move c5h3 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c5h3", "_legality_check_reason_label": "own_piece_destination", "move": "c5h3", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_01437", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnbqkb1r/pp3ppp/3ppn2/2p5/2B1P3/3P1N2/PPP2PPP/RNBQ1RK1 b kq - 0 5", "prompt": "FEN: rnbqkb1r/pp3ppp/3ppn2/2p5/2B1P3/3P1N2/PPP2PPP/RNBQ1RK1 b kq - 0 5\nList pseudo-legal moves from d6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d6: d6d5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d6", "diagnostic": true, "hard_gate": false, "source_square": "d6"}}
{"example_id": "rules_01438", "split": "rules", "task_type": "piece_legal_filter", "fen": "r4rk1/3qbppp/1p2pn2/3p4/2pP4/p3PP2/R5PP/1NQ1K1NR w K - 0 18", "prompt": "FEN: r4rk1/3qbppp/1p2pn2/3p4/2pP4/p3PP2/R5PP/1NQ1K1NR w K - 0 18\nFor the piece on b1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b1: b1a3 b1c3 b1d2.\nLegal: b1a3 b1c3 b1d2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01439", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bqkbnr/ppp2ppp/2n1p3/1N1p4/3P1B2/8/PPP1PPPP/R2QKBNR b KQkq - 1 4", "prompt": "FEN: r1bqkbnr/ppp2ppp/2n1p3/1N1p4/3P1B2/8/PPP1PPPP/R2QKBNR b KQkq - 1 4\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01440", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r4r1k/pb1nqn1p/4p1p1/5pP1/1p1P1P1P/3BN3/PPQ1N3/2KR3R w - - 2 21", "prompt": "FEN: r4r1k/pb1nqn1p/4p1p1/5pP1/1p1P1P1P/3BN3/PPQ1N3/2KR3R w - - 2 21\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c1 white king; d1 white rook; h1 white rook; a2 white pawn; b2 white pawn; c2 white queen; e2 white knight; d3 white bishop; e3 white knight; d4 white pawn; f4 white pawn; h4 white pawn; g5 white pawn.\nMoves by piece:\nc1 white king: c1b1 c1d2\nd1 white rook: d1d2 d1e1 d1f1 d1g1\nh1 white rook: h1e1 h1f1 h1g1 h1h2 h1h3\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3\nc2 white queen: c2a4 c2b1 c2b3 c2c3 c2c4 c2c5 c2c6 c2c7 c2c8 c2d2\ne2 white knight: e2c3 e2g1 e2g3\nd3 white bishop: d3a6 d3b5 d3c4 d3e4 d3f5\ne3 white knight: e3c4 e3d5 e3f1 e3f5 e3g2 e3g4\nd4 white pawn: d4d5\nf4 white pawn: no legal moves\nh4 white pawn: h4h5\ng5 white pawn: no legal moves\nAll legal moves: a2a3 a2a4 b2b3 c1b1 c1d2 c2a4 c2b1 c2b3 c2c3 c2c4 c2c5 c2c6 c2c7 c2c8 c2d2 d1d2 d1e1 d1f1 d1g1 d3a6 d3b5 d3c4 d3e4 d3f5 d4d5 e2c3 e2g1 e2g3 e3c4 e3d5 e3f1 e3f5 e3g2 e3g4 h1e1 h1f1 h1g1 h1h2 h1h3 h4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c1": ["c1b1", "c1d2"], "d1": ["d1d2", "d1e1", "d1f1", "d1g1"], "h1": ["h1e1", "h1f1", "h1g1", "h1h2", "h1h3"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3"], "c2": ["c2a4", "c2b1", "c2b3", "c2c3", "c2c4", "c2c5", "c2c6", "c2c7", "c2c8", "c2d2"], "e2": ["e2c3", "e2g1", "e2g3"], "d3": ["d3a6", "d3b5", "d3c4", "d3e4", "d3f5"], "e3": ["e3c4", "e3d5", "e3f1", "e3f5", "e3g2", "e3g4"], "d4": ["d4d5"], "f4": [], "h4": ["h4h5"], "g5": []}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b2b3 c1b1 c1d2 c2a4 c2b1 c2b3 c2c3 c2c4 c2c5 c2c6 c2c7 c2c8 c2d2 d1d2 d1e1 d1f1 d1g1 d3a6 d3b5 d3c4 d3e4 d3f5 d4d5 e2c3 e2g1 e2g3 e3c4 e3d5 e3f1 e3f5 e3g2 e3g4 h1e1 h1f1 h1g1 h1h2 h1h3 h4h5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c1": ["c1b1", "c1d2"], "d1": ["d1d2", "d1e1", "d1f1", "d1g1"], "h1": ["h1e1", "h1f1", "h1g1", "h1h2", "h1h3"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3"], "c2": ["c2a4", "c2b1", "c2b3", "c2c3", "c2c4", "c2c5", "c2c6", "c2c7", "c2c8", "c2d2"], "e2": ["e2c3", "e2g1", "e2g3"], "d3": ["d3a6", "d3b5", "d3c4", "d3e4", "d3f5"], "e3": ["e3c4", "e3d5", "e3f1", "e3f5", "e3g2", "e3g4"], "d4": ["d4d5"], "f4": [], "h4": ["h4h5"], "g5": []}, "legal_moves": "a2a3 a2a4 b2b3 c1b1 c1d2 c2a4 c2b1 c2b3 c2c3 c2c4 c2c5 c2c6 c2c7 c2c8 c2d2 d1d2 d1e1 d1f1 d1g1 d3a6 d3b5 d3c4 d3e4 d3f5 d4d5 e2c3 e2g1 e2g3 e3c4 e3d5 e3f1 e3f5 e3g2 e3g4 h1e1 h1f1 h1g1 h1h2 h1h3 h4h5"}}
{"example_id": "rules_01441", "split": "rules", "task_type": "ray_walk", "fen": "rn1qkb1r/ppp1nppp/8/3p4/3P4/3B1Q2/PPP2PPP/RNB2RK1 b kq - 1 8", "prompt": "FEN: rn1qkb1r/ppp1nppp/8/3p4/3P4/3B1Q2/PPP2PPP/RNB2RK1 b kq - 1 8\nWalk each ray for the slider on a8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a8 black rook.\nRay N: edge.\nRay E: b8 black knight: own piece (stop, excluded).\nRay S: a7 black pawn: own piece (stop, excluded).\nRay W: edge.\nMoves from rays: none", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a8", "diagnostic": true, "hard_gate": false, "source_square": "a8"}}
{"example_id": "rules_01442", "split": "rules", "task_type": "legal_moves", "fen": "3b2k1/pb3pp1/1pq1p2p/2p5/4PB2/2P2P1P/PPB1Q1P1/6K1 w - - 0 21", "prompt": "FEN: 3b2k1/pb3pp1/1pq1p2p/2p5/4PB2/2P2P1P/PPB1Q1P1/6K1 w - - 0 21\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 b2b4 c2a4 c2b1 c2b3 c2d1 c2d3 c3c4 e2a6 e2b5 e2c4 e2d1 e2d2 e2d3 e2e1 e2e3 e2f1 e2f2 e4e5 f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4g5 f4h2 f4h6 g1f1 g1f2 g1h1 g1h2 g2g3 g2g4 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01443", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/p3bppp/1p2p3/3b4/1n1p4/1P3NP1/PB1QPPBP/R4RK1 w - -", "prompt": "FEN: r2q1rk1/p3bppp/1p2p3/3b4/1n1p4/1P3NP1/PB1QPPBP/R4RK1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a1d1 a1e1 a2a3 a2a4 b2a3 b2c1 b2c3 b2d4 d2b4 d2c1 d2c2 d2c3 d2d1 d2d3 d2d4 d2e1 d2e3 d2f4 d2g5 d2h6 e2e3 e2e4 f1b1 f1c1 f1d1 f1e1 f3d4 f3e1 f3e5 f3g5 f3h4 g1h1 g2h1 g2h3 g3g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01444", "split": "rules", "task_type": "side_piece_inventory", "fen": "6k1/6pp/3p4/4p3/p1PpP3/P2R3P/1r4r1/1K1R4 w - - 3 29", "prompt": "FEN: 6k1/6pp/3p4/4p3/p1PpP3/P2R3P/1r4r1/1K1R4 w - - 3 29\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: b1 white king; d1 white rook; a3 white pawn; d3 white rook; h3 white pawn; c4 white pawn; e4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "b1", "piece": "white king"}, {"square": "d1", "piece": "white rook"}, {"square": "a3", "piece": "white pawn"}, {"square": "d3", "piece": "white rook"}, {"square": "h3", "piece": "white pawn"}, {"square": "c4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "b1", "piece": "white king"}, {"square": "d1", "piece": "white rook"}, {"square": "a3", "piece": "white pawn"}, {"square": "d3", "piece": "white rook"}, {"square": "h3", "piece": "white pawn"}, {"square": "c4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}]}}
{"example_id": "rules_01445", "split": "rules", "task_type": "piece_legal_moves", "fen": "1rb2rk1/2qn1pp1/4p2p/2P5/8/6P1/2Q1NPBP/R1R3K1 b - -", "prompt": "FEN: 1rb2rk1/2qn1pp1/4p2p/2P5/8/6P1/2Q1NPBP/R1R3K1 b - -\nWhat legal moves does the piece on g7 have?", "gold_answer": "g7g5 g7g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "g7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g7", "piece": "pawn"}}
{"example_id": "rules_01446", "split": "rules", "task_type": "check_detection", "fen": "1r3rk1/1q3p1p/2pp2p1/8/1pPPB2Q/1N3R2/6P1/1R4K1 b - - 1 24", "prompt": "FEN: 1r3rk1/1q3p1p/2pp2p1/8/1pPPB2Q/1N3R2/6P1/1R4K1 b - - 1 24\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01447", "split": "rules", "task_type": "captures", "fen": "rn1q1rk1/1p1bb1pp/p2p1n2/2pPp3/2P1Pp2/2NB2P1/PP3PKP/R1BQNR2 b - - 1 12", "prompt": "FEN: rn1q1rk1/1p1bb1pp/p2p1n2/2pPp3/2P1Pp2/2NB2P1/PP3PKP/R1BQNR2 b - - 1 12\nList all capture moves available.", "gold_answer": "f4g3 f6d5 f6e4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01448", "split": "rules", "task_type": "special_rules", "fen": "2r5/pp3k1p/3bNp2/3P4/2P2p2/2K2P2/P6P/4R3 w - - 0 27", "prompt": "Given FEN: 2r5/pp3k1p/3bNp2/3P4/2P2p2/2K2P2/P6P/4R3 w - - 0 27\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01449", "split": "rules", "task_type": "legality_check", "fen": "3kq2r/3p2pp/3B3n/1B3P2/p7/5P2/PP4PP/2RR2K1 b - - 0 28", "prompt": "FEN: 3kq2r/3p2pp/3B3n/1B3P2/p7/5P2/PP4PP/2RR2K1 b - - 0 28\nIs the move h7e1 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "h7e1", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "h7e1", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_01450", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "1r6/4ppkp/3p2p1/2pP4/1nq1P1P1/2N2PKP/1P1Q4/1R6 w - -", "prompt": "FEN: 1r6/4ppkp/3p2p1/2pP4/1nq1P1P1/2N2PKP/1P1Q4/1R6 w - -\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a1 b1c1 b1d1 b1e1 b1f1 b1g1 b1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01451", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1bqk2r/2p1bppp/1nN1p3/p2n4/Q1pP4/6P1/P3PPBP/RNB2RK1 w kq -", "prompt": "FEN: r1bqk2r/2p1bppp/1nN1p3/p2n4/Q1pP4/6P1/P3PPBP/RNB2RK1 w kq -\nFor the piece on b1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b1: b1a3 b1c3 b1d2.\nLegal: b1a3 b1c3 b1d2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01452", "split": "rules", "task_type": "king_safety_filter", "fen": "2kr2nQ/2pq1p1p/p5p1/1pb5/3pP3/PP6/1P2NPPP/RNB2RK1 b - - 0 14", "prompt": "FEN: 2kr2nQ/2pq1p1p/p5p1/1pb5/3pP3/PP6/1P2NPPP/RNB2RK1 b - - 0 14\nFor move a6a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a6a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a6a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a6a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01453", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2k4r/p1p1bppp/1p3n2/1P6/P3n3/4B3/1PP1NP1P/2KR4 b - - 4 19", "prompt": "FEN: 2k4r/p1p1bppp/1p3n2/1P6/P3n3/4B3/1PP1NP1P/2KR4 b - - 4 19\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e4 black knight; b6 black pawn; f6 black knight; a7 black pawn; c7 black pawn; e7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; c8 black king; h8 black rook.\nMoves by piece:\ne4 black knight: e4c3 e4c5 e4d2 e4d6 e4f2 e4g3 e4g5\nb6 black pawn: no legal moves\nf6 black knight: f6d5 f6d7 f6e8 f6g4 f6g8 f6h5\na7 black pawn: a7a5 a7a6\nc7 black pawn: c7c5 c7c6\ne7 black bishop: e7a3 e7b4 e7c5 e7d6 e7d8 e7f8\nf7 black pawn: no legal moves\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\nc8 black king: c8b7 c8b8\nh8 black rook: h8d8 h8e8 h8f8 h8g8\nAll legal moves: a7a5 a7a6 c7c5 c7c6 c8b7 c8b8 e4c3 e4c5 e4d2 e4d6 e4f2 e4g3 e4g5 e7a3 e7b4 e7c5 e7d6 e7d8 e7f8 f6d5 f6d7 f6e8 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8d8 h8e8 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e4": ["e4c3", "e4c5", "e4d2", "e4d6", "e4f2", "e4g3", "e4g5"], "b6": [], "f6": ["f6d5", "f6d7", "f6e8", "f6g4", "f6g8", "f6h5"], "a7": ["a7a5", "a7a6"], "c7": ["c7c5", "c7c6"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6", "e7d8", "e7f8"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8b7", "c8b8"], "h8": ["h8d8", "h8e8", "h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 c7c5 c7c6 c8b7 c8b8 e4c3 e4c5 e4d2 e4d6 e4f2 e4g3 e4g5 e7a3 e7b4 e7c5 e7d6 e7d8 e7f8 f6d5 f6d7 f6e8 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8d8 h8e8 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e4": ["e4c3", "e4c5", "e4d2", "e4d6", "e4f2", "e4g3", "e4g5"], "b6": [], "f6": ["f6d5", "f6d7", "f6e8", "f6g4", "f6g8", "f6h5"], "a7": ["a7a5", "a7a6"], "c7": ["c7c5", "c7c6"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6", "e7d8", "e7f8"], "f7": [], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "c8": ["c8b7", "c8b8"], "h8": ["h8d8", "h8e8", "h8f8", "h8g8"]}, "legal_moves": "a7a5 a7a6 c7c5 c7c6 c8b7 c8b8 e4c3 e4c5 e4d2 e4d6 e4f2 e4g3 e4g5 e7a3 e7b4 e7c5 e7d6 e7d8 e7f8 f6d5 f6d7 f6e8 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8d8 h8e8 h8f8 h8g8"}}
{"example_id": "rules_01454", "split": "rules", "task_type": "ray_walk", "fen": "1r6/p1rnkpp1/1p1pp2p/P2p4/3P4/R2BP3/1PPK1PPP/2R5 w - -", "prompt": "FEN: 1r6/p1rnkpp1/1p1pp2p/P2p4/3P4/R2BP3/1PPK1PPP/2R5 w - -\nWalk each ray for the slider on c1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c1 white rook.\nRay N: c2 white pawn: own piece (stop, excluded).\nRay E: d1 empty; e1 empty; f1 empty; g1 empty; h1 empty; edge.\nRay S: edge.\nRay W: b1 empty; a1 empty; edge.\nMoves from rays: c1a1 c1b1 c1d1 c1e1 c1f1 c1g1 c1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_01455", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/p3bppp/1p1p4/4N3/4Q3/1P6/nBP2PPP/3R1RK1 w - - 0 16", "prompt": "FEN: r2q1rk1/p3bppp/1p1p4/4N3/4Q3/1P6/nBP2PPP/3R1RK1 w - - 0 16\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b2a1 b2a3 b2c1 b2c3 b2d4 b3b4 c2c3 c2c4 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1e1 e4a4 e4a8 e4b4 e4b7 e4c4 e4c6 e4d3 e4d4 e4d5 e4e1 e4e2 e4e3 e4f3 e4f4 e4f5 e4g4 e4g6 e4h4 e4h7 e5c4 e5c6 e5d3 e5d7 e5f3 e5f7 e5g4 e5g6 f1e1 f2f3 f2f4 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01456", "split": "rules", "task_type": "legal_moves", "fen": "r3r1k1/1pp2pp1/p1n5/P4b2/1PN1pb1N/2P4P/1K2R3/4RB2 b - - 1 31", "prompt": "FEN: r3r1k1/1pp2pp1/p1n5/P4b2/1PN1pb1N/2P4P/1K2R3/4RB2 b - - 1 31\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a8a7 a8b8 a8c8 a8d8 b7b5 b7b6 c6a5 c6a7 c6b4 c6b8 c6d4 c6d8 c6e5 c6e7 e4e3 e8b8 e8c8 e8d8 e8e5 e8e6 e8e7 e8f8 f4c1 f4d2 f4d6 f4e3 f4e5 f4g3 f4g5 f4h2 f4h6 f5c8 f5d7 f5e6 f5g4 f5g6 f5h3 f5h7 f7f6 g7g5 g7g6 g8f8 g8h7 g8h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01457", "split": "rules", "task_type": "side_piece_inventory", "fen": "3rkr2/1pq2p1Q/2b1pPp1/pp5p/5P2/P2B4/2P3PP/3R1R1K w - - 5 31", "prompt": "FEN: 3rkr2/1pq2p1Q/2b1pPp1/pp5p/5P2/P2B4/2P3PP/3R1R1K w - - 5 31\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: d1 white rook; f1 white rook; h1 white king; c2 white pawn; g2 white pawn; h2 white pawn; a3 white pawn; d3 white bishop; f4 white pawn; f6 white pawn; h7 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "d1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "h1", "piece": "white king"}, {"square": "c2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "f4", "piece": "white pawn"}, {"square": "f6", "piece": "white pawn"}, {"square": "h7", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "d1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "h1", "piece": "white king"}, {"square": "c2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "f4", "piece": "white pawn"}, {"square": "f6", "piece": "white pawn"}, {"square": "h7", "piece": "white queen"}]}}
{"example_id": "rules_01458", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnbqkb1r/pp2pppp/2p2n2/6N1/4p3/2N4P/PPPP1PP1/R1BQKB1R b KQkq -", "prompt": "FEN: rnbqkb1r/pp2pppp/2p2n2/6N1/4p3/2N4P/PPPP1PP1/R1BQKB1R b KQkq -\nWhat legal moves does the piece on e8 have?", "gold_answer": "e8d7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "e8", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "e8", "piece": "king"}}
{"example_id": "rules_01459", "split": "rules", "task_type": "check_detection", "fen": "8/pp5R/b2p1k2/K2n4/8/8/8/8 b - - 1 48", "prompt": "FEN: 8/pp5R/b2p1k2/K2n4/8/8/8/8 b - - 1 48\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01460", "split": "rules", "task_type": "captures", "fen": "rnbqkb1r/ppp1nppp/4p3/3p4/3P1B2/4PN2/PPP2PPP/RN1QKB1R b KQkq - 0 4", "prompt": "FEN: rnbqkb1r/ppp1nppp/4p3/3p4/3P1B2/4PN2/PPP2PPP/RN1QKB1R b KQkq - 0 4\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01461", "split": "rules", "task_type": "special_rules", "fen": "8/6pk/4R3/1rb3Kp/8/3P4/7P/8 w - - 0 40", "prompt": "Given FEN: 8/6pk/4R3/1rb3Kp/8/3P4/7P/8 w - - 0 40\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01462", "split": "rules", "task_type": "legality_check", "fen": "2k1r3/1p1r1p1p/p7/2p1Pn2/3P1P2/1P1R2P1/P3N2P/2K4R b - - 0 23", "prompt": "FEN: 2k1r3/1p1r1p1p/p7/2p1Pn2/3P1P2/1P1R2P1/P3N2P/2K4R b - - 0 23\nIs the move e8a4 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "e8a4", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "e8a4", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_01463", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rn1qkbnr/ppp1ppp1/7p/3p1b2/2PP1B2/2N5/PP2PPPP/R2QKBNR b KQkq - 1 4", "prompt": "FEN: rn1qkbnr/ppp1ppp1/7p/3p1b2/2PP1B2/2N5/PP2PPPP/R2QKBNR b KQkq - 1 4\nList pseudo-legal moves from d5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d5: d5c4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_01464", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/8/1Pk2pp1/7p/7P/b3B1P1/5PK1/8 w - -", "prompt": "FEN: 8/8/1Pk2pp1/7p/7P/b3B1P1/5PK1/8 w - -\nFor the piece on f2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f2: f2f3 f2f4.\nLegal: f2f3 f2f4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "f2", "diagnostic": true, "hard_gate": false, "source_square": "f2"}}
{"example_id": "rules_01465", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbqk2r/p1pp1p1p/1p2pbp1/7n/1Q2P2P/6P1/PPPP1P2/RNB1KBNR b KQkq - 1 8", "prompt": "FEN: rnbqk2r/p1pp1p1p/1p2pbp1/7n/1Q2P2P/6P1/PPPP1P2/RNB1KBNR b KQkq - 1 8\nFor move e8e7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e8e7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e8e7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e8e7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01466", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rn1qk2r/ppp1bppp/8/3pPb2/3Nn3/3B4/PPP2PPP/RNBQ1RK1 b kq -", "prompt": "FEN: rn1qk2r/ppp1bppp/8/3pPb2/3Nn3/3B4/PPP2PPP/RNBQ1RK1 b kq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e4 black knight; d5 black pawn; f5 black bishop; a7 black pawn; b7 black pawn; c7 black pawn; e7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; d8 black queen; e8 black king; h8 black rook.\nMoves by piece:\ne4 black knight: e4c3 e4c5 e4d2 e4d6 e4f2 e4f6 e4g3 e4g5\nd5 black pawn: no legal moves\nf5 black bishop: f5c8 f5d7 f5e6 f5g4 f5g6 f5h3\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nc7 black pawn: c7c5 c7c6\ne7 black bishop: e7a3 e7b4 e7c5 e7d6 e7f6 e7f8 e7g5 e7h4\nf7 black pawn: f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: no legal moves\nb8 black knight: b8a6 b8c6 b8d7\nd8 black queen: d8c8 d8d6 d8d7\ne8 black king: e8d7 e8f8 e8g8\nh8 black rook: h8f8 h8g8\nAll legal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c7c5 c7c6 d8c8 d8d6 d8d7 e4c3 e4c5 e4d2 e4d6 e4f2 e4f6 e4g3 e4g5 e7a3 e7b4 e7c5 e7d6 e7f6 e7f8 e7g5 e7h4 e8d7 e8f8 e8g8 f5c8 f5d7 f5e6 f5g4 f5g6 f5h3 f7f6 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e4": ["e4c3", "e4c5", "e4d2", "e4d6", "e4f2", "e4f6", "e4g3", "e4g5"], "d5": [], "f5": ["f5c8", "f5d7", "f5e6", "f5g4", "f5g6", "f5h3"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7c5", "c7c6"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6", "e7f6", "e7f8", "e7g5", "e7h4"], "f7": ["f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8c6", "b8d7"], "d8": ["d8c8", "d8d6", "d8d7"], "e8": ["e8d7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c7c5 c7c6 d8c8 d8d6 d8d7 e4c3 e4c5 e4d2 e4d6 e4f2 e4f6 e4g3 e4g5 e7a3 e7b4 e7c5 e7d6 e7f6 e7f8 e7g5 e7h4 e8d7 e8f8 e8g8 f5c8 f5d7 f5e6 f5g4 f5g6 f5h3 f7f6 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e4": ["e4c3", "e4c5", "e4d2", "e4d6", "e4f2", "e4f6", "e4g3", "e4g5"], "d5": [], "f5": ["f5c8", "f5d7", "f5e6", "f5g4", "f5g6", "f5h3"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": ["c7c5", "c7c6"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6", "e7f6", "e7f8", "e7g5", "e7h4"], "f7": ["f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8c6", "b8d7"], "d8": ["d8c8", "d8d6", "d8d7"], "e8": ["e8d7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "legal_moves": "a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c7c5 c7c6 d8c8 d8d6 d8d7 e4c3 e4c5 e4d2 e4d6 e4f2 e4f6 e4g3 e4g5 e7a3 e7b4 e7c5 e7d6 e7f6 e7f8 e7g5 e7h4 e8d7 e8f8 e8g8 f5c8 f5d7 f5e6 f5g4 f5g6 f5h3 f7f6 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8"}}
{"example_id": "rules_01467", "split": "rules", "task_type": "ray_walk", "fen": "r3k2r/ppq1bp2/1np1pnbp/3pP1p1/3P4/PPN2PP1/2PBN1BP/R2Q1RK1 b kq -", "prompt": "FEN: r3k2r/ppq1bp2/1np1pnbp/3pP1p1/3P4/PPN2PP1/2PBN1BP/R2Q1RK1 b kq -\nWalk each ray for the slider on g6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: g6 black bishop.\nRay NE: h7 empty; edge.\nRay SE: h5 empty; edge.\nRay SW: f5 empty; e4 empty; d3 empty; c2 white pawn: capture (stop, included).\nRay NW: f7 black pawn: own piece (stop, excluded).\nMoves from rays: g6c2 g6d3 g6e4 g6f5 g6h5 g6h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "g6", "diagnostic": true, "hard_gate": false, "source_square": "g6"}}
{"example_id": "rules_01468", "split": "rules", "task_type": "legal_moves", "fen": "rn1qkb1r/ppp1n3/3ppp1p/6p1/2BPP3/4BQ1P/PPPN1PP1/R4RK1 b kq - 1 10", "prompt": "FEN: rn1qkb1r/ppp1n3/3ppp1p/6p1/2BPP3/4BQ1P/PPPN1PP1/R4RK1 b kq - 1 10\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c7c5 c7c6 d6d5 d8c8 d8d7 e6e5 e7c6 e7c8 e7d5 e7f5 e7g6 e7g8 e8d7 e8f7 f6f5 f8g7 g5g4 h6h5 h8g8 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01469", "split": "rules", "task_type": "legal_moves", "fen": "1R6/2Q5/8/6P1/6K1/k7/8/8 w - - 13 59", "prompt": "FEN: 1R6/2Q5/8/6P1/6K1/k7/8/8 w - - 13 59\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b8a8 b8b1 b8b2 b8b3 b8b4 b8b5 b8b6 b8b7 b8c8 b8d8 b8e8 b8f8 b8g8 b8h8 c7a5 c7a7 c7b6 c7b7 c7c1 c7c2 c7c3 c7c4 c7c5 c7c6 c7c8 c7d6 c7d7 c7d8 c7e5 c7e7 c7f4 c7f7 c7g3 c7g7 c7h2 c7h7 g4f3 g4f4 g4f5 g4g3 g4h3 g4h4 g4h5 g5g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01470", "split": "rules", "task_type": "side_piece_inventory", "fen": "rnbqkbnr/p1pp1ppp/1p2p3/8/3PP3/2N5/PPP2PPP/R1BQKBNR b KQkq - 0 3", "prompt": "FEN: rnbqkbnr/p1pp1ppp/1p2p3/8/3PP3/2N5/PPP2PPP/R1BQKBNR b KQkq - 0 3\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: b6 black pawn; e6 black pawn; a7 black pawn; c7 black pawn; d7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "b6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "d7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "b6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "d7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_01471", "split": "rules", "task_type": "piece_legal_moves", "fen": "1B6/3k4/pp2p2p/5n2/6p1/5pP1/PPP2P1P/4K3 b - - 1 28", "prompt": "FEN: 1B6/3k4/pp2p2p/5n2/6p1/5pP1/PPP2P1P/4K3 b - - 1 28\nWhat legal moves does the piece on a6 have?", "gold_answer": "a6a5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a6", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a6", "piece": "pawn"}}
{"example_id": "rules_01472", "split": "rules", "task_type": "check_detection", "fen": "2r4b/8/1pk1p1pp/2p1p3/2P1N3/R3P2P/1P2KPP1/8 b - -", "prompt": "FEN: 2r4b/8/1pk1p1pp/2p1p3/2P1N3/R3P2P/1P2KPP1/8 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01473", "split": "rules", "task_type": "captures", "fen": "r1bqr3/pp1nppkp/2p3p1/8/2P5/1P1n4/P2PNPPP/RN1Q1RK1 w - - 0 14", "prompt": "FEN: r1bqr3/pp1nppkp/2p3p1/8/2P5/1P1n4/P2PNPPP/RN1Q1RK1 w - - 0 14\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01474", "split": "rules", "task_type": "special_rules", "fen": "5rk1/pr3p2/1pp1p2p/2P3p1/PP1PR1P1/3Q1P1q/1B5b/R6K w - - 0 30", "prompt": "Given FEN: 5rk1/pr3p2/1pp1p2p/2P3p1/PP1PR1P1/3Q1P1q/1B5b/R6K w - - 0 30\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01475", "split": "rules", "task_type": "legality_check", "fen": "3k4/7R/5pp1/3K4/8/7P/6P1/8 b - - 9 58", "prompt": "FEN: 3k4/7R/5pp1/3K4/8/7P/6P1/8 b - - 9 58\nIs the move h2d6 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "h2d6", "_legality_check_reason_label": "empty_source", "move": "h2d6", "legality_reason_label": "empty_source"}}
{"example_id": "rules_01476", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2b1rk1/2p2ppp/p3b3/1p4B1/8/1P3N2/1PP2PPP/R4RK1 w - - 0 18", "prompt": "FEN: r2b1rk1/2p2ppp/p3b3/1p4B1/8/1P3N2/1PP2PPP/R4RK1 w - - 0 18\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1a2 a1a3 a1a4 a1a5 a1a6 a1b1 a1c1 a1d1 a1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01477", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnbqk2r/1pp1bppp/p2p1n2/8/3NP3/2NB4/PPP2PPP/R1BQK2R w KQkq - 2 7", "prompt": "FEN: rnbqk2r/1pp1bppp/p2p1n2/8/3NP3/2NB4/PPP2PPP/R1BQK2R w KQkq - 2 7\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1.\nLegal: a1b1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01478", "split": "rules", "task_type": "king_safety_filter", "fen": "1r3rk1/5pp1/p6p/4PPb1/2q5/1P3N1P/P5K1/1R3R2 w - - 0 33", "prompt": "FEN: 1r3rk1/5pp1/p6p/4PPb1/2q5/1P3N1P/P5K1/1R3R2 w - - 0 33\nFor move a2a3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a2a3.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a2a3", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a2a3", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01479", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/2k5/1p2R3/1B2P3/P2P1pp1/4n3/1PP4r/6K1 b - - 2 33", "prompt": "FEN: 8/2k5/1p2R3/1B2P3/P2P1pp1/4n3/1PP4r/6K1 b - - 2 33\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: h2 black rook; e3 black knight; f4 black pawn; g4 black pawn; b6 black pawn; c7 black king.\nMoves by piece:\nh2 black rook: h2c2 h2d2 h2e2 h2f2 h2g2 h2h1 h2h3 h2h4 h2h5 h2h6 h2h7 h2h8\ne3 black knight: e3c2 e3c4 e3d1 e3d5 e3f1 e3f5 e3g2\nf4 black pawn: f4f3\ng4 black pawn: g4g3\nb6 black pawn: no legal moves\nc7 black king: c7b7 c7b8 c7c8 c7d8\nAll legal moves: c7b7 c7b8 c7c8 c7d8 e3c2 e3c4 e3d1 e3d5 e3f1 e3f5 e3g2 f4f3 g4g3 h2c2 h2d2 h2e2 h2f2 h2g2 h2h1 h2h3 h2h4 h2h5 h2h6 h2h7 h2h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"h2": ["h2c2", "h2d2", "h2e2", "h2f2", "h2g2", "h2h1", "h2h3", "h2h4", "h2h5", "h2h6", "h2h7", "h2h8"], "e3": ["e3c2", "e3c4", "e3d1", "e3d5", "e3f1", "e3f5", "e3g2"], "f4": ["f4f3"], "g4": ["g4g3"], "b6": [], "c7": ["c7b7", "c7b8", "c7c8", "c7d8"]}, "_legal_moves_by_piece_moves": "c7b7 c7b8 c7c8 c7d8 e3c2 e3c4 e3d1 e3d5 e3f1 e3f5 e3g2 f4f3 g4g3 h2c2 h2d2 h2e2 h2f2 h2g2 h2h1 h2h3 h2h4 h2h5 h2h6 h2h7 h2h8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"h2": ["h2c2", "h2d2", "h2e2", "h2f2", "h2g2", "h2h1", "h2h3", "h2h4", "h2h5", "h2h6", "h2h7", "h2h8"], "e3": ["e3c2", "e3c4", "e3d1", "e3d5", "e3f1", "e3f5", "e3g2"], "f4": ["f4f3"], "g4": ["g4g3"], "b6": [], "c7": ["c7b7", "c7b8", "c7c8", "c7d8"]}, "legal_moves": "c7b7 c7b8 c7c8 c7d8 e3c2 e3c4 e3d1 e3d5 e3f1 e3f5 e3g2 f4f3 g4g3 h2c2 h2d2 h2e2 h2f2 h2g2 h2h1 h2h3 h2h4 h2h5 h2h6 h2h7 h2h8"}}
{"example_id": "rules_01480", "split": "rules", "task_type": "ray_walk", "fen": "r1b1k2r/2qp1ppp/p1pb1n2/8/P3PB2/2N5/1PP1BQPP/R4RK1 b kq -", "prompt": "FEN: r1b1k2r/2qp1ppp/p1pb1n2/8/P3PB2/2N5/1PP1BQPP/R4RK1 b kq -\nWalk each ray for the slider on d6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d6 black bishop.\nRay NE: e7 empty; f8 empty; edge.\nRay SE: e5 empty; f4 white bishop: capture (stop, included).\nRay SW: c5 empty; b4 empty; a3 empty; edge.\nRay NW: c7 black queen: own piece (stop, excluded).\nMoves from rays: d6a3 d6b4 d6c5 d6e5 d6e7 d6f4 d6f8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "d6", "diagnostic": true, "hard_gate": false, "source_square": "d6"}}
{"example_id": "rules_01481", "split": "rules", "task_type": "legal_moves", "fen": "3q4/4prkp/3p1pp1/1prP4/p1P2P2/1P1Q3P/P5P1/3RR2K b - -", "prompt": "FEN: 3q4/4prkp/3p1pp1/1prP4/p1P2P2/1P1Q3P/P5P1/3RR2K b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a4a3 a4b3 b5b4 b5c4 c5c4 c5c6 c5c7 c5c8 c5d5 d8a5 d8a8 d8b6 d8b8 d8c7 d8c8 d8d7 d8e8 d8f8 d8g8 d8h8 e7e5 e7e6 f6f5 f7f8 g6g5 g7f8 g7g8 g7h6 g7h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01482", "split": "rules", "task_type": "legal_moves", "fen": "r2qkbnr/pp1n1ppp/4p3/1BppPb2/3P4/2P2N1P/PP3PP1/RNBQK2R b KQkq -", "prompt": "FEN: r2qkbnr/pp1n1ppp/4p3/1BppPb2/3P4/2P2N1P/PP3PP1/RNBQK2R b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 a8c8 b7b6 c5c4 c5d4 d8a5 d8b6 d8b8 d8c7 d8c8 d8e7 d8f6 d8g5 d8h4 e8e7 f5b1 f5c2 f5d3 f5e4 f5g4 f5g6 f5h3 f7f6 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01483", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/6p1/p4p2/1p2kPp1/1P6/3K3B/1P3n2/8 w - - 4 50", "prompt": "FEN: 8/6p1/p4p2/1p2kPp1/1P6/3K3B/1P3n2/8 w - - 4 50\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: b2 white pawn; d3 white king; h3 white bishop; b4 white pawn; f5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "b2", "piece": "white pawn"}, {"square": "d3", "piece": "white king"}, {"square": "h3", "piece": "white bishop"}, {"square": "b4", "piece": "white pawn"}, {"square": "f5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "b2", "piece": "white pawn"}, {"square": "d3", "piece": "white king"}, {"square": "h3", "piece": "white bishop"}, {"square": "b4", "piece": "white pawn"}, {"square": "f5", "piece": "white pawn"}]}}
{"example_id": "rules_01484", "split": "rules", "task_type": "piece_legal_moves", "fen": "3kr1r1/pp2n2p/2pQ4/2n5/8/6P1/PPPP1PKP/R1B4R b - - 0 18", "prompt": "FEN: 3kr1r1/pp2n2p/2pQ4/2n5/8/6P1/PPPP1PKP/R1B4R b - - 0 18\nWhat legal moves does the piece on d8 have?", "gold_answer": "d8c8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "d8", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "d8", "piece": "king"}}
{"example_id": "rules_01485", "split": "rules", "task_type": "check_detection", "fen": "6rk/6pp/8/5Q2/r1q5/6P1/P4P1P/R4RK1 w - - 1 28", "prompt": "FEN: 6rk/6pp/8/5Q2/r1q5/6P1/P4P1P/R4RK1 w - - 1 28\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01486", "split": "rules", "task_type": "captures", "fen": "1K6/8/7p/8/6p1/7k/8/8 b - - 1 54", "prompt": "FEN: 1K6/8/7p/8/6p1/7k/8/8 b - - 1 54\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01487", "split": "rules", "task_type": "special_rules", "fen": "r4rk1/1b3ppp/pp3n2/3qn3/P7/2B1PN2/4BPPP/2RQ1RK1 b - - 1 19", "prompt": "Given FEN: r4rk1/1b3ppp/pp3n2/3qn3/P7/2B1PN2/4BPPP/2RQ1RK1 b - - 1 19\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01488", "split": "rules", "task_type": "legality_check", "fen": "r3k3/ppp1r2N/3b2Q1/5p2/2n5/2P5/P1P2PbP/R1K4R b - - 0 23", "prompt": "FEN: r3k3/ppp1r2N/3b2Q1/5p2/2n5/2P5/P1P2PbP/R1K4R b - - 0 23\nIs the move a7e8 legal?", "gold_answer": "No, illegal. Reason: own piece destination.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "a7e8", "_legality_check_reason_label": "own_piece_destination", "move": "a7e8", "legality_reason_label": "own_piece_destination"}}
{"example_id": "rules_01489", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1b2rk1/pp2ppbp/1qn2np1/2pp4/3P1B2/2PBPN2/PP1N1PPP/R1Q2RK1 b - -", "prompt": "FEN: r1b2rk1/pp2ppbp/1qn2np1/2pp4/3P1B2/2PBPN2/PP1N1PPP/R1Q2RK1 b - -\nList pseudo-legal moves from c5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c5: c5c4 c5d4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_01490", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/2qk3p/P1b2p1P/Q1B1p1p1/2P5/5P2/5KP1/8 w - -", "prompt": "FEN: 8/2qk3p/P1b2p1P/Q1B1p1p1/2P5/5P2/5KP1/8 w - -\nFor the piece on f2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f2: f2e1 f2e2 f2e3 f2f1 f2g1 f2g3.\nLegal: f2e1 f2e2 f2e3 f2f1 f2g1 f2g3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "f2", "diagnostic": true, "hard_gate": false, "source_square": "f2"}}
{"example_id": "rules_01491", "split": "rules", "task_type": "king_safety_filter", "fen": "5r2/p2nkp1Q/3p4/2pP4/2Pp1Nr1/5K2/P1P2P2/8 b - - 4 23", "prompt": "FEN: 5r2/p2nkp1Q/3p4/2pP4/2Pp1Nr1/5K2/P1P2P2/8 b - - 4 23\nFor move e7e6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e7e6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e7e6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e7e6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01492", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "4n2k/4R1p1/2b4p/p1pp4/3p4/P2P3P/B1PB1PP1/6K1 w - - 1 32", "prompt": "FEN: 4n2k/4R1p1/2b4p/p1pp4/3p4/P2P3P/B1PB1PP1/6K1 w - - 1 32\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: g1 white king; a2 white bishop; c2 white pawn; d2 white bishop; f2 white pawn; g2 white pawn; a3 white pawn; d3 white pawn; h3 white pawn; e7 white rook.\nMoves by piece:\ng1 white king: g1f1 g1h1 g1h2\na2 white bishop: a2b1 a2b3 a2c4 a2d5\nc2 white pawn: c2c3 c2c4\nd2 white bishop: d2a5 d2b4 d2c1 d2c3 d2e1 d2e3 d2f4 d2g5 d2h6\nf2 white pawn: f2f3 f2f4\ng2 white pawn: g2g3 g2g4\na3 white pawn: a3a4\nd3 white pawn: no legal moves\nh3 white pawn: h3h4\ne7 white rook: e7a7 e7b7 e7c7 e7d7 e7e1 e7e2 e7e3 e7e4 e7e5 e7e6 e7e8 e7f7 e7g7\nAll legal moves: a2b1 a2b3 a2c4 a2d5 a3a4 c2c3 c2c4 d2a5 d2b4 d2c1 d2c3 d2e1 d2e3 d2f4 d2g5 d2h6 e7a7 e7b7 e7c7 e7d7 e7e1 e7e2 e7e3 e7e4 e7e5 e7e6 e7e8 e7f7 e7g7 f2f3 f2f4 g1f1 g1h1 g1h2 g2g3 g2g4 h3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"g1": ["g1f1", "g1h1", "g1h2"], "a2": ["a2b1", "a2b3", "a2c4", "a2d5"], "c2": ["c2c3", "c2c4"], "d2": ["d2a5", "d2b4", "d2c1", "d2c3", "d2e1", "d2e3", "d2f4", "d2g5", "d2h6"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "a3": ["a3a4"], "d3": [], "h3": ["h3h4"], "e7": ["e7a7", "e7b7", "e7c7", "e7d7", "e7e1", "e7e2", "e7e3", "e7e4", "e7e5", "e7e6", "e7e8", "e7f7", "e7g7"]}, "_legal_moves_by_piece_moves": "a2b1 a2b3 a2c4 a2d5 a3a4 c2c3 c2c4 d2a5 d2b4 d2c1 d2c3 d2e1 d2e3 d2f4 d2g5 d2h6 e7a7 e7b7 e7c7 e7d7 e7e1 e7e2 e7e3 e7e4 e7e5 e7e6 e7e8 e7f7 e7g7 f2f3 f2f4 g1f1 g1h1 g1h2 g2g3 g2g4 h3h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"g1": ["g1f1", "g1h1", "g1h2"], "a2": ["a2b1", "a2b3", "a2c4", "a2d5"], "c2": ["c2c3", "c2c4"], "d2": ["d2a5", "d2b4", "d2c1", "d2c3", "d2e1", "d2e3", "d2f4", "d2g5", "d2h6"], "f2": ["f2f3", "f2f4"], "g2": ["g2g3", "g2g4"], "a3": ["a3a4"], "d3": [], "h3": ["h3h4"], "e7": ["e7a7", "e7b7", "e7c7", "e7d7", "e7e1", "e7e2", "e7e3", "e7e4", "e7e5", "e7e6", "e7e8", "e7f7", "e7g7"]}, "legal_moves": "a2b1 a2b3 a2c4 a2d5 a3a4 c2c3 c2c4 d2a5 d2b4 d2c1 d2c3 d2e1 d2e3 d2f4 d2g5 d2h6 e7a7 e7b7 e7c7 e7d7 e7e1 e7e2 e7e3 e7e4 e7e5 e7e6 e7e8 e7f7 e7g7 f2f3 f2f4 g1f1 g1h1 g1h2 g2g3 g2g4 h3h4"}}
{"example_id": "rules_01493", "split": "rules", "task_type": "legal_moves", "fen": "8/8/p3bk2/1p1p3p/1P1P1P2/P3N1K1/8/8 w - -", "prompt": "FEN: 8/8/p3bk2/1p1p3p/1P1P1P2/P3N1K1/8/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 e3c2 e3c4 e3d1 e3d5 e3f1 e3f5 e3g2 e3g4 f4f5 g3f2 g3f3 g3g2 g3h2 g3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": ""}}
{"example_id": "rules_01494", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/1p6/8/8/4k1K1/8/1P6/8 b - -", "prompt": "FEN: 8/1p6/8/8/4k1K1/8/1P6/8 b - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e4 black king; b7 black pawn.\nFilter by piece:\ne4 black king: pseudo-legal e4d3 e4d4 e4d5 e4e3 e4e5 e4f3 e4f4 e4f5 | rejected e4f3 king_would_be_in_check; e4f4 king_would_be_in_check; e4f5 king_would_be_in_check | legal e4d3 e4d4 e4d5 e4e3 e4e5\nb7 black pawn: pseudo-legal b7b5 b7b6 | rejected none | legal b7b5 b7b6\nAll legal moves: b7b5 b7b6 e4d3 e4d4 e4d5 e4e3 e4e5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01495", "split": "rules", "task_type": "legal_moves", "fen": "r2qkb1r/pp1n1ppp/5n2/2pp1b2/3P1B2/2P2N2/PP1N1PPP/R2QKB1R w KQkq -", "prompt": "FEN: r2qkb1r/pp1n1ppp/5n2/2pp1b2/3P1B2/2P2N2/PP1N1PPP/R2QKB1R w KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a2a3 a2a4 b2b3 b2b4 c3c4 d1a4 d1b1 d1b3 d1c1 d1c2 d1e2 d2b1 d2b3 d2c4 d2e4 d4c5 e1e2 f1a6 f1b5 f1c4 f1d3 f1e2 f3e5 f3g1 f3g5 f3h4 f4b8 f4c7 f4d6 f4e3 f4e5 f4g3 f4g5 f4h6 g2g3 g2g4 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01496", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1b1r1k1/1p3ppp/p1qp1b2/2n1p3/4P3/2N3NP/PPP1BPP1/1R1Q1RK1 w - -", "prompt": "FEN: r1b1r1k1/1p3ppp/p1qp1b2/2n1p3/4P3/2N3NP/PPP1BPP1/1R1Q1RK1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: b1 white rook; d1 white queen; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; c2 white pawn; e2 white bishop; f2 white pawn; g2 white pawn; c3 white knight; g3 white knight; h3 white pawn; e4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "g3", "piece": "white knight"}, {"square": "h3", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "g3", "piece": "white knight"}, {"square": "h3", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}]}}
{"example_id": "rules_01497", "split": "rules", "task_type": "piece_legal_moves", "fen": "r2q1rk1/pb1nbppp/1p2p3/8/3PP3/5NP1/P4PBP/R1BQR1K1 w - -", "prompt": "FEN: r2q1rk1/pb1nbppp/1p2p3/8/3PP3/5NP1/P4PBP/R1BQR1K1 w - -\nWhat legal moves does the piece on d1 have?", "gold_answer": "d1a4 d1b3 d1c2 d1d2 d1d3 d1e2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "d1", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "d1", "piece": "queen"}}
{"example_id": "rules_01498", "split": "rules", "task_type": "check_detection", "fen": "r1bq1rk1/pp1p1ppp/2n2n2/8/1bP1p3/2N1PN2/PP1B1PPP/R2QKB1R w KQ -", "prompt": "FEN: r1bq1rk1/pp1p1ppp/2n2n2/8/1bP1p3/2N1PN2/PP1B1PPP/R2QKB1R w KQ -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01499", "split": "rules", "task_type": "captures", "fen": "r1bqkb1r/pppp2pp/2n2n2/5P2/2B1p3/8/PPPP1PPP/RNBQK1NR w KQkq -", "prompt": "FEN: r1bqkb1r/pppp2pp/2n2n2/5P2/2B1p3/8/PPPP1PPP/RNBQK1NR w KQkq -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01500", "split": "rules", "task_type": "special_rules", "fen": "5rk1/4qppp/ppr1pn2/6N1/2b2P2/2P1Q3/6PP/R4RK1 w - - 0 27", "prompt": "Given FEN: 5rk1/4qppp/ppr1pn2/6N1/2b2P2/2P1Q3/6PP/R4RK1 w - - 0 27\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01501", "split": "rules", "task_type": "legality_check", "fen": "7k/5p1p/4R3/6p1/8/6P1/5PBP/5K2 w - -", "prompt": "FEN: 7k/5p1p/4R3/6p1/8/6P1/5PBP/5K2 w - -\nIs the move h8f5 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "h8f5", "_legality_check_reason_label": "wrong_side_piece", "move": "h8f5", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01502", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2r3k1/4r2p/p5p1/5p2/2PN3q/Q3PB2/P2n4/1R3RK1 b - -", "prompt": "FEN: 2r3k1/4r2p/p5p1/5p2/2PN3q/Q3PB2/P2n4/1R3RK1 b - -\nList pseudo-legal moves from d2.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d2: d2b1 d2b3 d2c4 d2e4 d2f1 d2f3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d2", "diagnostic": true, "hard_gate": false, "source_square": "d2"}}
{"example_id": "rules_01503", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn1q1rk1/pp1bb1pp/3p4/3P1p2/3Pp3/5N2/PP2BPPP/R1BQ1RK1 w - - 0 12", "prompt": "FEN: rn1q1rk1/pp1bb1pp/3p4/3P1p2/3Pp3/5N2/PP2BPPP/R1BQ1RK1 w - - 0 12\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1.\nLegal: a1b1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01504", "split": "rules", "task_type": "king_safety_filter", "fen": "r4rk1/p5bp/1p2b1p1/3P2Bq/6pP/Q7/PP3P2/3R1RK1 w - -", "prompt": "FEN: r4rk1/p5bp/1p2b1p1/3P2Bq/6pP/Q7/PP3P2/3R1RK1 w - -\nFor move a3a4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a3a4.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a3a4", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a3a4", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01505", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1rbq1rk1/p3ppbp/2np1np1/2p5/1p2PPP1/3PNN2/PPP3BP/R1BQ1RK1 b - -", "prompt": "FEN: 1rbq1rk1/p3ppbp/2np1np1/2p5/1p2PPP1/3PNN2/PPP3BP/R1BQ1RK1 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b4 black pawn; c5 black pawn; c6 black knight; d6 black pawn; f6 black knight; g6 black pawn; a7 black pawn; e7 black pawn; f7 black pawn; g7 black bishop; h7 black pawn; b8 black rook; c8 black bishop; d8 black queen; f8 black rook; g8 black king.\nMoves by piece:\nb4 black pawn: b4b3\nc5 black pawn: c5c4\nc6 black knight: c6a5 c6d4 c6e5\nd6 black pawn: d6d5\nf6 black knight: f6d5 f6d7 f6e4 f6e8 f6g4 f6h5\ng6 black pawn: g6g5\na7 black pawn: a7a5 a7a6\ne7 black pawn: e7e5 e7e6\nf7 black pawn: no legal moves\ng7 black bishop: g7h6 g7h8\nh7 black pawn: h7h5 h7h6\nb8 black rook: b8a8 b8b5 b8b6 b8b7\nc8 black bishop: c8a6 c8b7 c8d7 c8e6 c8f5 c8g4\nd8 black queen: d8a5 d8b6 d8c7 d8d7 d8e8\nf8 black rook: f8e8\ng8 black king: g8h8\nAll legal moves: a7a5 a7a6 b4b3 b8a8 b8b5 b8b6 b8b7 c5c4 c6a5 c6d4 c6e5 c8a6 c8b7 c8d7 c8e6 c8f5 c8g4 d6d5 d8a5 d8b6 d8c7 d8d7 d8e8 e7e5 e7e6 f6d5 f6d7 f6e4 f6e8 f6g4 f6h5 f8e8 g6g5 g7h6 g7h8 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b4": ["b4b3"], "c5": ["c5c4"], "c6": ["c6a5", "c6d4", "c6e5"], "d6": ["d6d5"], "f6": ["f6d5", "f6d7", "f6e4", "f6e8", "f6g4", "f6h5"], "g6": ["g6g5"], "a7": ["a7a5", "a7a6"], "e7": ["e7e5", "e7e6"], "f7": [], "g7": ["g7h6", "g7h8"], "h7": ["h7h5", "h7h6"], "b8": ["b8a8", "b8b5", "b8b6", "b8b7"], "c8": ["c8a6", "c8b7", "c8d7", "c8e6", "c8f5", "c8g4"], "d8": ["d8a5", "d8b6", "d8c7", "d8d7", "d8e8"], "f8": ["f8e8"], "g8": ["g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b4b3 b8a8 b8b5 b8b6 b8b7 c5c4 c6a5 c6d4 c6e5 c8a6 c8b7 c8d7 c8e6 c8f5 c8g4 d6d5 d8a5 d8b6 d8c7 d8d7 d8e8 e7e5 e7e6 f6d5 f6d7 f6e4 f6e8 f6g4 f6h5 f8e8 g6g5 g7h6 g7h8 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b4": ["b4b3"], "c5": ["c5c4"], "c6": ["c6a5", "c6d4", "c6e5"], "d6": ["d6d5"], "f6": ["f6d5", "f6d7", "f6e4", "f6e8", "f6g4", "f6h5"], "g6": ["g6g5"], "a7": ["a7a5", "a7a6"], "e7": ["e7e5", "e7e6"], "f7": [], "g7": ["g7h6", "g7h8"], "h7": ["h7h5", "h7h6"], "b8": ["b8a8", "b8b5", "b8b6", "b8b7"], "c8": ["c8a6", "c8b7", "c8d7", "c8e6", "c8f5", "c8g4"], "d8": ["d8a5", "d8b6", "d8c7", "d8d7", "d8e8"], "f8": ["f8e8"], "g8": ["g8h8"]}, "legal_moves": "a7a5 a7a6 b4b3 b8a8 b8b5 b8b6 b8b7 c5c4 c6a5 c6d4 c6e5 c8a6 c8b7 c8d7 c8e6 c8f5 c8g4 d6d5 d8a5 d8b6 d8c7 d8d7 d8e8 e7e5 e7e6 f6d5 f6d7 f6e4 f6e8 f6g4 f6h5 f8e8 g6g5 g7h6 g7h8 g8h8 h7h5 h7h6"}}
{"example_id": "rules_01506", "split": "rules", "task_type": "ray_walk", "fen": "rn2k2r/pp3ppp/4bq2/1Bbp4/8/2N2N2/PPP2PPP/R2QK2R b KQkq -", "prompt": "FEN: rn2k2r/pp3ppp/4bq2/1Bbp4/8/2N2N2/PPP2PPP/R2QK2R b KQkq -\nWalk each ray for the slider on c5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c5 black bishop.\nRay NE: d6 empty; e7 empty; f8 empty; edge.\nRay SE: d4 empty; e3 empty; f2 white pawn: capture (stop, included).\nRay SW: b4 empty; a3 empty; edge.\nRay NW: b6 empty; a7 black pawn: own piece (stop, excluded).\nMoves from rays: c5a3 c5b4 c5b6 c5d4 c5d6 c5e3 c5e7 c5f2 c5f8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c5", "diagnostic": true, "hard_gate": false, "source_square": "c5"}}
{"example_id": "rules_01507", "split": "rules", "task_type": "legal_moves", "fen": "r2qkbnr/ppp2pp1/2np3p/4p3/2B1P1b1/2NPBN2/PPP2PPP/R2QK2R b KQkq - 3 6", "prompt": "FEN: r2qkbnr/ppp2pp1/2np3p/4p3/2B1P1b1/2NPBN2/PPP2PPP/R2QK2R b KQkq - 3 6\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 a8c8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6e7 d6d5 d8b8 d8c8 d8d7 d8e7 d8f6 d8g5 d8h4 e8d7 e8e7 f7f5 f7f6 f8e7 g4c8 g4d7 g4e6 g4f3 g4f5 g4h3 g4h5 g7g5 g7g6 g8e7 g8f6 h6h5 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01508", "split": "rules", "task_type": "legal_moves", "fen": "6k1/pbqp1pp1/1p1b3p/2pP4/2B3n1/2NQB1P1/PP3P1P/4N1K1 b - - 1 20", "prompt": "FEN: 6k1/pbqp1pp1/1p1b3p/2pP4/2B3n1/2NQB1P1/PP3P1P/4N1K1 b - - 1 20\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6b5 b7a6 b7a8 b7c6 b7c8 b7d5 c7b8 c7c6 c7c8 c7d8 d6e5 d6e7 d6f4 d6f8 d6g3 f7f5 f7f6 g4e3 g4e5 g4f2 g4f6 g4h2 g7g5 g7g6 g8f8 g8h8 h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01509", "split": "rules", "task_type": "side_piece_inventory", "fen": "3r4/pB2rp1k/6p1/2P1b2p/3N2b1/4P1P1/P4KP1/1R3R2 b - - 0 25", "prompt": "FEN: 3r4/pB2rp1k/6p1/2P1b2p/3N2b1/4P1P1/P4KP1/1R3R2 b - - 0 25\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: g4 black bishop; e5 black bishop; h5 black pawn; g6 black pawn; a7 black pawn; e7 black rook; f7 black pawn; h7 black king; d8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "g4", "piece": "black bishop"}, {"square": "e5", "piece": "black bishop"}, {"square": "h5", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "e7", "piece": "black rook"}, {"square": "f7", "piece": "black pawn"}, {"square": "h7", "piece": "black king"}, {"square": "d8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "g4", "piece": "black bishop"}, {"square": "e5", "piece": "black bishop"}, {"square": "h5", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "e7", "piece": "black rook"}, {"square": "f7", "piece": "black pawn"}, {"square": "h7", "piece": "black king"}, {"square": "d8", "piece": "black rook"}]}}
{"example_id": "rules_01510", "split": "rules", "task_type": "piece_legal_moves", "fen": "r2qkb1r/p2n1ppp/2p2n2/2ppp2b/PP1P4/4PP2/1B1N2PP/R2QKBNR w KQkq - 0 10", "prompt": "FEN: r2qkb1r/p2n1ppp/2p2n2/2ppp2b/PP1P4/4PP2/1B1N2PP/R2QKBNR w KQkq - 0 10\nWhat legal moves does the piece on d2 have?", "gold_answer": "d2b1 d2b3 d2c4 d2e4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "d2", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "d2", "piece": "knight"}}
{"example_id": "rules_01511", "split": "rules", "task_type": "check_detection", "fen": "r3k2r/pp3nbp/3p1Np1/q1pNp3/4P3/3P1Q1P/PPP2PP1/R4RK1 b kq - 0 16", "prompt": "FEN: r3k2r/pp3nbp/3p1Np1/q1pNp3/4P3/3P1Q1P/PPP2PP1/R4RK1 b kq - 0 16\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01512", "split": "rules", "task_type": "captures", "fen": "2rq1rk1/3nbpp1/p1n4p/1pP1p2b/1P1pP3/P2B1N1P/1BQN1PP1/R3R1K1 w - - 5 18", "prompt": "FEN: 2rq1rk1/3nbpp1/p1n4p/1pP1p2b/1P1pP3/P2B1N1P/1BQN1PP1/R3R1K1 w - - 5 18\nList all capture moves available.", "gold_answer": "b2d4 d3b5 f3d4 f3e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01513", "split": "rules", "task_type": "special_rules", "fen": "r7/2q3pk/p1n2p1b/1p3P2/4Q3/2P5/PP3PP1/R6K w - - 1 28", "prompt": "Given FEN: r7/2q3pk/p1n2p1b/1p3P2/4Q3/2P5/PP3PP1/R6K w - - 1 28\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01514", "split": "rules", "task_type": "legality_check", "fen": "2r2rk1/3qbpp1/1pn1pn1p/1N1p4/5B2/PP2PB1P/5PP1/1QRR2K1 b - -", "prompt": "FEN: 2r2rk1/3qbpp1/1pn1pn1p/1N1p4/5B2/PP2PB1P/5PP1/1QRR2K1 b - -\nIs the move e6e5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "e6e5", "_legality_check_reason_label": "legal", "move": "e6e5", "legality_reason_label": "legal"}}
{"example_id": "rules_01515", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnbqkbnr/ppp3pp/4pp2/3p4/3PP3/2N2N2/PPP2PPP/R1BQKB1R b KQkq - 1 4", "prompt": "FEN: rnbqkbnr/ppp3pp/4pp2/3p4/3PP3/2N2N2/PPP2PPP/R1BQKB1R b KQkq - 1 4\nList pseudo-legal moves from d5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d5: d5e4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_01516", "split": "rules", "task_type": "piece_legal_filter", "fen": "5rk1/1p2bqpp/1P1p1p2/2pPpN2/4P3/3QB2P/5PP1/1R4K1 w - - 5 25", "prompt": "FEN: 5rk1/1p2bqpp/1P1p1p2/2pPpN2/4P3/3QB2P/5PP1/1R4K1 w - - 5 25\nFor the piece on b1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b1: b1a1 b1b2 b1b3 b1b4 b1b5 b1c1 b1d1 b1e1 b1f1.\nLegal: b1a1 b1b2 b1b3 b1b4 b1b5 b1c1 b1d1 b1e1 b1f1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01517", "split": "rules", "task_type": "king_safety_filter", "fen": "r3r1k1/p4ppp/2p1bn2/2ppN3/8/2PP2P1/PPB3P1/R3R1K1 b - - 4 20", "prompt": "FEN: r3r1k1/p4ppp/2p1bn2/2ppN3/8/2PP2P1/PPB3P1/R3R1K1 b - - 4 20\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01518", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2k5/3R4/2K5/2P5/8/8/2r5/8 w - -", "prompt": "FEN: 2k5/3R4/2K5/2P5/8/8/2r5/8 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c5 white pawn; c6 white king; d7 white rook.\nMoves by piece:\nc5 white pawn: no legal moves\nc6 white king: c6b5 c6b6 c6d5 c6d6\nd7 white rook: d7a7 d7b7 d7c7 d7d1 d7d2 d7d3 d7d4 d7d5 d7d6 d7d8 d7e7 d7f7 d7g7 d7h7\nAll legal moves: c6b5 c6b6 c6d5 c6d6 d7a7 d7b7 d7c7 d7d1 d7d2 d7d3 d7d4 d7d5 d7d6 d7d8 d7e7 d7f7 d7g7 d7h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": [], "c6": ["c6b5", "c6b6", "c6d5", "c6d6"], "d7": ["d7a7", "d7b7", "d7c7", "d7d1", "d7d2", "d7d3", "d7d4", "d7d5", "d7d6", "d7d8", "d7e7", "d7f7", "d7g7", "d7h7"]}, "_legal_moves_by_piece_moves": "c6b5 c6b6 c6d5 c6d6 d7a7 d7b7 d7c7 d7d1 d7d2 d7d3 d7d4 d7d5 d7d6 d7d8 d7e7 d7f7 d7g7 d7h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": [], "c6": ["c6b5", "c6b6", "c6d5", "c6d6"], "d7": ["d7a7", "d7b7", "d7c7", "d7d1", "d7d2", "d7d3", "d7d4", "d7d5", "d7d6", "d7d8", "d7e7", "d7f7", "d7g7", "d7h7"]}, "legal_moves": "c6b5 c6b6 c6d5 c6d6 d7a7 d7b7 d7c7 d7d1 d7d2 d7d3 d7d4 d7d5 d7d6 d7d8 d7e7 d7f7 d7g7 d7h7"}}
{"example_id": "rules_01519", "split": "rules", "task_type": "ray_walk", "fen": "3r3r/1pk2p1p/6p1/2Q5/1n1p1PqP/8/PPP1P3/2K2R1R b - - 0 23", "prompt": "FEN: 3r3r/1pk2p1p/6p1/2Q5/1n1p1PqP/8/PPP1P3/2K2R1R b - - 0 23\nWalk each ray for the slider on g4: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: g4 black queen.\nRay N: g5 empty; g6 black pawn: own piece (stop, excluded).\nRay NE: h5 empty; edge.\nRay E: h4 white pawn: capture (stop, included).\nRay SE: h3 empty; edge.\nRay S: g3 empty; g2 empty; g1 empty; edge.\nRay SW: f3 empty; e2 white pawn: capture (stop, included).\nRay W: f4 white pawn: capture (stop, included).\nRay NW: f5 empty; e6 empty; d7 empty; c8 empty; edge.\nMoves from rays: g4c8 g4d7 g4e2 g4e6 g4f3 g4f4 g4f5 g4g1 g4g2 g4g3 g4g5 g4h3 g4h4 g4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "g4", "diagnostic": true, "hard_gate": false, "source_square": "g4"}}
{"example_id": "rules_01520", "split": "rules", "task_type": "legal_moves", "fen": "r6r/1p1bkppp/p7/4B3/2B1P3/5N2/PPP1nPPP/2KR3R w - - 1 16", "prompt": "FEN: r6r/1p1bkppp/p7/4B3/2B1P3/5N2/PPP1nPPP/2KR3R w - - 1 16\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: c1b1 c1d2 c4e2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01521", "split": "rules", "task_type": "legal_moves", "fen": "4rk2/ppp3p1/2np3p/2b5/2B2Bnq/2N5/PP4PP/4RR1K w - -", "prompt": "FEN: 4rk2/ppp3p1/2np3p/2b5/2B2Bnq/2N5/PP4PP/4RR1K w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 b2b4 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f7 c4g8 e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1e8 f1f2 f1f3 f1g1 f4c1 f4d2 f4d6 f4e3 f4e5 f4g3 f4g5 f4h6 g2g3 h2h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01522", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/2k3Q1/1rpnq1n1/5p2/5P1p/4P2P/P4R2/5BK1 b - - 5 36", "prompt": "FEN: 8/2k3Q1/1rpnq1n1/5p2/5P1p/4P2P/P4R2/5BK1 b - - 5 36\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: h4 black pawn; f5 black pawn; b6 black rook; c6 black pawn; d6 black knight; e6 black queen; g6 black knight; c7 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "h4", "piece": "black pawn"}, {"square": "f5", "piece": "black pawn"}, {"square": "b6", "piece": "black rook"}, {"square": "c6", "piece": "black pawn"}, {"square": "d6", "piece": "black knight"}, {"square": "e6", "piece": "black queen"}, {"square": "g6", "piece": "black knight"}, {"square": "c7", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "h4", "piece": "black pawn"}, {"square": "f5", "piece": "black pawn"}, {"square": "b6", "piece": "black rook"}, {"square": "c6", "piece": "black pawn"}, {"square": "d6", "piece": "black knight"}, {"square": "e6", "piece": "black queen"}, {"square": "g6", "piece": "black knight"}, {"square": "c7", "piece": "black king"}]}}
{"example_id": "rules_01523", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/2R5/5q2/3k4/8/1P6/K7/2b5 w - - 4 56", "prompt": "FEN: 8/2R5/5q2/3k4/8/1P6/K7/2b5 w - - 4 56\nWhat legal moves does the piece on b3 have?", "gold_answer": "b3b4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b3", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "b3", "piece": "pawn"}}
{"example_id": "rules_01524", "split": "rules", "task_type": "check_detection", "fen": "8/2k3p1/2p1n3/2P2K2/2r5/8/8/8 b - - 1 49", "prompt": "FEN: 8/2k3p1/2p1n3/2P2K2/2r5/8/8/8 b - - 1 49\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01525", "split": "rules", "task_type": "captures", "fen": "8/8/1k6/4BN2/4K3/8/8/8 w - -", "prompt": "FEN: 8/8/1k6/4BN2/4K3/8/8/8 w - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01526", "split": "rules", "task_type": "special_rules", "fen": "r3k2r/1p1nbppp/p3pn2/P1pp3b/Nq1P1B2/2PBPN1P/5PP1/R2QR1K1 b kq -", "prompt": "Given FEN: r3k2r/1p1nbppp/p3pn2/P1pp3b/Nq1P1B2/2PBPN1P/5PP1/R2QR1K1 b kq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside, queenside.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01527", "split": "rules", "task_type": "legality_check", "fen": "2kr3r/1ppq1pb1/p2p1n1p/3P4/1P1pP2P/P2P1QP1/6B1/R1B2RK1 b - - 0 17", "prompt": "FEN: 2kr3r/1ppq1pb1/p2p1n1p/3P4/1P1pP2P/P2P1QP1/6B1/R1B2RK1 b - - 0 17\nIs the move c7c6 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c7c6", "_legality_check_reason_label": "legal", "move": "c7c6", "legality_reason_label": "legal"}}
{"example_id": "rules_01528", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/1p6/pn3p2/3p1Pp1/1P1Pb1P1/P3BB2/2k2K2/8 w - -", "prompt": "FEN: 8/1p6/pn3p2/3p1Pp1/1P1Pb1P1/P3BB2/2k2K2/8 w - -\nList pseudo-legal moves from f2.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from f2: f2e1 f2e2 f2f1 f2g1 f2g2 f2g3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "f2", "diagnostic": true, "hard_gate": false, "source_square": "f2"}}
{"example_id": "rules_01529", "split": "rules", "task_type": "piece_legal_filter", "fen": "r7/1p3k2/p3b1p1/P4p2/1P1qp3/R2p4/4R2P/2Q4K b - - 0 38", "prompt": "FEN: r7/1p3k2/p3b1p1/P4p2/1P1qp3/R2p4/4R2P/2Q4K b - - 0 38\nFor the piece on d3, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d3: d3d2 d3e2.\nLegal: d3d2 d3e2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "d3", "diagnostic": true, "hard_gate": false, "source_square": "d3"}}
{"example_id": "rules_01530", "split": "rules", "task_type": "king_safety_filter", "fen": "8/2kP1R2/8/6P1/8/3r3p/6K1/8 w - - 0 44", "prompt": "FEN: 8/2kP1R2/8/6P1/8/3r3p/6K1/8 w - - 0 44\nFor move d7d8b, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: d7d8b.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "d7d8b", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "d7d8b", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_01531", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1b1k1nr/p1ppqppp/2p5/2b5/4P3/2N2Q2/PPP2PPP/R1B1KB1R b KQkq -", "prompt": "FEN: r1b1k1nr/p1ppqppp/2p5/2b5/4P3/2N2Q2/PPP2PPP/R1B1KB1R b KQkq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black bishop; c6 black pawn; a7 black pawn; c7 black pawn; d7 black pawn; e7 black queen; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; e8 black king; g8 black knight; h8 black rook.\nMoves by piece:\nc5 black bishop: c5a3 c5b4 c5b6 c5d4 c5d6 c5e3 c5f2\nc6 black pawn: no legal moves\na7 black pawn: a7a5 a7a6\nc7 black pawn: no legal moves\nd7 black pawn: d7d5 d7d6\ne7 black queen: e7d6 e7d8 e7e4 e7e5 e7e6 e7f6 e7f8 e7g5 e7h4\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8\nc8 black bishop: c8a6 c8b7\ne8 black king: e8d8 e8f8\ng8 black knight: g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a7a5 a7a6 a8b8 c5a3 c5b4 c5b6 c5d4 c5d6 c5e3 c5f2 c8a6 c8b7 d7d5 d7d6 e7d6 e7d8 e7e4 e7e5 e7e6 e7f6 e7f8 e7g5 e7h4 e8d8 e8f8 f7f5 f7f6 g7g5 g7g6 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": ["c5a3", "c5b4", "c5b6", "c5d4", "c5d6", "c5e3", "c5f2"], "c6": [], "a7": ["a7a5", "a7a6"], "c7": [], "d7": ["d7d5", "d7d6"], "e7": ["e7d6", "e7d8", "e7e4", "e7e5", "e7e6", "e7f6", "e7f8", "e7g5", "e7h4"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8a6", "c8b7"], "e8": ["e8d8", "e8f8"], "g8": ["g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 c5a3 c5b4 c5b6 c5d4 c5d6 c5e3 c5f2 c8a6 c8b7 d7d5 d7d6 e7d6 e7d8 e7e4 e7e5 e7e6 e7f6 e7f8 e7g5 e7h4 e8d8 e8f8 f7f5 f7f6 g7g5 g7g6 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": ["c5a3", "c5b4", "c5b6", "c5d4", "c5d6", "c5e3", "c5f2"], "c6": [], "a7": ["a7a5", "a7a6"], "c7": [], "d7": ["d7d5", "d7d6"], "e7": ["e7d6", "e7d8", "e7e4", "e7e5", "e7e6", "e7f6", "e7f8", "e7g5", "e7h4"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8a6", "c8b7"], "e8": ["e8d8", "e8f8"], "g8": ["g8f6", "g8h6"], "h8": []}, "legal_moves": "a7a5 a7a6 a8b8 c5a3 c5b4 c5b6 c5d4 c5d6 c5e3 c5f2 c8a6 c8b7 d7d5 d7d6 e7d6 e7d8 e7e4 e7e5 e7e6 e7f6 e7f8 e7g5 e7h4 e8d8 e8f8 f7f5 f7f6 g7g5 g7g6 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_01532", "split": "rules", "task_type": "ray_walk", "fen": "r1b1kb1r/1pqn1ppp/p1n1p3/3pP3/3N1PQ1/P1N1B3/1PP3PP/R3KB1R b KQkq -", "prompt": "FEN: r1b1kb1r/1pqn1ppp/p1n1p3/3pP3/3N1PQ1/P1N1B3/1PP3PP/R3KB1R b KQkq -\nWalk each ray for the slider on c7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c7 black queen.\nRay N: c8 black bishop: own piece (stop, excluded).\nRay NE: d8 empty; edge.\nRay E: d7 black knight: own piece (stop, excluded).\nRay SE: d6 empty; e5 white pawn: capture (stop, included).\nRay S: c6 black knight: own piece (stop, excluded).\nRay SW: b6 empty; a5 empty; edge.\nRay W: b7 black pawn: own piece (stop, excluded).\nRay NW: b8 empty; edge.\nMoves from rays: c7a5 c7b6 c7b8 c7d6 c7d8 c7e5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "c7", "diagnostic": true, "hard_gate": false, "source_square": "c7"}}
{"example_id": "rules_01533", "split": "rules", "task_type": "legal_moves", "fen": "8/p4k1p/8/1P2P1r1/1b3N2/P4b1K/1P6/3R4 b - -", "prompt": "FEN: 8/p4k1p/8/1P2P1r1/1b3N2/P4b1K/1P6/3R4 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7 b4f8 f3a8 f3b7 f3c6 f3d1 f3d5 f3e2 f3e4 f3g2 f3g4 f3h1 f3h5 f7e7 f7e8 f7f8 f7g7 f7g8 g5e5 g5f5 g5g1 g5g2 g5g3 g5g4 g5g6 g5g7 g5g8 g5h5 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01534", "split": "rules", "task_type": "legal_moves", "fen": "rnbq1rk1/pp1n1pbp/3p2p1/2pPP3/2P1P3/2N2N2/PP2B1PP/R1BQK2R b KQ - 0 9", "prompt": "FEN: rnbq1rk1/pp1n1pbp/3p2p1/2pPP3/2P1P3/2N2N2/PP2B1PP/R1BQK2R b KQ - 0 9\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 d6e5 d7b6 d7e5 d7f6 d8a5 d8b6 d8c7 d8e7 d8e8 d8f6 d8g5 d8h4 f7f5 f7f6 f8e8 g6g5 g7e5 g7f6 g7h6 g7h8 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01535", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2q3k/pppnbrp1/3p2bp/3Pp3/1PP5/P4N1P/1B2BPP1/R2QR1K1 b - - 3 23", "prompt": "FEN: r2q3k/pppnbrp1/3p2bp/3Pp3/1PP5/P4N1P/1B2BPP1/R2QR1K1 b - - 3 23\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: e5 black pawn; d6 black pawn; g6 black bishop; h6 black pawn; a7 black pawn; b7 black pawn; c7 black pawn; d7 black knight; e7 black bishop; f7 black rook; g7 black pawn; a8 black rook; d8 black queen; h8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "g6", "piece": "black bishop"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black rook"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "h8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "g6", "piece": "black bishop"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black rook"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "h8", "piece": "black king"}]}}
{"example_id": "rules_01536", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnbqk1nr/pBp1b1pp/3ppp2/8/8/3P2P1/PPP1PP1P/RNBQK1NR w KQkq - 0 5", "prompt": "FEN: rnbqk1nr/pBp1b1pp/3ppp2/8/8/3P2P1/PPP1PP1P/RNBQK1NR w KQkq - 0 5\nWhat legal moves does the piece on a2 have?", "gold_answer": "a2a3 a2a4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a2", "piece": "pawn"}}
{"example_id": "rules_01537", "split": "rules", "task_type": "check_detection", "fen": "3r1q2/2b1kp2/1RQ5/pK2N3/8/1P6/8/8 w - -", "prompt": "FEN: 3r1q2/2b1kp2/1RQ5/pK2N3/8/1P6/8/8 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01538", "split": "rules", "task_type": "captures", "fen": "8/p4pk1/1p3Q1p/2p3pP/3p2P1/3P4/PPPK1P2/8 b - - 0 30", "prompt": "FEN: 8/p4pk1/1p3Q1p/2p3pP/3p2P1/3P4/PPPK1P2/8 b - - 0 30\nList all capture moves available.", "gold_answer": "g7f6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01539", "split": "rules", "task_type": "special_rules", "fen": "rnb1k1nr/ppp2ppp/3p1q2/8/3PPp1b/5N2/PPPKQ1PP/RNB2B1R w kq - 0 7", "prompt": "Given FEN: rnb1k1nr/ppp2ppp/3p1q2/8/3PPp1b/5N2/PPPKQ1PP/RNB2B1R w kq - 0 7\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01540", "split": "rules", "task_type": "legality_check", "fen": "rn1qkbnr/pp2pppp/8/2p5/3pP1b1/2PP1N1P/PP3PP1/RNBQKB1R b KQkq - 0 5", "prompt": "FEN: rn1qkbnr/pp2pppp/8/2p5/3pP1b1/2PP1N1P/PP3PP1/RNBQKB1R b KQkq - 0 5\nIs the move e7f6 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "e7f6", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "e7f6", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_01541", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r4rk1/1pp1qp1n/3p4/p2b3Q/3pP1p1/P2P2P1/1PP2PBP/R4RK1 w - - 0 17", "prompt": "FEN: r4rk1/1pp1qp1n/3p4/p2b3Q/3pP1p1/P2P2P1/1PP2PBP/R4RK1 w - - 0 17\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1a2 a1b1 a1c1 a1d1 a1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01542", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2qk1nr/pp1bbppp/8/1B1p4/3p2Q1/8/PPPP1PPP/RNB1R1K1 b kq - 5 10", "prompt": "FEN: r2qk1nr/pp1bbppp/8/1B1p4/3p2Q1/8/PPPP1PPP/RNB1R1K1 b kq - 5 10\nFor the piece on d7, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d7: d7b5 d7c6 d7c8 d7e6 d7f5 d7g4.\nLegal: d7b5 d7c6.\nRejected: d7c8 pinned_piece_exposes_king; d7e6 pinned_piece_exposes_king; d7f5 pinned_piece_exposes_king; d7g4 pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "d7", "diagnostic": true, "hard_gate": false, "source_square": "d7"}}
{"example_id": "rules_01543", "split": "rules", "task_type": "king_safety_filter", "fen": "r2q1rk1/p3ppbp/1p1p1np1/1Pp2b2/2n1P3/P1NP1N2/1BQ2PPP/1R2KB1R b K -", "prompt": "FEN: r2q1rk1/p3ppbp/1p1p1np1/1Pp2b2/2n1P3/P1NP1N2/1BQ2PPP/1R2KB1R b K -\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01544", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/5b1k/5Q2/7K/8/8/8/8 w - -", "prompt": "FEN: 8/5b1k/5Q2/7K/8/8/8/8 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: h5 white king; f6 white queen.\nMoves by piece:\nh5 white king: h5g4 h5g5 h5h4\nf6 white queen: f6f7 f6g6\nAll legal moves: f6f7 f6g6 h5g4 h5g5 h5h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"h5": ["h5g4", "h5g5", "h5h4"], "f6": ["f6f7", "f6g6"]}, "_legal_moves_by_piece_moves": "f6f7 f6g6 h5g4 h5g5 h5h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"h5": ["h5g4", "h5g5", "h5h4"], "f6": ["f6f7", "f6g6"]}, "legal_moves": "f6f7 f6g6 h5g4 h5g5 h5h4"}}
{"example_id": "rules_01545", "split": "rules", "task_type": "ray_walk", "fen": "r1b1k2r/4qpbp/p2p4/1p2pP2/8/N1PB4/PP3PPP/R2QK2R b KQkq -", "prompt": "FEN: r1b1k2r/4qpbp/p2p4/1p2pP2/8/N1PB4/PP3PPP/R2QK2R b KQkq -\nWalk each ray for the slider on e7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e7 black queen.\nRay N: e8 black king: own piece (stop, excluded).\nRay NE: f8 empty; edge.\nRay E: f7 black pawn: own piece (stop, excluded).\nRay SE: f6 empty; g5 empty; h4 empty; edge.\nRay S: e6 empty; e5 black pawn: own piece (stop, excluded).\nRay SW: d6 black pawn: own piece (stop, excluded).\nRay W: d7 empty; c7 empty; b7 empty; a7 empty; edge.\nRay NW: d8 empty; edge.\nMoves from rays: e7a7 e7b7 e7c7 e7d7 e7d8 e7e6 e7f6 e7f8 e7g5 e7h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "e7", "diagnostic": true, "hard_gate": false, "source_square": "e7"}}
{"example_id": "rules_01546", "split": "rules", "task_type": "legal_moves", "fen": "3r3k/1q4pb/p3Qb1p/1p6/5BPP/3r4/PP5K/4RR2 w - - 1 30", "prompt": "FEN: 3r3k/1q4pb/p3Qb1p/1p6/5BPP/3r4/PP5K/4RR2 w - - 1 30\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 b2b4 e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e6a6 e6b3 e6b6 e6c4 e6c6 e6c8 e6d5 e6d6 e6d7 e6e2 e6e3 e6e4 e6e5 e6e7 e6e8 e6f5 e6f6 e6f7 e6g8 f1f2 f1f3 f1g1 f1h1 f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4g5 f4h6 g4g5 h2g1 h4h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01547", "split": "rules", "task_type": "legal_moves", "fen": "r2qkb1r/pp2nppp/3p4/1QpPp1B1/4n1b1/2P5/PP3PPP/RN2KBNR b KQkq - 1 9", "prompt": "FEN: r2qkb1r/pp2nppp/3p4/1QpPp1B1/4n1b1/2P5/PP3PPP/RN2KBNR b KQkq - 1 9\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: d8d7 e7c6 g4d7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01548", "split": "rules", "task_type": "side_piece_inventory", "fen": "3r1rk1/qb1pn1pp/p1n1p3/1pP1Pp2/1P6/P1N2N2/1Q1RBPPP/2R3K1 w - f6 0 20", "prompt": "FEN: 3r1rk1/qb1pn1pp/p1n1p3/1pP1Pp2/1P6/P1N2N2/1Q1RBPPP/2R3K1 w - f6 0 20\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: c1 white rook; g1 white king; b2 white queen; d2 white rook; e2 white bishop; f2 white pawn; g2 white pawn; h2 white pawn; a3 white pawn; c3 white knight; f3 white knight; b4 white pawn; c5 white pawn; e5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "c1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white queen"}, {"square": "d2", "piece": "white rook"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "f3", "piece": "white knight"}, {"square": "b4", "piece": "white pawn"}, {"square": "c5", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "c1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white queen"}, {"square": "d2", "piece": "white rook"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "f3", "piece": "white knight"}, {"square": "b4", "piece": "white pawn"}, {"square": "c5", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}]}}
{"example_id": "rules_01549", "split": "rules", "task_type": "piece_legal_moves", "fen": "3r1b1r/pp2k1pp/4p3/4q3/8/1P2P3/P1P1QPPP/3R1RK1 b - - 3 17", "prompt": "FEN: 3r1b1r/pp2k1pp/4p3/4q3/8/1P2P3/P1P1QPPP/3R1RK1 b - - 3 17\nWhat legal moves does the piece on e5 have?", "gold_answer": "e5a1 e5a5 e5b2 e5b5 e5b8 e5c3 e5c5 e5c7 e5d4 e5d5 e5d6 e5e3 e5e4 e5f4 e5f5 e5f6 e5g3 e5g5 e5h2 e5h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "e5", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "e5", "piece": "queen"}}
{"example_id": "rules_01550", "split": "rules", "task_type": "check_detection", "fen": "r3kb1r/ppp1qppp/2np2b1/8/4n1P1/5N1P/PPPPQPB1/RNB1K2R w KQkq - 1 10", "prompt": "FEN: r3kb1r/ppp1qppp/2np2b1/8/4n1P1/5N1P/PPPPQPB1/RNB1K2R w KQkq - 1 10\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01551", "split": "rules", "task_type": "captures", "fen": "2r3k1/pp3p1p/2n1r1p1/2p1pqB1/3p3Q/1P1P2P1/P1P2P2/R3R1K1 b - - 0 23", "prompt": "FEN: 2r3k1/pp3p1p/2n1r1p1/2p1pqB1/3p3Q/1P1P2P1/P1P2P2/R3R1K1 b - - 0 23\nList all capture moves available.", "gold_answer": "f5d3 f5f2 f5g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01552", "split": "rules", "task_type": "special_rules", "fen": "4b3/5N2/3p3P/ppkP1p2/2PR1P2/1P2K3/P7/8 w - - 1 38", "prompt": "Given FEN: 4b3/5N2/3p3P/ppkP1p2/2PR1P2/1P2K3/P7/8 w - - 1 38\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01553", "split": "rules", "task_type": "legality_check", "fen": "r2r2k1/1p3pp1/p5n1/2BP4/1P2P2b/P4pP1/8/RN1R1K2 b - - 3 29", "prompt": "FEN: r2r2k1/1p3pp1/p5n1/2BP4/1P2P2b/P4pP1/8/RN1R1K2 b - - 3 29\nIs the move g8f8 legal?", "gold_answer": "No, illegal. Reason: king would be in check.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g8f8", "_legality_check_reason_label": "king_would_be_in_check", "move": "g8f8", "legality_reason_label": "king_would_be_in_check"}}
{"example_id": "rules_01554", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1b1k2r/pp3pbp/4p1p1/3q4/3n4/4BP2/PPPQB1PP/2KR3R b kq - 1 12", "prompt": "FEN: r1b1k2r/pp3pbp/4p1p1/3q4/3n4/4BP2/PPPQB1PP/2KR3R b kq - 1 12\nList pseudo-legal moves from d4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d4: d4b3 d4b5 d4c2 d4c6 d4e2 d4f3 d4f5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_01555", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnbqk2r/pp2npbp/2p3p1/4p3/4P3/2NB1P2/PPP1N1PP/R1BQK2R w KQkq - 2 8", "prompt": "FEN: rnbqk2r/pp2npbp/2p3p1/4p3/4P3/2NB1P2/PPP1N1PP/R1BQK2R w KQkq - 2 8\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1.\nLegal: a1b1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01556", "split": "rules", "task_type": "king_safety_filter", "fen": "r4rk1/p4p1p/2q3p1/2b1p3/2n5/4B2Q/P4PPP/RNR3K1 w - - 2 23", "prompt": "FEN: r4rk1/p4p1p/2q3p1/2b1p3/2n5/4B2Q/P4PPP/RNR3K1 w - - 2 23\nFor move a2a3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a2a3.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a2a3", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a2a3", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01557", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "4rrk1/6Rp/4p1p1/3p3n/2pQ1qP1/7P/1P3PB1/4R1K1 b - -", "prompt": "FEN: 4rrk1/6Rp/4p1p1/3p3n/2pQ1qP1/7P/1P3PB1/4R1K1 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c4 black pawn; f4 black queen; d5 black pawn; h5 black knight; e6 black pawn; g6 black pawn; h7 black pawn; e8 black rook; f8 black rook; g8 black king.\nMoves by piece:\nc4 black pawn: no legal moves\nf4 black queen: no legal moves\nd5 black pawn: no legal moves\nh5 black knight: h5g7\ne6 black pawn: no legal moves\ng6 black pawn: no legal moves\nh7 black pawn: no legal moves\ne8 black rook: no legal moves\nf8 black rook: no legal moves\ng8 black king: g8h8\nAll legal moves: g8h8 h5g7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c4": [], "f4": [], "d5": [], "h5": ["h5g7"], "e6": [], "g6": [], "h7": [], "e8": [], "f8": [], "g8": ["g8h8"]}, "_legal_moves_by_piece_moves": "g8h8 h5g7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c4": [], "f4": [], "d5": [], "h5": ["h5g7"], "e6": [], "g6": [], "h7": [], "e8": [], "f8": [], "g8": ["g8h8"]}, "legal_moves": "g8h8 h5g7"}}
{"example_id": "rules_01558", "split": "rules", "task_type": "ray_walk", "fen": "r3nrk1/pp1q1pb1/2ppb1pp/8/4P3/2PPB1NP/PP1N1QP1/R4RK1 w - - 0 17", "prompt": "FEN: r3nrk1/pp1q1pb1/2ppb1pp/8/4P3/2PPB1NP/PP1N1QP1/R4RK1 w - - 0 17\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 empty; e1 empty; f1 white rook: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1 a1d1 a1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01559", "split": "rules", "task_type": "legal_filter_trace", "fen": "1N6/8/3K4/5B2/8/8/8/1k6 b - -", "prompt": "FEN: 1N6/8/3K4/5B2/8/8/8/1k6 b - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b1 black king.\nFilter by piece:\nb1 black king: pseudo-legal b1a1 b1a2 b1b2 b1c1 b1c2 | rejected b1c2 does_not_resolve_check | legal b1a1 b1a2 b1b2 b1c1\nAll legal moves: b1a1 b1a2 b1b2 b1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01560", "split": "rules", "task_type": "legal_moves", "fen": "3q4/p4pk1/2p2NpR/2P3P1/1P6/P7/1RK2P2/8 b - -", "prompt": "FEN: 3q4/p4pk1/2p2NpR/2P3P1/1P6/P7/1RK2P2/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 d8a5 d8a8 d8b6 d8b8 d8c7 d8c8 d8d1 d8d2 d8d3 d8d4 d8d5 d8d6 d8d7 d8e7 d8e8 d8f6 d8f8 d8g8 d8h8 g7f8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01561", "split": "rules", "task_type": "side_piece_inventory", "fen": "rnbqk1nr/pp1p1pbp/2p1p1p1/8/8/3PP3/PPPBBPPP/RN1QK1NR w KQkq - 0 5", "prompt": "FEN: rnbqk1nr/pp1p1pbp/2p1p1p1/8/8/3PP3/PPPBBPPP/RN1QK1NR w KQkq - 0 5\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; d1 white queen; e1 white king; g1 white knight; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; d2 white bishop; e2 white bishop; f2 white pawn; g2 white pawn; h2 white pawn; d3 white pawn; e3 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}]}}
{"example_id": "rules_01562", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bqkb1r/pp3ppp/2nppn2/1B6/3NPB2/2N5/PPP2PPP/R2QK2R b KQkq -", "prompt": "FEN: r1bqkb1r/pp3ppp/2nppn2/1B6/3NPB2/2N5/PPP2PPP/R2QK2R b KQkq -\nWhat legal moves does the piece on g7 have?", "gold_answer": "g7g5 g7g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "g7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g7", "piece": "pawn"}}
{"example_id": "rules_01563", "split": "rules", "task_type": "check_detection", "fen": "8/4k3/8/4N3/8/3QK3/8/8 w - -", "prompt": "FEN: 8/4k3/8/4N3/8/3QK3/8/8 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01564", "split": "rules", "task_type": "captures", "fen": "6k1/1p2q1pp/p1p1p3/1n6/1P2Pn2/P3QP2/1B3KPP/8 b - - 5 28", "prompt": "FEN: 6k1/1p2q1pp/p1p1p3/1n6/1P2Pn2/P3QP2/1B3KPP/8 b - - 5 28\nList all capture moves available.", "gold_answer": "b5a3 e7b4 f4g2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01565", "split": "rules", "task_type": "special_rules", "fen": "7k/2p3p1/6rp/8/4b3/P3b1BP/1P3R1P/R5K1 b - -", "prompt": "Given FEN: 7k/2p3p1/6rp/8/4b3/P3b1BP/1P3R1P/R5K1 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01566", "split": "rules", "task_type": "legality_check", "fen": "3rr1k1/pp4pp/6b1/2pN4/2PqNn2/1P1P1P2/P2K3P/R4Q2 w - - 8 28", "prompt": "FEN: 3rr1k1/pp4pp/6b1/2pN4/2PqNn2/1P1P1P2/P2K3P/R4Q2 w - - 8 28\nIs the move e8a2 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "e8a2", "_legality_check_reason_label": "wrong_side_piece", "move": "e8a2", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01567", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnbk1b1r/p3q1pp/8/1p1NNp2/3P4/1Q6/PP3PPP/2KR3R b - - 0 15", "prompt": "FEN: rnbk1b1r/p3q1pp/8/1p1NNp2/3P4/1Q6/PP3PPP/2KR3R b - - 0 15\nList pseudo-legal moves from b5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b5: b5b4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b5", "diagnostic": true, "hard_gate": false, "source_square": "b5"}}
{"example_id": "rules_01568", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/1p6/5k1p/1p1p2p1/1P1P1KPP/P7/8/8 w - -", "prompt": "FEN: 8/1p6/5k1p/1p1p2p1/1P1P1KPP/P7/8/8 w - -\nFor the piece on a3, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a3: a3a4.\nLegal: none.\nRejected: a3a4 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a3", "diagnostic": true, "hard_gate": false, "source_square": "a3"}}
{"example_id": "rules_01569", "split": "rules", "task_type": "king_safety_filter", "fen": "8/p5p1/4k2p/P2pP2P/4n1P1/2p1PK2/8/8 b - - 1 33", "prompt": "FEN: 8/p5p1/4k2p/P2pP2P/4n1P1/2p1PK2/8/8 b - - 1 33\nFor move e6d6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e6d6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e6d6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e6d6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01570", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "6b1/k1p3p1/8/P1p1P1N1/5P2/2KB4/6PP/8 b - - 0 39", "prompt": "FEN: 6b1/k1p3p1/8/P1p1P1N1/5P2/2KB4/6PP/8 b - - 0 39\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black pawn; a7 black king; c7 black pawn; g7 black pawn; g8 black bishop.\nMoves by piece:\nc5 black pawn: c5c4\na7 black king: a7a8 a7b7 a7b8\nc7 black pawn: c7c6\ng7 black pawn: g7g6\ng8 black bishop: g8a2 g8b3 g8c4 g8d5 g8e6 g8f7 g8h7\nAll legal moves: a7a8 a7b7 a7b8 c5c4 c7c6 g7g6 g8a2 g8b3 g8c4 g8d5 g8e6 g8f7 g8h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": ["c5c4"], "a7": ["a7a8", "a7b7", "a7b8"], "c7": ["c7c6"], "g7": ["g7g6"], "g8": ["g8a2", "g8b3", "g8c4", "g8d5", "g8e6", "g8f7", "g8h7"]}, "_legal_moves_by_piece_moves": "a7a8 a7b7 a7b8 c5c4 c7c6 g7g6 g8a2 g8b3 g8c4 g8d5 g8e6 g8f7 g8h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": ["c5c4"], "a7": ["a7a8", "a7b7", "a7b8"], "c7": ["c7c6"], "g7": ["g7g6"], "g8": ["g8a2", "g8b3", "g8c4", "g8d5", "g8e6", "g8f7", "g8h7"]}, "legal_moves": "a7a8 a7b7 a7b8 c5c4 c7c6 g7g6 g8a2 g8b3 g8c4 g8d5 g8e6 g8f7 g8h7"}}
{"example_id": "rules_01571", "split": "rules", "task_type": "ray_walk", "fen": "6n1/1p1b1kp1/p2Bnp2/8/2P1q1P1/PK6/1P3P2/2r5 b - - 3 31", "prompt": "FEN: 6n1/1p1b1kp1/p2Bnp2/8/2P1q1P1/PK6/1P3P2/2r5 b - - 3 31\nWalk each ray for the slider on c1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c1 black rook.\nRay N: c2 empty; c3 empty; c4 white pawn: capture (stop, included).\nRay E: d1 empty; e1 empty; f1 empty; g1 empty; h1 empty; edge.\nRay S: edge.\nRay W: b1 empty; a1 empty; edge.\nMoves from rays: c1a1 c1b1 c1c2 c1c3 c1c4 c1d1 c1e1 c1f1 c1g1 c1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_01572", "split": "rules", "task_type": "legal_filter_trace", "fen": "4b3/8/8/R3K1k1/8/8/8/8 w - - 23 78", "prompt": "FEN: 4b3/8/8/R3K1k1/8/8/8/8 w - - 23 78\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a5 white rook; e5 white king.\nFilter by piece:\na5 white rook: pseudo-legal a5a1 a5a2 a5a3 a5a4 a5a6 a5a7 a5a8 a5b5 a5c5 a5d5 | rejected none | legal a5a1 a5a2 a5a3 a5a4 a5a6 a5a7 a5a8 a5b5 a5c5 a5d5\ne5 white king: pseudo-legal e5d4 e5d5 e5d6 e5e4 e5e6 e5f4 e5f5 e5f6 | rejected e5f4 king_would_be_in_check; e5f5 king_would_be_in_check; e5f6 king_would_be_in_check | legal e5d4 e5d5 e5d6 e5e4 e5e6\nAll legal moves: a5a1 a5a2 a5a3 a5a4 a5a6 a5a7 a5a8 a5b5 a5c5 a5d5 e5d4 e5d5 e5d6 e5e4 e5e6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01573", "split": "rules", "task_type": "legal_moves", "fen": "r1bq1rk1/3n1ppp/p1pbpn2/1p6/3P4/2NBPN2/PPQ2PPP/R1B1R1K1 b - - 3 11", "prompt": "FEN: r1bq1rk1/3n1ppp/p1pbpn2/1p6/3P4/2NBPN2/PPQ2PPP/R1B1R1K1 b - - 3 11\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 a8b8 b5b4 c6c5 c8b7 d6a3 d6b4 d6b8 d6c5 d6c7 d6e5 d6e7 d6f4 d6g3 d6h2 d7b6 d7b8 d7c5 d7e5 d8a5 d8b6 d8c7 d8e7 d8e8 e6e5 f6d5 f6e4 f6e8 f6g4 f6h5 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01574", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/8/8/5B2/8/4N3/5K1k/8 w - -", "prompt": "FEN: 8/8/8/5B2/8/4N3/5K1k/8 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: f2 white king; e3 white knight; f5 white bishop.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "f2", "piece": "white king"}, {"square": "e3", "piece": "white knight"}, {"square": "f5", "piece": "white bishop"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "f2", "piece": "white king"}, {"square": "e3", "piece": "white knight"}, {"square": "f5", "piece": "white bishop"}]}}
{"example_id": "rules_01575", "split": "rules", "task_type": "piece_legal_moves", "fen": "3r2k1/R3Qpp1/7p/8/5K2/8/1P3rPP/3n4 w - -", "prompt": "FEN: 3r2k1/R3Qpp1/7p/8/5K2/8/1P3rPP/3n4 w - -\nWhat legal moves does the piece on g2 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "g2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g2", "piece": "pawn"}}
{"example_id": "rules_01576", "split": "rules", "task_type": "check_detection", "fen": "r1b1kb1r/pp2pppp/2n5/3q4/8/5N2/PP1P1PPP/R1BQKB1R w KQkq -", "prompt": "FEN: r1b1kb1r/pp2pppp/2n5/3q4/8/5N2/PP1P1PPP/R1BQKB1R w KQkq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01577", "split": "rules", "task_type": "captures", "fen": "4k3/1bR1Npbp/p5p1/1p6/1B6/1P2PP1P/4r1P1/6K1 b - - 1 30", "prompt": "FEN: 4k3/1bR1Npbp/p5p1/1p6/1B6/1P2PP1P/4r1P1/6K1 b - - 1 30\nList all capture moves available.", "gold_answer": "b7f3 e2e3 e2g2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01578", "split": "rules", "task_type": "special_rules", "fen": "8/8/8/R7/3k4/8/8/6K1 w - -", "prompt": "Given FEN: 8/8/8/R7/3k4/8/8/6K1 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01579", "split": "rules", "task_type": "legality_check", "fen": "3R4/8/8/1r6/8/K1k5/3p4/8 w - -", "prompt": "FEN: 3R4/8/8/1r6/8/K1k5/3p4/8 w - -\nIs the move d8h5 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "d8h5", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "d8h5", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_01580", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnq1nk2/1p1b2bN/p5p1/8/8/8/PP1PQPPP/R1B2RK1 b - -", "prompt": "FEN: rnq1nk2/1p1b2bN/p5p1/8/8/8/PP1PQPPP/R1B2RK1 b - -\nList pseudo-legal moves from a6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a6: a6a5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a6", "diagnostic": true, "hard_gate": false, "source_square": "a6"}}
{"example_id": "rules_01581", "split": "rules", "task_type": "piece_legal_filter", "fen": "2kr1bnr/ppp1pppp/q7/3P3b/1nN5/1QN5/PP1BPPPP/R3KB1R b KQ - 8 10", "prompt": "FEN: 2kr1bnr/ppp1pppp/q7/3P3b/1nN5/1QN5/PP1BPPPP/R3KB1R b KQ - 8 10\nFor the piece on b4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b4: b4a2 b4c2 b4c6 b4d3 b4d5.\nLegal: b4a2 b4c2 b4c6 b4d3 b4d5.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_01582", "split": "rules", "task_type": "king_safety_filter", "fen": "rn1qk2r/ppb1nppp/2p1p3/3pPb2/1P1P4/P1N2N2/2PB1PPP/R2QKB1R w KQkq -", "prompt": "FEN: rn1qk2r/ppb1nppp/2p1p3/3pPb2/1P1P4/P1N2N2/2PB1PPP/R2QKB1R w KQkq -\nFor move a1a2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1a2.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a1a2", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1a2", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01583", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rn2kbnr/pp1bq2p/2p1pp2/3p4/3P3P/2P5/PP2PPB1/RNBQK1NR w KQkq - 0 9", "prompt": "FEN: rn2kbnr/pp1bq2p/2p1pp2/3p4/3P3P/2P5/PP2PPB1/RNBQK1NR w KQkq - 0 9\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; c1 white bishop; d1 white queen; e1 white king; g1 white knight; h1 white rook; a2 white pawn; b2 white pawn; e2 white pawn; f2 white pawn; g2 white bishop; c3 white pawn; d4 white pawn; h4 white pawn.\nMoves by piece:\na1 white rook: no legal moves\nb1 white knight: b1a3 b1d2\nc1 white bishop: c1d2 c1e3 c1f4 c1g5 c1h6\nd1 white queen: d1a4 d1b3 d1c2 d1d2 d1d3\ne1 white king: e1d2 e1f1\ng1 white knight: g1f3 g1h3\nh1 white rook: h1h2 h1h3\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\ne2 white pawn: e2e3 e2e4\nf2 white pawn: f2f3 f2f4\ng2 white bishop: g2d5 g2e4 g2f1 g2f3 g2h3\nc3 white pawn: c3c4\nd4 white pawn: no legal moves\nh4 white pawn: h4h5\nAll legal moves: a2a3 a2a4 b1a3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3c4 d1a4 d1b3 d1c2 d1d2 d1d3 e1d2 e1f1 e2e3 e2e4 f2f3 f2f4 g1f3 g1h3 g2d5 g2e4 g2f1 g2f3 g2h3 h1h2 h1h3 h4h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": [], "b1": ["b1a3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1a4", "d1b3", "d1c2", "d1d2", "d1d3"], "e1": ["e1d2", "e1f1"], "g1": ["g1f3", "g1h3"], "h1": ["h1h2", "h1h3"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "e2": ["e2e3", "e2e4"], "f2": ["f2f3", "f2f4"], "g2": ["g2d5", "g2e4", "g2f1", "g2f3", "g2h3"], "c3": ["c3c4"], "d4": [], "h4": ["h4h5"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b1a3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3c4 d1a4 d1b3 d1c2 d1d2 d1d3 e1d2 e1f1 e2e3 e2e4 f2f3 f2f4 g1f3 g1h3 g2d5 g2e4 g2f1 g2f3 g2h3 h1h2 h1h3 h4h5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": [], "b1": ["b1a3", "b1d2"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1a4", "d1b3", "d1c2", "d1d2", "d1d3"], "e1": ["e1d2", "e1f1"], "g1": ["g1f3", "g1h3"], "h1": ["h1h2", "h1h3"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "e2": ["e2e3", "e2e4"], "f2": ["f2f3", "f2f4"], "g2": ["g2d5", "g2e4", "g2f1", "g2f3", "g2h3"], "c3": ["c3c4"], "d4": [], "h4": ["h4h5"]}, "legal_moves": "a2a3 a2a4 b1a3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c3c4 d1a4 d1b3 d1c2 d1d2 d1d3 e1d2 e1f1 e2e3 e2e4 f2f3 f2f4 g1f3 g1h3 g2d5 g2e4 g2f1 g2f3 g2h3 h1h2 h1h3 h4h5"}}
{"example_id": "rules_01584", "split": "rules", "task_type": "ray_walk", "fen": "rnb2r2/pp2ppkp/5np1/q1P5/4N3/5N2/PPPQ1PPP/R3KB1R b KQ -", "prompt": "FEN: rnb2r2/pp2ppkp/5np1/q1P5/4N3/5N2/PPPQ1PPP/R3KB1R b KQ -\nWalk each ray for the slider on a5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a5 black queen.\nRay N: a6 empty; a7 black pawn: own piece (stop, excluded).\nRay NE: b6 empty; c7 empty; d8 empty; edge.\nRay E: b5 empty; c5 white pawn: capture (stop, included).\nRay SE: b4 empty; c3 empty; d2 white queen: capture (stop, included).\nRay S: a4 empty; a3 empty; a2 white pawn: capture (stop, included).\nRay SW: edge.\nRay W: edge.\nRay NW: edge.\nMoves from rays: a5a2 a5a3 a5a4 a5a6 a5b4 a5b5 a5b6 a5c3 a5c5 a5c7 a5d2 a5d8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_01585", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/2p3p1/1p1k3p/1p2RB2/1P1P1P2/5PK1/r5PP/8 b - - 5 36", "prompt": "FEN: 8/2p3p1/1p1k3p/1p2RB2/1P1P1P2/5PK1/r5PP/8 b - - 5 36\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a2 black rook; b5 black pawn; b6 black pawn; d6 black king; h6 black pawn; c7 black pawn; g7 black pawn.\nFilter by piece:\na2 black rook: pseudo-legal a2a1 a2a3 a2a4 a2a5 a2a6 a2a7 a2a8 a2b2 a2c2 a2d2 a2e2 a2f2 a2g2 | rejected none | legal a2a1 a2a3 a2a4 a2a5 a2a6 a2a7 a2a8 a2b2 a2c2 a2d2 a2e2 a2f2 a2g2\nb5 black pawn: pseudo-legal none | rejected none | legal none\nb6 black pawn: pseudo-legal none | rejected none | legal none\nd6 black king: pseudo-legal d6c5 d6c6 d6d5 d6d7 d6e5 d6e6 d6e7 | rejected d6c5 king_would_be_in_check; d6d5 king_would_be_in_check; d6d7 king_would_be_in_check; d6e5 king_would_be_in_check; d6e6 king_would_be_in_check; d6e7 king_would_be_in_check | legal d6c6\nh6 black pawn: pseudo-legal h6h5 | rejected none | legal h6h5\nc7 black pawn: pseudo-legal c7c5 c7c6 | rejected none | legal c7c5 c7c6\ng7 black pawn: pseudo-legal g7g5 g7g6 | rejected none | legal g7g5 g7g6\nAll legal moves: a2a1 a2a3 a2a4 a2a5 a2a6 a2a7 a2a8 a2b2 a2c2 a2d2 a2e2 a2f2 a2g2 c7c5 c7c6 d6c6 g7g5 g7g6 h6h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01586", "split": "rules", "task_type": "legal_moves", "fen": "r2qk2r/pp3ppp/2nbpn2/2pp4/3P1Bb1/2N1PN2/PPP1BPPP/R2Q1RK1 w kq -", "prompt": "FEN: r2qk2r/pp3ppp/2nbpn2/2pp4/3P1Bb1/2N1PN2/PPP1BPPP/R2Q1RK1 w kq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a2a3 a2a4 b2b3 b2b4 c3a4 c3b1 c3b5 c3d5 c3e4 d1b1 d1c1 d1d2 d1d3 d1e1 d4c5 e2a6 e2b5 e2c4 e2d3 e3e4 f1e1 f3d2 f3e1 f3e5 f3g5 f3h4 f4d6 f4e5 f4g3 f4g5 f4h6 g1h1 g2g3 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01587", "split": "rules", "task_type": "side_piece_inventory", "fen": "rnb1k1nr/ppp3pp/3p4/4ppq1/2P5/2PBPQ2/P2P1PPP/R1B1K1NR w KQkq -", "prompt": "FEN: rnb1k1nr/ppp3pp/3p4/4ppq1/2P5/2PBPQ2/P2P1PPP/R1B1K1NR w KQkq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; e1 white king; g1 white knight; h1 white rook; a2 white pawn; d2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white pawn; d3 white bishop; e3 white pawn; f3 white queen; c4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "e1", "piece": "white king"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "d2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white queen"}, {"square": "c4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "e1", "piece": "white king"}, {"square": "g1", "piece": "white knight"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "d2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "d3", "piece": "white bishop"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white queen"}, {"square": "c4", "piece": "white pawn"}]}}
{"example_id": "rules_01588", "split": "rules", "task_type": "piece_legal_moves", "fen": "5B2/2R3pk/4p2p/5p2/1P1Pp2P/2P1PnP1/5PK1/r7 b - -", "prompt": "FEN: 5B2/2R3pk/4p2p/5p2/1P1Pp2P/2P1PnP1/5PK1/r7 b - -\nWhat legal moves does the piece on f3 have?", "gold_answer": "f3d2 f3d4 f3e1 f3e5 f3g1 f3g5 f3h2 f3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f3", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "f3", "piece": "knight"}}
{"example_id": "rules_01589", "split": "rules", "task_type": "check_detection", "fen": "r2q1rk1/1b2b1p1/2p1p2p/p1ppPn2/P1P5/1PNP3N/6PP/R1BQ1R1K b - - 0 16", "prompt": "FEN: r2q1rk1/1b2b1p1/2p1p2p/p1ppPn2/P1P5/1PNP3N/6PP/R1BQ1R1K b - - 0 16\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01590", "split": "rules", "task_type": "captures", "fen": "r2qk2r/ppb2ppp/2p1pn2/8/3P4/2P2Q1P/PPBB1PP1/R4RK1 b kq - 2 14", "prompt": "FEN: r2qk2r/ppb2ppp/2p1pn2/8/3P4/2P2Q1P/PPBB1PP1/R4RK1 b kq - 2 14\nList all capture moves available.", "gold_answer": "d8d4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01591", "split": "rules", "task_type": "special_rules", "fen": "8/8/5k2/1Br1p1p1/P2b2P1/K7/8/4q3 b - - 2 56", "prompt": "Given FEN: 8/8/5k2/1Br1p1p1/P2b2P1/K7/8/4q3 b - - 2 56\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01592", "split": "rules", "task_type": "legality_check", "fen": "2r1kr2/2NRb3/2p1P3/p3Rp1p/2P3p1/1P6/P4PP1/6K1 b - - 3 30", "prompt": "FEN: 2r1kr2/2NRb3/2p1P3/p3Rp1p/2P3p1/1P6/P4PP1/6K1 b - - 3 30\nIs the move c8c7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c8c7", "_legality_check_reason_label": "legal", "move": "c8c7", "legality_reason_label": "legal"}}
{"example_id": "rules_01593", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnbqk2r/ppppnpbp/4p1p1/8/2B1PN2/5Q2/PPPP1PPP/RNB1K2R b KQkq - 3 5", "prompt": "FEN: rnbqk2r/ppppnpbp/4p1p1/8/2B1PN2/5Q2/PPPP1PPP/RNB1K2R b KQkq - 3 5\nList pseudo-legal moves from e6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e6: e6e5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e6", "diagnostic": true, "hard_gate": false, "source_square": "e6"}}
{"example_id": "rules_01594", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/1p2k2p/p5p1/2pRp3/P3P1K1/1P5P/2r5/4R3 b - - 2 34", "prompt": "FEN: 8/1p2k2p/p5p1/2pRp3/P3P1K1/1P5P/2r5/4R3 b - - 2 34\nFor the piece on e7, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e7: e7d6 e7d7 e7d8 e7e6 e7e8 e7f6 e7f7 e7f8.\nLegal: e7e6 e7e8 e7f6 e7f7 e7f8.\nRejected: e7d6 king_would_be_in_check; e7d7 king_would_be_in_check; e7d8 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "e7", "diagnostic": true, "hard_gate": false, "source_square": "e7"}}
{"example_id": "rules_01595", "split": "rules", "task_type": "king_safety_filter", "fen": "8/6p1/2k5/2p1q3/2Qp3p/7P/3K2P1/2R5 b - - 3 45", "prompt": "FEN: 8/6p1/2k5/2p1q3/2Qp3p/7P/3K2P1/2R5 b - - 3 45\nFor move c6b5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c6b5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "c6b5", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "c6b5", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01596", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnbqkbnr/pp2pppp/2p5/3p4/8/1QP1P3/PP1P1PPP/RNB1KBNR b KQkq - 1 3", "prompt": "FEN: rnbqkbnr/pp2pppp/2p5/3p4/8/1QP1P3/PP1P1PPP/RNB1KBNR b KQkq - 1 3\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; c6 black pawn; a7 black pawn; b7 black pawn; e7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\nd5 black pawn: d5d4\nc6 black pawn: c6c5\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\ne7 black pawn: e7e5 e7e6\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: no legal moves\nb8 black knight: b8a6 b8d7\nc8 black bishop: c8d7 c8e6 c8f5 c8g4 c8h3\nd8 black queen: d8a5 d8b6 d8c7 d8d6 d8d7\ne8 black king: e8d7\nf8 black bishop: no legal moves\ng8 black knight: g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8d7 c6c5 c8d7 c8e6 c8f5 c8g4 c8h3 d5d4 d8a5 d8b6 d8c7 d8d6 d8d7 e7e5 e7e6 e8d7 f7f5 f7f6 g7g5 g7g6 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d5": ["d5d4"], "c6": ["c6c5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "e7": ["e7e5", "e7e6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8d7"], "c8": ["c8d7", "c8e6", "c8f5", "c8g4", "c8h3"], "d8": ["d8a5", "d8b6", "d8c7", "d8d6", "d8d7"], "e8": ["e8d7"], "f8": [], "g8": ["g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a7a5 a7a6 b7b5 b7b6 b8a6 b8d7 c6c5 c8d7 c8e6 c8f5 c8g4 c8h3 d5d4 d8a5 d8b6 d8c7 d8d6 d8d7 e7e5 e7e6 e8d7 f7f5 f7f6 g7g5 g7g6 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d5": ["d5d4"], "c6": ["c6c5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "e7": ["e7e5", "e7e6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": [], "b8": ["b8a6", "b8d7"], "c8": ["c8d7", "c8e6", "c8f5", "c8g4", "c8h3"], "d8": ["d8a5", "d8b6", "d8c7", "d8d6", "d8d7"], "e8": ["e8d7"], "f8": [], "g8": ["g8f6", "g8h6"], "h8": []}, "legal_moves": "a7a5 a7a6 b7b5 b7b6 b8a6 b8d7 c6c5 c8d7 c8e6 c8f5 c8g4 c8h3 d5d4 d8a5 d8b6 d8c7 d8d6 d8d7 e7e5 e7e6 e8d7 f7f5 f7f6 g7g5 g7g6 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_01597", "split": "rules", "task_type": "ray_walk", "fen": "5r2/8/6pk/1Q2p2p/1b3p2/1P5P/2P3PK/8 b - - 2 41", "prompt": "FEN: 5r2/8/6pk/1Q2p2p/1b3p2/1P5P/2P3PK/8 b - - 2 41\nWalk each ray for the slider on b4: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b4 black bishop.\nRay NE: c5 empty; d6 empty; e7 empty; f8 black rook: own piece (stop, excluded).\nRay SE: c3 empty; d2 empty; e1 empty; edge.\nRay SW: a3 empty; edge.\nRay NW: a5 empty; edge.\nMoves from rays: b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_01598", "split": "rules", "task_type": "legal_filter_trace", "fen": "3r3r/p3k1pp/2p1b1p1/1p6/1P2P3/1B6/P4PPP/RN3RK1 w - - 2 20", "prompt": "FEN: 3r3r/p3k1pp/2p1b1p1/1p6/1P2P3/1B6/P4PPP/RN3RK1 w - - 2 20\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; f1 white rook; g1 white king; a2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; b3 white bishop; b4 white pawn; e4 white pawn.\nFilter by piece:\na1 white rook: pseudo-legal none | rejected none | legal none\nb1 white knight: pseudo-legal b1a3 b1c3 b1d2 | rejected none | legal b1a3 b1c3 b1d2\nf1 white rook: pseudo-legal f1c1 f1d1 f1e1 | rejected none | legal f1c1 f1d1 f1e1\ng1 white king: pseudo-legal g1h1 | rejected none | legal g1h1\na2 white pawn: pseudo-legal a2a3 a2a4 | rejected none | legal a2a3 a2a4\nf2 white pawn: pseudo-legal f2f3 f2f4 | rejected none | legal f2f3 f2f4\ng2 white pawn: pseudo-legal g2g3 g2g4 | rejected none | legal g2g3 g2g4\nh2 white pawn: pseudo-legal h2h3 h2h4 | rejected none | legal h2h3 h2h4\nb3 white bishop: pseudo-legal b3a4 b3c2 b3c4 b3d1 b3d5 b3e6 | rejected none | legal b3a4 b3c2 b3c4 b3d1 b3d5 b3e6\nb4 white pawn: pseudo-legal none | rejected none | legal none\ne4 white pawn: pseudo-legal e4e5 | rejected none | legal e4e5\nAll legal moves: a2a3 a2a4 b1a3 b1c3 b1d2 b3a4 b3c2 b3c4 b3d1 b3d5 b3e6 e4e5 f1c1 f1d1 f1e1 f2f3 f2f4 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01599", "split": "rules", "task_type": "legal_moves", "fen": "r1b1k2r/ppppbppp/2n2q2/2n5/2B5/2Pp1N2/PPQ2PPP/RNB1R1K1 w kq -", "prompt": "FEN: r1b1k2r/ppppbppp/2n2q2/2n5/2B5/2Pp1N2/PPQ2PPP/RNB1R1K1 w kq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a3 b1d2 b2b3 b2b4 c1d2 c1e3 c1f4 c1g5 c1h6 c2a4 c2b3 c2d1 c2d2 c2d3 c2e2 c4a6 c4b3 c4b5 c4d3 c4d5 c4e6 c4f7 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1f1 f3d2 f3d4 f3e5 f3g5 f3h4 g1f1 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01600", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/8/5b2/8/8/5kp1/4p3/6K1 w - - 0 65", "prompt": "FEN: 8/8/5b2/8/8/5kp1/4p3/6K1 w - - 0 65\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: g1 white king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "g1", "piece": "white king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "g1", "piece": "white king"}]}}
{"example_id": "rules_01601", "split": "rules", "task_type": "piece_legal_moves", "fen": "r2qkb1r/ppp2p1p/2n1b1p1/3np1NQ/2BP4/8/PPP2PPP/RNB1K2R w KQkq -", "prompt": "FEN: r2qkb1r/ppp2p1p/2n1b1p1/3np1NQ/2BP4/8/PPP2PPP/RNB1K2R w KQkq -\nWhat legal moves does the piece on e1 have?", "gold_answer": "e1d1 e1d2 e1e2 e1f1 e1g1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "e1", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "e1", "piece": "king"}}
{"example_id": "rules_01602", "split": "rules", "task_type": "check_detection", "fen": "2B5/8/7p/p1p1kPp1/2P3P1/P1pKp3/7P/8 w - - 0 36", "prompt": "FEN: 2B5/8/7p/p1p1kPp1/2P3P1/P1pKp3/7P/8 w - - 0 36\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01603", "split": "rules", "task_type": "captures", "fen": "6k1/6p1/1p3p2/5Pp1/1N4P1/3pn2P/5K2/8 b - -", "prompt": "FEN: 6k1/6p1/1p3p2/5Pp1/1N4P1/3pn2P/5K2/8 b - -\nList all capture moves available.", "gold_answer": "e3f5 e3g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01604", "split": "rules", "task_type": "special_rules", "fen": "1k2rb2/pN6/2P4p/1r3p2/5P2/7P/6P1/2R1R1K1 b - - 0 36", "prompt": "Given FEN: 1k2rb2/pN6/2P4p/1r3p2/5P2/7P/6P1/2R1R1K1 b - - 0 36\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01605", "split": "rules", "task_type": "legality_check", "fen": "r1b2rk1/1pp1qpp1/7p/p1b1p3/3n4/P1BP1NP1/1P2PPBP/2RQ1RK1 w - -", "prompt": "FEN: r1b2rk1/1pp1qpp1/7p/p1b1p3/3n4/P1BP1NP1/1P2PPBP/2RQ1RK1 w - -\nIs the move f3e5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f3e5", "_legality_check_reason_label": "legal", "move": "f3e5", "legality_reason_label": "legal"}}
{"example_id": "rules_01606", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2bq1rk1/1p3ppp/3b1n2/1p6/8/2Q1PN2/4BPPP/B4RK1 w - - 0 19", "prompt": "FEN: 2bq1rk1/1p3ppp/3b1n2/1p6/8/2Q1PN2/4BPPP/B4RK1 w - - 0 19\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01607", "split": "rules", "task_type": "piece_legal_filter", "fen": "5r1k/p5p1/3R3p/2p2pn1/4r3/2P3PP/PP3P1K/8 b - - 0 27", "prompt": "FEN: 5r1k/p5p1/3R3p/2p2pn1/4r3/2P3PP/PP3P1K/8 b - - 0 27\nFor the piece on e4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e4: e4a4 e4b4 e4c4 e4d4 e4e1 e4e2 e4e3 e4e5 e4e6 e4e7 e4e8 e4f4 e4g4 e4h4.\nLegal: e4a4 e4b4 e4c4 e4d4 e4e1 e4e2 e4e3 e4e5 e4e6 e4e7 e4e8 e4f4 e4g4 e4h4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "e4", "diagnostic": true, "hard_gate": false, "source_square": "e4"}}
{"example_id": "rules_01608", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbqkbnr/pp3p1p/2ppp1p1/8/3PP3/2N2N2/PPP2PPP/R1BQKB1R w KQkq - 0 5", "prompt": "FEN: rnbqkbnr/pp3p1p/2ppp1p1/8/3PP3/2N2N2/PPP2PPP/R1BQKB1R w KQkq - 0 5\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01609", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2rq1rk1/6pp/3pbb2/1p6/3pN3/6P1/PP3PBP/R2Q1RK1 w - -", "prompt": "FEN: 2rq1rk1/6pp/3pbb2/1p6/3pN3/6P1/PP3PBP/R2Q1RK1 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white queen; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; f2 white pawn; g2 white bishop; h2 white pawn; g3 white pawn; e4 white knight.\nMoves by piece:\na1 white rook: a1b1 a1c1\nd1 white queen: d1a4 d1b1 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1e1 d1e2 d1f3 d1g4 d1h5\nf1 white rook: f1e1\ng1 white king: g1h1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nf2 white pawn: f2f3 f2f4\ng2 white bishop: g2f3 g2h1 g2h3\nh2 white pawn: h2h3 h2h4\ng3 white pawn: g3g4\ne4 white knight: e4c3 e4c5 e4d2 e4d6 e4f6 e4g5\nAll legal moves: a1b1 a1c1 a2a3 a2a4 b2b3 b2b4 d1a4 d1b1 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1e1 d1e2 d1f3 d1g4 d1h5 e4c3 e4c5 e4d2 e4d6 e4f6 e4g5 f1e1 f2f3 f2f4 g1h1 g2f3 g2h1 g2h3 g3g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1", "a1c1"], "d1": ["d1a4", "d1b1", "d1b3", "d1c1", "d1c2", "d1d2", "d1d3", "d1d4", "d1e1", "d1e2", "d1f3", "d1g4", "d1h5"], "f1": ["f1e1"], "g1": ["g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": ["f2f3", "f2f4"], "g2": ["g2f3", "g2h1", "g2h3"], "h2": ["h2h3", "h2h4"], "g3": ["g3g4"], "e4": ["e4c3", "e4c5", "e4d2", "e4d6", "e4f6", "e4g5"]}, "_legal_moves_by_piece_moves": "a1b1 a1c1 a2a3 a2a4 b2b3 b2b4 d1a4 d1b1 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1e1 d1e2 d1f3 d1g4 d1h5 e4c3 e4c5 e4d2 e4d6 e4f6 e4g5 f1e1 f2f3 f2f4 g1h1 g2f3 g2h1 g2h3 g3g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1", "a1c1"], "d1": ["d1a4", "d1b1", "d1b3", "d1c1", "d1c2", "d1d2", "d1d3", "d1d4", "d1e1", "d1e2", "d1f3", "d1g4", "d1h5"], "f1": ["f1e1"], "g1": ["g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": ["f2f3", "f2f4"], "g2": ["g2f3", "g2h1", "g2h3"], "h2": ["h2h3", "h2h4"], "g3": ["g3g4"], "e4": ["e4c3", "e4c5", "e4d2", "e4d6", "e4f6", "e4g5"]}, "legal_moves": "a1b1 a1c1 a2a3 a2a4 b2b3 b2b4 d1a4 d1b1 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1e1 d1e2 d1f3 d1g4 d1h5 e4c3 e4c5 e4d2 e4d6 e4f6 e4g5 f1e1 f2f3 f2f4 g1h1 g2f3 g2h1 g2h3 g3g4 h2h3 h2h4"}}
{"example_id": "rules_01610", "split": "rules", "task_type": "ray_walk", "fen": "8/1r3pp1/3n2k1/1N1p1p1p/1R5P/3K2P1/8/8 w - - 0 35", "prompt": "FEN: 8/1r3pp1/3n2k1/1N1p1p1p/1R5P/3K2P1/8/8 w - - 0 35\nWalk each ray for the slider on b4: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b4 white rook.\nRay N: b5 white knight: own piece (stop, excluded).\nRay E: c4 empty; d4 empty; e4 empty; f4 empty; g4 empty; h4 white pawn: own piece (stop, excluded).\nRay S: b3 empty; b2 empty; b1 empty; edge.\nRay W: a4 empty; edge.\nMoves from rays: b4a4 b4b1 b4b2 b4b3 b4c4 b4d4 b4e4 b4f4 b4g4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_01611", "split": "rules", "task_type": "legal_moves", "fen": "rnbqkb1r/pppppp1p/5np1/8/2PP4/6P1/PP2PP1P/RNBQKBNR b KQkq - 0 3", "prompt": "FEN: rnbqkb1r/pppppp1p/5np1/8/2PP4/6P1/PP2PP1P/RNBQKBNR b KQkq - 0 3\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 c7c5 c7c6 d7d5 d7d6 e7e5 e7e6 f6d5 f6e4 f6g4 f6g8 f6h5 f8g7 f8h6 g6g5 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_openings", "is_chess960": false}}
{"example_id": "rules_01612", "split": "rules", "task_type": "legal_moves", "fen": "2kr3r/1pq2p2/p1bpp3/4P1pp/8/2N2PQ1/PPP3PP/2KR3R b - -", "prompt": "FEN: 2kr3r/1pq2p2/p1bpp3/4P1pp/8/2N2PQ1/PPP3PP/2KR3R b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 b7b5 b7b6 c6a4 c6b5 c6d5 c6d7 c6e4 c6e8 c6f3 c7a5 c7b6 c7b8 c7d7 c7e7 c8b8 c8d7 d6d5 d6e5 d8d7 d8e8 d8f8 d8g8 f7f5 f7f6 g5g4 h5h4 h8e8 h8f8 h8g8 h8h6 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01613", "split": "rules", "task_type": "side_piece_inventory", "fen": "rnbq1rk1/ppp2ppp/1b2pn2/8/1PBPP3/P1N2N2/5PPP/R1BQK2R w KQ - 3 9", "prompt": "FEN: rnbq1rk1/ppp2ppp/1b2pn2/8/1PBPP3/P1N2N2/5PPP/R1BQK2R w KQ - 3 9\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; e1 white king; h1 white rook; f2 white pawn; g2 white pawn; h2 white pawn; a3 white pawn; c3 white knight; f3 white knight; b4 white pawn; c4 white bishop; d4 white pawn; e4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "f3", "piece": "white knight"}, {"square": "b4", "piece": "white pawn"}, {"square": "c4", "piece": "white bishop"}, {"square": "d4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "h1", "piece": "white rook"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "f3", "piece": "white knight"}, {"square": "b4", "piece": "white pawn"}, {"square": "c4", "piece": "white bishop"}, {"square": "d4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}]}}
{"example_id": "rules_01614", "split": "rules", "task_type": "piece_legal_moves", "fen": "r5kr/p4pp1/1pq4p/n7/3P4/Q4N2/PP3PPP/1KR1R3 b - - 1 20", "prompt": "FEN: r5kr/p4pp1/1pq4p/n7/3P4/Q4N2/PP3PPP/1KR1R3 b - - 1 20\nWhat legal moves does the piece on h6 have?", "gold_answer": "h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h6", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "h6", "piece": "pawn"}}
{"example_id": "rules_01615", "split": "rules", "task_type": "check_detection", "fen": "6k1/7r/8/p4PPP/3p4/8/1n1R4/6K1 b - -", "prompt": "FEN: 6k1/7r/8/p4PPP/3p4/8/1n1R4/6K1 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01616", "split": "rules", "task_type": "captures", "fen": "5K2/3k1P2/8/8/8/6rp/7R/8 w - -", "prompt": "FEN: 5K2/3k1P2/8/8/8/6rp/7R/8 w - -\nList all capture moves available.", "gold_answer": "h2h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01617", "split": "rules", "task_type": "special_rules", "fen": "r2r2k1/pbqn1ppp/1p2p3/3n4/4QP2/P1P3N1/1PB3PP/R1B2RK1 b - - 4 17", "prompt": "Given FEN: r2r2k1/pbqn1ppp/1p2p3/3n4/4QP2/P1P3N1/1PB3PP/R1B2RK1 b - - 4 17\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01618", "split": "rules", "task_type": "legality_check", "fen": "2k2r1r/p1p2pp1/1p2pn1p/3p4/3P4/2qB4/P1P2QPP/3NRRK1 b - - 1 22", "prompt": "FEN: 2k2r1r/p1p2pp1/1p2pn1p/3p4/3P4/2qB4/P1P2QPP/3NRRK1 b - - 1 22\nIs the move f2a1 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f2a1", "_legality_check_reason_label": "wrong_side_piece", "move": "f2a1", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01619", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2kr3r/1pp1q3/p2pBb2/4np1p/NPP3p1/P3P1P1/1B3P1P/R2QR1K1 b - - 0 20", "prompt": "FEN: 2kr3r/1pp1q3/p2pBb2/4np1p/NPP3p1/P3P1P1/1B3P1P/R2QR1K1 b - - 0 20\nList pseudo-legal moves from e5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e5: e5c4 e5c6 e5d3 e5d7 e5f3 e5f7 e5g6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e5", "diagnostic": true, "hard_gate": false, "source_square": "e5"}}
{"example_id": "rules_01620", "split": "rules", "task_type": "piece_legal_filter", "fen": "6R1/7R/5K2/4B3/4k3/8/1P6/8 w - - 1 48", "prompt": "FEN: 6R1/7R/5K2/4B3/4k3/8/1P6/8 w - - 1 48\nFor the piece on f6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f6: f6e6 f6e7 f6f5 f6f7 f6g5 f6g6 f6g7.\nLegal: f6e6 f6e7 f6f7 f6g5 f6g6 f6g7.\nRejected: f6f5 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "f6", "diagnostic": true, "hard_gate": false, "source_square": "f6"}}
{"example_id": "rules_01621", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbqk2r/ppp1p1bp/3p1np1/5pB1/2PP4/2N1PN2/PP3PPP/R2QKB1R b KQkq -", "prompt": "FEN: rnbqk2r/ppp1p1bp/3p1np1/5pB1/2PP4/2N1PN2/PP3PPP/R2QKB1R b KQkq -\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01622", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "1r4k1/5p1p/p5p1/5p2/3P1q2/2P1R3/2RK4/8 b - - 26 58", "prompt": "FEN: 1r4k1/5p1p/p5p1/5p2/3P1q2/2P1R3/2RK4/8 b - - 26 58\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: f4 black queen; f5 black pawn; a6 black pawn; g6 black pawn; f7 black pawn; h7 black pawn; b8 black rook; g8 black king.\nMoves by piece:\nf4 black queen: f4c7 f4d4 f4d6 f4e3 f4e4 f4e5 f4f1 f4f2 f4f3 f4g3 f4g4 f4g5 f4h2 f4h4 f4h6\nf5 black pawn: no legal moves\na6 black pawn: a6a5\ng6 black pawn: g6g5\nf7 black pawn: f7f6\nh7 black pawn: h7h5 h7h6\nb8 black rook: b8a8 b8b1 b8b2 b8b3 b8b4 b8b5 b8b6 b8b7 b8c8 b8d8 b8e8 b8f8\ng8 black king: g8f8 g8g7 g8h8\nAll legal moves: a6a5 b8a8 b8b1 b8b2 b8b3 b8b4 b8b5 b8b6 b8b7 b8c8 b8d8 b8e8 b8f8 f4c7 f4d4 f4d6 f4e3 f4e4 f4e5 f4f1 f4f2 f4f3 f4g3 f4g4 f4g5 f4h2 f4h4 f4h6 f7f6 g6g5 g8f8 g8g7 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"f4": ["f4c7", "f4d4", "f4d6", "f4e3", "f4e4", "f4e5", "f4f1", "f4f2", "f4f3", "f4g3", "f4g4", "f4g5", "f4h2", "f4h4", "f4h6"], "f5": [], "a6": ["a6a5"], "g6": ["g6g5"], "f7": ["f7f6"], "h7": ["h7h5", "h7h6"], "b8": ["b8a8", "b8b1", "b8b2", "b8b3", "b8b4", "b8b5", "b8b6", "b8b7", "b8c8", "b8d8", "b8e8", "b8f8"], "g8": ["g8f8", "g8g7", "g8h8"]}, "_legal_moves_by_piece_moves": "a6a5 b8a8 b8b1 b8b2 b8b3 b8b4 b8b5 b8b6 b8b7 b8c8 b8d8 b8e8 b8f8 f4c7 f4d4 f4d6 f4e3 f4e4 f4e5 f4f1 f4f2 f4f3 f4g3 f4g4 f4g5 f4h2 f4h4 f4h6 f7f6 g6g5 g8f8 g8g7 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"f4": ["f4c7", "f4d4", "f4d6", "f4e3", "f4e4", "f4e5", "f4f1", "f4f2", "f4f3", "f4g3", "f4g4", "f4g5", "f4h2", "f4h4", "f4h6"], "f5": [], "a6": ["a6a5"], "g6": ["g6g5"], "f7": ["f7f6"], "h7": ["h7h5", "h7h6"], "b8": ["b8a8", "b8b1", "b8b2", "b8b3", "b8b4", "b8b5", "b8b6", "b8b7", "b8c8", "b8d8", "b8e8", "b8f8"], "g8": ["g8f8", "g8g7", "g8h8"]}, "legal_moves": "a6a5 b8a8 b8b1 b8b2 b8b3 b8b4 b8b5 b8b6 b8b7 b8c8 b8d8 b8e8 b8f8 f4c7 f4d4 f4d6 f4e3 f4e4 f4e5 f4f1 f4f2 f4f3 f4g3 f4g4 f4g5 f4h2 f4h4 f4h6 f7f6 g6g5 g8f8 g8g7 g8h8 h7h5 h7h6"}}
{"example_id": "rules_01623", "split": "rules", "task_type": "ray_walk", "fen": "rr4k1/3n1ppp/pq6/1p1Pp3/1Bp1P3/2P2Q2/R4PPP/R5K1 b - - 6 22", "prompt": "FEN: rr4k1/3n1ppp/pq6/1p1Pp3/1Bp1P3/2P2Q2/R4PPP/R5K1 b - - 6 22\nWalk each ray for the slider on b6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b6 black queen.\nRay N: b7 empty; b8 black rook: own piece (stop, excluded).\nRay NE: c7 empty; d8 empty; edge.\nRay E: c6 empty; d6 empty; e6 empty; f6 empty; g6 empty; h6 empty; edge.\nRay SE: c5 empty; d4 empty; e3 empty; f2 white pawn: capture (stop, included).\nRay S: b5 black pawn: own piece (stop, excluded).\nRay SW: a5 empty; edge.\nRay W: a6 black pawn: own piece (stop, excluded).\nRay NW: a7 empty; edge.\nMoves from rays: b6a5 b6a7 b6b7 b6c5 b6c6 b6c7 b6d4 b6d6 b6d8 b6e3 b6e6 b6f2 b6f6 b6g6 b6h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "b6", "diagnostic": true, "hard_gate": false, "source_square": "b6"}}
{"example_id": "rules_01624", "split": "rules", "task_type": "legal_moves", "fen": "rn2r1k1/1p1q1ppp/p4n2/2pP4/P7/2N2QB1/1P3PPP/R4RK1 w - - 5 18", "prompt": "FEN: rn2r1k1/1p1q1ppp/p4n2/2pP4/P7/2N2QB1/1P3PPP/R4RK1 w - - 5 18\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 a1b1 a1c1 a1d1 a1e1 a4a5 b2b3 b2b4 c3a2 c3b1 c3b5 c3d1 c3e2 c3e4 d5d6 f1b1 f1c1 f1d1 f1e1 f3d1 f3d3 f3e2 f3e3 f3e4 f3f4 f3f5 f3f6 f3g4 f3h5 g1h1 g3b8 g3c7 g3d6 g3e5 g3f4 g3h4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01625", "split": "rules", "task_type": "legal_moves", "fen": "8/4r3/P7/2p1k1p1/2B3P1/1P2K3/8/8 w - -", "prompt": "FEN: 8/4r3/P7/2p1k1p1/2B3P1/1P2K3/8/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a6a7 b3b4 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 c4g8 e3d2 e3d3 e3e2 e3f2 e3f3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01626", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqr1k1/ppp2ppp/3p1b2/2nPp3/2B1P3/2N2N1P/PPP2PP1/R2Q1RK1 b - - 6 10", "prompt": "FEN: r1bqr1k1/ppp2ppp/3p1b2/2nPp3/2B1P3/2N2N1P/PPP2PP1/R2Q1RK1 b - - 6 10\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: c5 black knight; e5 black pawn; d6 black pawn; f6 black bishop; a7 black pawn; b7 black pawn; c7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "c5", "piece": "black knight"}, {"square": "e5", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "f6", "piece": "black bishop"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "c5", "piece": "black knight"}, {"square": "e5", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "f6", "piece": "black bishop"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01627", "split": "rules", "task_type": "piece_legal_moves", "fen": "3r2k1/5p2/8/2p2p2/8/P1P5/1K6/7q w - - 0 46", "prompt": "FEN: 3r2k1/5p2/8/2p2p2/8/P1P5/1K6/7q w - - 0 46\nWhat legal moves does the piece on c3 have?", "gold_answer": "c3c4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c3", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "c3", "piece": "pawn"}}
{"example_id": "rules_01628", "split": "rules", "task_type": "check_detection", "fen": "r3r1k1/1bqn1pbp/pp1R1np1/8/4P3/1PN2P2/PBP1Q1PP/2K2B1R w - - 1 15", "prompt": "FEN: r3r1k1/1bqn1pbp/pp1R1np1/8/4P3/1PN2P2/PBP1Q1PP/2K2B1R w - - 1 15\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01629", "split": "rules", "task_type": "captures", "fen": "6k1/5p1p/p7/3ppb2/1n6/NP6/1K2BPPP/8 w - - 2 25", "prompt": "FEN: 6k1/5p1p/p7/3ppb2/1n6/NP6/1K2BPPP/8 w - - 2 25\nList all capture moves available.", "gold_answer": "e2a6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01630", "split": "rules", "task_type": "special_rules", "fen": "r1b2k1r/pp3ppp/2n1pn2/2Pp4/P2Nq3/2PBB1Q1/2P2PPP/R3K2R b KQ - 9 14", "prompt": "Given FEN: r1b2k1r/pp3ppp/2n1pn2/2Pp4/P2Nq3/2PBB1Q1/2P2PPP/R3K2R b KQ - 9 14\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01631", "split": "rules", "task_type": "legality_check", "fen": "r4rk1/1p2qp1p/3pbnp1/p3p3/1nP2P2/1NBBP2P/PPQ3P1/1K1R3R w - - 1 16", "prompt": "FEN: r4rk1/1p2qp1p/3pbnp1/p3p3/1nP2P2/1NBBP2P/PPQ3P1/1K1R3R w - - 1 16\nIs the move h1h2 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "h1h2", "_legality_check_reason_label": "legal", "move": "h1h2", "legality_reason_label": "legal"}}
{"example_id": "rules_01632", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2k5/pp4pp/2p1N3/2K1P3/4P3/8/P2r3P/3n4 b - - 0 28", "prompt": "FEN: 2k5/pp4pp/2p1N3/2K1P3/4P3/8/P2r3P/3n4 b - - 0 28\nList pseudo-legal moves from d1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d1: d1b2 d1c3 d1e3 d1f2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_01633", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn1qk2r/pp3ppp/2pbpnb1/3p4/3P1B2/2PBPN2/PP1N1PPP/R2QK2R w KQkq -", "prompt": "FEN: rn1qk2r/pp3ppp/2pbpnb1/3p4/3P1B2/2PBPN2/PP1N1PPP/R2QK2R w KQkq -\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1 a1c1.\nLegal: a1b1 a1c1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01634", "split": "rules", "task_type": "king_safety_filter", "fen": "8/3k1ppp/8/1ppr1n2/6P1/5P1P/P3RK2/8 b - - 0 35", "prompt": "FEN: 8/3k1ppp/8/1ppr1n2/6P1/5P1P/P3RK2/8 b - - 0 35\nFor move d7e6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: d7e6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "d7e6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "d7e6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01635", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rn1qkb1r/pp1B1ppp/8/3pp3/3Nn3/8/PPP2PPP/RNBQ1RK1 b kq - 0 9", "prompt": "FEN: rn1qkb1r/pp1B1ppp/8/3pp3/3Nn3/8/PPP2PPP/RNBQ1RK1 b kq - 0 9\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e4 black knight; d5 black pawn; e5 black pawn; a7 black pawn; b7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; d8 black queen; e8 black king; f8 black bishop; h8 black rook.\nMoves by piece:\ne4 black knight: no legal moves\nd5 black pawn: no legal moves\ne5 black pawn: no legal moves\na7 black pawn: no legal moves\nb7 black pawn: no legal moves\nf7 black pawn: no legal moves\ng7 black pawn: no legal moves\nh7 black pawn: no legal moves\na8 black rook: no legal moves\nb8 black knight: b8d7\nd8 black queen: d8d7\ne8 black king: e8d7 e8e7\nf8 black bishop: no legal moves\nh8 black rook: no legal moves\nAll legal moves: b8d7 d8d7 e8d7 e8e7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e4": [], "d5": [], "e5": [], "a7": [], "b7": [], "f7": [], "g7": [], "h7": [], "a8": [], "b8": ["b8d7"], "d8": ["d8d7"], "e8": ["e8d7", "e8e7"], "f8": [], "h8": []}, "_legal_moves_by_piece_moves": "b8d7 d8d7 e8d7 e8e7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e4": [], "d5": [], "e5": [], "a7": [], "b7": [], "f7": [], "g7": [], "h7": [], "a8": [], "b8": ["b8d7"], "d8": ["d8d7"], "e8": ["e8d7", "e8e7"], "f8": [], "h8": []}, "legal_moves": "b8d7 d8d7 e8d7 e8e7"}}
{"example_id": "rules_01636", "split": "rules", "task_type": "ray_walk", "fen": "r2q2k1/2p3p1/p1pp3p/4n3/4N3/3P3Q/PPP3P1/5NK1 w - -", "prompt": "FEN: r2q2k1/2p3p1/p1pp3p/4n3/4N3/3P3Q/PPP3P1/5NK1 w - -\nWalk each ray for the slider on h3: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: h3 white queen.\nRay N: h4 empty; h5 empty; h6 black pawn: capture (stop, included).\nRay NE: edge.\nRay E: edge.\nRay SE: edge.\nRay S: h2 empty; h1 empty; edge.\nRay SW: g2 white pawn: own piece (stop, excluded).\nRay W: g3 empty; f3 empty; e3 empty; d3 white pawn: own piece (stop, excluded).\nRay NW: g4 empty; f5 empty; e6 empty; d7 empty; c8 empty; edge.\nMoves from rays: h3c8 h3d7 h3e3 h3e6 h3f3 h3f5 h3g3 h3g4 h3h1 h3h2 h3h4 h3h5 h3h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "h3", "diagnostic": true, "hard_gate": false, "source_square": "h3"}}
{"example_id": "rules_01637", "split": "rules", "task_type": "legal_moves", "fen": "2kr2r1/pb4qp/1b2p3/1Pp5/4N3/3P2P1/4QPBP/R4RK1 b - - 0 23", "prompt": "FEN: 2kr2r1/pb4qp/1b2p3/1Pp5/4N3/3P2P1/4QPBP/R4RK1 b - - 0 23\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6a5 b6c7 b7a6 b7a8 b7c6 b7d5 b7e4 c5c4 c8b8 c8c7 c8d7 d8d3 d8d4 d8d5 d8d6 d8d7 d8e8 d8f8 e6e5 g7a1 g7b2 g7c3 g7c7 g7d4 g7d7 g7e5 g7e7 g7f6 g7f7 g7f8 g7g3 g7g4 g7g5 g7g6 g7h6 g7h8 g8e8 g8f8 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01638", "split": "rules", "task_type": "legal_moves", "fen": "rnb1k2r/pp2ppbp/2p3p1/3qP1Q1/8/5p2/PPPP2PP/RNB1K1NR w KQkq - 0 10", "prompt": "FEN: rnb1k2r/pp2ppbp/2p3p1/3qP1Q1/8/5p2/PPPP2PP/RNB1K1NR w KQkq - 0 10\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a3 b1c3 b2b3 b2b4 c2c3 c2c4 d2d3 d2d4 e1d1 e1f1 e1f2 e5e6 g1e2 g1f3 g1h3 g2f3 g2g3 g2g4 g5e3 g5e7 g5f4 g5f5 g5f6 g5g3 g5g4 g5g6 g5h4 g5h5 g5h6 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01639", "split": "rules", "task_type": "side_piece_inventory", "fen": "r4rk1/5pp1/p2ppq1p/1p1n4/3Pb3/P3PN1P/1P1QBPP1/2R2RK1 w - - 6 20", "prompt": "FEN: r4rk1/5pp1/p2ppq1p/1p1n4/3Pb3/P3PN1P/1P1QBPP1/2R2RK1 w - - 6 20\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: c1 white rook; f1 white rook; g1 white king; b2 white pawn; d2 white queen; e2 white bishop; f2 white pawn; g2 white pawn; a3 white pawn; e3 white pawn; f3 white knight; h3 white pawn; d4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "c1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white queen"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "h3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "c1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white queen"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "e3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "h3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}]}}
{"example_id": "rules_01640", "split": "rules", "task_type": "piece_legal_moves", "fen": "6k1/4r3/4P3/N2r1Bpp/8/1R6/6PP/6K1 w - - 2 41", "prompt": "FEN: 6k1/4r3/4P3/N2r1Bpp/8/1R6/6PP/6K1 w - - 2 41\nWhat legal moves does the piece on a5 have?", "gold_answer": "a5b7 a5c4 a5c6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a5", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "a5", "piece": "knight"}}
{"example_id": "rules_01641", "split": "rules", "task_type": "check_detection", "fen": "3r2k1/6pp/pp1p4/4p3/8/4KP2/P1P3PP/3R4 b - -", "prompt": "FEN: 3r2k1/6pp/pp1p4/4p3/8/4KP2/P1P3PP/3R4 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01642", "split": "rules", "task_type": "captures", "fen": "r1bqkbnr/1p1p1ppp/p3p3/2p5/4P3/2NB1Q2/PPPP1PPP/R1B1K2R w KQkq -", "prompt": "FEN: r1bqkbnr/1p1p1ppp/p3p3/2p5/4P3/2NB1Q2/PPPP1PPP/R1B1K2R w KQkq -\nList all capture moves available.", "gold_answer": "d3a6 f3f7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01643", "split": "rules", "task_type": "special_rules", "fen": "rnbqk2r/pp3ppp/4pn2/3p4/3P4/1Pb2N2/P1PNBPPP/1RBQK2R b Kkq -", "prompt": "Given FEN: rnbqk2r/pp3ppp/4pn2/3p4/3P4/1Pb2N2/P1PNBPPP/1RBQK2R b Kkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01644", "split": "rules", "task_type": "legality_check", "fen": "r2q1rk1/1b2bppp/p1p1p3/1p1n4/n3N3/3P2P1/1P1B1PBP/2RQNRK1 w - - 0 16", "prompt": "FEN: r2q1rk1/1b2bppp/p1p1p3/1p1n4/n3N3/3P2P1/1P1B1PBP/2RQNRK1 w - - 0 16\nIs the move h2h3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "h2h3", "_legality_check_reason_label": "legal", "move": "h2h3", "legality_reason_label": "legal"}}
{"example_id": "rules_01645", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/4r1k1/P5p1/1Bp1b3/P2pP1K1/3P4/2P5/5R2 w - - 5 49", "prompt": "FEN: 8/4r1k1/P5p1/1Bp1b3/P2pP1K1/3P4/2P5/5R2 w - - 5 49\nList pseudo-legal moves from f1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from f1: f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f1f4 f1f5 f1f6 f1f7 f1f8 f1g1 f1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "f1", "diagnostic": true, "hard_gate": false, "source_square": "f1"}}
{"example_id": "rules_01646", "split": "rules", "task_type": "piece_legal_filter", "fen": "1r6/pprnkpp1/3pp2p/P2p4/3P4/3BP3/1PPK1PPP/R1R5 w - -", "prompt": "FEN: 1r6/pprnkpp1/3pp2p/P2p4/3P4/3BP3/1PPK1PPP/R1R5 w - -\nFor the piece on d2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d2: d2c3 d2d1 d2e1 d2e2.\nLegal: d2d1 d2e1 d2e2.\nRejected: d2c3 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "d2", "diagnostic": true, "hard_gate": false, "source_square": "d2"}}
{"example_id": "rules_01647", "split": "rules", "task_type": "king_safety_filter", "fen": "8/3Q4/8/5pK1/6p1/4r2p/R1k5/8 b - -", "prompt": "FEN: 8/3Q4/8/5pK1/6p1/4r2p/R1k5/8 b - -\nFor move c2b2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c2b2.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "c2b2", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "c2b2", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_01648", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r4rk1/pb3pp1/1p2pq2/2pN4/8/1P2P1Q1/PBPP2PP/R5K1 b - -", "prompt": "FEN: r4rk1/pb3pp1/1p2pq2/2pN4/8/1P2P1Q1/PBPP2PP/R5K1 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black pawn; b6 black pawn; e6 black pawn; f6 black queen; a7 black pawn; b7 black bishop; f7 black pawn; g7 black pawn; a8 black rook; f8 black rook; g8 black king.\nMoves by piece:\nc5 black pawn: c5c4\nb6 black pawn: b6b5\ne6 black pawn: e6d5 e6e5\nf6 black queen: f6b2 f6c3 f6d4 f6d8 f6e5 f6e7 f6f1 f6f2 f6f3 f6f4 f6f5 f6g5 f6g6 f6h4 f6h6\na7 black pawn: a7a5 a7a6\nb7 black bishop: b7a6 b7c6 b7c8 b7d5\nf7 black pawn: no legal moves\ng7 black pawn: g7g5 g7g6\na8 black rook: a8b8 a8c8 a8d8 a8e8\nf8 black rook: f8b8 f8c8 f8d8 f8e8\ng8 black king: g8h7 g8h8\nAll legal moves: a7a5 a7a6 a8b8 a8c8 a8d8 a8e8 b6b5 b7a6 b7c6 b7c8 b7d5 c5c4 e6d5 e6e5 f6b2 f6c3 f6d4 f6d8 f6e5 f6e7 f6f1 f6f2 f6f3 f6f4 f6f5 f6g5 f6g6 f6h4 f6h6 f8b8 f8c8 f8d8 f8e8 g7g5 g7g6 g8h7 g8h8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": ["c5c4"], "b6": ["b6b5"], "e6": ["e6d5", "e6e5"], "f6": ["f6b2", "f6c3", "f6d4", "f6d8", "f6e5", "f6e7", "f6f1", "f6f2", "f6f3", "f6f4", "f6f5", "f6g5", "f6g6", "f6h4", "f6h6"], "a7": ["a7a5", "a7a6"], "b7": ["b7a6", "b7c6", "b7c8", "b7d5"], "f7": [], "g7": ["g7g5", "g7g6"], "a8": ["a8b8", "a8c8", "a8d8", "a8e8"], "f8": ["f8b8", "f8c8", "f8d8", "f8e8"], "g8": ["g8h7", "g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 a8c8 a8d8 a8e8 b6b5 b7a6 b7c6 b7c8 b7d5 c5c4 e6d5 e6e5 f6b2 f6c3 f6d4 f6d8 f6e5 f6e7 f6f1 f6f2 f6f3 f6f4 f6f5 f6g5 f6g6 f6h4 f6h6 f8b8 f8c8 f8d8 f8e8 g7g5 g7g6 g8h7 g8h8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": ["c5c4"], "b6": ["b6b5"], "e6": ["e6d5", "e6e5"], "f6": ["f6b2", "f6c3", "f6d4", "f6d8", "f6e5", "f6e7", "f6f1", "f6f2", "f6f3", "f6f4", "f6f5", "f6g5", "f6g6", "f6h4", "f6h6"], "a7": ["a7a5", "a7a6"], "b7": ["b7a6", "b7c6", "b7c8", "b7d5"], "f7": [], "g7": ["g7g5", "g7g6"], "a8": ["a8b8", "a8c8", "a8d8", "a8e8"], "f8": ["f8b8", "f8c8", "f8d8", "f8e8"], "g8": ["g8h7", "g8h8"]}, "legal_moves": "a7a5 a7a6 a8b8 a8c8 a8d8 a8e8 b6b5 b7a6 b7c6 b7c8 b7d5 c5c4 e6d5 e6e5 f6b2 f6c3 f6d4 f6d8 f6e5 f6e7 f6f1 f6f2 f6f3 f6f4 f6f5 f6g5 f6g6 f6h4 f6h6 f8b8 f8c8 f8d8 f8e8 g7g5 g7g6 g8h7 g8h8"}}
{"example_id": "rules_01649", "split": "rules", "task_type": "legal_moves", "fen": "5n2/pp2k1p1/2p2p2/3p2p1/3P4/2P2PP1/PP2NKP1/8 b - - 1 25", "prompt": "FEN: 5n2/pp2k1p1/2p2p2/3p2p1/3P4/2P2PP1/PP2NKP1/8 b - - 1 25\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 c6c5 e7d6 e7d7 e7d8 e7e6 e7e8 e7f7 f6f5 f8d7 f8e6 f8g6 f8h7 g5g4 g7g6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": ""}}
{"example_id": "rules_01650", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/8/2kp4/3P4/K1P1p3/2B1P3/8/1r6 b - - 0 43", "prompt": "FEN: 8/8/2kp4/3P4/K1P1p3/2B1P3/8/1r6 b - - 0 43\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b1 black rook; e4 black pawn; c6 black king; d6 black pawn.\nFilter by piece:\nb1 black rook: pseudo-legal b1a1 b1b2 b1b3 b1b4 b1b5 b1b6 b1b7 b1b8 b1c1 b1d1 b1e1 b1f1 b1g1 b1h1 | rejected b1a1 does_not_resolve_check; b1b2 does_not_resolve_check; b1b3 does_not_resolve_check; b1b4 does_not_resolve_check; b1b5 does_not_resolve_check; b1b6 does_not_resolve_check; b1b7 does_not_resolve_check; b1b8 does_not_resolve_check; b1c1 does_not_resolve_check; b1d1 does_not_resolve_check; b1e1 does_not_resolve_check; b1f1 does_not_resolve_check; b1g1 does_not_resolve_check; b1h1 does_not_resolve_check | legal none\ne4 black pawn: pseudo-legal none | rejected none | legal none\nc6 black king: pseudo-legal c6b5 c6b6 c6b7 c6c5 c6c7 c6d5 c6d7 | rejected c6b5 does_not_resolve_check; c6d5 does_not_resolve_check | legal c6b6 c6b7 c6c5 c6c7 c6d7\nd6 black pawn: pseudo-legal none | rejected none | legal none\nAll legal moves: c6b6 c6b7 c6c5 c6c7 c6d7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01651", "split": "rules", "task_type": "legal_moves", "fen": "rnbqkbnr/ppp2ppp/3p4/8/3p4/1P6/PBP1PPPP/RN1QKBNR w KQkq -", "prompt": "FEN: rnbqkbnr/ppp2ppp/3p4/8/3p4/1P6/PBP1PPPP/RN1QKBNR w KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a3 b1c3 b1d2 b2a3 b2c1 b2c3 b2d4 b3b4 c2c3 c2c4 d1c1 d1d2 d1d3 d1d4 e1d2 e2e3 e2e4 f2f3 f2f4 g1f3 g1h3 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01652", "split": "rules", "task_type": "side_piece_inventory", "fen": "2r2rk1/pp3ppp/4p3/3pPnq1/8/P1N2Q1P/1P3PP1/2R1R1K1 w - -", "prompt": "FEN: 2r2rk1/pp3ppp/4p3/3pPnq1/8/P1N2Q1P/1P3PP1/2R1R1K1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: c1 white rook; e1 white rook; g1 white king; b2 white pawn; f2 white pawn; g2 white pawn; a3 white pawn; c3 white knight; f3 white queen; h3 white pawn; e5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "c1", "piece": "white rook"}, {"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "f3", "piece": "white queen"}, {"square": "h3", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "c1", "piece": "white rook"}, {"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "a3", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "f3", "piece": "white queen"}, {"square": "h3", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}]}}
{"example_id": "rules_01653", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bq3r/ppppnpp1/1b1n2k1/3P2N1/7P/8/PP3PP1/RNBQR1K1 w - -", "prompt": "FEN: r1bq3r/ppppnpp1/1b1n2k1/3P2N1/7P/8/PP3PP1/RNBQR1K1 w - -\nWhat legal moves does the piece on d1 have?", "gold_answer": "d1a4 d1b3 d1c2 d1d2 d1d3 d1d4 d1e2 d1f3 d1g4 d1h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "d1", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "d1", "piece": "queen"}}
{"example_id": "rules_01654", "split": "rules", "task_type": "check_detection", "fen": "r1b2rk1/3nbppp/nqp1p3/p1N5/1p1PN3/1P2Q1P1/1B2PPBP/R4RK1 w - -", "prompt": "FEN: r1b2rk1/3nbppp/nqp1p3/p1N5/1p1PN3/1P2Q1P1/1B2PPBP/R4RK1 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01655", "split": "rules", "task_type": "captures", "fen": "5k2/8/4BBK1/8/8/8/8/8 w - -", "prompt": "FEN: 5k2/8/4BBK1/8/8/8/8/8 w - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01656", "split": "rules", "task_type": "special_rules", "fen": "8/1p6/8/2p5/2k5/8/3Q2PP/R5K1 b - -", "prompt": "Given FEN: 8/1p6/8/2p5/2k5/8/3Q2PP/R5K1 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01657", "split": "rules", "task_type": "legality_check", "fen": "5rk1/4bppp/4pn2/NB4q1/Pp6/5P2/1P1R1P1P/R4Q1K b - -", "prompt": "FEN: 5rk1/4bppp/4pn2/NB4q1/Pp6/5P2/1P1R1P1P/R4Q1K b - -\nIs the move h7h5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "h7h5", "_legality_check_reason_label": "legal", "move": "h7h5", "legality_reason_label": "legal"}}
{"example_id": "rules_01658", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/1n1PK3/B7/8/4k3/7p/8/8 b - -", "prompt": "FEN: 8/1n1PK3/B7/8/4k3/7p/8/8 b - -\nList pseudo-legal moves from h3.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from h3: h3h2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "h3", "diagnostic": true, "hard_gate": false, "source_square": "h3"}}
{"example_id": "rules_01659", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn1qk2r/pbppbppp/1p2pn2/8/2PP4/P1N2N2/1PQ1PPPP/R1B1KB1R b KQkq -", "prompt": "FEN: rn1qk2r/pbppbppp/1p2pn2/8/2PP4/P1N2N2/1PQ1PPPP/R1B1KB1R b KQkq -\nFor the piece on b6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b6: b6b5.\nLegal: b6b5.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "b6", "diagnostic": true, "hard_gate": false, "source_square": "b6"}}
{"example_id": "rules_01660", "split": "rules", "task_type": "king_safety_filter", "fen": "2k4r/1pp2ppp/pr2p3/5q2/1PP5/P3Q2P/5PP1/2R1R1K1 w - - 1 23", "prompt": "FEN: 2k4r/1pp2ppp/pr2p3/5q2/1PP5/P3Q2P/5PP1/2R1R1K1 w - - 1 23\nFor move a3a4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a3a4.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a3a4", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a3a4", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01661", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r3r1k1/ppp2ppp/2b2n2/3qpNB1/8/1PPP1P1P/P5P1/1R1QR1K1 b - - 0 18", "prompt": "FEN: r3r1k1/ppp2ppp/2b2n2/3qpNB1/8/1PPP1P1P/P5P1/1R1QR1K1 b - - 0 18\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d5 black queen; e5 black pawn; c6 black bishop; f6 black knight; a7 black pawn; b7 black pawn; c7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; e8 black rook; g8 black king.\nMoves by piece:\nd5 black queen: d5a5 d5b3 d5b5 d5c4 d5c5 d5d3 d5d4 d5d6 d5d7 d5d8 d5e4 d5e6 d5f3\ne5 black pawn: e5e4\nc6 black bishop: c6a4 c6b5 c6d7\nf6 black knight: f6d7 f6e4 f6g4 f6h5\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nc7 black pawn: no legal moves\nf7 black pawn: no legal moves\ng7 black pawn: g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8 a8c8 a8d8\ne8 black rook: e8b8 e8c8 e8d8 e8e6 e8e7 e8f8\ng8 black king: g8f8 g8h8\nAll legal moves: a7a5 a7a6 a8b8 a8c8 a8d8 b7b5 b7b6 c6a4 c6b5 c6d7 d5a5 d5b3 d5b5 d5c4 d5c5 d5d3 d5d4 d5d6 d5d7 d5d8 d5e4 d5e6 d5f3 e5e4 e8b8 e8c8 e8d8 e8e6 e8e7 e8f8 f6d7 f6e4 f6g4 f6h5 g7g6 g8f8 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d5": ["d5a5", "d5b3", "d5b5", "d5c4", "d5c5", "d5d3", "d5d4", "d5d6", "d5d7", "d5d8", "d5e4", "d5e6", "d5f3"], "e5": ["e5e4"], "c6": ["c6a4", "c6b5", "c6d7"], "f6": ["f6d7", "f6e4", "f6g4", "f6h5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": [], "f7": [], "g7": ["g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8", "a8c8", "a8d8"], "e8": ["e8b8", "e8c8", "e8d8", "e8e6", "e8e7", "e8f8"], "g8": ["g8f8", "g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 a8c8 a8d8 b7b5 b7b6 c6a4 c6b5 c6d7 d5a5 d5b3 d5b5 d5c4 d5c5 d5d3 d5d4 d5d6 d5d7 d5d8 d5e4 d5e6 d5f3 e5e4 e8b8 e8c8 e8d8 e8e6 e8e7 e8f8 f6d7 f6e4 f6g4 f6h5 g7g6 g8f8 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d5": ["d5a5", "d5b3", "d5b5", "d5c4", "d5c5", "d5d3", "d5d4", "d5d6", "d5d7", "d5d8", "d5e4", "d5e6", "d5f3"], "e5": ["e5e4"], "c6": ["c6a4", "c6b5", "c6d7"], "f6": ["f6d7", "f6e4", "f6g4", "f6h5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "c7": [], "f7": [], "g7": ["g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8", "a8c8", "a8d8"], "e8": ["e8b8", "e8c8", "e8d8", "e8e6", "e8e7", "e8f8"], "g8": ["g8f8", "g8h8"]}, "legal_moves": "a7a5 a7a6 a8b8 a8c8 a8d8 b7b5 b7b6 c6a4 c6b5 c6d7 d5a5 d5b3 d5b5 d5c4 d5c5 d5d3 d5d4 d5d6 d5d7 d5d8 d5e4 d5e6 d5f3 e5e4 e8b8 e8c8 e8d8 e8e6 e8e7 e8f8 f6d7 f6e4 f6g4 f6h5 g7g6 g8f8 g8h8 h7h5 h7h6"}}
{"example_id": "rules_01662", "split": "rules", "task_type": "ray_walk", "fen": "r1b1k1nr/pppp1ppp/2n5/8/2B1PP1q/2P5/P5PP/R1BQK1NR w KQkq -", "prompt": "FEN: r1b1k1nr/pppp1ppp/2n5/8/2B1PP1q/2P5/P5PP/R1BQK1NR w KQkq -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 white bishop: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01663", "split": "rules", "task_type": "legal_moves", "fen": "r1bqk1nr/ppp2ppp/2np4/b7/Q1BpP3/2P2N2/P4PPP/RNB1K2R w KQkq -", "prompt": "FEN: r1bqk1nr/ppp2ppp/2np4/b7/Q1BpP3/2P2N2/P4PPP/RNB1K2R w KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a4a3 a4a5 a4b3 a4b4 a4b5 a4c2 a4c6 a4d1 b1a3 b1d2 c1a3 c1b2 c1d2 c1e3 c1f4 c1g5 c1h6 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f1 c4f7 e1d1 e1d2 e1e2 e1f1 e1g1 e4e5 f3d2 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01664", "split": "rules", "task_type": "legal_moves", "fen": "r1bqkb1r/ppp2pp1/3p1n1p/4n1N1/B2QP3/8/PPP2PPP/RNB1K2R b KQkq - 1 8", "prompt": "FEN: r1bqkb1r/ppp2pp1/3p1n1p/4n1N1/B2QP3/8/PPP2PPP/RNB1K2R b KQkq - 1 8\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b7b5 c7c6 c8d7 d8d7 e5c6 e5d7 e8e7 f6d7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01665", "split": "rules", "task_type": "side_piece_inventory", "fen": "3k4/8/8/2Q5/5N2/5K2/8/8 w - -", "prompt": "FEN: 3k4/8/8/2Q5/5N2/5K2/8/8 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: f3 white king; f4 white knight; c5 white queen.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "f3", "piece": "white king"}, {"square": "f4", "piece": "white knight"}, {"square": "c5", "piece": "white queen"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "f3", "piece": "white king"}, {"square": "f4", "piece": "white knight"}, {"square": "c5", "piece": "white queen"}]}}
{"example_id": "rules_01666", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/8/2k5/8/2B5/1K1N4/8/8 w - -", "prompt": "FEN: 8/8/2k5/8/2B5/1K1N4/8/8 w - -\nWhat legal moves does the piece on c4 have?", "gold_answer": "c4a6 c4b5 c4d5 c4e6 c4f7 c4g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "c4", "_piece_legal_moves_piece": "bishop", "diagnostic": true, "hard_gate": false, "source_square": "c4", "piece": "bishop"}}
{"example_id": "rules_01667", "split": "rules", "task_type": "check_detection", "fen": "3r3r/pk2n3/1p1p4/1PpP1p1p/q3nPpP/3QP1P1/1NK1N3/3R3R w - - 2 28", "prompt": "FEN: 3r3r/pk2n3/1p1p4/1PpP1p1p/q3nPpP/3QP1P1/1NK1N3/3R3R w - - 2 28\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01668", "split": "rules", "task_type": "captures", "fen": "Q1b1kb1r/2p2ppp/8/p3N3/1p2P3/8/PPPP1PPP/RNB1K2R w KQk -", "prompt": "FEN: Q1b1kb1r/2p2ppp/8/p3N3/1p2P3/8/PPPP1PPP/RNB1K2R w KQk -\nList all capture moves available.", "gold_answer": "a8a5 a8c8 e5f7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01669", "split": "rules", "task_type": "special_rules", "fen": "2qr2k1/1p1b1ppn/p2p2p1/2pP4/P1P1NPPP/4N1K1/1P1Q4/4R3 b - - 2 27", "prompt": "Given FEN: 2qr2k1/1p1b1ppn/p2p2p1/2pP4/P1P1NPPP/4N1K1/1P1Q4/4R3 b - - 2 27\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01670", "split": "rules", "task_type": "legality_check", "fen": "r4rk1/N1R3p1/6n1/5pp1/8/5PB1/5P1P/5RK1 w - - 0 27", "prompt": "FEN: r4rk1/N1R3p1/6n1/5pp1/8/5PB1/5P1P/5RK1 w - - 0 27\nIs the move a7b5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "a7b5", "_legality_check_reason_label": "legal", "move": "a7b5", "legality_reason_label": "legal"}}
{"example_id": "rules_01671", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rnb4r/pp4pp/3R4/3pp2N/4k3/8/PPP2PPP/1K6 w - -", "prompt": "FEN: rnb4r/pp4pp/3R4/3pp2N/4k3/8/PPP2PPP/1K6 w - -\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a1 b1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01672", "split": "rules", "task_type": "piece_legal_filter", "fen": "rnbq1rk1/ppp1ppbp/3p1np1/8/2PP1B2/4PN2/PP1N1PPP/R2QKB1R b KQ - 0 6", "prompt": "FEN: rnbq1rk1/ppp1ppbp/3p1np1/8/2PP1B2/4PN2/PP1N1PPP/R2QKB1R b KQ - 0 6\nFor the piece on d6, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d6: d6d5.\nLegal: d6d5.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "d6", "diagnostic": true, "hard_gate": false, "source_square": "d6"}}
{"example_id": "rules_01673", "split": "rules", "task_type": "king_safety_filter", "fen": "4k3/7R/8/3KN1rP/3p4/2b5/8/8 b - -", "prompt": "FEN: 4k3/7R/8/3KN1rP/3p4/2b5/8/8 b - -\nFor move e8d7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e8d7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "e8d7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e8d7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01674", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2kr1bnr/1pp1n1pp/p4p2/4p3/PP2P1b1/2P1BN2/3N1PPP/R3K2R w - - 1 14", "prompt": "FEN: 2kr1bnr/1pp1n1pp/p4p2/4p3/PP2P1b1/2P1BN2/3N1PPP/R3K2R w - - 1 14\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; e1 white king; h1 white rook; d2 white knight; f2 white pawn; g2 white pawn; h2 white pawn; c3 white pawn; e3 white bishop; f3 white knight; a4 white pawn; b4 white pawn; e4 white pawn.\nMoves by piece:\na1 white rook: a1a2 a1a3 a1b1 a1c1 a1d1\ne1 white king: e1d1 e1e2 e1f1\nh1 white rook: h1f1 h1g1\nd2 white knight: d2b1 d2b3 d2c4 d2f1\nf2 white pawn: no legal moves\ng2 white pawn: g2g3\nh2 white pawn: h2h3 h2h4\nc3 white pawn: c3c4\ne3 white bishop: e3a7 e3b6 e3c5 e3d4 e3f4 e3g5 e3h6\nf3 white knight: f3d4 f3e5 f3g1 f3g5 f3h4\na4 white pawn: a4a5\nb4 white pawn: b4b5\ne4 white pawn: no legal moves\nAll legal moves: a1a2 a1a3 a1b1 a1c1 a1d1 a4a5 b4b5 c3c4 d2b1 d2b3 d2c4 d2f1 e1d1 e1e2 e1f1 e3a7 e3b6 e3c5 e3d4 e3f4 e3g5 e3h6 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 h1f1 h1g1 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1a2", "a1a3", "a1b1", "a1c1", "a1d1"], "e1": ["e1d1", "e1e2", "e1f1"], "h1": ["h1f1", "h1g1"], "d2": ["d2b1", "d2b3", "d2c4", "d2f1"], "f2": [], "g2": ["g2g3"], "h2": ["h2h3", "h2h4"], "c3": ["c3c4"], "e3": ["e3a7", "e3b6", "e3c5", "e3d4", "e3f4", "e3g5", "e3h6"], "f3": ["f3d4", "f3e5", "f3g1", "f3g5", "f3h4"], "a4": ["a4a5"], "b4": ["b4b5"], "e4": []}, "_legal_moves_by_piece_moves": "a1a2 a1a3 a1b1 a1c1 a1d1 a4a5 b4b5 c3c4 d2b1 d2b3 d2c4 d2f1 e1d1 e1e2 e1f1 e3a7 e3b6 e3c5 e3d4 e3f4 e3g5 e3h6 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 h1f1 h1g1 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1a2", "a1a3", "a1b1", "a1c1", "a1d1"], "e1": ["e1d1", "e1e2", "e1f1"], "h1": ["h1f1", "h1g1"], "d2": ["d2b1", "d2b3", "d2c4", "d2f1"], "f2": [], "g2": ["g2g3"], "h2": ["h2h3", "h2h4"], "c3": ["c3c4"], "e3": ["e3a7", "e3b6", "e3c5", "e3d4", "e3f4", "e3g5", "e3h6"], "f3": ["f3d4", "f3e5", "f3g1", "f3g5", "f3h4"], "a4": ["a4a5"], "b4": ["b4b5"], "e4": []}, "legal_moves": "a1a2 a1a3 a1b1 a1c1 a1d1 a4a5 b4b5 c3c4 d2b1 d2b3 d2c4 d2f1 e1d1 e1e2 e1f1 e3a7 e3b6 e3c5 e3d4 e3f4 e3g5 e3h6 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 h1f1 h1g1 h2h3 h2h4"}}
{"example_id": "rules_01675", "split": "rules", "task_type": "ray_walk", "fen": "r3k2r/p2q1p1p/1p2p3/3p4/3Q1P2/4P3/P1P3PP/R1B1K2R b KQ - 3 16", "prompt": "FEN: r3k2r/p2q1p1p/1p2p3/3p4/3Q1P2/4P3/P1P3PP/R1B1K2R b KQ - 3 16\nWalk each ray for the slider on d7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d7 black queen.\nRay N: d8 empty; edge.\nRay NE: e8 black king: own piece (stop, excluded).\nRay E: e7 empty; f7 black pawn: own piece (stop, excluded).\nRay SE: e6 black pawn: own piece (stop, excluded).\nRay S: d6 empty; d5 black pawn: own piece (stop, excluded).\nRay SW: c6 empty; b5 empty; a4 empty; edge.\nRay W: c7 empty; b7 empty; a7 black pawn: own piece (stop, excluded).\nRay NW: c8 empty; edge.\nMoves from rays: d7a4 d7b5 d7b7 d7c6 d7c7 d7c8 d7d6 d7d8 d7e7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "d7", "diagnostic": true, "hard_gate": false, "source_square": "d7"}}
{"example_id": "rules_01676", "split": "rules", "task_type": "legal_filter_trace", "fen": "7k/p1p2ppp/1p1p1n2/3P4/2BP1n1P/8/PPPK1P2/8 b - - 2 28", "prompt": "FEN: 7k/p1p2ppp/1p1p1n2/3P4/2BP1n1P/8/PPPK1P2/8 b - - 2 28\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: f4 black knight; b6 black pawn; d6 black pawn; f6 black knight; a7 black pawn; c7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; h8 black king.\nFilter by piece:\nf4 black knight: pseudo-legal f4d3 f4d5 f4e2 f4e6 f4g2 f4g6 f4h3 f4h5 | rejected none | legal f4d3 f4d5 f4e2 f4e6 f4g2 f4g6 f4h3 f4h5\nb6 black pawn: pseudo-legal b6b5 | rejected none | legal b6b5\nd6 black pawn: pseudo-legal none | rejected none | legal none\nf6 black knight: pseudo-legal f6d5 f6d7 f6e4 f6e8 f6g4 f6g8 f6h5 | rejected none | legal f6d5 f6d7 f6e4 f6e8 f6g4 f6g8 f6h5\na7 black pawn: pseudo-legal a7a5 a7a6 | rejected none | legal a7a5 a7a6\nc7 black pawn: pseudo-legal c7c5 c7c6 | rejected none | legal c7c5 c7c6\nf7 black pawn: pseudo-legal none | rejected none | legal none\ng7 black pawn: pseudo-legal g7g5 g7g6 | rejected none | legal g7g5 g7g6\nh7 black pawn: pseudo-legal h7h5 h7h6 | rejected none | legal h7h5 h7h6\nh8 black king: pseudo-legal h8g8 | rejected none | legal h8g8\nAll legal moves: a7a5 a7a6 b6b5 c7c5 c7c6 f4d3 f4d5 f4e2 f4e6 f4g2 f4g6 f4h3 f4h5 f6d5 f6d7 f6e4 f6e8 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01677", "split": "rules", "task_type": "legal_moves", "fen": "r1bqkbnr/ppp2pp1/4n2p/3BN2Q/4P3/8/PPPP1PPP/RNB2RK1 b kq - 2 7", "prompt": "FEN: r1bqkbnr/ppp2pp1/4n2p/3BN2Q/4P3/8/PPPP1PPP/RNB2RK1 b kq - 2 7\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c7c5 c7c6 c8d7 d8d5 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e6c5 e6d4 e6f4 e6g5 e8e7 f8a3 f8b4 f8c5 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 h8h7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01678", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/8/P1k3p1/4RpP1/3P3P/8/5K2/8 b - - 2 56", "prompt": "FEN: 8/8/P1k3p1/4RpP1/3P3P/8/5K2/8 b - - 2 56\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: f5 black pawn; c6 black king; g6 black pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "f5", "piece": "black pawn"}, {"square": "c6", "piece": "black king"}, {"square": "g6", "piece": "black pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "f5", "piece": "black pawn"}, {"square": "c6", "piece": "black king"}, {"square": "g6", "piece": "black pawn"}]}}
{"example_id": "rules_01679", "split": "rules", "task_type": "piece_legal_moves", "fen": "2k5/8/2B5/8/1P2PKN1/4B2r/8/8 b - - 0 54", "prompt": "FEN: 2k5/8/2B5/8/1P2PKN1/4B2r/8/8 b - - 0 54\nWhat legal moves does the piece on c8 have?", "gold_answer": "c8b8 c8c7 c8d8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c8", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "c8", "piece": "king"}}
{"example_id": "rules_01680", "split": "rules", "task_type": "check_detection", "fen": "4r3/2b2ppk/1n1p1n1p/2pP4/1p2P3/1P2BP1P/3N1KP1/R3N3 w - - 3 27", "prompt": "FEN: 4r3/2b2ppk/1n1p1n1p/2pP4/1p2P3/1P2BP1P/3N1KP1/R3N3 w - - 3 27\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01681", "split": "rules", "task_type": "captures", "fen": "r2qkb1r/p2b1ppp/2n1pn2/3p4/P2P1B2/2N2NP1/4PPBP/R2Q1RK1 b kq - 4 11", "prompt": "FEN: r2qkb1r/p2b1ppp/2n1pn2/3p4/P2P1B2/2N2NP1/4PPBP/R2Q1RK1 b kq - 4 11\nList all capture moves available.", "gold_answer": "c6d4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01682", "split": "rules", "task_type": "special_rules", "fen": "rn1k2nQ/ppp4p/3p4/4p1q1/6b1/3P1B2/PPP1KP1P/RNB4R b - - 0 14", "prompt": "Given FEN: rn1k2nQ/ppp4p/3p4/4p1q1/6b1/3P1B2/PPP1KP1P/RNB4R b - - 0 14\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01683", "split": "rules", "task_type": "legality_check", "fen": "r1b2r2/pp3pk1/2pp3p/2b1p1p1/2B1P3/2PP1PB1/PP3P1P/3R1RK1 b - - 1 15", "prompt": "FEN: r1b2r2/pp3pk1/2pp3p/2b1p1p1/2B1P3/2PP1PB1/PP3P1P/3R1RK1 b - - 1 15\nIs the move f3h7 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f3h7", "_legality_check_reason_label": "wrong_side_piece", "move": "f3h7", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01684", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/8/5k2/1p3P2/2p1PPn1/2P2K2/B7/8 b - - 2 39", "prompt": "FEN: 8/8/5k2/1p3P2/2p1PPn1/2P2K2/B7/8 b - - 2 39\nList pseudo-legal moves from g4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g4: g4e3 g4e5 g4f2 g4h2 g4h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g4", "diagnostic": true, "hard_gate": false, "source_square": "g4"}}
{"example_id": "rules_01685", "split": "rules", "task_type": "piece_legal_filter", "fen": "2k2b1r/ppp2ppp/8/q3p3/3r2n1/2N4P/PPPB1PP1/R2Q1RK1 b - - 0 12", "prompt": "FEN: 2k2b1r/ppp2ppp/8/q3p3/3r2n1/2N4P/PPPB1PP1/R2Q1RK1 b - - 0 12\nFor the piece on d4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d4: d4a4 d4b4 d4c4 d4d2 d4d3 d4d5 d4d6 d4d7 d4d8 d4e4 d4f4.\nLegal: d4a4 d4b4 d4c4 d4d2 d4d3 d4d5 d4d6 d4d7 d4d8 d4e4 d4f4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_01686", "split": "rules", "task_type": "king_safety_filter", "fen": "r2q1rk1/npp2ppp/4pn2/1P1p1b2/Pb1P4/2N1PN2/1B3PPP/R2QKB1R b KQ - 4 11", "prompt": "FEN: r2q1rk1/npp2ppp/4pn2/1P1p1b2/Pb1P4/2N1PN2/1B3PPP/R2QKB1R b KQ - 4 11\nFor move a7b5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7b5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7b5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7b5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01687", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/8/4q3/8/2k2K2/8/8/8 w - -", "prompt": "FEN: 8/8/4q3/8/2k2K2/8/8/8 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: f4 white king.\nMoves by piece:\nf4 white king: f4f3 f4g3 f4g5\nAll legal moves: f4f3 f4g3 f4g5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"f4": ["f4f3", "f4g3", "f4g5"]}, "_legal_moves_by_piece_moves": "f4f3 f4g3 f4g5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"f4": ["f4f3", "f4g3", "f4g5"]}, "legal_moves": "f4f3 f4g3 f4g5"}}
{"example_id": "rules_01688", "split": "rules", "task_type": "ray_walk", "fen": "4b3/7k/3R3p/p1p2Np1/2P2p2/7P/P5P1/2K2R2 b - - 3 33", "prompt": "FEN: 4b3/7k/3R3p/p1p2Np1/2P2p2/7P/P5P1/2K2R2 b - - 3 33\nWalk each ray for the slider on e8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e8 black bishop.\nRay NE: edge.\nRay SE: f7 empty; g6 empty; h5 empty; edge.\nRay SW: d7 empty; c6 empty; b5 empty; a4 empty; edge.\nRay NW: edge.\nMoves from rays: e8a4 e8b5 e8c6 e8d7 e8f7 e8g6 e8h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "e8", "diagnostic": true, "hard_gate": false, "source_square": "e8"}}
{"example_id": "rules_01689", "split": "rules", "task_type": "legal_filter_trace", "fen": "8/8/6pp/1q3p2/4pP1P/2k3P1/5P2/K7 b - - 12 65", "prompt": "FEN: 8/8/6pp/1q3p2/4pP1P/2k3P1/5P2/K7 b - - 12 65\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c3 black king; e4 black pawn; b5 black queen; f5 black pawn; g6 black pawn; h6 black pawn.\nFilter by piece:\nc3 black king: pseudo-legal c3b2 c3b3 c3b4 c3c2 c3c4 c3d2 c3d3 c3d4 | rejected c3b2 king_would_be_in_check | legal c3b3 c3b4 c3c2 c3c4 c3d2 c3d3 c3d4\ne4 black pawn: pseudo-legal e4e3 | rejected none | legal e4e3\nb5 black queen: pseudo-legal b5a4 b5a5 b5a6 b5b1 b5b2 b5b3 b5b4 b5b6 b5b7 b5b8 b5c4 b5c5 b5c6 b5d3 b5d5 b5d7 b5e2 b5e5 b5e8 b5f1 | rejected none | legal b5a4 b5a5 b5a6 b5b1 b5b2 b5b3 b5b4 b5b6 b5b7 b5b8 b5c4 b5c5 b5c6 b5d3 b5d5 b5d7 b5e2 b5e5 b5e8 b5f1\nf5 black pawn: pseudo-legal none | rejected none | legal none\ng6 black pawn: pseudo-legal g6g5 | rejected none | legal g6g5\nh6 black pawn: pseudo-legal h6h5 | rejected none | legal h6h5\nAll legal moves: b5a4 b5a5 b5a6 b5b1 b5b2 b5b3 b5b4 b5b6 b5b7 b5b8 b5c4 b5c5 b5c6 b5d3 b5d5 b5d7 b5e2 b5e5 b5e8 b5f1 c3b3 c3b4 c3c2 c3c4 c3d2 c3d3 c3d4 e4e3 g6g5 h6h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01690", "split": "rules", "task_type": "legal_moves", "fen": "1k2r3/b1p2p2/Pp4p1/1Rp1P2p/2P2P2/6N1/6PP/4K3 b - - 0 34", "prompt": "FEN: 1k2r3/b1p2p2/Pp4p1/1Rp1P2p/2P2P2/6N1/6PP/4K3 b - - 0 34\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b8a8 b8c8 c7c6 e8c8 e8d8 e8e5 e8e6 e8e7 e8f8 e8g8 e8h8 f7f5 f7f6 g6g5 h5h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01691", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/8/8/8/3N2pp/6k1/8/6K1 w - - 6 60", "prompt": "FEN: 8/8/8/8/3N2pp/6k1/8/6K1 w - - 6 60\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: g1 white king; d4 white knight.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "g1", "piece": "white king"}, {"square": "d4", "piece": "white knight"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "g1", "piece": "white king"}, {"square": "d4", "piece": "white knight"}]}}
{"example_id": "rules_01692", "split": "rules", "task_type": "piece_legal_moves", "fen": "r4rk1/1p1bnp2/p1n1p1p1/2b3Np/q2pPQ2/P2P2N1/2P2PPP/R1B2RK1 w - - 2 17", "prompt": "FEN: r4rk1/1p1bnp2/p1n1p1p1/2b3Np/q2pPQ2/P2P2N1/2P2PPP/R1B2RK1 w - - 2 17\nWhat legal moves does the piece on f2 have?", "gold_answer": "f2f3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f2", "piece": "pawn"}}
{"example_id": "rules_01693", "split": "rules", "task_type": "check_detection", "fen": "r1b1k1nr/ppp2ppp/n7/1Nb5/3N4/3B4/PPP2PPP/R1B1K2R w KQkq - 3 10", "prompt": "FEN: r1b1k1nr/ppp2ppp/n7/1Nb5/3N4/3B4/PPP2PPP/R1B1K2R w KQkq - 3 10\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01694", "split": "rules", "task_type": "captures", "fen": "rnbq1rk1/pp2b1pp/2pp1n2/5pB1/2P1p3/2NPPN2/PP2BPPP/R2Q1RK1 w - - 0 9", "prompt": "FEN: rnbq1rk1/pp2b1pp/2pp1n2/5pB1/2P1p3/2NPPN2/PP2BPPP/R2Q1RK1 w - - 0 9\nList all capture moves available.", "gold_answer": "c3e4 d3e4 g5f6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01695", "split": "rules", "task_type": "special_rules", "fen": "5rk1/R5p1/1p5p/2pP4/2P5/5bK1/P2R3P/5r2 w - - 0 36", "prompt": "Given FEN: 5rk1/R5p1/1p5p/2pP4/2P5/5bK1/P2R3P/5r2 w - - 0 36\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01696", "split": "rules", "task_type": "legality_check", "fen": "r1bqk2r/ppp2ppp/2n5/2b1P3/2BNp3/2P1B3/PP3PPP/R2QK2R b KQkq - 2 10", "prompt": "FEN: r1bqk2r/ppp2ppp/2n5/2b1P3/2BNp3/2P1B3/PP3PPP/R2QK2R b KQkq - 2 10\nIs the move b7b5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b7b5", "_legality_check_reason_label": "legal", "move": "b7b5", "legality_reason_label": "legal"}}
{"example_id": "rules_01697", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r4k1r/p2b1ppp/2pN1n2/2p2P2/4P3/6P1/PPP3BP/R1B2RK1 w - - 1 17", "prompt": "FEN: r4k1r/p2b1ppp/2pN1n2/2p2P2/4P3/6P1/PPP3BP/R1B2RK1 w - - 1 17\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01698", "split": "rules", "task_type": "piece_legal_filter", "fen": "5rk1/4bp2/6q1/3PP1p1/1p1P4/pP3P2/P3Q3/2K4R b - - 2 40", "prompt": "FEN: 5rk1/4bp2/6q1/3PP1p1/1p1P4/pP3P2/P3Q3/2K4R b - - 2 40\nFor the piece on g8, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g8: g8g7 g8h7 g8h8.\nLegal: g8g7.\nRejected: g8h7 king_would_be_in_check; g8h8 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "g8", "diagnostic": true, "hard_gate": false, "source_square": "g8"}}
{"example_id": "rules_01699", "split": "rules", "task_type": "king_safety_filter", "fen": "r2kr3/p1pp2pp/2b2p2/8/1p1P4/2N5/PPP2PPP/R1BQ2K1 w - -", "prompt": "FEN: r2kr3/p1pp2pp/2b2p2/8/1p1P4/2N5/PPP2PPP/R1BQ2K1 w - -\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01700", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/1pk4p/2ppP2N/p7/4P1P1/8/PB3r1K/8 w - - 1 34", "prompt": "FEN: 8/1pk4p/2ppP2N/p7/4P1P1/8/PB3r1K/8 w - - 1 34\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a2 white pawn; b2 white bishop; h2 white king; e4 white pawn; g4 white pawn; e6 white pawn; h6 white knight.\nMoves by piece:\na2 white pawn: no legal moves\nb2 white bishop: no legal moves\nh2 white king: h2g1 h2g3 h2h1 h2h3\ne4 white pawn: no legal moves\ng4 white pawn: no legal moves\ne6 white pawn: no legal moves\nh6 white knight: no legal moves\nAll legal moves: h2g1 h2g3 h2h1 h2h3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a2": [], "b2": [], "h2": ["h2g1", "h2g3", "h2h1", "h2h3"], "e4": [], "g4": [], "e6": [], "h6": []}, "_legal_moves_by_piece_moves": "h2g1 h2g3 h2h1 h2h3", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a2": [], "b2": [], "h2": ["h2g1", "h2g3", "h2h1", "h2h3"], "e4": [], "g4": [], "e6": [], "h6": []}, "legal_moves": "h2g1 h2g3 h2h1 h2h3"}}
{"example_id": "rules_01701", "split": "rules", "task_type": "ray_walk", "fen": "6r1/8/3RR1pk/pbp2p2/8/1P5N/P1P2PPP/2K5 w - - 3 33", "prompt": "FEN: 6r1/8/3RR1pk/pbp2p2/8/1P5N/P1P2PPP/2K5 w - - 3 33\nWalk each ray for the slider on d6: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d6 white rook.\nRay N: d7 empty; d8 empty; edge.\nRay E: e6 white rook: own piece (stop, excluded).\nRay S: d5 empty; d4 empty; d3 empty; d2 empty; d1 empty; edge.\nRay W: c6 empty; b6 empty; a6 empty; edge.\nMoves from rays: d6a6 d6b6 d6c6 d6d1 d6d2 d6d3 d6d4 d6d5 d6d7 d6d8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "d6", "diagnostic": true, "hard_gate": false, "source_square": "d6"}}
{"example_id": "rules_01702", "split": "rules", "task_type": "legal_filter_trace", "fen": "6k1/5pp1/4p3/pr1r3p/n7/P1P3RP/5PP1/4R1K1 w - -", "prompt": "FEN: 6k1/5pp1/4p3/pr1r3p/n7/P1P3RP/5PP1/4R1K1 w - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: e1 white rook; g1 white king; f2 white pawn; g2 white pawn; a3 white pawn; c3 white pawn; g3 white rook; h3 white pawn.\nFilter by piece:\ne1 white rook: pseudo-legal e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1f1 | rejected none | legal e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1f1\ng1 white king: pseudo-legal g1f1 g1h1 g1h2 | rejected none | legal g1f1 g1h1 g1h2\nf2 white pawn: pseudo-legal f2f3 f2f4 | rejected none | legal f2f3 f2f4\ng2 white pawn: pseudo-legal none | rejected none | legal none\na3 white pawn: pseudo-legal none | rejected none | legal none\nc3 white pawn: pseudo-legal c3c4 | rejected none | legal c3c4\ng3 white rook: pseudo-legal g3d3 g3e3 g3f3 g3g4 g3g5 g3g6 g3g7 | rejected none | legal g3d3 g3e3 g3f3 g3g4 g3g5 g3g6 g3g7\nh3 white pawn: pseudo-legal h3h4 | rejected none | legal h3h4\nAll legal moves: c3c4 e1a1 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1f1 f2f3 f2f4 g1f1 g1h1 g1h2 g3d3 g3e3 g3f3 g3g4 g3g5 g3g6 g3g7 h3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01703", "split": "rules", "task_type": "legal_moves", "fen": "r1b1kbnr/1pp2ppp/p1npp2q/8/1P6/P2BPN2/1BPP1PPP/RN1QK2R w KQkq - 0 7", "prompt": "FEN: r1b1kbnr/1pp2ppp/p1npp2q/8/1P6/P2BPN2/1BPP1PPP/RN1QK2R w KQkq - 0 7\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a3a4 b1c3 b2c1 b2c3 b2d4 b2e5 b2f6 b2g7 b4b5 c2c3 c2c4 d1c1 d1e2 d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 d3g6 d3h7 e1e2 e1f1 e1g1 e3e4 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01704", "split": "rules", "task_type": "side_piece_inventory", "fen": "r2q1k2/pb3ppp/1p1p4/2pP4/2P3n1/5NP1/PPQ2PBP/4R1K1 b - -", "prompt": "FEN: r2q1k2/pb3ppp/1p1p4/2pP4/2P3n1/5NP1/PPQ2PBP/4R1K1 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: g4 black knight; c5 black pawn; b6 black pawn; d6 black pawn; a7 black pawn; b7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; d8 black queen; f8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "g4", "piece": "black knight"}, {"square": "c5", "piece": "black pawn"}, {"square": "b6", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "g4", "piece": "black knight"}, {"square": "c5", "piece": "black pawn"}, {"square": "b6", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black king"}]}}
{"example_id": "rules_01705", "split": "rules", "task_type": "piece_legal_moves", "fen": "1k6/4N3/2Q5/4K3/8/8/8/8 w - -", "prompt": "FEN: 1k6/4N3/2Q5/4K3/8/8/8/8 w - -\nWhat legal moves does the piece on e5 have?", "gold_answer": "e5d4 e5d5 e5d6 e5e4 e5e6 e5f4 e5f5 e5f6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "e5", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "e5", "piece": "king"}}
{"example_id": "rules_01706", "split": "rules", "task_type": "check_detection", "fen": "rn1qkbnr/pp2pppp/8/2pp4/3P2b1/2P2N2/PP2PPPP/RNBQKB1R w KQkq -", "prompt": "FEN: rn1qkbnr/pp2pppp/8/2pp4/3P2b1/2P2N2/PP2PPPP/RNBQKB1R w KQkq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01707", "split": "rules", "task_type": "captures", "fen": "1r1q1rk1/p4pp1/B2pb2p/2b2n2/3P4/P4N1P/1P3PP1/R1BQ1RK1 b - - 0 16", "prompt": "FEN: 1r1q1rk1/p4pp1/B2pb2p/2b2n2/3P4/P4N1P/1P3PP1/R1BQ1RK1 b - - 0 16\nList all capture moves available.", "gold_answer": "b8b2 c5a3 c5d4 f5d4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01708", "split": "rules", "task_type": "special_rules", "fen": "r1bqk1nr/pp1pppbp/6p1/4N3/4Q3/8/PPP2PPP/RNB1KB1R b KQkq -", "prompt": "Given FEN: r1bqk1nr/pp1pppbp/6p1/4N3/4Q3/8/PPP2PPP/RNB1KB1R b KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01709", "split": "rules", "task_type": "legality_check", "fen": "rn1k1b1r/pp3ppp/2p2n2/4p3/2b5/2N1B1P1/PP2PPBP/R3K1NR w KQ -", "prompt": "FEN: rn1k1b1r/pp3ppp/2p2n2/4p3/2b5/2N1B1P1/PP2PPBP/R3K1NR w KQ -\nIs the move b3h3 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "b3h3", "_legality_check_reason_label": "empty_source", "move": "b3h3", "legality_reason_label": "empty_source"}}
{"example_id": "rules_01710", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/p2rkb1p/1p2pB2/5p2/5PpP/P2qP1P1/1Q4BK/8 b - -", "prompt": "FEN: 8/p2rkb1p/1p2pB2/5p2/5PpP/P2qP1P1/1Q4BK/8 b - -\nList pseudo-legal moves from d3.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d3: d3a3 d3a6 d3b1 d3b3 d3b5 d3c2 d3c3 d3c4 d3d1 d3d2 d3d4 d3d5 d3d6 d3e2 d3e3 d3e4 d3f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d3", "diagnostic": true, "hard_gate": false, "source_square": "d3"}}
{"example_id": "rules_01711", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1b1kbnr/2ppq1pp/p7/1p2N2Q/4P3/1P6/1PP2PPP/RNB1K2R b KQkq - 2 10", "prompt": "FEN: r1b1kbnr/2ppq1pp/p7/1p2N2Q/4P3/1P6/1PP2PPP/RNB1K2R b KQkq - 2 10\nFor the piece on b5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b5: b5b4.\nLegal: none.\nRejected: b5b4 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b5", "diagnostic": true, "hard_gate": false, "source_square": "b5"}}
{"example_id": "rules_01712", "split": "rules", "task_type": "king_safety_filter", "fen": "8/p3k3/3b1p1p/2p3p1/P1R5/2P5/r5PP/5K2 w - - 1 33", "prompt": "FEN: 8/p3k3/3b1p1p/2p3p1/P1R5/2P5/r5PP/5K2 w - - 1 33\nFor move f1e2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: f1e2.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "f1e2", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "f1e2", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01713", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r5k1/pbppq1p1/np3n1p/2b1p3/1PN1P3/2PP1Q2/P4PPP/R1B2RK1 b - - 0 13", "prompt": "FEN: r5k1/pbppq1p1/np3n1p/2b1p3/1PN1P3/2PP1Q2/P4PPP/R1B2RK1 b - - 0 13\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black bishop; e5 black pawn; a6 black knight; b6 black pawn; f6 black knight; h6 black pawn; a7 black pawn; b7 black bishop; c7 black pawn; d7 black pawn; e7 black queen; g7 black pawn; a8 black rook; g8 black king.\nMoves by piece:\nc5 black bishop: c5b4 c5d4 c5d6 c5e3 c5f2\ne5 black pawn: no legal moves\na6 black knight: a6b4 a6b8\nb6 black pawn: b6b5\nf6 black knight: f6d5 f6e4 f6e8 f6g4 f6h5 f6h7\nh6 black pawn: h6h5\na7 black pawn: no legal moves\nb7 black bishop: b7c6 b7c8 b7d5 b7e4\nc7 black pawn: c7c6\nd7 black pawn: d7d5 d7d6\ne7 black queen: e7d6 e7d8 e7e6 e7e8 e7f7 e7f8\ng7 black pawn: g7g5 g7g6\na8 black rook: a8b8 a8c8 a8d8 a8e8 a8f8\ng8 black king: g8f7 g8f8 g8h7 g8h8\nAll legal moves: a6b4 a6b8 a8b8 a8c8 a8d8 a8e8 a8f8 b6b5 b7c6 b7c8 b7d5 b7e4 c5b4 c5d4 c5d6 c5e3 c5f2 c7c6 d7d5 d7d6 e7d6 e7d8 e7e6 e7e8 e7f7 e7f8 f6d5 f6e4 f6e8 f6g4 f6h5 f6h7 g7g5 g7g6 g8f7 g8f8 g8h7 g8h8 h6h5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": ["c5b4", "c5d4", "c5d6", "c5e3", "c5f2"], "e5": [], "a6": ["a6b4", "a6b8"], "b6": ["b6b5"], "f6": ["f6d5", "f6e4", "f6e8", "f6g4", "f6h5", "f6h7"], "h6": ["h6h5"], "a7": [], "b7": ["b7c6", "b7c8", "b7d5", "b7e4"], "c7": ["c7c6"], "d7": ["d7d5", "d7d6"], "e7": ["e7d6", "e7d8", "e7e6", "e7e8", "e7f7", "e7f8"], "g7": ["g7g5", "g7g6"], "a8": ["a8b8", "a8c8", "a8d8", "a8e8", "a8f8"], "g8": ["g8f7", "g8f8", "g8h7", "g8h8"]}, "_legal_moves_by_piece_moves": "a6b4 a6b8 a8b8 a8c8 a8d8 a8e8 a8f8 b6b5 b7c6 b7c8 b7d5 b7e4 c5b4 c5d4 c5d6 c5e3 c5f2 c7c6 d7d5 d7d6 e7d6 e7d8 e7e6 e7e8 e7f7 e7f8 f6d5 f6e4 f6e8 f6g4 f6h5 f6h7 g7g5 g7g6 g8f7 g8f8 g8h7 g8h8 h6h5", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": ["c5b4", "c5d4", "c5d6", "c5e3", "c5f2"], "e5": [], "a6": ["a6b4", "a6b8"], "b6": ["b6b5"], "f6": ["f6d5", "f6e4", "f6e8", "f6g4", "f6h5", "f6h7"], "h6": ["h6h5"], "a7": [], "b7": ["b7c6", "b7c8", "b7d5", "b7e4"], "c7": ["c7c6"], "d7": ["d7d5", "d7d6"], "e7": ["e7d6", "e7d8", "e7e6", "e7e8", "e7f7", "e7f8"], "g7": ["g7g5", "g7g6"], "a8": ["a8b8", "a8c8", "a8d8", "a8e8", "a8f8"], "g8": ["g8f7", "g8f8", "g8h7", "g8h8"]}, "legal_moves": "a6b4 a6b8 a8b8 a8c8 a8d8 a8e8 a8f8 b6b5 b7c6 b7c8 b7d5 b7e4 c5b4 c5d4 c5d6 c5e3 c5f2 c7c6 d7d5 d7d6 e7d6 e7d8 e7e6 e7e8 e7f7 e7f8 f6d5 f6e4 f6e8 f6g4 f6h5 f6h7 g7g5 g7g6 g8f7 g8f8 g8h7 g8h8 h6h5"}}
{"example_id": "rules_01714", "split": "rules", "task_type": "ray_walk", "fen": "rnbq1rk1/1pp2pbp/p2ppnp1/8/P1BPP3/2N2N2/1PP2PPP/R1BQ1RK1 w - -", "prompt": "FEN: rnbq1rk1/1pp2pbp/p2ppnp1/8/P1BPP3/2N2N2/1PP2PPP/R1BQ1RK1 w - -\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 empty; a3 empty; a4 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 white bishop: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1a2 a1a3 a1b1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01715", "split": "rules", "task_type": "legal_moves", "fen": "rnbqk1nr/pp5p/2p1p2b/3p1p2/3P2p1/2NBPNBP/PPP2PP1/R2QK2R w KQkq - 0 9", "prompt": "FEN: rnbqk1nr/pp5p/2p1p2b/3p1p2/3P2p1/2NBPNBP/PPP2PP1/R2QK2R w KQkq - 0 9\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a2a3 a2a4 b2b3 b2b4 c3a4 c3b1 c3b5 c3d5 c3e2 c3e4 d1b1 d1c1 d1d2 d1e2 d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 e1d2 e1e2 e1f1 e1g1 e3e4 f3d2 f3e5 f3g1 f3g5 f3h2 f3h4 g3b8 g3c7 g3d6 g3e5 g3f4 g3h2 g3h4 h1f1 h1g1 h1h2 h3g4 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01716", "split": "rules", "task_type": "legal_moves", "fen": "r2qkb1r/pppbnppp/1n1pp3/8/3PP3/1BN2N2/PPP2PPP/R1BQK2R w KQkq -", "prompt": "FEN: r2qkb1r/pppbnppp/1n1pp3/8/3PP3/1BN2N2/PPP2PPP/R1BQK2R w KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a2a3 a2a4 b3a4 b3c4 b3d5 b3e6 c1d2 c1e3 c1f4 c1g5 c1h6 c3a4 c3b1 c3b5 c3d5 c3e2 d1d2 d1d3 d1e2 d4d5 e1d2 e1e2 e1f1 e1g1 e4e5 f3d2 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01717", "split": "rules", "task_type": "side_piece_inventory", "fen": "r3k2r/pp1bbppp/1qn1p3/3pPn2/3P4/5N2/PPN1BPPP/R1BQ1RK1 w kq - 7 11", "prompt": "FEN: r3k2r/pp1bbppp/1qn1p3/3pPn2/3P4/5N2/PPN1BPPP/R1BQ1RK1 w kq - 7 11\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; c2 white knight; e2 white bishop; f2 white pawn; g2 white pawn; h2 white pawn; f3 white knight; d4 white pawn; e5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white knight"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "d4", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "c1", "piece": "white bishop"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white knight"}, {"square": "e2", "piece": "white bishop"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "d4", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}]}}
{"example_id": "rules_01718", "split": "rules", "task_type": "piece_legal_moves", "fen": "3b4/3k4/2pp4/pp5p/6rP/P5P1/3R1P1K/4R3 w - - 0 36", "prompt": "FEN: 3b4/3k4/2pp4/pp5p/6rP/P5P1/3R1P1K/4R3 w - - 0 36\nWhat legal moves does the piece on a3 have?", "gold_answer": "a3a4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a3", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "a3", "piece": "pawn"}}
{"example_id": "rules_01719", "split": "rules", "task_type": "check_detection", "fen": "6k1/5p2/1p5p/2b2R2/p1rpp1Q1/P1P4R/1P3P1P/6K1 b - - 0 42", "prompt": "FEN: 6k1/5p2/1p5p/2b2R2/p1rpp1Q1/P1P4R/1P3P1P/6K1 b - - 0 42\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01720", "split": "rules", "task_type": "captures", "fen": "rn1q1r2/pppbbkpp/3p1n2/5P2/3PP3/2N5/PPP3PP/R1BQKB1R w KQ -", "prompt": "FEN: rn1q1r2/pppbbkpp/3p1n2/5P2/3PP3/2N5/PPP3PP/R1BQKB1R w KQ -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01721", "split": "rules", "task_type": "special_rules", "fen": "6k1/1b3pp1/7p/1p6/5qQ1/2PKr1NP/1P6/R7 w - -", "prompt": "Given FEN: 6k1/1b3pp1/7p/1p6/5qQ1/2PKr1NP/1P6/R7 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01722", "split": "rules", "task_type": "legality_check", "fen": "r1b1k2r/pp1n1ppp/2p5/q2pP1B1/1bP1n3/2N1P3/PP1N1PPP/2RQKB1R w Kkq -", "prompt": "FEN: r1b1k2r/pp1n1ppp/2p5/q2pP1B1/1bP1n3/2N1P3/PP1N1PPP/2RQKB1R w Kkq -\nIs the move g2g3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "g2g3", "_legality_check_reason_label": "legal", "move": "g2g3", "legality_reason_label": "legal"}}
{"example_id": "rules_01723", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rn1qk2r/pbppbppp/1p2pn2/8/3P1P2/4PN2/PPP1B1PP/RNBQ1RK1 b kq -", "prompt": "FEN: rn1qk2r/pbppbppp/1p2pn2/8/3P1P2/4PN2/PPP1B1PP/RNBQ1RK1 b kq -\nList pseudo-legal moves from b6.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b6: b6b5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b6", "diagnostic": true, "hard_gate": false, "source_square": "b6"}}
{"example_id": "rules_01724", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1b1qrk1/pp1n2b1/2pp3p/3PppNn/2P4B/2N1P3/PPB2PPP/2RQ1RK1 w - -", "prompt": "FEN: r1b1qrk1/pp1n2b1/2pp3p/3PppNn/2P4B/2N1P3/PPB2PPP/2RQ1RK1 w - -\nFor the piece on c1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c1: c1a1 c1b1.\nLegal: c1a1 c1b1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_01725", "split": "rules", "task_type": "king_safety_filter", "fen": "2kr2n1/1pp2p1p/p1q3r1/3pP3/P2P4/R2b3P/2PQ1PP1/1N2K1NR w K - 0 19", "prompt": "FEN: 2kr2n1/1pp2p1p/p1q3r1/3pP3/P2P4/R2b3P/2PQ1PP1/1N2K1NR w K - 0 19\nFor move e1e2, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e1e2.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e1e2", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e1e2", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01726", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/8/5k2/8/5K2/5PP1/8/8 b - - 3 55", "prompt": "FEN: 8/8/5k2/8/5K2/5PP1/8/8 b - - 3 55\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: f6 black king.\nMoves by piece:\nf6 black king: f6e6 f6e7 f6f7 f6g6 f6g7\nAll legal moves: f6e6 f6e7 f6f7 f6g6 f6g7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"f6": ["f6e6", "f6e7", "f6f7", "f6g6", "f6g7"]}, "_legal_moves_by_piece_moves": "f6e6 f6e7 f6f7 f6g6 f6g7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"f6": ["f6e6", "f6e7", "f6f7", "f6g6", "f6g7"]}, "legal_moves": "f6e6 f6e7 f6f7 f6g6 f6g7"}}
{"example_id": "rules_01727", "split": "rules", "task_type": "ray_walk", "fen": "2rq1rk1/pb2bppp/1p2pn2/2n5/8/P3PNB1/1P1NBPPP/2RQ1RK1 w - - 1 14", "prompt": "FEN: 2rq1rk1/pb2bppp/1p2pn2/2n5/8/P3PNB1/1P1NBPPP/2RQ1RK1 w - - 1 14\nWalk each ray for the slider on c1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: c1 white rook.\nRay N: c2 empty; c3 empty; c4 empty; c5 black knight: capture (stop, included).\nRay E: d1 white queen: own piece (stop, excluded).\nRay S: edge.\nRay W: b1 empty; a1 empty; edge.\nMoves from rays: c1a1 c1b1 c1c2 c1c3 c1c4 c1c5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_01728", "split": "rules", "task_type": "legal_moves", "fen": "r1bq1rk1/ppp1p2p/6p1/3pbp2/3nB2P/1PP5/P4PP1/RNBQK1NR b KQ - 0 11", "prompt": "FEN: r1bq1rk1/ppp1p2p/6p1/3pbp2/3nB2P/1PP5/P4PP1/RNBQK1NR b KQ - 0 11\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c7c5 c7c6 c8d7 c8e6 d4b3 d4b5 d4c2 d4c6 d4e2 d4e6 d4f3 d5e4 d8d6 d8d7 d8e8 e5d6 e5f4 e5f6 e5g3 e5g7 e5h2 e5h8 e7e6 f5e4 f5f4 f8e8 f8f6 f8f7 g6g5 g8f7 g8g7 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01729", "split": "rules", "task_type": "legal_moves", "fen": "3r2k1/pp3ppp/8/2p5/6P1/2P2PNb/PP2rq1P/6RK w - -", "prompt": "FEN: 3r2k1/pp3ppp/8/2p5/6P1/2P2PNb/PP2rq1P/6RK w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 b2b4 c3c4 f3f4 g1a1 g1b1 g1c1 g1d1 g1e1 g1f1 g1g2 g3e2 g3e4 g3f1 g3f5 g3h5 g4g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01730", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/8/8/3K4/R7/4kp2/8/8 w - -", "prompt": "FEN: 8/8/8/3K4/R7/4kp2/8/8 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a4 white rook; d5 white king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a4", "piece": "white rook"}, {"square": "d5", "piece": "white king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a4", "piece": "white rook"}, {"square": "d5", "piece": "white king"}]}}
{"example_id": "rules_01731", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnb1kbnr/pppp1ppp/4p3/8/2PPq3/2N2N2/PP2PPPP/R1BQKB1R b KQkq - 4 4", "prompt": "FEN: rnb1kbnr/pppp1ppp/4p3/8/2PPq3/2N2N2/PP2PPPP/R1BQKB1R b KQkq - 4 4\nWhat legal moves does the piece on c7 have?", "gold_answer": "c7c5 c7c6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "c7", "piece": "pawn"}}
{"example_id": "rules_01732", "split": "rules", "task_type": "check_detection", "fen": "5rk1/Qp1n2pp/2pb4/1P1p4/8/P1NP1q2/2P3R1/4R2K b - - 3 27", "prompt": "FEN: 5rk1/Qp1n2pp/2pb4/1P1p4/8/P1NP1q2/2P3R1/4R2K b - - 3 27\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01733", "split": "rules", "task_type": "captures", "fen": "2kr3r/5p1p/p1n5/4P3/1pp1p1P1/1P2P3/P5P1/R2K1B1R w - -", "prompt": "FEN: 2kr3r/5p1p/p1n5/4P3/1pp1p1P1/1P2P3/P5P1/R2K1B1R w - -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01734", "split": "rules", "task_type": "special_rules", "fen": "r1bqkb1r/2p2ppp/p1np1n2/1p1Pp3/4P3/1B3N2/PPP2PPP/RNBQK2R b KQkq -", "prompt": "Given FEN: r1bqkb1r/2p2ppp/p1np1n2/1p1Pp3/4P3/1B3N2/PPP2PPP/RNBQK2R b KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01735", "split": "rules", "task_type": "legality_check", "fen": "rn1qkb1r/pbpppp1p/1p4pB/8/3PP3/6P1/PPP2PBP/RN1QK1NR b KQkq - 0 5", "prompt": "FEN: rn1qkb1r/pbpppp1p/1p4pB/8/3PP3/6P1/PPP2PBP/RN1QK1NR b KQkq - 0 5\nIs the move b8c6 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b8c6", "_legality_check_reason_label": "legal", "move": "b8c6", "legality_reason_label": "legal"}}
{"example_id": "rules_01736", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "4k3/2p5/3p1p2/4pP2/2P3P1/PQ1P2P1/4K3/6n1 w - - 5 46", "prompt": "FEN: 4k3/2p5/3p1p2/4pP2/2P3P1/PQ1P2P1/4K3/6n1 w - - 5 46\nList pseudo-legal moves from e2.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e2: e2d1 e2d2 e2e1 e2e3 e2f1 e2f2 e2f3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e2", "diagnostic": true, "hard_gate": false, "source_square": "e2"}}
{"example_id": "rules_01737", "split": "rules", "task_type": "piece_legal_filter", "fen": "7k/5R1p/1N4p1/1Kp5/2Pb4/8/1r6/8 w - - 1 46", "prompt": "FEN: 7k/5R1p/1N4p1/1Kp5/2Pb4/8/1r6/8 w - - 1 46\nFor the piece on b5, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b5: b5a4 b5a5 b5a6 b5b4 b5c5 b5c6.\nLegal: b5a4 b5a5 b5a6 b5c6.\nRejected: b5b4 does_not_resolve_check; b5c5 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b5", "diagnostic": true, "hard_gate": false, "source_square": "b5"}}
{"example_id": "rules_01738", "split": "rules", "task_type": "king_safety_filter", "fen": "8/8/3k4/Q4B2/5K2/8/8/8 w - -", "prompt": "FEN: 8/8/3k4/Q4B2/5K2/8/8/8 w - -\nFor move f4e5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: f4e5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "f4e5", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "f4e5", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01739", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r3r1k1/pp3pp1/1q4b1/3R1p1p/1P5P/P1N1pPPB/2P1Qn2/5RK1 w - - 1 21", "prompt": "FEN: r3r1k1/pp3pp1/1q4b1/3R1p1p/1P5P/P1N1pPPB/2P1Qn2/5RK1 w - - 1 21\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: f1 white rook; g1 white king; c2 white pawn; e2 white queen; a3 white pawn; c3 white knight; f3 white pawn; g3 white pawn; h3 white bishop; b4 white pawn; h4 white pawn; d5 white rook.\nMoves by piece:\nf1 white rook: f1a1 f1b1 f1c1 f1d1 f1e1 f1f2\ng1 white king: g1g2 g1h2\nc2 white pawn: no legal moves\ne2 white queen: e2a6 e2b5 e2c4 e2d1 e2d2 e2d3 e2e1 e2e3 e2f2\na3 white pawn: a3a4\nc3 white knight: c3a2 c3a4 c3b1 c3b5 c3d1 c3e4\nf3 white pawn: f3f4\ng3 white pawn: g3g4\nh3 white bishop: h3f5 h3g2 h3g4\nb4 white pawn: b4b5\nh4 white pawn: no legal moves\nd5 white rook: d5a5 d5b5 d5c5 d5d1 d5d2 d5d3 d5d4 d5d6 d5d7 d5d8 d5e5 d5f5\nAll legal moves: a3a4 b4b5 c3a2 c3a4 c3b1 c3b5 c3d1 c3e4 d5a5 d5b5 d5c5 d5d1 d5d2 d5d3 d5d4 d5d6 d5d7 d5d8 d5e5 d5f5 e2a6 e2b5 e2c4 e2d1 e2d2 e2d3 e2e1 e2e3 e2f2 f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f3f4 g1g2 g1h2 g3g4 h3f5 h3g2 h3g4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"f1": ["f1a1", "f1b1", "f1c1", "f1d1", "f1e1", "f1f2"], "g1": ["g1g2", "g1h2"], "c2": [], "e2": ["e2a6", "e2b5", "e2c4", "e2d1", "e2d2", "e2d3", "e2e1", "e2e3", "e2f2"], "a3": ["a3a4"], "c3": ["c3a2", "c3a4", "c3b1", "c3b5", "c3d1", "c3e4"], "f3": ["f3f4"], "g3": ["g3g4"], "h3": ["h3f5", "h3g2", "h3g4"], "b4": ["b4b5"], "h4": [], "d5": ["d5a5", "d5b5", "d5c5", "d5d1", "d5d2", "d5d3", "d5d4", "d5d6", "d5d7", "d5d8", "d5e5", "d5f5"]}, "_legal_moves_by_piece_moves": "a3a4 b4b5 c3a2 c3a4 c3b1 c3b5 c3d1 c3e4 d5a5 d5b5 d5c5 d5d1 d5d2 d5d3 d5d4 d5d6 d5d7 d5d8 d5e5 d5f5 e2a6 e2b5 e2c4 e2d1 e2d2 e2d3 e2e1 e2e3 e2f2 f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f3f4 g1g2 g1h2 g3g4 h3f5 h3g2 h3g4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"f1": ["f1a1", "f1b1", "f1c1", "f1d1", "f1e1", "f1f2"], "g1": ["g1g2", "g1h2"], "c2": [], "e2": ["e2a6", "e2b5", "e2c4", "e2d1", "e2d2", "e2d3", "e2e1", "e2e3", "e2f2"], "a3": ["a3a4"], "c3": ["c3a2", "c3a4", "c3b1", "c3b5", "c3d1", "c3e4"], "f3": ["f3f4"], "g3": ["g3g4"], "h3": ["h3f5", "h3g2", "h3g4"], "b4": ["b4b5"], "h4": [], "d5": ["d5a5", "d5b5", "d5c5", "d5d1", "d5d2", "d5d3", "d5d4", "d5d6", "d5d7", "d5d8", "d5e5", "d5f5"]}, "legal_moves": "a3a4 b4b5 c3a2 c3a4 c3b1 c3b5 c3d1 c3e4 d5a5 d5b5 d5c5 d5d1 d5d2 d5d3 d5d4 d5d6 d5d7 d5d8 d5e5 d5f5 e2a6 e2b5 e2c4 e2d1 e2d2 e2d3 e2e1 e2e3 e2f2 f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f3f4 g1g2 g1h2 g3g4 h3f5 h3g2 h3g4"}}
{"example_id": "rules_01740", "split": "rules", "task_type": "ray_walk", "fen": "8/5k2/6p1/5P2/6P1/r7/6K1/4R3 b - -", "prompt": "FEN: 8/5k2/6p1/5P2/6P1/r7/6K1/4R3 b - -\nWalk each ray for the slider on a3: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a3 black rook.\nRay N: a4 empty; a5 empty; a6 empty; a7 empty; a8 empty; edge.\nRay E: b3 empty; c3 empty; d3 empty; e3 empty; f3 empty; g3 empty; h3 empty; edge.\nRay S: a2 empty; a1 empty; edge.\nRay W: edge.\nMoves from rays: a3a1 a3a2 a3a4 a3a5 a3a6 a3a7 a3a8 a3b3 a3c3 a3d3 a3e3 a3f3 a3g3 a3h3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a3", "diagnostic": true, "hard_gate": false, "source_square": "a3"}}
{"example_id": "rules_01741", "split": "rules", "task_type": "legal_moves", "fen": "6n1/3B1kbr/1p1Bp3/3p4/3P2np/1Pr5/P1P2PPP/R3R1K1 w - - 0 28", "prompt": "FEN: 6n1/3B1kbr/1p1Bp3/3p4/3P2np/1Pr5/P1P2PPP/R3R1K1 w - - 0 28\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a1d1 a2a3 a2a4 b3b4 d6a3 d6b4 d6b8 d6c5 d6c7 d6e5 d6e7 d6f4 d6f8 d6g3 d7a4 d7b5 d7c6 d7c8 d7e6 d7e8 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1f1 f2f3 f2f4 g1f1 g1h1 g2g3 h2h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01742", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/3nbppp/pp2pn2/1Np5/P7/1P3N2/1BPP1PPP/R2QR1K1 w - - 0 13", "prompt": "FEN: r2q1rk1/3nbppp/pp2pn2/1Np5/P7/1P3N2/1BPP1PPP/R2QR1K1 w - - 0 13\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 a1b1 a1c1 a4a5 b2a3 b2c1 b2c3 b2d4 b2e5 b2f6 b3b4 b5a3 b5a7 b5c3 b5c7 b5d4 b5d6 c2c3 c2c4 d1b1 d1c1 d1e2 d2d3 d2d4 e1e2 e1e3 e1e4 e1e5 e1e6 e1f1 f3d4 f3e5 f3g5 f3h4 g1f1 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01743", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqk1nr/ppp2ppp/1N1p4/8/1PB1P3/8/P1Q2PPP/R1B2RK1 b kq - 0 11", "prompt": "FEN: r1bqk1nr/ppp2ppp/1N1p4/8/1PB1P3/8/P1Q2PPP/R1B2RK1 b kq - 0 11\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: d6 black pawn; a7 black pawn; b7 black pawn; c7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black king; g8 black knight; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "d6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "d6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "e8", "piece": "black king"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_01744", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bqr1k1/1p3pbp/n1pp1np1/4p3/1PP5/2NP1NP1/3BPPBP/1RQ2RK1 w - -", "prompt": "FEN: r1bqr1k1/1p3pbp/n1pp1np1/4p3/1PP5/2NP1NP1/3BPPBP/1RQ2RK1 w - -\nWhat legal moves does the piece on c3 have?", "gold_answer": "c3a2 c3a4 c3b5 c3d1 c3d5 c3e4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "c3", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "c3", "piece": "knight"}}
{"example_id": "rules_01745", "split": "rules", "task_type": "check_detection", "fen": "rn1qk2r/ppp2ppp/4pn2/3p4/1b1P2b1/5NP1/PPP1PPBP/RNBQ1RK1 w kq -", "prompt": "FEN: rn1qk2r/ppp2ppp/4pn2/3p4/1b1P2b1/5NP1/PPP1PPBP/RNBQ1RK1 w kq -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01746", "split": "rules", "task_type": "captures", "fen": "rnbqk2r/pppp1ppp/3Bp3/8/3Pn3/5P2/PPP1P1PP/RN1QKBNR b KQkq -", "prompt": "FEN: rnbqk2r/pppp1ppp/3Bp3/8/3Pn3/5P2/PPP1P1PP/RN1QKBNR b KQkq -\nList all capture moves available.", "gold_answer": "c7d6 e4d6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01747", "split": "rules", "task_type": "special_rules", "fen": "r1bq1rk1/pp1p1ppp/5n2/2p1p3/1nP1P3/1QNP1N2/1P3PPP/R1B1KB1R b KQ - 0 8", "prompt": "Given FEN: r1bq1rk1/pp1p1ppp/5n2/2p1p3/1nP1P3/1QNP1N2/1P3PPP/R1B1KB1R b KQ - 0 8\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01748", "split": "rules", "task_type": "legality_check", "fen": "r2qkb1r/4pppp/4b3/nB1n4/Q2P4/5N2/PP3PPP/R1B1K2R b KQkq -", "prompt": "FEN: r2qkb1r/4pppp/4b3/nB1n4/Q2P4/5N2/PP3PPP/R1B1K2R b KQkq -\nIs the move d1h2 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "d1h2", "_legality_check_reason_label": "empty_source", "move": "d1h2", "legality_reason_label": "empty_source"}}
{"example_id": "rules_01749", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/pp6/3pk3/1P2p3/1nP3p1/6K1/8/8 b - - 3 43", "prompt": "FEN: 8/pp6/3pk3/1P2p3/1nP3p1/6K1/8/8 b - - 3 43\nList pseudo-legal moves from b4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b4: b4a2 b4a6 b4c2 b4c6 b4d3 b4d5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_01750", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/8/5p2/3k4/6P1/6P1/6K1/8 w - -", "prompt": "FEN: 8/8/5p2/3k4/6P1/6P1/6K1/8 w - -\nFor the piece on g2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g2: g2f1 g2f2 g2f3 g2g1 g2h1 g2h2 g2h3.\nLegal: g2f1 g2f2 g2f3 g2g1 g2h1 g2h2 g2h3.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "g2", "diagnostic": true, "hard_gate": false, "source_square": "g2"}}
{"example_id": "rules_01751", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bqkbnr/pp2pppp/2p5/n2P4/Q1p5/2N5/PP2PPPP/R1B1KBNR w KQkq -", "prompt": "FEN: r1bqkbnr/pp2pppp/2p5/n2P4/Q1p5/2N5/PP2PPPP/R1B1KBNR w KQkq -\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01752", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2k2b1r/1b1r1qpp/1Bnp4/1B2p3/1P2n3/2P2PP1/R6P/1N1QK1NR w K - 0 19", "prompt": "FEN: 2k2b1r/1b1r1qpp/1Bnp4/1B2p3/1P2n3/2P2PP1/R6P/1N1QK1NR w K - 0 19\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: b1 white knight; d1 white queen; e1 white king; g1 white knight; h1 white rook; a2 white rook; h2 white pawn; c3 white pawn; f3 white pawn; g3 white pawn; b4 white pawn; b5 white bishop; b6 white bishop.\nMoves by piece:\nb1 white knight: b1a3 b1d2\nd1 white queen: d1a4 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1d5 d1d6 d1e2\ne1 white king: e1e2 e1f1\ng1 white knight: g1e2 g1h3\nh1 white rook: no legal moves\na2 white rook: a2a1 a2a3 a2a4 a2a5 a2a6 a2a7 a2a8 a2b2 a2c2 a2d2 a2e2 a2f2 a2g2\nh2 white pawn: h2h3 h2h4\nc3 white pawn: c3c4\nf3 white pawn: f3e4 f3f4\ng3 white pawn: g3g4\nb4 white pawn: no legal moves\nb5 white bishop: b5a4 b5a6 b5c4 b5c6 b5d3 b5e2 b5f1\nb6 white bishop: b6a5 b6a7 b6c5 b6c7 b6d4 b6d8 b6e3 b6f2\nAll legal moves: a2a1 a2a3 a2a4 a2a5 a2a6 a2a7 a2a8 a2b2 a2c2 a2d2 a2e2 a2f2 a2g2 b1a3 b1d2 b5a4 b5a6 b5c4 b5c6 b5d3 b5e2 b5f1 b6a5 b6a7 b6c5 b6c7 b6d4 b6d8 b6e3 b6f2 c3c4 d1a4 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1d5 d1d6 d1e2 e1e2 e1f1 f3e4 f3f4 g1e2 g1h3 g3g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b1": ["b1a3", "b1d2"], "d1": ["d1a4", "d1b3", "d1c1", "d1c2", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1e2"], "e1": ["e1e2", "e1f1"], "g1": ["g1e2", "g1h3"], "h1": [], "a2": ["a2a1", "a2a3", "a2a4", "a2a5", "a2a6", "a2a7", "a2a8", "a2b2", "a2c2", "a2d2", "a2e2", "a2f2", "a2g2"], "h2": ["h2h3", "h2h4"], "c3": ["c3c4"], "f3": ["f3e4", "f3f4"], "g3": ["g3g4"], "b4": [], "b5": ["b5a4", "b5a6", "b5c4", "b5c6", "b5d3", "b5e2", "b5f1"], "b6": ["b6a5", "b6a7", "b6c5", "b6c7", "b6d4", "b6d8", "b6e3", "b6f2"]}, "_legal_moves_by_piece_moves": "a2a1 a2a3 a2a4 a2a5 a2a6 a2a7 a2a8 a2b2 a2c2 a2d2 a2e2 a2f2 a2g2 b1a3 b1d2 b5a4 b5a6 b5c4 b5c6 b5d3 b5e2 b5f1 b6a5 b6a7 b6c5 b6c7 b6d4 b6d8 b6e3 b6f2 c3c4 d1a4 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1d5 d1d6 d1e2 e1e2 e1f1 f3e4 f3f4 g1e2 g1h3 g3g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b1": ["b1a3", "b1d2"], "d1": ["d1a4", "d1b3", "d1c1", "d1c2", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1e2"], "e1": ["e1e2", "e1f1"], "g1": ["g1e2", "g1h3"], "h1": [], "a2": ["a2a1", "a2a3", "a2a4", "a2a5", "a2a6", "a2a7", "a2a8", "a2b2", "a2c2", "a2d2", "a2e2", "a2f2", "a2g2"], "h2": ["h2h3", "h2h4"], "c3": ["c3c4"], "f3": ["f3e4", "f3f4"], "g3": ["g3g4"], "b4": [], "b5": ["b5a4", "b5a6", "b5c4", "b5c6", "b5d3", "b5e2", "b5f1"], "b6": ["b6a5", "b6a7", "b6c5", "b6c7", "b6d4", "b6d8", "b6e3", "b6f2"]}, "legal_moves": "a2a1 a2a3 a2a4 a2a5 a2a6 a2a7 a2a8 a2b2 a2c2 a2d2 a2e2 a2f2 a2g2 b1a3 b1d2 b5a4 b5a6 b5c4 b5c6 b5d3 b5e2 b5f1 b6a5 b6a7 b6c5 b6c7 b6d4 b6d8 b6e3 b6f2 c3c4 d1a4 d1b3 d1c1 d1c2 d1d2 d1d3 d1d4 d1d5 d1d6 d1e2 e1e2 e1f1 f3e4 f3f4 g1e2 g1h3 g3g4 h2h3 h2h4"}}
{"example_id": "rules_01753", "split": "rules", "task_type": "ray_walk", "fen": "1r6/4q1bk/3p2pp/p1pBp3/1pP1P3/3P1N2/PP1N1PPR/2K4R b - - 1 27", "prompt": "FEN: 1r6/4q1bk/3p2pp/p1pBp3/1pP1P3/3P1N2/PP1N1PPR/2K4R b - - 1 27\nWalk each ray for the slider on e7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e7 black queen.\nRay N: e8 empty; edge.\nRay NE: f8 empty; edge.\nRay E: f7 empty; g7 black bishop: own piece (stop, excluded).\nRay SE: f6 empty; g5 empty; h4 empty; edge.\nRay S: e6 empty; e5 black pawn: own piece (stop, excluded).\nRay SW: d6 black pawn: own piece (stop, excluded).\nRay W: d7 empty; c7 empty; b7 empty; a7 empty; edge.\nRay NW: d8 empty; edge.\nMoves from rays: e7a7 e7b7 e7c7 e7d7 e7d8 e7e6 e7e8 e7f6 e7f7 e7f8 e7g5 e7h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "e7", "diagnostic": true, "hard_gate": false, "source_square": "e7"}}
{"example_id": "rules_01754", "split": "rules", "task_type": "legal_moves", "fen": "r2qkb1r/pp1npp1p/2p2np1/3p1b2/3P4/BP3NP1/P1P1PPBP/RN1QK2R w KQkq - 0 7", "prompt": "FEN: r2qkb1r/pp1npp1p/2p2np1/3p1b2/3P4/BP3NP1/P1P1PPBP/RN1QK2R w KQkq - 0 7\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3b2 a3b4 a3c1 a3c5 a3d6 a3e7 b1c3 b1d2 b3b4 c2c3 c2c4 d1c1 d1d2 d1d3 e1d2 e1f1 e1g1 e2e3 e2e4 f3d2 f3e5 f3g1 f3g5 f3h4 g2f1 g2h3 g3g4 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01755", "split": "rules", "task_type": "legal_moves", "fen": "8/8/5kpp/3p1p2/Pb3PP1/4K2P/PpB5/8 b - - 6 48", "prompt": "FEN: 8/8/5kpp/3p1p2/Pb3PP1/4K2P/PpB5/8 b - - 6 48\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b2b1b b2b1n b2b1q b2b1r b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7 b4f8 d5d4 f5g4 f6e6 f6e7 f6f7 f6g7 g6g5 h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01756", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/1b6/5k2/5p2/BP3P1K/P7/8/8 b - -", "prompt": "FEN: 8/1b6/5k2/5p2/BP3P1K/P7/8/8 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: f5 black pawn; f6 black king; b7 black bishop.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "f5", "piece": "black pawn"}, {"square": "f6", "piece": "black king"}, {"square": "b7", "piece": "black bishop"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "f5", "piece": "black pawn"}, {"square": "f6", "piece": "black king"}, {"square": "b7", "piece": "black bishop"}]}}
{"example_id": "rules_01757", "split": "rules", "task_type": "piece_legal_moves", "fen": "rnbqkb1r/ppp2ppp/1n1pp3/4P3/8/1B3N2/PPPP1PPP/RNBQK2R w KQkq - 0 6", "prompt": "FEN: rnbqkb1r/ppp2ppp/1n1pp3/4P3/8/1B3N2/PPPP1PPP/RNBQK2R w KQkq - 0 6\nWhat legal moves does the piece on b2 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "b2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "b2", "piece": "pawn"}}
{"example_id": "rules_01758", "split": "rules", "task_type": "check_detection", "fen": "rn3rk1/pQ4bp/2p1P3/4p3/4q3/3B3P/PPK2pP1/3R3R b - - 3 20", "prompt": "FEN: rn3rk1/pQ4bp/2p1P3/4p3/4q3/3B3P/PPK2pP1/3R3R b - - 3 20\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01759", "split": "rules", "task_type": "captures", "fen": "r3kb1r/pbq2ppp/1pn1p3/2ppPn2/5P2/2PP2P1/PP1NN1BP/R1BQ1RK1 b kq - 4 10", "prompt": "FEN: r3kb1r/pbq2ppp/1pn1p3/2ppPn2/5P2/2PP2P1/PP1NN1BP/R1BQ1RK1 b kq - 4 10\nList all capture moves available.", "gold_answer": "c6e5 c7e5 f5g3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01760", "split": "rules", "task_type": "special_rules", "fen": "r1bqk2r/p4ppp/2pb4/n3p3/8/3P1N2/PP1P1PPP/RNBQR1K1 b kq -", "prompt": "Given FEN: r1bqk2r/p4ppp/2pb4/n3p3/8/3P1N2/PP1P1PPP/RNBQR1K1 b kq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01761", "split": "rules", "task_type": "legality_check", "fen": "8/8/6p1/1R4k1/nP4N1/7P/6P1/6K1 b - - 0 51", "prompt": "FEN: 8/8/6p1/1R4k1/nP4N1/7P/6P1/6K1 b - - 0 51\nIs the move a4c5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "a4c5", "_legality_check_reason_label": "legal", "move": "a4c5", "legality_reason_label": "legal"}}
{"example_id": "rules_01762", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "1K6/P2q4/8/8/4k3/8/8/8 b - - 6 61", "prompt": "FEN: 1K6/P2q4/8/8/4k3/8/8/8 b - - 6 61\nList pseudo-legal moves from e4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from e4: e4d3 e4d4 e4d5 e4e3 e4e5 e4f3 e4f4 e4f5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "e4", "diagnostic": true, "hard_gate": false, "source_square": "e4"}}
{"example_id": "rules_01763", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/5p2/7p/2n5/3K4/1k2N2P/1rp2PP1/2R5 b - - 2 41", "prompt": "FEN: 8/5p2/7p/2n5/3K4/1k2N2P/1rp2PP1/2R5 b - - 2 41\nFor the piece on b3, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b3: b3a2 b3a3 b3a4 b3b4 b3c3 b3c4.\nLegal: b3a2 b3a3 b3a4 b3b4.\nRejected: b3c3 king_would_be_in_check; b3c4 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b3", "diagnostic": true, "hard_gate": false, "source_square": "b3"}}
{"example_id": "rules_01764", "split": "rules", "task_type": "king_safety_filter", "fen": "3r2k1/3b1p2/2p1p1p1/p1p1P2p/P1Pp1P2/1r1P4/1P2K1PP/1RB3R1 w - -", "prompt": "FEN: 3r2k1/3b1p2/2p1p1p1/p1p1P2p/P1Pp1P2/1r1P4/1P2K1PP/1RB3R1 w - -\nFor move e2e3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e2e3.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "e2e3", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e2e3", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01765", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/p6p/k4pp1/8/2r2B2/2P5/PP3PPP/3R1RK1 w - - 1 25", "prompt": "FEN: 8/p6p/k4pp1/8/2r2B2/2P5/PP3PPP/3R1RK1 w - - 1 25\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: d1 white rook; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white pawn; f4 white bishop.\nMoves by piece:\nd1 white rook: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1\nf1 white rook: f1e1\ng1 white king: g1h1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nf2 white pawn: f2f3\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nc3 white pawn: no legal moves\nf4 white bishop: f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4g5 f4h6\nAll legal moves: a2a3 a2a4 b2b3 b2b4 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 f1e1 f2f3 f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4g5 f4h6 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d1": ["d1a1", "d1b1", "d1c1", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1d7", "d1d8", "d1e1"], "f1": ["f1e1"], "g1": ["g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": ["f2f3"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c3": [], "f4": ["f4b8", "f4c1", "f4c7", "f4d2", "f4d6", "f4e3", "f4e5", "f4g3", "f4g5", "f4h6"]}, "_legal_moves_by_piece_moves": "a2a3 a2a4 b2b3 b2b4 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 f1e1 f2f3 f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4g5 f4h6 g1h1 g2g3 g2g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d1": ["d1a1", "d1b1", "d1c1", "d1d2", "d1d3", "d1d4", "d1d5", "d1d6", "d1d7", "d1d8", "d1e1"], "f1": ["f1e1"], "g1": ["g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": ["f2f3"], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c3": [], "f4": ["f4b8", "f4c1", "f4c7", "f4d2", "f4d6", "f4e3", "f4e5", "f4g3", "f4g5", "f4h6"]}, "legal_moves": "a2a3 a2a4 b2b3 b2b4 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 f1e1 f2f3 f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4g5 f4h6 g1h1 g2g3 g2g4 h2h3 h2h4"}}
{"example_id": "rules_01766", "split": "rules", "task_type": "ray_walk", "fen": "6k1/1p1r1ppp/p4nq1/P2p4/3NpB2/2P4r/1P1R2P1/R4NK1 b - - 1 26", "prompt": "FEN: 6k1/1p1r1ppp/p4nq1/P2p4/3NpB2/2P4r/1P1R2P1/R4NK1 b - - 1 26\nWalk each ray for the slider on h3: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: h3 black rook.\nRay N: h4 empty; h5 empty; h6 empty; h7 black pawn: own piece (stop, excluded).\nRay E: edge.\nRay S: h2 empty; h1 empty; edge.\nRay W: g3 empty; f3 empty; e3 empty; d3 empty; c3 white pawn: capture (stop, included).\nMoves from rays: h3c3 h3d3 h3e3 h3f3 h3g3 h3h1 h3h2 h3h4 h3h5 h3h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "h3", "diagnostic": true, "hard_gate": false, "source_square": "h3"}}
{"example_id": "rules_01767", "split": "rules", "task_type": "legal_moves", "fen": "r2qk2r/pp3ppp/2nbbn2/2ppp3/8/1P2P1P1/PBPPNPBP/RN1Q1RK1 w kq -", "prompt": "FEN: r2qk2r/pp3ppp/2nbbn2/2ppp3/8/1P2P1P1/PBPPNPBP/RN1Q1RK1 w kq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b1a3 b1c3 b2a3 b2c1 b2c3 b2d4 b2e5 b3b4 c2c3 c2c4 d1c1 d1e1 d2d3 d2d4 e2c1 e2c3 e2d4 e2f4 e3e4 f1e1 f2f3 f2f4 g1h1 g2d5 g2e4 g2f3 g2h1 g2h3 g3g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01768", "split": "rules", "task_type": "legal_moves", "fen": "2q3k1/p2n1pp1/bpr1p2p/3p4/3P1B2/PPb1P1NP/1Q3PP1/1B1R2K1 w - -", "prompt": "FEN: 2q3k1/p2n1pp1/bpr1p2p/3p4/3P1B2/PPb1P1NP/1Q3PP1/1B1R2K1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a4 b1a2 b1c2 b1d3 b1e4 b1f5 b1g6 b1h7 b2a1 b2a2 b2c1 b2c2 b2c3 b2d2 b2e2 b3b4 d1c1 d1d2 d1d3 d1e1 d1f1 e3e4 f2f3 f4b8 f4c7 f4d6 f4e5 f4g5 f4h6 g1h1 g1h2 g3e2 g3e4 g3f1 g3f5 g3h1 g3h5 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01769", "split": "rules", "task_type": "side_piece_inventory", "fen": "r3k2r/1bq1bppp/p1nppn2/1p6/4P2P/PNN1B1Q1/1PP1BPP1/R4RK1 b kq -", "prompt": "FEN: r3k2r/1bq1bppp/p1nppn2/1p6/4P2P/PNN1B1Q1/1PP1BPP1/R4RK1 b kq -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: b5 black pawn; a6 black pawn; c6 black knight; d6 black pawn; e6 black pawn; f6 black knight; b7 black bishop; c7 black queen; e7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; e8 black king; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "b5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "d6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "b7", "piece": "black bishop"}, {"square": "c7", "piece": "black queen"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "b5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "c6", "piece": "black knight"}, {"square": "d6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "f6", "piece": "black knight"}, {"square": "b7", "piece": "black bishop"}, {"square": "c7", "piece": "black queen"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "e8", "piece": "black king"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_01770", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1b1kb1r/1pp1pppp/p1n5/2Pp4/1P1P2n1/4P3/P2BBPPP/RN2K1NR b KQkq - 1 8", "prompt": "FEN: r1b1kb1r/1pp1pppp/p1n5/2Pp4/1P1P2n1/4P3/P2BBPPP/RN2K1NR b KQkq - 1 8\nWhat legal moves does the piece on f7 have?", "gold_answer": "f7f5 f7f6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f7", "piece": "pawn"}}
{"example_id": "rules_01771", "split": "rules", "task_type": "check_detection", "fen": "8/2k5/p7/2p1K3/1pP5/1P6/P7/8 w - -", "prompt": "FEN: 8/2k5/p7/2p1K3/1pP5/1P6/P7/8 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01772", "split": "rules", "task_type": "captures", "fen": "r1bqk2r/1p3ppp/p1n1pn2/3pB3/3P4/2N1P3/PP2BPPP/R2QK2R b KQkq -", "prompt": "FEN: r1bqk2r/1p3ppp/p1n1pn2/3pB3/3P4/2N1P3/PP2BPPP/R2QK2R b KQkq -\nList all capture moves available.", "gold_answer": "c6d4 c6e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01773", "split": "rules", "task_type": "special_rules", "fen": "r5k1/q4pp1/3b1n2/p1p4p/P2p1P2/1P1P1QP1/3B3P/R4RK1 b - - 0 26", "prompt": "Given FEN: r5k1/q4pp1/3b1n2/p1p4p/P2p1P2/1P1P1QP1/3B3P/R4RK1 b - - 0 26\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01774", "split": "rules", "task_type": "legality_check", "fen": "rnbqk2r/ppppb2p/4pnpP/5pB1/3P4/2N5/PPP1PPP1/R2QKBNR b KQkq -", "prompt": "FEN: rnbqk2r/ppppb2p/4pnpP/5pB1/3P4/2N5/PPP1PPP1/R2QKBNR b KQkq -\nIs the move f6g4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f6g4", "_legality_check_reason_label": "legal", "move": "f6g4", "legality_reason_label": "legal"}}
{"example_id": "rules_01775", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r2qr1k1/p4pp1/2p1bn1p/3p4/1b3B2/P1NB1Q1P/1PP2PP1/3R1RK1 b - -", "prompt": "FEN: r2qr1k1/p4pp1/2p1bn1p/3p4/1b3B2/P1NB1Q1P/1PP2PP1/3R1RK1 b - -\nList pseudo-legal moves from b4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b4: b4a3 b4a5 b4c3 b4c5 b4d6 b4e7 b4f8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b4", "diagnostic": true, "hard_gate": false, "source_square": "b4"}}
{"example_id": "rules_01776", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/1k5p/1p4p1/1N6/2P5/1P3RB1/P1r3rP/R4K2 b - - 2 31", "prompt": "FEN: 8/1k5p/1p4p1/1N6/2P5/1P3RB1/P1r3rP/R4K2 b - - 2 31\nFor the piece on b7, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b7: b7a6 b7a7 b7a8 b7b8 b7c6 b7c7 b7c8.\nLegal: b7a6 b7a8 b7c6 b7c8.\nRejected: b7a7 king_would_be_in_check; b7b8 king_would_be_in_check; b7c7 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b7", "diagnostic": true, "hard_gate": false, "source_square": "b7"}}
{"example_id": "rules_01777", "split": "rules", "task_type": "king_safety_filter", "fen": "r1bqk1nr/1p2bppp/p1n5/2pB4/8/2N5/PPPPQPPP/R1B1K1NR w KQkq - 3 8", "prompt": "FEN: r1bqk1nr/1p2bppp/p1n5/2pB4/8/2N5/PPPPQPPP/R1B1K1NR w KQkq - 3 8\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01778", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/3B1k2/8/8/3Q4/4K3/8/8 w - -", "prompt": "FEN: 8/3B1k2/8/8/3Q4/4K3/8/8 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: e3 white king; d4 white queen; d7 white bishop.\nMoves by piece:\ne3 white king: e3d2 e3d3 e3e2 e3e4 e3f2 e3f3 e3f4\nd4 white queen: d4a1 d4a4 d4a7 d4b2 d4b4 d4b6 d4c3 d4c4 d4c5 d4d1 d4d2 d4d3 d4d5 d4d6 d4e4 d4e5 d4f4 d4f6 d4g4 d4g7 d4h4 d4h8\nd7 white bishop: d7a4 d7b5 d7c6 d7c8 d7e6 d7e8 d7f5 d7g4 d7h3\nAll legal moves: d4a1 d4a4 d4a7 d4b2 d4b4 d4b6 d4c3 d4c4 d4c5 d4d1 d4d2 d4d3 d4d5 d4d6 d4e4 d4e5 d4f4 d4f6 d4g4 d4g7 d4h4 d4h8 d7a4 d7b5 d7c6 d7c8 d7e6 d7e8 d7f5 d7g4 d7h3 e3d2 e3d3 e3e2 e3e4 e3f2 e3f3 e3f4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e3": ["e3d2", "e3d3", "e3e2", "e3e4", "e3f2", "e3f3", "e3f4"], "d4": ["d4a1", "d4a4", "d4a7", "d4b2", "d4b4", "d4b6", "d4c3", "d4c4", "d4c5", "d4d1", "d4d2", "d4d3", "d4d5", "d4d6", "d4e4", "d4e5", "d4f4", "d4f6", "d4g4", "d4g7", "d4h4", "d4h8"], "d7": ["d7a4", "d7b5", "d7c6", "d7c8", "d7e6", "d7e8", "d7f5", "d7g4", "d7h3"]}, "_legal_moves_by_piece_moves": "d4a1 d4a4 d4a7 d4b2 d4b4 d4b6 d4c3 d4c4 d4c5 d4d1 d4d2 d4d3 d4d5 d4d6 d4e4 d4e5 d4f4 d4f6 d4g4 d4g7 d4h4 d4h8 d7a4 d7b5 d7c6 d7c8 d7e6 d7e8 d7f5 d7g4 d7h3 e3d2 e3d3 e3e2 e3e4 e3f2 e3f3 e3f4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e3": ["e3d2", "e3d3", "e3e2", "e3e4", "e3f2", "e3f3", "e3f4"], "d4": ["d4a1", "d4a4", "d4a7", "d4b2", "d4b4", "d4b6", "d4c3", "d4c4", "d4c5", "d4d1", "d4d2", "d4d3", "d4d5", "d4d6", "d4e4", "d4e5", "d4f4", "d4f6", "d4g4", "d4g7", "d4h4", "d4h8"], "d7": ["d7a4", "d7b5", "d7c6", "d7c8", "d7e6", "d7e8", "d7f5", "d7g4", "d7h3"]}, "legal_moves": "d4a1 d4a4 d4a7 d4b2 d4b4 d4b6 d4c3 d4c4 d4c5 d4d1 d4d2 d4d3 d4d5 d4d6 d4e4 d4e5 d4f4 d4f6 d4g4 d4g7 d4h4 d4h8 d7a4 d7b5 d7c6 d7c8 d7e6 d7e8 d7f5 d7g4 d7h3 e3d2 e3d3 e3e2 e3e4 e3f2 e3f3 e3f4"}}
{"example_id": "rules_01779", "split": "rules", "task_type": "legal_moves", "fen": "8/5k2/3K4/4Q3/8/3B4/8/8 b - -", "prompt": "FEN: 8/5k2/3K4/4Q3/8/3B4/8/8 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: f7f8 f7g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": ""}}
{"example_id": "rules_01780", "split": "rules", "task_type": "legal_moves", "fen": "r4rk1/ppqn1ppp/2pb4/3p2B1/3P1PP1/3Q2NP/P1P3K1/R4R2 w - -", "prompt": "FEN: r4rk1/ppqn1ppp/2pb4/3p2B1/3P1PP1/3Q2NP/P1P3K1/R4R2 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1b1 a1c1 a1d1 a1e1 a2a3 a2a4 c2c3 c2c4 d3a3 d3a6 d3b3 d3b5 d3c3 d3c4 d3d1 d3d2 d3e2 d3e3 d3e4 d3f3 d3f5 d3g6 d3h7 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f1g1 f1h1 f4f5 g2f2 g2f3 g2g1 g2h1 g2h2 g3e2 g3e4 g3f5 g3h1 g3h5 g5d8 g5e7 g5f6 g5h4 g5h6 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01781", "split": "rules", "task_type": "legal_moves", "fen": "5r2/1p4pk/pb5p/P3P3/1P1p4/1b1K4/3B3P/4R3 b - - 0 35", "prompt": "FEN: 5r2/1p4pk/pb5p/P3P3/1P1p4/1b1K4/3B3P/4R3 b - - 0 35\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: b3a2 b3a4 b3c2 b3c4 b3d1 b3d5 b3e6 b3f7 b3g8 b6a5 b6a7 b6c5 b6c7 b6d8 f8a8 f8b8 f8c8 f8d8 f8e8 f8f1 f8f2 f8f3 f8f4 f8f5 f8f6 f8f7 f8g8 f8h8 g7g5 g7g6 h6h5 h7g6 h7g8 h7h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01782", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqk2r/ppp2pp1/2np1n1p/2b1p1B1/2B1P3/3P1N2/PPP2PPP/RN1Q1RK1 w kq - 0 7", "prompt": "FEN: r1bqk2r/ppp2pp1/2np1n1p/2b1p1B1/2B1P3/3P1N2/PPP2PPP/RN1Q1RK1 w kq - 0 7\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; d1 white queen; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; d3 white pawn; f3 white knight; c4 white bishop; e4 white pawn; g5 white bishop.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "c4", "piece": "white bishop"}, {"square": "e4", "piece": "white pawn"}, {"square": "g5", "piece": "white bishop"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "d1", "piece": "white queen"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "c4", "piece": "white bishop"}, {"square": "e4", "piece": "white pawn"}, {"square": "g5", "piece": "white bishop"}]}}
{"example_id": "rules_01783", "split": "rules", "task_type": "piece_legal_moves", "fen": "2r3k1/R5pp/5p2/1p1p1p2/1K2r3/8/2P3PP/8 w - - 4 33", "prompt": "FEN: 2r3k1/R5pp/5p2/1p1p1p2/1K2r3/8/2P3PP/8 w - - 4 33\nWhat legal moves does the piece on c2 have?", "gold_answer": "c2c4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "c2", "piece": "pawn"}}
{"example_id": "rules_01784", "split": "rules", "task_type": "check_detection", "fen": "rnb1kb1r/ppppqpp1/5n1p/4p3/2B1P3/1P3N2/P1PP1PPP/RNBQK2R w KQkq - 1 5", "prompt": "FEN: rnb1kb1r/ppppqpp1/5n1p/4p3/2B1P3/1P3N2/P1PP1PPP/RNBQK2R w KQkq - 1 5\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01785", "split": "rules", "task_type": "captures", "fen": "8/8/3n4/3k1pKp/7P/5NP1/8/8 b - - 7 47", "prompt": "FEN: 8/8/3n4/3k1pKp/7P/5NP1/8/8 b - - 7 47\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01786", "split": "rules", "task_type": "special_rules", "fen": "r1b1k2r/p4ppp/1qp2n2/8/1PpPpP2/2P3P1/5PBP/R1BQK2R b KQkq - 0 14", "prompt": "Given FEN: r1b1k2r/p4ppp/1qp2n2/8/1PpPpP2/2P3P1/5PBP/R1BQK2R b KQkq - 0 14\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01787", "split": "rules", "task_type": "legality_check", "fen": "2kr1b1r/1bppq2p/p1n2pn1/1p2p1pQ/4P3/PBNP1NB1/1PP2PPP/R4RK1 b - - 0 12", "prompt": "FEN: 2kr1b1r/1bppq2p/p1n2pn1/1p2p1pQ/4P3/PBNP1NB1/1PP2PPP/R4RK1 b - - 0 12\nIs the move b5b6 legal?", "gold_answer": "No, illegal. Reason: illegal piece movement or blocked path.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b5b6", "_legality_check_reason_label": "illegal_piece_movement_or_blocked_path", "move": "b5b6", "legality_reason_label": "illegal_piece_movement_or_blocked_path"}}
{"example_id": "rules_01788", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/8/r1k3p1/P4p1p/2K2P1P/6P1/R7/8 w - -", "prompt": "FEN: 8/8/r1k3p1/P4p1p/2K2P1P/6P1/R7/8 w - -\nList pseudo-legal moves from a2.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a2: a2a1 a2a3 a2a4 a2b2 a2c2 a2d2 a2e2 a2f2 a2g2 a2h2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a2", "diagnostic": true, "hard_gate": false, "source_square": "a2"}}
{"example_id": "rules_01789", "split": "rules", "task_type": "piece_legal_filter", "fen": "r5k1/5p2/p6p/1p4p1/2p5/2P3P1/PP2QP1q/R4K2 b - -", "prompt": "FEN: r5k1/5p2/p6p/1p4p1/2p5/2P3P1/PP2QP1q/R4K2 b - -\nFor the piece on h2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from h2: h2f2 h2g1 h2g2 h2g3 h2h1 h2h3 h2h4 h2h5.\nLegal: h2f2 h2g1 h2g2 h2g3 h2h1 h2h3 h2h4 h2h5.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "h2", "diagnostic": true, "hard_gate": false, "source_square": "h2"}}
{"example_id": "rules_01790", "split": "rules", "task_type": "king_safety_filter", "fen": "rnb1k2r/2p2ppp/1p2p3/3p1qB1/3P2n1/P1P2N2/4PPBP/R2QK2R b KQkq - 0 11", "prompt": "FEN: rnb1k2r/2p2ppp/1p2p3/3p1qB1/3P2n1/P1P2N2/4PPBP/R2QK2R b KQkq - 0 11\nFor move e8d8, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e8d8.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e8d8", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e8d8", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01791", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "2r5/1p1R1R2/1r5p/p1p1P2P/4kP2/1P6/P7/6K1 b - - 2 36", "prompt": "FEN: 2r5/1p1R1R2/1r5p/p1p1P2P/4kP2/1P6/P7/6K1 b - - 2 36\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: e4 black king; a5 black pawn; c5 black pawn; b6 black rook; h6 black pawn; b7 black pawn; c8 black rook.\nMoves by piece:\ne4 black king: e4e3 e4f3\na5 black pawn: a5a4\nc5 black pawn: c5c4\nb6 black rook: b6a6 b6b3 b6b4 b6b5 b6c6 b6d6 b6e6 b6f6 b6g6\nh6 black pawn: no legal moves\nb7 black pawn: no legal moves\nc8 black rook: c8a8 c8b8 c8c6 c8c7 c8d8 c8e8 c8f8 c8g8 c8h8\nAll legal moves: a5a4 b6a6 b6b3 b6b4 b6b5 b6c6 b6d6 b6e6 b6f6 b6g6 c5c4 c8a8 c8b8 c8c6 c8c7 c8d8 c8e8 c8f8 c8g8 c8h8 e4e3 e4f3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"e4": ["e4e3", "e4f3"], "a5": ["a5a4"], "c5": ["c5c4"], "b6": ["b6a6", "b6b3", "b6b4", "b6b5", "b6c6", "b6d6", "b6e6", "b6f6", "b6g6"], "h6": [], "b7": [], "c8": ["c8a8", "c8b8", "c8c6", "c8c7", "c8d8", "c8e8", "c8f8", "c8g8", "c8h8"]}, "_legal_moves_by_piece_moves": "a5a4 b6a6 b6b3 b6b4 b6b5 b6c6 b6d6 b6e6 b6f6 b6g6 c5c4 c8a8 c8b8 c8c6 c8c7 c8d8 c8e8 c8f8 c8g8 c8h8 e4e3 e4f3", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"e4": ["e4e3", "e4f3"], "a5": ["a5a4"], "c5": ["c5c4"], "b6": ["b6a6", "b6b3", "b6b4", "b6b5", "b6c6", "b6d6", "b6e6", "b6f6", "b6g6"], "h6": [], "b7": [], "c8": ["c8a8", "c8b8", "c8c6", "c8c7", "c8d8", "c8e8", "c8f8", "c8g8", "c8h8"]}, "legal_moves": "a5a4 b6a6 b6b3 b6b4 b6b5 b6c6 b6d6 b6e6 b6f6 b6g6 c5c4 c8a8 c8b8 c8c6 c8c7 c8d8 c8e8 c8f8 c8g8 c8h8 e4e3 e4f3"}}
{"example_id": "rules_01792", "split": "rules", "task_type": "ray_walk", "fen": "7r/3n1pkp/Q2p2p1/3P2q1/2B5/3K1P2/6PP/7R b - - 0 28", "prompt": "FEN: 7r/3n1pkp/Q2p2p1/3P2q1/2B5/3K1P2/6PP/7R b - - 0 28\nWalk each ray for the slider on g5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: g5 black queen.\nRay N: g6 black pawn: own piece (stop, excluded).\nRay NE: h6 empty; edge.\nRay E: h5 empty; edge.\nRay SE: h4 empty; edge.\nRay S: g4 empty; g3 empty; g2 white pawn: capture (stop, included).\nRay SW: f4 empty; e3 empty; d2 empty; c1 empty; edge.\nRay W: f5 empty; e5 empty; d5 white pawn: capture (stop, included).\nRay NW: f6 empty; e7 empty; d8 empty; edge.\nMoves from rays: g5c1 g5d2 g5d5 g5d8 g5e3 g5e5 g5e7 g5f4 g5f5 g5f6 g5g2 g5g3 g5g4 g5h4 g5h5 g5h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "g5", "diagnostic": true, "hard_gate": false, "source_square": "g5"}}
{"example_id": "rules_01793", "split": "rules", "task_type": "legal_filter_trace", "fen": "7R/8/8/R7/K7/8/3k4/8 w - -", "prompt": "FEN: 7R/8/8/R7/K7/8/3k4/8 w - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a4 white king; a5 white rook; h8 white rook.\nFilter by piece:\na4 white king: pseudo-legal a4a3 a4b3 a4b4 a4b5 | rejected none | legal a4a3 a4b3 a4b4 a4b5\na5 white rook: pseudo-legal a5a6 a5a7 a5a8 a5b5 a5c5 a5d5 a5e5 a5f5 a5g5 a5h5 | rejected none | legal a5a6 a5a7 a5a8 a5b5 a5c5 a5d5 a5e5 a5f5 a5g5 a5h5\nh8 white rook: pseudo-legal h8a8 h8b8 h8c8 h8d8 h8e8 h8f8 h8g8 h8h1 h8h2 h8h3 h8h4 h8h5 h8h6 h8h7 | rejected none | legal h8a8 h8b8 h8c8 h8d8 h8e8 h8f8 h8g8 h8h1 h8h2 h8h3 h8h4 h8h5 h8h6 h8h7\nAll legal moves: a4a3 a4b3 a4b4 a4b5 a5a6 a5a7 a5a8 a5b5 a5c5 a5d5 a5e5 a5f5 a5g5 a5h5 h8a8 h8b8 h8c8 h8d8 h8e8 h8f8 h8g8 h8h1 h8h2 h8h3 h8h4 h8h5 h8h6 h8h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01794", "split": "rules", "task_type": "legal_moves", "fen": "rnbq1rk1/pp2ppbp/3p1np1/2pP2B1/2P1P3/2N2N2/PP3PPP/R2QKB1R b KQ - 0 7", "prompt": "FEN: rnbq1rk1/pp2ppbp/3p1np1/2pP2B1/2P1P3/2N2N2/PP3PPP/R2QKB1R b KQ - 0 7\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 c8d7 c8e6 c8f5 c8g4 c8h3 d8a5 d8b6 d8c7 d8d7 d8e8 e7e5 e7e6 f6d5 f6d7 f6e4 f6e8 f6g4 f6h5 f8e8 g7h6 g7h8 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01795", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1r3k1/2Rnqpbp/1p2p1p1/p2p4/3P1B2/3P1N1P/PP1Q1PP1/2R3K1 b - -", "prompt": "FEN: r1r3k1/2Rnqpbp/1p2p1p1/p2p4/3P1B2/3P1N1P/PP1Q1PP1/2R3K1 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: a5 black pawn; d5 black pawn; b6 black pawn; e6 black pawn; g6 black pawn; d7 black knight; e7 black queen; f7 black pawn; g7 black bishop; h7 black pawn; a8 black rook; c8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "a5", "piece": "black pawn"}, {"square": "d5", "piece": "black pawn"}, {"square": "b6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black queen"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black bishop"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "a5", "piece": "black pawn"}, {"square": "d5", "piece": "black pawn"}, {"square": "b6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "g6", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black queen"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black bishop"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01796", "split": "rules", "task_type": "piece_legal_moves", "fen": "2b1kb2/2pp1p2/1p3p2/8/2NPB3/1PP1P3/P3N3/R3K3 w Q - 1 23", "prompt": "FEN: 2b1kb2/2pp1p2/1p3p2/8/2NPB3/1PP1P3/P3N3/R3K3 w Q - 1 23\nWhat legal moves does the piece on c4 have?", "gold_answer": "c4a3 c4a5 c4b2 c4b6 c4d2 c4d6 c4e5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c4", "_piece_legal_moves_piece": "knight", "diagnostic": true, "hard_gate": false, "source_square": "c4", "piece": "knight"}}
{"example_id": "rules_01797", "split": "rules", "task_type": "check_detection", "fen": "2k1r3/pppr1p1n/4pq1p/PP1p2p1/3P2B1/4PQ1P/2P2PP1/R3K2R b KQ - 0 19", "prompt": "FEN: 2k1r3/pppr1p1n/4pq1p/PP1p2p1/3P2B1/4PQ1P/2P2PP1/R3K2R b KQ - 0 19\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01798", "split": "rules", "task_type": "captures", "fen": "r4rk1/p1qn1pp1/2pb1np1/1p1p2B1/3P2P1/2NB1Q1P/PPP2P2/1R3RK1 w - -", "prompt": "FEN: r4rk1/p1qn1pp1/2pb1np1/1p1p2B1/3P2P1/2NB1Q1P/PPP2P2/1R3RK1 w - -\nList all capture moves available.", "gold_answer": "c3b5 c3d5 d3b5 d3g6 f3d5 f3f6 g5f6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01799", "split": "rules", "task_type": "special_rules", "fen": "r1bqkbnr/ppp3pp/2np4/4pp2/4P3/3P1N2/PPPN1PPP/R1BQKB1R w KQkq -", "prompt": "Given FEN: r1bqkbnr/ppp3pp/2np4/4pp2/4P3/3P1N2/PPPN1PPP/R1BQKB1R w KQkq -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01800", "split": "rules", "task_type": "legality_check", "fen": "r2r2k1/p1qbbppp/4pn2/8/Q7/2N1B3/PP2BPPP/R4RK1 w - -", "prompt": "FEN: r2r2k1/p1qbbppp/4pn2/8/Q7/2N1B3/PP2BPPP/R4RK1 w - -\nIs the move c3d1 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "c3d1", "_legality_check_reason_label": "legal", "move": "c3d1", "legality_reason_label": "legal"}}
{"example_id": "rules_01801", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1b4r/p2npkN1/2pq1npB/1p2p2p/3P4/2N4P/PPP2PP1/R1Q1K2R b KQ -", "prompt": "FEN: r1b4r/p2npkN1/2pq1npB/1p2p2p/3P4/2N4P/PPP2PP1/R1Q1K2R b KQ -\nList pseudo-legal moves from b5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b5: b5b4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b5", "diagnostic": true, "hard_gate": false, "source_square": "b5"}}
{"example_id": "rules_01802", "split": "rules", "task_type": "piece_legal_filter", "fen": "1k6/pbnp4/1p1p4/3Pqp2/2B4p/P1NQP2P/1PR2P2/3K2r1 w - - 0 25", "prompt": "FEN: 1k6/pbnp4/1p1p4/3Pqp2/2B4p/P1NQP2P/1PR2P2/3K2r1 w - - 0 25\nFor the piece on d1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from d1: d1c1 d1d2 d1e1 d1e2.\nLegal: d1d2 d1e2.\nRejected: d1c1 does_not_resolve_check; d1e1 does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_01803", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbq1rk1/pp1p1p1p/2p2npB/2b1p3/4P3/3P2Q1/PPP1BPPP/RN2K1NR w KQ - 0 7", "prompt": "FEN: rnbq1rk1/pp1p1p1p/2p2npB/2b1p3/4P3/3P2Q1/PPP1BPPP/RN2K1NR w KQ - 0 7\nFor move a2a3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a2a3.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a2a3", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a2a3", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01804", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "3k4/4R3/3K4/8/6P1/P7/8/8 b - - 20 62", "prompt": "FEN: 3k4/4R3/3K4/8/6P1/P7/8/8 b - - 20 62\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: d8 black king.\nMoves by piece:\nd8 black king: d8c8\nAll legal moves: d8c8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d8": ["d8c8"]}, "_legal_moves_by_piece_moves": "d8c8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d8": ["d8c8"]}, "legal_moves": "d8c8"}}
{"example_id": "rules_01805", "split": "rules", "task_type": "ray_walk", "fen": "3rr1k1/p1p2pp1/5n2/6Q1/4P2P/BPq3Pb/P4P2/5RK1 w - - 3 27", "prompt": "FEN: 3rr1k1/p1p2pp1/5n2/6Q1/4P2P/BPq3Pb/P4P2/5RK1 w - - 3 27\nWalk each ray for the slider on f1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: f1 white rook.\nRay N: f2 white pawn: own piece (stop, excluded).\nRay E: g1 white king: own piece (stop, excluded).\nRay S: edge.\nRay W: e1 empty; d1 empty; c1 empty; b1 empty; a1 empty; edge.\nMoves from rays: f1a1 f1b1 f1c1 f1d1 f1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "f1", "diagnostic": true, "hard_gate": false, "source_square": "f1"}}
{"example_id": "rules_01806", "split": "rules", "task_type": "legal_moves", "fen": "r1bk3r/ppp2ppp/4p3/4P3/RPPn1P2/8/3K2PP/2B2B1R b - - 0 15", "prompt": "FEN: r1bk3r/ppp2ppp/4p3/4P3/RPPn1P2/8/3K2PP/2B2B1R b - - 0 15\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c7c5 c7c6 c8d7 d4b3 d4b5 d4c2 d4c6 d4e2 d4f3 d4f5 d8d7 d8e7 d8e8 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01807", "split": "rules", "task_type": "legal_moves", "fen": "5rk1/pp1b3p/4pp2/1P1p1np1/r4P2/6B1/3RN1PP/5RK1 w - - 0 25", "prompt": "FEN: 5rk1/pp1b3p/4pp2/1P1p1np1/r4P2/6B1/3RN1PP/5RK1 w - - 0 25\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b5b6 d2a2 d2b2 d2c2 d2d1 d2d3 d2d4 d2d5 e2c1 e2c3 e2d4 f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f4g5 g1f2 g1h1 g3e1 g3f2 g3h4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01808", "split": "rules", "task_type": "side_piece_inventory", "fen": "1rbq1rk1/ppp2pp1/4p2p/n7/1bpP4/2N1P1P1/PPQN1PBP/R4RK1 w - -", "prompt": "FEN: 1rbq1rk1/ppp2pp1/4p2p/n7/1bpP4/2N1P1P1/PPQN1PBP/R4RK1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; c2 white queen; d2 white knight; f2 white pawn; g2 white bishop; h2 white pawn; c3 white knight; e3 white pawn; g3 white pawn; d4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white queen"}, {"square": "d2", "piece": "white knight"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white bishop"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "e3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "c2", "piece": "white queen"}, {"square": "d2", "piece": "white knight"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white bishop"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white knight"}, {"square": "e3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "d4", "piece": "white pawn"}]}}
{"example_id": "rules_01809", "split": "rules", "task_type": "piece_legal_moves", "fen": "rn1qr1k1/pp3pp1/2pb1B1p/3pN3/3P4/8/PPP1QPPP/RN2R1K1 b - - 0 12", "prompt": "FEN: rn1qr1k1/pp3pp1/2pb1B1p/3pN3/3P4/8/PPP1QPPP/RN2R1K1 b - - 0 12\nWhat legal moves does the piece on a8 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "a8", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "a8", "piece": "rook"}}
{"example_id": "rules_01810", "split": "rules", "task_type": "check_detection", "fen": "rnbq1rk1/1pp2pbp/3p1np1/p2Pp3/2P1P3/2N1B1PP/PP2BP2/R2QK1NR w KQ -", "prompt": "FEN: rnbq1rk1/1pp2pbp/3p1np1/p2Pp3/2P1P3/2N1B1PP/PP2BP2/R2QK1NR w KQ -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01811", "split": "rules", "task_type": "captures", "fen": "r2q1rk1/pp3ppp/2nbpn2/3p1b2/3P3N/2P3P1/PP2QPBP/RNB2RK1 b - - 7 11", "prompt": "FEN: r2q1rk1/pp3ppp/2nbpn2/3p1b2/3P3N/2P3P1/PP2QPBP/RNB2RK1 b - - 7 11\nList all capture moves available.", "gold_answer": "c6d4 d6g3 f5b1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01812", "split": "rules", "task_type": "special_rules", "fen": "8/5k2/6p1/R5Pp/p6b/8/4K3/8 w - -", "prompt": "Given FEN: 8/5k2/6p1/R5Pp/p6b/8/4K3/8 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01813", "split": "rules", "task_type": "legality_check", "fen": "rr4k1/2p1qp1p/2b1pb2/2Pp2p1/pR1P1B2/P1Q1PN2/5PPP/1R4K1 w - - 0 20", "prompt": "FEN: rr4k1/2p1qp1p/2b1pb2/2Pp2p1/pR1P1B2/P1Q1PN2/5PPP/1R4K1 w - - 0 20\nIs the move b8f7 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b8f7", "_legality_check_reason_label": "wrong_side_piece", "move": "b8f7", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01814", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "3r2k1/p3b1p1/1p2p1rp/1qp1Bp2/3Pp3/P1P1P2P/1P3PPQ/3R1RK1 w - - 12 28", "prompt": "FEN: 3r2k1/p3b1p1/1p2p1rp/1qp1Bp2/3Pp3/P1P1P2P/1P3PPQ/3R1RK1 w - - 12 28\nList pseudo-legal moves from d1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d1: d1a1 d1b1 d1c1 d1d2 d1d3 d1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_01815", "split": "rules", "task_type": "piece_legal_filter", "fen": "r6k/6R1/7K/7P/8/8/8/8 b - -", "prompt": "FEN: r6k/6R1/7K/7P/8/8/8/8 b - -\nFor the piece on h8, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from h8: h8g7 h8g8 h8h7.\nLegal: none.\nRejected: h8g7 king_would_be_in_check; h8g8 king_would_be_in_check; h8h7 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "h8", "diagnostic": true, "hard_gate": false, "source_square": "h8"}}
{"example_id": "rules_01816", "split": "rules", "task_type": "king_safety_filter", "fen": "8/3R3p/6p1/4k3/7P/1P2pP2/P3N1P1/6K1 b - - 3 43", "prompt": "FEN: 8/3R3p/6p1/4k3/7P/1P2pP2/P3N1P1/6K1 b - - 3 43\nFor move e5d4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e5d4.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e5d4", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e5d4", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01817", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqkb1r/1p1n1ppp/p3pn2/2p5/2BP4/2N1PN2/PP3PPP/R1BQ1RK1 w kq -", "prompt": "FEN: r1bqkb1r/1p1n1ppp/p3pn2/2p5/2BP4/2N1PN2/PP3PPP/R1BQ1RK1 w kq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; c3 white knight; e3 white pawn; f3 white knight; c4 white bishop; d4 white pawn.\nMoves by piece:\na1 white rook: a1b1\nc1 white bishop: c1d2\nd1 white queen: d1a4 d1b3 d1c2 d1d2 d1d3 d1e1 d1e2\nf1 white rook: f1e1\ng1 white king: g1h1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nf2 white pawn: no legal moves\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nc3 white knight: c3a4 c3b1 c3b5 c3d5 c3e2 c3e4\ne3 white pawn: e3e4\nf3 white knight: f3d2 f3e1 f3e5 f3g5 f3h4\nc4 white bishop: c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6\nd4 white pawn: d4c5 d4d5\nAll legal moves: a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c3a4 c3b1 c3b5 c3d5 c3e2 c3e4 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 d1a4 d1b3 d1c2 d1d2 d1d3 d1e1 d1e2 d4c5 d4d5 e3e4 f1e1 f3d2 f3e1 f3e5 f3g5 f3h4 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1"], "c1": ["c1d2"], "d1": ["d1a4", "d1b3", "d1c2", "d1d2", "d1d3", "d1e1", "d1e2"], "f1": ["f1e1"], "g1": ["g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c3": ["c3a4", "c3b1", "c3b5", "c3d5", "c3e2", "c3e4"], "e3": ["e3e4"], "f3": ["f3d2", "f3e1", "f3e5", "f3g5", "f3h4"], "c4": ["c4a6", "c4b3", "c4b5", "c4d3", "c4d5", "c4e2", "c4e6"], "d4": ["d4c5", "d4d5"]}, "_legal_moves_by_piece_moves": "a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c3a4 c3b1 c3b5 c3d5 c3e2 c3e4 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 d1a4 d1b3 d1c2 d1d2 d1d3 d1e1 d1e2 d4c5 d4d5 e3e4 f1e1 f3d2 f3e1 f3e5 f3g5 f3h4 g1h1 g2g3 g2g4 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1"], "c1": ["c1d2"], "d1": ["d1a4", "d1b3", "d1c2", "d1d2", "d1d3", "d1e1", "d1e2"], "f1": ["f1e1"], "g1": ["g1h1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "c3": ["c3a4", "c3b1", "c3b5", "c3d5", "c3e2", "c3e4"], "e3": ["e3e4"], "f3": ["f3d2", "f3e1", "f3e5", "f3g5", "f3h4"], "c4": ["c4a6", "c4b3", "c4b5", "c4d3", "c4d5", "c4e2", "c4e6"], "d4": ["d4c5", "d4d5"]}, "legal_moves": "a1b1 a2a3 a2a4 b2b3 b2b4 c1d2 c3a4 c3b1 c3b5 c3d5 c3e2 c3e4 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 d1a4 d1b3 d1c2 d1d2 d1d3 d1e1 d1e2 d4c5 d4d5 e3e4 f1e1 f3d2 f3e1 f3e5 f3g5 f3h4 g1h1 g2g3 g2g4 h2h3 h2h4"}}
{"example_id": "rules_01818", "split": "rules", "task_type": "legal_moves", "fen": "8/1K4r1/P7/2k5/8/8/8/8 w - -", "prompt": "FEN: 8/1K4r1/P7/2k5/8/8/8/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b7a8 b7b8 b7c8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": ""}}
{"example_id": "rules_01819", "split": "rules", "task_type": "legal_moves", "fen": "R3r1k1/8/3p1p2/2pPnQp1/1P2P1P1/2P5/8/R4K1q w - -", "prompt": "FEN: R3r1k1/8/3p1p2/2pPnQp1/1P2P1P1/2P5/8/R4K1q w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: f1e2 f1f2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01820", "split": "rules", "task_type": "legal_moves", "fen": "1r1k1r2/3b1p1R/2np3R/p2Np3/1p2P1p1/3P2P1/PPP2P2/2K5 w - - 12 27", "prompt": "FEN: 1r1k1r2/3b1p1R/2np3R/p2Np3/1p2P1p1/3P2P1/PPP2P2/2K5 w - - 12 27\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 c1b1 c1d1 c1d2 c2c3 c2c4 d3d4 d5b4 d5b6 d5c3 d5c7 d5e3 d5e7 d5f4 d5f6 f2f3 f2f4 h6d6 h6e6 h6f6 h6g6 h6h1 h6h2 h6h3 h6h4 h6h5 h7f7 h7g7 h7h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01821", "split": "rules", "task_type": "side_piece_inventory", "fen": "r4rk1/1p1nbppp/1q1p4/p1p5/2P1PP2/PPN1B2P/2P3P1/1R1QK2R b K - 0 15", "prompt": "FEN: r4rk1/1p1nbppp/1q1p4/p1p5/2P1PP2/PPN1B2P/2P3P1/1R1QK2R b K - 0 15\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: a5 black pawn; c5 black pawn; b6 black queen; d6 black pawn; b7 black pawn; d7 black knight; e7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "a5", "piece": "black pawn"}, {"square": "c5", "piece": "black pawn"}, {"square": "b6", "piece": "black queen"}, {"square": "d6", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "a5", "piece": "black pawn"}, {"square": "c5", "piece": "black pawn"}, {"square": "b6", "piece": "black queen"}, {"square": "d6", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black bishop"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01822", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bq1rk1/ppp2ppp/2np1n2/8/4PP2/2NBB3/PPP3PP/R2QK1NR b KQ - 5 9", "prompt": "FEN: r1bq1rk1/ppp2ppp/2np1n2/8/4PP2/2NBB3/PPP3PP/R2QK1NR b KQ - 5 9\nWhat legal moves does the piece on f8 have?", "gold_answer": "f8e8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f8", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "f8", "piece": "rook"}}
{"example_id": "rules_01823", "split": "rules", "task_type": "check_detection", "fen": "4rk2/p4r2/3R3p/1p3b2/3P2p1/1Q6/PP3b2/2BK4 w - - 0 34", "prompt": "FEN: 4rk2/p4r2/3R3p/1p3b2/3P2p1/1Q6/PP3b2/2BK4 w - - 0 34\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01824", "split": "rules", "task_type": "captures", "fen": "4r1k1/1p1Q1pp1/4q2p/8/p7/B1N1N3/1P2KP1P/3R4 b - -", "prompt": "FEN: 4r1k1/1p1Q1pp1/4q2p/8/p7/B1N1N3/1P2KP1P/3R4 b - -\nList all capture moves available.", "gold_answer": "e6d7 e6e3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01825", "split": "rules", "task_type": "special_rules", "fen": "4k3/8/8/3q4/8/8/2Q5/4K3 w - -", "prompt": "Given FEN: 4k3/8/8/3q4/8/8/2Q5/4K3 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01826", "split": "rules", "task_type": "legality_check", "fen": "2k4r/p1p1np1p/Bpn1b1p1/2q3P1/4p3/7P/2PB1P2/3QK2R b K - 3 22", "prompt": "FEN: 2k4r/p1p1np1p/Bpn1b1p1/2q3P1/4p3/7P/2PB1P2/3QK2R b K - 3 22\nIs the move c8d7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c8d7", "_legality_check_reason_label": "legal", "move": "c8d7", "legality_reason_label": "legal"}}
{"example_id": "rules_01827", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "1rr5/1p1qnppk/p1pp1nbp/3Pp3/2PbP2N/3B1QNP/PP3PP1/1RB1R1K1 w - -", "prompt": "FEN: 1rr5/1p1qnppk/p1pp1nbp/3Pp3/2PbP2N/3B1QNP/PP3PP1/1RB1R1K1 w - -\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01828", "split": "rules", "task_type": "piece_legal_filter", "fen": "2r3k1/pp1q1ppp/4pb2/3p4/P1r5/2NRQ3/1PP2PPP/R5K1 b - - 5 20", "prompt": "FEN: 2r3k1/pp1q1ppp/4pb2/3p4/P1r5/2NRQ3/1PP2PPP/R5K1 b - - 5 20\nFor the piece on c4, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c4: c4a4 c4b4 c4c3 c4c5 c4c6 c4c7 c4d4 c4e4 c4f4 c4g4 c4h4.\nLegal: c4a4 c4b4 c4c3 c4c5 c4c6 c4c7 c4d4 c4e4 c4f4 c4g4 c4h4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "c4", "diagnostic": true, "hard_gate": false, "source_square": "c4"}}
{"example_id": "rules_01829", "split": "rules", "task_type": "king_safety_filter", "fen": "r1b2rk1/pp3ppp/1bn1pn2/8/PPB5/2P2N1P/5PP1/RNB2RK1 b - - 0 14", "prompt": "FEN: r1b2rk1/pp3ppp/1bn1pn2/8/PPB5/2P2N1P/5PP1/RNB2RK1 b - - 0 14\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01830", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "6rk/p3qp1p/1pb2B2/2p5/2P3R1/1P2P1P1/P4Q1P/R5K1 b - -", "prompt": "FEN: 6rk/p3qp1p/1pb2B2/2p5/2P3R1/1P2P1P1/P4Q1P/R5K1 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black pawn; b6 black pawn; c6 black bishop; a7 black pawn; e7 black queen; f7 black pawn; h7 black pawn; g8 black rook; h8 black king.\nMoves by piece:\nc5 black pawn: no legal moves\nb6 black pawn: no legal moves\nc6 black bishop: no legal moves\na7 black pawn: no legal moves\ne7 black queen: e7f6\nf7 black pawn: no legal moves\nh7 black pawn: no legal moves\ng8 black rook: g8g7\nh8 black king: no legal moves\nAll legal moves: e7f6 g8g7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": [], "b6": [], "c6": [], "a7": [], "e7": ["e7f6"], "f7": [], "h7": [], "g8": ["g8g7"], "h8": []}, "_legal_moves_by_piece_moves": "e7f6 g8g7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": [], "b6": [], "c6": [], "a7": [], "e7": ["e7f6"], "f7": [], "h7": [], "g8": ["g8g7"], "h8": []}, "legal_moves": "e7f6 g8g7"}}
{"example_id": "rules_01831", "split": "rules", "task_type": "ray_walk", "fen": "rn2k2r/1bq1n2p/4p1pR/p1pP4/Np6/1B1P1N2/PPPQ1PP1/R3K3 b Qkq - 0 15", "prompt": "FEN: rn2k2r/1bq1n2p/4p1pR/p1pP4/Np6/1B1P1N2/PPPQ1PP1/R3K3 b Qkq - 0 15\nWalk each ray for the slider on b7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b7 black bishop.\nRay NE: c8 empty; edge.\nRay SE: c6 empty; d5 white pawn: capture (stop, included).\nRay SW: a6 empty; edge.\nRay NW: a8 black rook: own piece (stop, excluded).\nMoves from rays: b7a6 b7c6 b7c8 b7d5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "b7", "diagnostic": true, "hard_gate": false, "source_square": "b7"}}
{"example_id": "rules_01832", "split": "rules", "task_type": "legal_moves", "fen": "rnbqk2r/ppp1ppbp/1n1p2p1/4P3/3P1B2/2N2N2/PPPQ1PPP/R3KB1R b KQkq -", "prompt": "FEN: rnbqk2r/ppp1ppbp/1n1p2p1/4P3/3P1B2/2N2N2/PPPQ1PPP/R3KB1R b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6a4 b6c4 b6d5 b6d7 b8a6 b8c6 b8d7 c7c5 c7c6 c8d7 c8e6 c8f5 c8g4 c8h3 d6d5 d6e5 d8d7 e7e6 e8d7 e8f8 e8g8 f7f5 f7f6 g6g5 g7e5 g7f6 g7f8 g7h6 h7h5 h7h6 h8f8 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01833", "split": "rules", "task_type": "legal_moves", "fen": "r1b1kbnr/ppp3pp/2n1pq2/3p4/3P1P2/2P5/PP4PP/RNBQKBNR b KQkq - 0 6", "prompt": "FEN: r1b1kbnr/ppp3pp/2n1pq2/3p4/3P1P2/2P5/PP4PP/RNBQKBNR b KQkq - 0 6\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c6a5 c6b4 c6b8 c6d4 c6d8 c6e5 c6e7 c8d7 e6e5 e8d7 e8d8 e8e7 e8f7 f6d4 f6d8 f6e5 f6e7 f6f4 f6f5 f6f7 f6g5 f6g6 f6h4 f6h6 f8a3 f8b4 f8c5 f8d6 f8e7 g7g5 g7g6 g8e7 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01834", "split": "rules", "task_type": "side_piece_inventory", "fen": "3Q2k1/q5p1/P4p1p/4p3/2P1B3/3P2PP/5PK1/R7 b - - 1 35", "prompt": "FEN: 3Q2k1/q5p1/P4p1p/4p3/2P1B3/3P2PP/5PK1/R7 b - - 1 35\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: e5 black pawn; f6 black pawn; h6 black pawn; a7 black queen; g7 black pawn; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black queen"}, {"square": "g7", "piece": "black pawn"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "e5", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "a7", "piece": "black queen"}, {"square": "g7", "piece": "black pawn"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01835", "split": "rules", "task_type": "piece_legal_moves", "fen": "5rk1/1pq3p1/p1n4p/2b5/P3Qp2/2Pr1N1P/1P4P1/3R1R1K w - - 0 24", "prompt": "FEN: 5rk1/1pq3p1/p1n4p/2b5/P3Qp2/2Pr1N1P/1P4P1/3R1R1K w - - 0 24\nWhat legal moves does the piece on h1 have?", "gold_answer": "h1h2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h1", "_piece_legal_moves_piece": "king", "diagnostic": true, "hard_gate": false, "source_square": "h1", "piece": "king"}}
{"example_id": "rules_01836", "split": "rules", "task_type": "check_detection", "fen": "1r1q1r1k/5pbp/3p1np1/2pPp3/1pP1Pnb1/1P1B1NN1/1B1Q1PPP/R2R2K1 w - -", "prompt": "FEN: 1r1q1r1k/5pbp/3p1np1/2pPp3/1pP1Pnb1/1P1B1NN1/1B1Q1PPP/R2R2K1 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01837", "split": "rules", "task_type": "captures", "fen": "8/8/5n2/R1K2k2/4p3/6r1/8/8 b - - 1 49", "prompt": "FEN: 8/8/5n2/R1K2k2/4p3/6r1/8/8 b - - 1 49\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01838", "split": "rules", "task_type": "special_rules", "fen": "2r3k1/1b1pbppp/pq2pn2/1p6/3PP3/P2B1N2/1PRBQPPP/6K1 w - - 1 18", "prompt": "Given FEN: 2r3k1/1b1pbppp/pq2pn2/1p6/3PP3/P2B1N2/1PRBQPPP/6K1 w - - 1 18\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01839", "split": "rules", "task_type": "legality_check", "fen": "5r1k/p1R2NRp/8/2p5/8/3b4/P4PPK/2r5 b - - 2 33", "prompt": "FEN: 5r1k/p1R2NRp/8/2p5/8/3b4/P4PPK/2r5 b - - 2 33\nIs the move g2h4 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g2h4", "_legality_check_reason_label": "wrong_side_piece", "move": "g2h4", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01840", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "4r1k1/pp1q1p1p/1n5p/8/8/2N3PP/PP4P1/3R2K1 w - -", "prompt": "FEN: 4r1k1/pp1q1p1p/1n5p/8/8/2N3PP/PP4P1/3R2K1 w - -\nList pseudo-legal moves from d1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d1: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1e1 d1f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_01841", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1bq1rk1/pppp1ppp/2n2n2/8/1b1PPB2/2NB4/PPP3PP/R2QK1NR w KQ - 1 7", "prompt": "FEN: r1bq1rk1/pppp1ppp/2n2n2/8/1b1PPB2/2NB4/PPP3PP/R2QK1NR w KQ - 1 7\nFor the piece on c3, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c3: c3a4 c3b1 c3b5 c3d5 c3e2.\nLegal: none.\nRejected: c3a4 pinned_piece_exposes_king; c3b1 pinned_piece_exposes_king; c3b5 pinned_piece_exposes_king; c3d5 pinned_piece_exposes_king; c3e2 pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "c3", "diagnostic": true, "hard_gate": false, "source_square": "c3"}}
{"example_id": "rules_01842", "split": "rules", "task_type": "king_safety_filter", "fen": "8/4k3/8/3R1p1p/3K1Pp1/6P1/7P/8 b - -", "prompt": "FEN: 8/4k3/8/3R1p1p/3K1Pp1/6P1/7P/8 b - -\nFor move e7d6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e7d6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "e7d6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e7d6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01843", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "k7/3Q4/8/8/8/3K4/8/8 w - -", "prompt": "FEN: k7/3Q4/8/8/8/3K4/8/8 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: d3 white king; d7 white queen.\nMoves by piece:\nd3 white king: d3c2 d3c3 d3c4 d3d2 d3d4 d3e2 d3e3 d3e4\nd7 white queen: d7a4 d7a7 d7b5 d7b7 d7c6 d7c7 d7c8 d7d4 d7d5 d7d6 d7d8 d7e6 d7e7 d7e8 d7f5 d7f7 d7g4 d7g7 d7h3 d7h7\nAll legal moves: d3c2 d3c3 d3c4 d3d2 d3d4 d3e2 d3e3 d3e4 d7a4 d7a7 d7b5 d7b7 d7c6 d7c7 d7c8 d7d4 d7d5 d7d6 d7d8 d7e6 d7e7 d7e8 d7f5 d7f7 d7g4 d7g7 d7h3 d7h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d3": ["d3c2", "d3c3", "d3c4", "d3d2", "d3d4", "d3e2", "d3e3", "d3e4"], "d7": ["d7a4", "d7a7", "d7b5", "d7b7", "d7c6", "d7c7", "d7c8", "d7d4", "d7d5", "d7d6", "d7d8", "d7e6", "d7e7", "d7e8", "d7f5", "d7f7", "d7g4", "d7g7", "d7h3", "d7h7"]}, "_legal_moves_by_piece_moves": "d3c2 d3c3 d3c4 d3d2 d3d4 d3e2 d3e3 d3e4 d7a4 d7a7 d7b5 d7b7 d7c6 d7c7 d7c8 d7d4 d7d5 d7d6 d7d8 d7e6 d7e7 d7e8 d7f5 d7f7 d7g4 d7g7 d7h3 d7h7", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d3": ["d3c2", "d3c3", "d3c4", "d3d2", "d3d4", "d3e2", "d3e3", "d3e4"], "d7": ["d7a4", "d7a7", "d7b5", "d7b7", "d7c6", "d7c7", "d7c8", "d7d4", "d7d5", "d7d6", "d7d8", "d7e6", "d7e7", "d7e8", "d7f5", "d7f7", "d7g4", "d7g7", "d7h3", "d7h7"]}, "legal_moves": "d3c2 d3c3 d3c4 d3d2 d3d4 d3e2 d3e3 d3e4 d7a4 d7a7 d7b5 d7b7 d7c6 d7c7 d7c8 d7d4 d7d5 d7d6 d7d8 d7e6 d7e7 d7e8 d7f5 d7f7 d7g4 d7g7 d7h3 d7h7"}}
{"example_id": "rules_01844", "split": "rules", "task_type": "ray_walk", "fen": "2B5/8/5P2/2kb4/7K/8/6P1/8 b - -", "prompt": "FEN: 2B5/8/5P2/2kb4/7K/8/6P1/8 b - -\nWalk each ray for the slider on d5: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: d5 black bishop.\nRay NE: e6 empty; f7 empty; g8 empty; edge.\nRay SE: e4 empty; f3 empty; g2 white pawn: capture (stop, included).\nRay SW: c4 empty; b3 empty; a2 empty; edge.\nRay NW: c6 empty; b7 empty; a8 empty; edge.\nMoves from rays: d5a2 d5a8 d5b3 d5b7 d5c4 d5c6 d5e4 d5e6 d5f3 d5f7 d5g2 d5g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "d5", "diagnostic": true, "hard_gate": false, "source_square": "d5"}}
{"example_id": "rules_01845", "split": "rules", "task_type": "legal_moves", "fen": "1r4k1/pp1n1pp1/4p2p/3pP3/2rP1N2/P1P3P1/3B1P1P/1R4K1 b - - 1 26", "prompt": "FEN: 1r4k1/pp1n1pp1/4p2p/3pP3/2rP1N2/P1P3P1/3B1P1P/1R4K1 b - - 1 26\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a8 b8c8 b8d8 b8e8 b8f8 c4a4 c4b4 c4c3 c4c5 c4c6 c4c7 c4c8 c4d4 d7b6 d7c5 d7e5 d7f6 d7f8 f7f5 f7f6 g7g5 g7g6 g8f8 g8h7 g8h8 h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01846", "split": "rules", "task_type": "legal_moves", "fen": "rn3rk1/pp3ppp/3P1n2/3p4/3Q2b1/2P5/PP1N2PP/R3KBNR b KQ - 0 14", "prompt": "FEN: rn3rk1/pp3ppp/3P1n2/3p4/3Q2b1/2P5/PP1N2PP/R3KBNR b KQ - 0 14\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b7b5 b7b6 b8a6 b8c6 b8d7 f6d7 f6e4 f6e8 f6h5 f8c8 f8d8 f8e8 g4c8 g4d1 g4d7 g4e2 g4e6 g4f3 g4f5 g4h3 g4h5 g7g5 g7g6 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01847", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/ppk1Q3/2p5/3p1P2/3P2P1/P6K/1P5P/8 b - - 2 44", "prompt": "FEN: 8/ppk1Q3/2p5/3p1P2/3P2P1/P6K/1P5P/8 b - - 2 44\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: d5 black pawn; c6 black pawn; a7 black pawn; b7 black pawn; c7 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "d5", "piece": "black pawn"}, {"square": "c6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "d5", "piece": "black pawn"}, {"square": "c6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black king"}]}}
{"example_id": "rules_01848", "split": "rules", "task_type": "piece_legal_moves", "fen": "1r1qrbk1/p4pp1/3p1n1p/2p5/N3PB2/1PQ2P2/P1P3PP/4RR1K b - - 10 22", "prompt": "FEN: 1r1qrbk1/p4pp1/3p1n1p/2p5/N3PB2/1PQ2P2/P1P3PP/4RR1K b - - 10 22\nWhat legal moves does the piece on e8 have?", "gold_answer": "e8e4 e8e5 e8e6 e8e7", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "e8", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "e8", "piece": "rook"}}
{"example_id": "rules_01849", "split": "rules", "task_type": "check_detection", "fen": "r2r2k1/p4ppp/8/qp6/8/bbRBP3/1N2KPPP/B7 b - - 1 23", "prompt": "FEN: r2r2k1/p4ppp/8/qp6/8/bbRBP3/1N2KPPP/B7 b - - 1 23\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01850", "split": "rules", "task_type": "captures", "fen": "8/1p1n4/p3k2p/P4pp1/5P2/1P1N1K2/2P4P/8 w - -", "prompt": "FEN: 8/1p1n4/p3k2p/P4pp1/5P2/1P1N1K2/2P4P/8 w - -\nList all capture moves available.", "gold_answer": "f4g5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01851", "split": "rules", "task_type": "special_rules", "fen": "8/8/1n1k4/6N1/2p1p2p/4P1P1/1PK2P1P/8 b - - 0 49", "prompt": "Given FEN: 8/8/1n1k4/6N1/2p1p2p/4P1P1/1PK2P1P/8 b - - 0 49\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01852", "split": "rules", "task_type": "legality_check", "fen": "5rk1/2p3pp/p3pn2/bb2N3/P1pqB3/2P5/1PQ2PPP/R1B1K2R w KQ - 0 17", "prompt": "FEN: 5rk1/2p3pp/p3pn2/bb2N3/P1pqB3/2P5/1PQ2PPP/R1B1K2R w KQ - 0 17\nIs the move a1a3 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "a1a3", "_legality_check_reason_label": "legal", "move": "a1a3", "legality_reason_label": "legal"}}
{"example_id": "rules_01853", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/8/3K4/3B4/3N1k2/8/8/8 b - -", "prompt": "FEN: 8/8/3K4/3B4/3N1k2/8/8/8 b - -\nList pseudo-legal moves from f4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from f4: f4e3 f4e4 f4e5 f4f3 f4f5 f4g3 f4g4 f4g5", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "f4", "diagnostic": true, "hard_gate": false, "source_square": "f4"}}
{"example_id": "rules_01854", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn2kr2/1p1q3p/p7/3P1p2/1P1Q1P2/P5P1/1B4KP/R7 w - - 1 24", "prompt": "FEN: rn2kr2/1p1q3p/p7/3P1p2/1P1Q1P2/P5P1/1B4KP/R7 w - - 1 24\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1a2 a1b1 a1c1 a1d1 a1e1 a1f1 a1g1 a1h1.\nLegal: a1a2 a1b1 a1c1 a1d1 a1e1 a1f1 a1g1 a1h1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01855", "split": "rules", "task_type": "king_safety_filter", "fen": "r2q1rk1/pp3ppp/2n2n2/3pN3/3P4/4P2P/P3bPP1/R1BQ1RK1 w - - 0 14", "prompt": "FEN: r2q1rk1/pp3ppp/2n2n2/3pN3/3P4/4P2P/P3bPP1/R1BQ1RK1 w - - 0 14\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01856", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "rnbnk2r/4qppp/p2pp3/8/PPBN4/2R1Q3/5PPP/2B1K1R1 b kq -", "prompt": "FEN: rnbnk2r/4qppp/p2pp3/8/PPBN4/2R1Q3/5PPP/2B1K1R1 b kq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a6 black pawn; d6 black pawn; e6 black pawn; e7 black queen; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; b8 black knight; c8 black bishop; d8 black knight; e8 black king; h8 black rook.\nMoves by piece:\na6 black pawn: a6a5\nd6 black pawn: d6d5\ne6 black pawn: e6e5\ne7 black queen: e7a7 e7b7 e7c7 e7d7 e7f6 e7f8 e7g5 e7h4\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8a7\nb8 black knight: b8c6 b8d7\nc8 black bishop: c8b7 c8d7\nd8 black knight: d8b7 d8c6\ne8 black king: e8d7 e8f8 e8g8\nh8 black rook: h8f8 h8g8\nAll legal moves: a6a5 a8a7 b8c6 b8d7 c8b7 c8d7 d6d5 d8b7 d8c6 e6e5 e7a7 e7b7 e7c7 e7d7 e7f6 e7f8 e7g5 e7h4 e8d7 e8f8 e8g8 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a6": ["a6a5"], "d6": ["d6d5"], "e6": ["e6e5"], "e7": ["e7a7", "e7b7", "e7c7", "e7d7", "e7f6", "e7f8", "e7g5", "e7h4"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8a7"], "b8": ["b8c6", "b8d7"], "c8": ["c8b7", "c8d7"], "d8": ["d8b7", "d8c6"], "e8": ["e8d7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "a6a5 a8a7 b8c6 b8d7 c8b7 c8d7 d6d5 d8b7 d8c6 e6e5 e7a7 e7b7 e7c7 e7d7 e7f6 e7f8 e7g5 e7h4 e8d7 e8f8 e8g8 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a6": ["a6a5"], "d6": ["d6d5"], "e6": ["e6e5"], "e7": ["e7a7", "e7b7", "e7c7", "e7d7", "e7f6", "e7f8", "e7g5", "e7h4"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8a7"], "b8": ["b8c6", "b8d7"], "c8": ["c8b7", "c8d7"], "d8": ["d8b7", "d8c6"], "e8": ["e8d7", "e8f8", "e8g8"], "h8": ["h8f8", "h8g8"]}, "legal_moves": "a6a5 a8a7 b8c6 b8d7 c8b7 c8d7 d6d5 d8b7 d8c6 e6e5 e7a7 e7b7 e7c7 e7d7 e7f6 e7f8 e7g5 e7h4 e8d7 e8f8 e8g8 f7f5 f7f6 g7g5 g7g6 h7h5 h7h6 h8f8 h8g8"}}
{"example_id": "rules_01857", "split": "rules", "task_type": "ray_walk", "fen": "rnbqk1nr/pp2bpp1/7p/2p1P3/3p1B2/3P1NN1/PPP3PP/R2QKB1R b KQkq - 1 9", "prompt": "FEN: rnbqk1nr/pp2bpp1/7p/2p1P3/3p1B2/3P1NN1/PPP3PP/R2QKB1R b KQkq - 1 9\nWalk each ray for the slider on e7: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: e7 black bishop.\nRay NE: f8 empty; edge.\nRay SE: f6 empty; g5 empty; h4 empty; edge.\nRay SW: d6 empty; c5 black pawn: own piece (stop, excluded).\nRay NW: d8 black queen: own piece (stop, excluded).\nMoves from rays: e7d6 e7f6 e7f8 e7g5 e7h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "e7", "diagnostic": true, "hard_gate": false, "source_square": "e7"}}
{"example_id": "rules_01858", "split": "rules", "task_type": "legal_filter_trace", "fen": "7Q/4K3/8/5P2/8/6kp/8/8 w - -", "prompt": "FEN: 7Q/4K3/8/5P2/8/6kp/8/8 w - -\nFor every side-to-move piece, list pseudo-legal moves, reject illegal ones with reasons, then give all legal moves.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Filter by piece:\", one line per side-to-move piece with \"pseudo-legal ... | rejected ... | legal ...\" fields, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: f5 white pawn; e7 white king; h8 white queen.\nFilter by piece:\nf5 white pawn: pseudo-legal f5f6 | rejected none | legal f5f6\ne7 white king: pseudo-legal e7d6 e7d7 e7d8 e7e6 e7e8 e7f6 e7f7 e7f8 | rejected none | legal e7d6 e7d7 e7d8 e7e6 e7e8 e7f6 e7f7 e7f8\nh8 white queen: pseudo-legal h8a1 h8a8 h8b2 h8b8 h8c3 h8c8 h8d4 h8d8 h8e5 h8e8 h8f6 h8f8 h8g7 h8g8 h8h3 h8h4 h8h5 h8h6 h8h7 | rejected none | legal h8a1 h8a8 h8b2 h8b8 h8c3 h8c8 h8d4 h8d8 h8e5 h8e8 h8f6 h8f8 h8g7 h8g8 h8h3 h8h4 h8h5 h8h6 h8h7\nAll legal moves: e7d6 e7d7 e7d8 e7e6 e7e8 e7f6 e7f7 e7f8 f5f6 h8a1 h8a8 h8b2 h8b8 h8c3 h8c8 h8d4 h8d8 h8e5 h8e8 h8f6 h8f8 h8g7 h8g8 h8h3 h8h4 h8h5 h8h6 h8h7", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "diagnostic": true, "hard_gate": false}}
{"example_id": "rules_01859", "split": "rules", "task_type": "legal_moves", "fen": "4k3/p4ppp/1p1p1n2/1P1pB3/8/5P1P/6PK/8 w - - 0 36", "prompt": "FEN: 4k3/p4ppp/1p1p1n2/1P1pB3/8/5P1P/6PK/8 w - - 0 36\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: e5a1 e5b2 e5c3 e5d4 e5d6 e5f4 e5f6 e5g3 f3f4 g2g3 g2g4 h2g1 h2g3 h2h1 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01860", "split": "rules", "task_type": "side_piece_inventory", "fen": "8/R4K2/1r5k/5P2/8/8/8/8 w - -", "prompt": "FEN: 8/R4K2/1r5k/5P2/8/8/8/8 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: f5 white pawn; a7 white rook; f7 white king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "f5", "piece": "white pawn"}, {"square": "a7", "piece": "white rook"}, {"square": "f7", "piece": "white king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "f5", "piece": "white pawn"}, {"square": "a7", "piece": "white rook"}, {"square": "f7", "piece": "white king"}]}}
{"example_id": "rules_01861", "split": "rules", "task_type": "piece_legal_moves", "fen": "4n3/5pk1/1p3rpp/3Pp3/p3P2P/N2R1PP1/PPK5/8 b - -", "prompt": "FEN: 4n3/5pk1/1p3rpp/3Pp3/p3P2P/N2R1PP1/PPK5/8 b - -\nWhat legal moves does the piece on f7 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f7", "piece": "pawn"}}
{"example_id": "rules_01862", "split": "rules", "task_type": "check_detection", "fen": "8/4k3/1K2n3/3Q4/8/8/8/8 w - -", "prompt": "FEN: 8/4k3/1K2n3/3Q4/8/8/8/8 w - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01863", "split": "rules", "task_type": "captures", "fen": "r1b1k2r/2p1bpp1/p4n1p/1p6/5B2/1BP5/PP3PPP/RN2R1K1 b kq -", "prompt": "FEN: r1b1k2r/2p1bpp1/p4n1p/1p6/5B2/1BP5/PP3PPP/RN2R1K1 b kq -\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01864", "split": "rules", "task_type": "special_rules", "fen": "1r1r4/1bq1ppkp/2p3p1/p3p3/4P1P1/2N1Q2P/PPP2P2/2KR3R w - - 0 19", "prompt": "Given FEN: 1r1r4/1bq1ppkp/2p3p1/p3p3/4P1P1/2N1Q2P/PPP2P2/2KR3R w - - 0 19\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01865", "split": "rules", "task_type": "legality_check", "fen": "2k5/5pr1/1B1R3p/p4Ppn/P1P1B1P1/6QK/3r4/4R3 w - -", "prompt": "FEN: 2k5/5pr1/1B1R3p/p4Ppn/P1P1B1P1/6QK/3r4/4R3 w - -\nIs the move f8e7 legal?", "gold_answer": "No, illegal. Reason: empty source.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "f8e7", "_legality_check_reason_label": "empty_source", "move": "f8e7", "legality_reason_label": "empty_source"}}
{"example_id": "rules_01866", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "5rk1/pr5p/b5p1/8/P1p5/2N1PP1P/6P1/3R2K1 w - - 1 26", "prompt": "FEN: 5rk1/pr5p/b5p1/8/P1p5/2N1PP1P/6P1/3R2K1 w - - 1 26\nList pseudo-legal moves from d1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d1: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_01867", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/6pp/5b1k/5Q1P/2r5/6PK/8/8 w - - 3 55", "prompt": "FEN: 8/6pp/5b1k/5Q1P/2r5/6PK/8/8 w - - 3 55\nFor the piece on h3, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from h3: h3g2 h3g4 h3h2 h3h4.\nLegal: h3g2 h3h2.\nRejected: h3g4 king_would_be_in_check; h3h4 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "h3", "diagnostic": true, "hard_gate": false, "source_square": "h3"}}
{"example_id": "rules_01868", "split": "rules", "task_type": "king_safety_filter", "fen": "rnbq1rk1/ppp2ppp/8/3n4/1bBP4/2N5/PP3PPP/R1BQK1NR w KQ -", "prompt": "FEN: rnbq1rk1/ppp2ppp/8/3n4/1bBP4/2N5/PP3PPP/R1BQK1NR w KQ -\nFor move c3a4, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c3a4.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "c3a4", "_king_safety_filter_reason_label": "pinned_piece_exposes_king", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "c3a4", "legality_reason_label": "pinned_piece_exposes_king", "expected_is_legal": false}}
{"example_id": "rules_01869", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/8/8/ppk5/2pp4/8/2K5/6b1 w - - 2 60", "prompt": "FEN: 8/8/8/ppk5/2pp4/8/2K5/6b1 w - - 2 60\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: c2 white king.\nMoves by piece:\nc2 white king: c2b1 c2b2 c2c1 c2d1 c2d2\nAll legal moves: c2b1 c2b2 c2c1 c2d1 c2d2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c2": ["c2b1", "c2b2", "c2c1", "c2d1", "c2d2"]}, "_legal_moves_by_piece_moves": "c2b1 c2b2 c2c1 c2d1 c2d2", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c2": ["c2b1", "c2b2", "c2c1", "c2d1", "c2d2"]}, "legal_moves": "c2b1 c2b2 c2c1 c2d1 c2d2"}}
{"example_id": "rules_01870", "split": "rules", "task_type": "legal_moves", "fen": "5k2/5Pp1/3b4/1p6/2p5/2P4K/1P3q2/8 w - -", "prompt": "FEN: 5k2/5Pp1/3b4/1p6/2p5/2P4K/1P3q2/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b2b3 b2b4 h3g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": ""}}
{"example_id": "rules_01871", "split": "rules", "task_type": "legal_moves", "fen": "r2q1rk1/ppp2ppp/1bn1pnb1/8/1P1P4/P1N1PN1P/3BBPP1/2RQ1RK1 b - - 2 13", "prompt": "FEN: r2q1rk1/ppp2ppp/1bn1pnb1/8/1P1P4/P1N1PN1P/3BBPP1/2RQ1RK1 b - - 2 13\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 a8c8 b6a5 b6c5 b6d4 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 d8b8 d8c8 d8d4 d8d5 d8d6 d8d7 d8e7 d8e8 e6e5 f6d5 f6d7 f6e4 f6e8 f6g4 f6h5 f8e8 g6b1 g6c2 g6d3 g6e4 g6f5 g6h5 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01872", "split": "rules", "task_type": "legal_moves", "fen": "6k1/p4p2/1p2pp1p/8/8/2P2P2/PP4PP/3r1RK1 b - -", "prompt": "FEN: 6k1/p4p2/1p2pp1p/8/8/2P2P2/PP4PP/3r1RK1 b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 b6b5 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1d7 d1d8 d1e1 d1f1 e6e5 f6f5 g8f8 g8g7 g8h7 g8h8 h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01873", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1nq1rk1/1b3pbp/p2p2p1/1p6/3NP3/1B6/PP3PPP/RN1QR1K1 w - -", "prompt": "FEN: r1nq1rk1/1b3pbp/p2p2p1/1p6/3NP3/1B6/PP3PPP/RN1QR1K1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; b1 white knight; d1 white queen; e1 white rook; g1 white king; a2 white pawn; b2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; b3 white bishop; d4 white knight; e4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "b3", "piece": "white bishop"}, {"square": "d4", "piece": "white knight"}, {"square": "e4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "b1", "piece": "white knight"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "f2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "b3", "piece": "white bishop"}, {"square": "d4", "piece": "white knight"}, {"square": "e4", "piece": "white pawn"}]}}
{"example_id": "rules_01874", "split": "rules", "task_type": "piece_legal_moves", "fen": "B7/6p1/k6p/8/2P5/1K6/6P1/8 w - -", "prompt": "FEN: B7/6p1/k6p/8/2P5/1K6/6P1/8 w - -\nWhat legal moves does the piece on a8 have?", "gold_answer": "a8b7 a8c6 a8d5 a8e4 a8f3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "a8", "_piece_legal_moves_piece": "bishop", "diagnostic": true, "hard_gate": false, "source_square": "a8", "piece": "bishop"}}
{"example_id": "rules_01875", "split": "rules", "task_type": "check_detection", "fen": "r1bq4/ppp2kp1/2np1n1p/2bNp3/4P3/3P4/PPP2PPP/R1BQ1RK1 b - - 1 10", "prompt": "FEN: r1bq4/ppp2kp1/2np1n1p/2bNp3/4P3/3P4/PPP2PPP/R1BQ1RK1 b - - 1 10\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01876", "split": "rules", "task_type": "captures", "fen": "6k1/ppp3b1/3p2r1/1P1Pp3/P4qp1/5P1P/4Q1K1/5R2 w - - 0 34", "prompt": "FEN: 6k1/ppp3b1/3p2r1/1P1Pp3/P4qp1/5P1P/4Q1K1/5R2 w - - 0 34\nList all capture moves available.", "gold_answer": "e2e5 f3g4 h3g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01877", "split": "rules", "task_type": "special_rules", "fen": "r1b1k1nr/2bp1ppp/pp2pq2/8/B1n1P3/2NNB3/PPP2PPP/R2Q1RK1 w kq - 2 13", "prompt": "Given FEN: r1b1k1nr/2bp1ppp/pp2pq2/8/B1n1P3/2NNB3/PPP2PPP/R2Q1RK1 w kq - 2 13\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01878", "split": "rules", "task_type": "legality_check", "fen": "r4r2/5pkp/N1p1p1p1/3n4/1P6/PR3B2/5PPP/R5K1 b - - 0 25", "prompt": "FEN: r4r2/5pkp/N1p1p1p1/3n4/1P6/PR3B2/5PPP/R5K1 b - - 0 25\nIs the move d5e7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "d5e7", "_legality_check_reason_label": "legal", "move": "d5e7", "legality_reason_label": "legal"}}
{"example_id": "rules_01879", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "r1b2kn1/pp1p1p1p/1q2p3/4Q3/2PbP3/8/PP1BK1PP/RN3B1R w - - 4 12", "prompt": "FEN: r1b2kn1/pp1p1p1p/1q2p3/4Q3/2PbP3/8/PP1BK1PP/RN3B1R w - - 4 12\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a3 b1c3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01880", "split": "rules", "task_type": "piece_legal_filter", "fen": "r4rk1/pppq1ppp/3pbn2/4p3/2PbP3/1B1P3P/PP1N1PP1/R1BQ1RK1 w - - 3 11", "prompt": "FEN: r4rk1/pppq1ppp/3pbn2/4p3/2PbP3/1B1P3P/PP1N1PP1/R1BQ1RK1 w - - 3 11\nFor the piece on f2, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f2: f2f3 f2f4.\nLegal: none.\nRejected: f2f3 pinned_piece_exposes_king; f2f4 pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "f2", "diagnostic": true, "hard_gate": false, "source_square": "f2"}}
{"example_id": "rules_01881", "split": "rules", "task_type": "king_safety_filter", "fen": "R4K1k/ppp3pp/3p4/2p2NP1/2b1rPN1/4P2R/PP1P2rP/8 w - -", "prompt": "FEN: R4K1k/ppp3pp/3p4/2p2NP1/2b1rPN1/4P2R/PP1P2rP/8 w - -\nFor move f8e7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: f8e7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "f8e7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "f8e7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01882", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bq1rk1/p2p2pp/2p2p2/1p5n/3PP2B/1PP2N2/2P3PP/R2QK2R b KQ - 1 14", "prompt": "FEN: r1bq1rk1/p2p2pp/2p2p2/1p5n/3PP2B/1PP2N2/2P3PP/R2QK2R b KQ - 1 14\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b5 black pawn; h5 black knight; c6 black pawn; f6 black pawn; a7 black pawn; d7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; f8 black rook; g8 black king.\nMoves by piece:\nb5 black pawn: b5b4\nh5 black knight: h5f4 h5g3\nc6 black pawn: c6c5\nf6 black pawn: f6f5\na7 black pawn: a7a5 a7a6\nd7 black pawn: d7d5 d7d6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h6\na8 black rook: a8b8\nc8 black bishop: c8a6 c8b7\nd8 black queen: d8a5 d8b6 d8c7 d8e7 d8e8\nf8 black rook: f8e8 f8f7\ng8 black king: g8f7 g8h8\nAll legal moves: a7a5 a7a6 a8b8 b5b4 c6c5 c8a6 c8b7 d7d5 d7d6 d8a5 d8b6 d8c7 d8e7 d8e8 f6f5 f8e8 f8f7 g7g5 g7g6 g8f7 g8h8 h5f4 h5g3 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b5": ["b5b4"], "h5": ["h5f4", "h5g3"], "c6": ["c6c5"], "f6": ["f6f5"], "a7": ["a7a5", "a7a6"], "d7": ["d7d5", "d7d6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h6"], "a8": ["a8b8"], "c8": ["c8a6", "c8b7"], "d8": ["d8a5", "d8b6", "d8c7", "d8e7", "d8e8"], "f8": ["f8e8", "f8f7"], "g8": ["g8f7", "g8h8"]}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 b5b4 c6c5 c8a6 c8b7 d7d5 d7d6 d8a5 d8b6 d8c7 d8e7 d8e8 f6f5 f8e8 f8f7 g7g5 g7g6 g8f7 g8h8 h5f4 h5g3 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b5": ["b5b4"], "h5": ["h5f4", "h5g3"], "c6": ["c6c5"], "f6": ["f6f5"], "a7": ["a7a5", "a7a6"], "d7": ["d7d5", "d7d6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h6"], "a8": ["a8b8"], "c8": ["c8a6", "c8b7"], "d8": ["d8a5", "d8b6", "d8c7", "d8e7", "d8e8"], "f8": ["f8e8", "f8f7"], "g8": ["g8f7", "g8h8"]}, "legal_moves": "a7a5 a7a6 a8b8 b5b4 c6c5 c8a6 c8b7 d7d5 d7d6 d8a5 d8b6 d8c7 d8e7 d8e8 f6f5 f8e8 f8f7 g7g5 g7g6 g8f7 g8h8 h5f4 h5g3 h7h6"}}
{"example_id": "rules_01883", "split": "rules", "task_type": "ray_walk", "fen": "rnbqkb1r/p2p1ppp/1p2pn2/2p5/3P1P2/3BPN2/PPP3PP/RNBQK2R b KQkq -", "prompt": "FEN: rnbqkb1r/p2p1ppp/1p2pn2/2p5/3P1P2/3BPN2/PPP3PP/RNBQK2R b KQkq -\nWalk each ray for the slider on a8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a8 black rook.\nRay N: edge.\nRay E: b8 black knight: own piece (stop, excluded).\nRay S: a7 black pawn: own piece (stop, excluded).\nRay W: edge.\nMoves from rays: none", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a8", "diagnostic": true, "hard_gate": false, "source_square": "a8"}}
{"example_id": "rules_01884", "split": "rules", "task_type": "legal_moves", "fen": "r6k/2p3pp/4N3/4P1B1/p2P3P/P7/1qPK2P1/5R2 w - - 1 27", "prompt": "FEN: r6k/2p3pp/4N3/4P1B1/p2P3P/P7/1qPK2P1/5R2 w - - 1 27\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: d2d1 d2d3 d2e1 d2e2 d2e3 d4d5 e6c5 e6c7 e6d8 e6f4 e6f8 e6g7 f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f1f4 f1f5 f1f6 f1f7 f1f8 f1g1 f1h1 g2g3 g2g4 g5d8 g5e3 g5e7 g5f4 g5f6 g5h6 h4h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01885", "split": "rules", "task_type": "legal_moves", "fen": "7r/p5pp/4p1q1/2k2p2/4b3/8/PP3PPP/2R2RK1 b - - 1 24", "prompt": "FEN: 7r/p5pp/4p1q1/2k2p2/4b3/8/PP3PPP/2R2RK1 b - - 1 24\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: c5b4 c5b5 c5b6 c5d4 c5d5 c5d6 e4c2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01886", "split": "rules", "task_type": "side_piece_inventory", "fen": "rrb3k1/2q1pp1p/3p1bp1/1ppP4/5PP1/1BPP1Q1P/1P1B4/1R2R1K1 w - - 1 22", "prompt": "FEN: rrb3k1/2q1pp1p/3p1bp1/1ppP4/5PP1/1BPP1Q1P/1P1B4/1R2R1K1 w - - 1 22\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: b1 white rook; e1 white rook; g1 white king; b2 white pawn; d2 white bishop; b3 white bishop; c3 white pawn; d3 white pawn; f3 white queen; h3 white pawn; f4 white pawn; g4 white pawn; d5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "b3", "piece": "white bishop"}, {"square": "c3", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "f3", "piece": "white queen"}, {"square": "h3", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "g4", "piece": "white pawn"}, {"square": "d5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "e1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "b3", "piece": "white bishop"}, {"square": "c3", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "f3", "piece": "white queen"}, {"square": "h3", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "g4", "piece": "white pawn"}, {"square": "d5", "piece": "white pawn"}]}}
{"example_id": "rules_01887", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/b1R4p/6p1/P5k1/8/8/6KP/8 b - - 2 40", "prompt": "FEN: 8/b1R4p/6p1/P5k1/8/8/6KP/8 b - - 2 40\nWhat legal moves does the piece on h7 have?", "gold_answer": "h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "h7", "piece": "pawn"}}
{"example_id": "rules_01888", "split": "rules", "task_type": "check_detection", "fen": "rnb1k1nr/pp2bpp1/2pp2qp/4p3/2B1P3/P1NP1N2/1PP2PPP/R1BQR1K1 b - -", "prompt": "FEN: rnb1k1nr/pp2bpp1/2pp2qp/4p3/2B1P3/P1NP1N2/1PP2PPP/R1BQR1K1 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01889", "split": "rules", "task_type": "captures", "fen": "rnbqk1nr/pppp1pbp/6p1/4p3/2P5/2NP1N2/PP2PPPP/R1BQKB1R b KQkq - 0 4", "prompt": "FEN: rnbqk1nr/pppp1pbp/6p1/4p3/2P5/2NP1N2/PP2PPPP/R1BQKB1R b KQkq - 0 4\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01890", "split": "rules", "task_type": "special_rules", "fen": "r2qk2r/ppp2ppp/2bp1n2/4P1B1/3Q4/8/PPP2PPP/RN3RK1 b kq - 0 10", "prompt": "Given FEN: r2qk2r/ppp2ppp/2bp1n2/4P1B1/3Q4/8/PPP2PPP/RN3RK1 b kq - 0 10\nList any special moves available (castling, en passant, promotion).", "gold_answer": "Castling available: kingside.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01891", "split": "rules", "task_type": "legality_check", "fen": "6k1/3r1p1p/2n1p1p1/p7/4p2P/5P2/P1N1K1P1/3r4 w - -", "prompt": "FEN: 6k1/3r1p1p/2n1p1p1/p7/4p2P/5P2/P1N1K1P1/3r4 w - -\nIs the move a2a4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "a2a4", "_legality_check_reason_label": "legal", "move": "a2a4", "legality_reason_label": "legal"}}
{"example_id": "rules_01892", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rn3rk1/1p2ppbp/1p1pb1p1/8/3PnB2/N1P2N1P/PP2BPP1/R3K2R w KQ -", "prompt": "FEN: rn3rk1/1p2ppbp/1p1pb1p1/8/3PnB2/N1P2N1P/PP2BPP1/R3K2R w KQ -\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1b1 a1c1 a1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01893", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/8/4p1k1/3p4/3P2P1/2P3K1/8/8 w - -", "prompt": "FEN: 8/8/4p1k1/3p4/3P2P1/2P3K1/8/8 w - -\nFor the piece on c3, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from c3: c3c4.\nLegal: c3c4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "c3", "diagnostic": true, "hard_gate": false, "source_square": "c3"}}
{"example_id": "rules_01894", "split": "rules", "task_type": "king_safety_filter", "fen": "8/4Nk2/8/3KQ3/8/8/8/8 w - -", "prompt": "FEN: 8/4Nk2/8/3KQ3/8/8/8/8 w - -\nFor move d5e6, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: d5e6.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "d5e6", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "d5e6", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01895", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "4r2k/p4R1p/3Qpp2/8/q7/4P2P/5PPK/8 b - -", "prompt": "FEN: 4r2k/p4R1p/3Qpp2/8/q7/4P2P/5PPK/8 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a4 black queen; e6 black pawn; f6 black pawn; a7 black pawn; h7 black pawn; e8 black rook; h8 black king.\nMoves by piece:\na4 black queen: a4a1 a4a2 a4a3 a4a5 a4a6 a4b3 a4b4 a4b5 a4c2 a4c4 a4c6 a4d1 a4d4 a4d7 a4e4 a4f4 a4g4 a4h4\ne6 black pawn: e6e5\nf6 black pawn: f6f5\na7 black pawn: a7a5 a7a6\nh7 black pawn: h7h5 h7h6\ne8 black rook: e8a8 e8b8 e8c8 e8d8 e8e7 e8f8 e8g8\nh8 black king: h8g8\nAll legal moves: a4a1 a4a2 a4a3 a4a5 a4a6 a4b3 a4b4 a4b5 a4c2 a4c4 a4c6 a4d1 a4d4 a4d7 a4e4 a4f4 a4g4 a4h4 a7a5 a7a6 e6e5 e8a8 e8b8 e8c8 e8d8 e8e7 e8f8 e8g8 f6f5 h7h5 h7h6 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a4": ["a4a1", "a4a2", "a4a3", "a4a5", "a4a6", "a4b3", "a4b4", "a4b5", "a4c2", "a4c4", "a4c6", "a4d1", "a4d4", "a4d7", "a4e4", "a4f4", "a4g4", "a4h4"], "e6": ["e6e5"], "f6": ["f6f5"], "a7": ["a7a5", "a7a6"], "h7": ["h7h5", "h7h6"], "e8": ["e8a8", "e8b8", "e8c8", "e8d8", "e8e7", "e8f8", "e8g8"], "h8": ["h8g8"]}, "_legal_moves_by_piece_moves": "a4a1 a4a2 a4a3 a4a5 a4a6 a4b3 a4b4 a4b5 a4c2 a4c4 a4c6 a4d1 a4d4 a4d7 a4e4 a4f4 a4g4 a4h4 a7a5 a7a6 e6e5 e8a8 e8b8 e8c8 e8d8 e8e7 e8f8 e8g8 f6f5 h7h5 h7h6 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a4": ["a4a1", "a4a2", "a4a3", "a4a5", "a4a6", "a4b3", "a4b4", "a4b5", "a4c2", "a4c4", "a4c6", "a4d1", "a4d4", "a4d7", "a4e4", "a4f4", "a4g4", "a4h4"], "e6": ["e6e5"], "f6": ["f6f5"], "a7": ["a7a5", "a7a6"], "h7": ["h7h5", "h7h6"], "e8": ["e8a8", "e8b8", "e8c8", "e8d8", "e8e7", "e8f8", "e8g8"], "h8": ["h8g8"]}, "legal_moves": "a4a1 a4a2 a4a3 a4a5 a4a6 a4b3 a4b4 a4b5 a4c2 a4c4 a4c6 a4d1 a4d4 a4d7 a4e4 a4f4 a4g4 a4h4 a7a5 a7a6 e6e5 e8a8 e8b8 e8c8 e8d8 e8e7 e8f8 e8g8 f6f5 h7h5 h7h6 h8g8"}}
{"example_id": "rules_01896", "split": "rules", "task_type": "ray_walk", "fen": "q3kR1Q/8/pp1p2P1/8/3pP2P/3P2rb/PP4P1/2R3K1 b - - 0 26", "prompt": "FEN: q3kR1Q/8/pp1p2P1/8/3pP2P/3P2rb/PP4P1/2R3K1 b - - 0 26\nWalk each ray for the slider on g3: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: g3 black rook.\nRay N: g4 empty; g5 empty; g6 white pawn: capture (stop, included).\nRay E: h3 black bishop: own piece (stop, excluded).\nRay S: g2 white pawn: capture (stop, included).\nRay W: f3 empty; e3 empty; d3 white pawn: capture (stop, included).\nMoves from rays: g3d3 g3e3 g3f3 g3g2 g3g4 g3g5 g3g6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "g3", "diagnostic": true, "hard_gate": false, "source_square": "g3"}}
{"example_id": "rules_01897", "split": "rules", "task_type": "legal_moves", "fen": "4r3/1p4b1/2p2k2/p1P1N3/1P2nPp1/P7/2b3K1/8 b - - 3 35", "prompt": "FEN: 4r3/1p4b1/2p2k2/p1P1N3/1P2nPp1/P7/2b3K1/8 b - - 3 35\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a5a4 a5b4 b7b5 b7b6 c2a4 c2b1 c2b3 c2d1 c2d3 e4c3 e4c5 e4d2 e4d6 e4f2 e4g3 e4g5 e8a8 e8b8 e8c8 e8d8 e8e5 e8e6 e8e7 e8f8 e8g8 e8h8 f6e6 f6e7 f6f5 g4g3 g7f8 g7h6 g7h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01898", "split": "rules", "task_type": "legal_moves", "fen": "4r1k1/2p4p/4N3/p4P2/1p6/4p3/PP2K1PP/8 b - - 1 30", "prompt": "FEN: 4r1k1/2p4p/4N3/p4P2/1p6/4p3/PP2K1PP/8 b - - 1 30\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a5a4 b4b3 c7c5 c7c6 e8a8 e8b8 e8c8 e8d8 e8e6 e8e7 e8f8 g8f7 g8h8 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01899", "split": "rules", "task_type": "side_piece_inventory", "fen": "rnb1kbnr/1p1p1pp1/p1p1p2p/q7/3PP2B/2N2N2/PPP2PPP/R2QKB1R b KQkq - 1 6", "prompt": "FEN: rnb1kbnr/1p1p1pp1/p1p1p2p/q7/3PP2B/2N2N2/PPP2PPP/R2QKB1R b KQkq - 1 6\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: a5 black queen; a6 black pawn; c6 black pawn; e6 black pawn; h6 black pawn; b7 black pawn; d7 black pawn; f7 black pawn; g7 black pawn; a8 black rook; b8 black knight; c8 black bishop; e8 black king; f8 black bishop; g8 black knight; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "a5", "piece": "black queen"}, {"square": "a6", "piece": "black pawn"}, {"square": "c6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "c8", "piece": "black bishop"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "a5", "piece": "black queen"}, {"square": "a6", "piece": "black pawn"}, {"square": "c6", "piece": "black pawn"}, {"square": "e6", "piece": "black pawn"}, {"square": "h6", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "c8", "piece": "black bishop"}, {"square": "e8", "piece": "black king"}, {"square": "f8", "piece": "black bishop"}, {"square": "g8", "piece": "black knight"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_01900", "split": "rules", "task_type": "piece_legal_moves", "fen": "rn1q1rk1/4bppp/p2pbn2/1pp1p3/P3P3/2NPBN1P/1PP1BPP1/R2QR1K1 b - -", "prompt": "FEN: rn1q1rk1/4bppp/p2pbn2/1pp1p3/P3P3/2NPBN1P/1PP1BPP1/R2QR1K1 b - -\nWhat legal moves does the piece on f8 have?", "gold_answer": "f8e8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f8", "_piece_legal_moves_piece": "rook", "diagnostic": true, "hard_gate": false, "source_square": "f8", "piece": "rook"}}
{"example_id": "rules_01901", "split": "rules", "task_type": "check_detection", "fen": "8/3k4/4r3/8/8/3K4/8/1R6 b - -", "prompt": "FEN: 8/3k4/4r3/8/8/3K4/8/1R6 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01902", "split": "rules", "task_type": "captures", "fen": "6k1/1R3p1p/p3p1p1/3pP3/6PP/8/8/r6K w - - 1 36", "prompt": "FEN: 6k1/1R3p1p/p3p1p1/3pP3/6PP/8/8/r6K w - - 1 36\nList all capture moves available.", "gold_answer": "No captures available.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01903", "split": "rules", "task_type": "special_rules", "fen": "3R4/8/8/5pp1/2k1p3/6P1/r4PK1/8 w - -", "prompt": "Given FEN: 3R4/8/8/5pp1/2k1p3/6P1/r4PK1/8 w - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01904", "split": "rules", "task_type": "legality_check", "fen": "8/8/2k5/7R/5N2/5Kp1/5b2/8 b - - 8 69", "prompt": "FEN: 8/8/2k5/7R/5N2/5Kp1/5b2/8 b - - 8 69\nIs the move f2a7 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "f2a7", "_legality_check_reason_label": "legal", "move": "f2a7", "legality_reason_label": "legal"}}
{"example_id": "rules_01905", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/1p6/1B1K4/P7/k7/8/2p5/8 w - -", "prompt": "FEN: 8/1p6/1B1K4/P7/k7/8/2p5/8 w - -\nList pseudo-legal moves from a5.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a5: a5a6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a5", "diagnostic": true, "hard_gate": false, "source_square": "a5"}}
{"example_id": "rules_01906", "split": "rules", "task_type": "piece_legal_filter", "fen": "4kb1r/1p1b1Rp1/p2Pp2q/8/4P1B1/2r3Q1/P5PP/5R1K w k -", "prompt": "FEN: 4kb1r/1p1b1Rp1/p2Pp2q/8/4P1B1/2r3Q1/P5PP/5R1K w k -\nFor the piece on f1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from f1: f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f1f4 f1f5 f1f6 f1g1.\nLegal: f1a1 f1b1 f1c1 f1d1 f1e1 f1f2 f1f3 f1f4 f1f5 f1f6 f1g1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "f1", "diagnostic": true, "hard_gate": false, "source_square": "f1"}}
{"example_id": "rules_01907", "split": "rules", "task_type": "king_safety_filter", "fen": "2k5/8/1P2K3/1B3p2/7p/8/8/8 b - - 0 43", "prompt": "FEN: 2k5/8/1P2K3/1B3p2/7p/8/8/8 b - - 0 43\nFor move c8c7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: c8c7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "c8c7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "c8c7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01908", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqkbnr/pp3ppp/2n1p3/2pp4/3P1P2/2PBP3/PP4PP/RNBQK1NR b KQkq - 2 5", "prompt": "FEN: r1bqkbnr/pp3ppp/2n1p3/2pp4/3P1P2/2PBP3/PP4PP/RNBQK1NR b KQkq - 2 5\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: c5 black pawn; d5 black pawn; c6 black knight; e6 black pawn; a7 black pawn; b7 black pawn; f7 black pawn; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; e8 black king; f8 black bishop; g8 black knight; h8 black rook.\nMoves by piece:\nc5 black pawn: c5c4 c5d4\nd5 black pawn: no legal moves\nc6 black knight: c6a5 c6b4 c6b8 c6d4 c6e5 c6e7\ne6 black pawn: e6e5\na7 black pawn: a7a5 a7a6\nb7 black pawn: b7b5 b7b6\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\na8 black rook: a8b8\nc8 black bishop: c8d7\nd8 black queen: d8a5 d8b6 d8c7 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4\ne8 black king: e8d7 e8e7\nf8 black bishop: f8d6 f8e7\ng8 black knight: g8e7 g8f6 g8h6\nh8 black rook: no legal moves\nAll legal moves: a7a5 a7a6 a8b8 b7b5 b7b6 c5c4 c5d4 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 c8d7 d8a5 d8b6 d8c7 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e6e5 e8d7 e8e7 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"c5": ["c5c4", "c5d4"], "d5": [], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5", "c6e7"], "e6": ["e6e5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7"], "d8": ["d8a5", "d8b6", "d8c7", "d8d6", "d8d7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8d7", "e8e7"], "f8": ["f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "_legal_moves_by_piece_moves": "a7a5 a7a6 a8b8 b7b5 b7b6 c5c4 c5d4 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 c8d7 d8a5 d8b6 d8c7 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e6e5 e8d7 e8e7 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"c5": ["c5c4", "c5d4"], "d5": [], "c6": ["c6a5", "c6b4", "c6b8", "c6d4", "c6e5", "c6e7"], "e6": ["e6e5"], "a7": ["a7a5", "a7a6"], "b7": ["b7b5", "b7b6"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "a8": ["a8b8"], "c8": ["c8d7"], "d8": ["d8a5", "d8b6", "d8c7", "d8d6", "d8d7", "d8e7", "d8f6", "d8g5", "d8h4"], "e8": ["e8d7", "e8e7"], "f8": ["f8d6", "f8e7"], "g8": ["g8e7", "g8f6", "g8h6"], "h8": []}, "legal_moves": "a7a5 a7a6 a8b8 b7b5 b7b6 c5c4 c5d4 c6a5 c6b4 c6b8 c6d4 c6e5 c6e7 c8d7 d8a5 d8b6 d8c7 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e6e5 e8d7 e8e7 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6"}}
{"example_id": "rules_01909", "split": "rules", "task_type": "ray_walk", "fen": "r1b4N/pp2k1pp/4p3/2b5/3nnB2/8/PP2K1PP/1N6 w - - 1 24", "prompt": "FEN: r1b4N/pp2k1pp/4p3/2b5/3nnB2/8/PP2K1PP/1N6 w - - 1 24\nWalk each ray for the slider on f4: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: f4 white bishop.\nRay NE: g5 empty; h6 empty; edge.\nRay SE: g3 empty; h2 white pawn: own piece (stop, excluded).\nRay SW: e3 empty; d2 empty; c1 empty; edge.\nRay NW: e5 empty; d6 empty; c7 empty; b8 empty; edge.\nMoves from rays: f4b8 f4c1 f4c7 f4d2 f4d6 f4e3 f4e5 f4g3 f4g5 f4h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "f4", "diagnostic": true, "hard_gate": false, "source_square": "f4"}}
{"example_id": "rules_01910", "split": "rules", "task_type": "legal_moves", "fen": "2kr3r/2p1q1p1/p1p5/Pp3p2/3pn2p/3QBP1P/1PP3P1/R2R2K1 w - - 0 18", "prompt": "FEN: 2kr3r/2p1q1p1/p1p5/Pp3p2/3pn2p/3QBP1P/1PP3P1/R2R2K1 w - - 0 18\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1a3 a1a4 a1b1 a1c1 b2b3 b2b4 c2c3 c2c4 d1b1 d1c1 d1d2 d1e1 d1f1 d3a3 d3b3 d3b5 d3c3 d3c4 d3d2 d3d4 d3e2 d3e4 d3f1 e3c1 e3d2 e3d4 e3f2 e3f4 e3g5 e3h6 f3e4 f3f4 g1f1 g1h1 g1h2 g2g3 g2g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01911", "split": "rules", "task_type": "legal_moves", "fen": "8/8/2k1B3/2B1K3/8/8/8/8 w - -", "prompt": "FEN: 8/8/2k1B3/2B1K3/8/8/8/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: c5a3 c5a7 c5b4 c5b6 c5d4 c5d6 c5e3 c5e7 c5f2 c5f8 c5g1 e5d4 e5e4 e5f4 e5f5 e5f6 e6a2 e6b3 e6c4 e6c8 e6d5 e6d7 e6f5 e6f7 e6g4 e6g8 e6h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01912", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1b2rk1/pp1nq1pp/2n1pp2/1NppP3/3P1P2/2P2N2/PP4PP/R2QKB1R w KQ -", "prompt": "FEN: r1b2rk1/pp1nq1pp/2n1pp2/1NppP3/3P1P2/2P2N2/PP4PP/R2QKB1R w KQ -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: a1 white rook; d1 white queen; e1 white king; f1 white bishop; h1 white rook; a2 white pawn; b2 white pawn; g2 white pawn; h2 white pawn; c3 white pawn; f3 white knight; d4 white pawn; f4 white pawn; b5 white knight; e5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "f1", "piece": "white bishop"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "d4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "b5", "piece": "white knight"}, {"square": "e5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "a1", "piece": "white rook"}, {"square": "d1", "piece": "white queen"}, {"square": "e1", "piece": "white king"}, {"square": "f1", "piece": "white bishop"}, {"square": "h1", "piece": "white rook"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "c3", "piece": "white pawn"}, {"square": "f3", "piece": "white knight"}, {"square": "d4", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "b5", "piece": "white knight"}, {"square": "e5", "piece": "white pawn"}]}}
{"example_id": "rules_01913", "split": "rules", "task_type": "piece_legal_moves", "fen": "1r5r/p2bk2p/2p1pp2/q7/5P2/1P1BQ3/P5PP/R2R3K w - -", "prompt": "FEN: 1r5r/p2bk2p/2p1pp2/q7/5P2/1P1BQ3/P5PP/R2R3K w - -\nWhat legal moves does the piece on e3 have?", "gold_answer": "e3a7 e3b6 e3c1 e3c5 e3d2 e3d4 e3e1 e3e2 e3e4 e3e5 e3e6 e3f2 e3f3 e3g1 e3g3 e3h3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "e3", "_piece_legal_moves_piece": "queen", "diagnostic": true, "hard_gate": false, "source_square": "e3", "piece": "queen"}}
{"example_id": "rules_01914", "split": "rules", "task_type": "check_detection", "fen": "r5k1/p1p3pp/2pp1pn1/5Q1P/3P4/2NB2P1/PPP2RK1/2q3r1 w - - 1 24", "prompt": "FEN: r5k1/p1p3pp/2pp1pn1/5Q1P/3P4/2NB2P1/PPP2RK1/2q3r1 w - - 1 24\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01915", "split": "rules", "task_type": "captures", "fen": "r1b1k2r/pp2ppbp/2p2np1/8/1q2P3/1BN1BP2/PPP3PP/R2QK2R b KQkq -", "prompt": "FEN: r1b1k2r/pp2ppbp/2p2np1/8/1q2P3/1BN1BP2/PPP3PP/R2QK2R b KQkq -\nList all capture moves available.", "gold_answer": "b4b3 b4c3 b4e4 f6e4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01916", "split": "rules", "task_type": "special_rules", "fen": "3N4/1R3pk1/4p1p1/4r2p/8/8/4nKPP/8 b - -", "prompt": "Given FEN: 3N4/1R3pk1/4p1p1/4r2p/8/8/4nKPP/8 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01917", "split": "rules", "task_type": "legality_check", "fen": "4r1k1/r6p/b4pq1/2pPnNp1/1pP1P1P1/pP2R1QP/P5B1/5R1K b - - 1 35", "prompt": "FEN: 4r1k1/r6p/b4pq1/2pPnNp1/1pP1P1P1/pP2R1QP/P5B1/5R1K b - - 1 35\nIs the move g4f1 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g4f1", "_legality_check_reason_label": "wrong_side_piece", "move": "g4f1", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01918", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "3r2k1/pB3ppp/3Prn2/8/5P2/2N5/PPP4P/3R1R1K w - - 1 24", "prompt": "FEN: 3r2k1/pB3ppp/3Prn2/8/5P2/2N5/PPP4P/3R1R1K w - - 1 24\nList pseudo-legal moves from d1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d1: d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1e1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d1", "diagnostic": true, "hard_gate": false, "source_square": "d1"}}
{"example_id": "rules_01919", "split": "rules", "task_type": "piece_legal_filter", "fen": "r2q1rk1/1pp3pp/2nppn2/p1b1p3/4P3/P1NP1N1P/1PP2PP1/R1BQ1RK1 w - - 0 10", "prompt": "FEN: r2q1rk1/1pp3pp/2nppn2/p1b1p3/4P3/P1NP1N1P/1PP2PP1/R1BQ1RK1 w - - 0 10\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1a2 a1b1.\nLegal: a1a2 a1b1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01920", "split": "rules", "task_type": "king_safety_filter", "fen": "r6k/2p5/5p1P/4p1p1/8/5N2/1Bq2K2/8 w - - 1 50", "prompt": "FEN: r6k/2p5/5p1P/4p1p1/8/5N2/1Bq2K2/8 w - - 1 50\nFor move b2a1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: b2a1.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "b2a1", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "b2a1", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_01921", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "8/8/2K5/7p/1r4k1/1P2R1P1/8/8 b - -", "prompt": "FEN: 8/8/2K5/7p/1r4k1/1P2R1P1/8/8 b - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b4 black rook; g4 black king; h5 black pawn.\nMoves by piece:\nb4 black rook: b4a4 b4b3 b4b5 b4b6 b4b7 b4b8 b4c4 b4d4 b4e4 b4f4\ng4 black king: g4f5 g4g5 g4h3\nh5 black pawn: h5h4\nAll legal moves: b4a4 b4b3 b4b5 b4b6 b4b7 b4b8 b4c4 b4d4 b4e4 b4f4 g4f5 g4g5 g4h3 h5h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b4": ["b4a4", "b4b3", "b4b5", "b4b6", "b4b7", "b4b8", "b4c4", "b4d4", "b4e4", "b4f4"], "g4": ["g4f5", "g4g5", "g4h3"], "h5": ["h5h4"]}, "_legal_moves_by_piece_moves": "b4a4 b4b3 b4b5 b4b6 b4b7 b4b8 b4c4 b4d4 b4e4 b4f4 g4f5 g4g5 g4h3 h5h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b4": ["b4a4", "b4b3", "b4b5", "b4b6", "b4b7", "b4b8", "b4c4", "b4d4", "b4e4", "b4f4"], "g4": ["g4f5", "g4g5", "g4h3"], "h5": ["h5h4"]}, "legal_moves": "b4a4 b4b3 b4b5 b4b6 b4b7 b4b8 b4c4 b4d4 b4e4 b4f4 g4f5 g4g5 g4h3 h5h4"}}
{"example_id": "rules_01922", "split": "rules", "task_type": "legal_moves", "fen": "b6k/4K1np/3Np3/8/8/8/8/8 w - -", "prompt": "FEN: b6k/4K1np/3Np3/8/8/8/8/8 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: d6b5 d6b7 d6c4 d6c8 d6e4 d6e8 d6f5 d6f7 e7d7 e7d8 e7f6 e7f7 e7f8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": ""}}
{"example_id": "rules_01923", "split": "rules", "task_type": "legal_moves", "fen": "r3kb1r/p2p1ppp/2qP4/p1B1P3/1P6/2P2N2/P1Q2PPP/R4K2 b kq - 0 18", "prompt": "FEN: r3kb1r/p2p1ppp/2qP4/p1B1P3/1P6/2P2N2/P1Q2PPP/R4K2 b kq - 0 18\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a5a4 a5b4 a7a6 a8b8 a8c8 a8d8 c6a4 c6a6 c6b5 c6b6 c6b7 c6c5 c6c7 c6c8 c6d5 c6d6 c6e4 c6f3 e8c8 e8d8 f7f5 f7f6 f8d6 f8e7 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01924", "split": "rules", "task_type": "legal_moves", "fen": "3qbk2/1QR2r2/1n1p4/2pPp1pp/2P1Pp2/2N2P1P/6PN/6K1 w - -", "prompt": "FEN: 3qbk2/1QR2r2/1n1p4/2pPp1pp/2P1Pp2/2N2P1P/6PN/6K1 w - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b7a6 b7a7 b7a8 b7b6 b7b8 b7c6 b7c8 c3a2 c3a4 c3b1 c3b5 c3d1 c3e2 c7c5 c7c6 c7c8 c7d7 c7e7 c7f7 g1f1 g1f2 g1h1 g2g3 g2g4 h2f1 h2g4 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01925", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bqrnk1/1p3ppp/pb6/3PP3/3p1P2/3P2P1/PP1BQ1BP/2R2RK1 w - -", "prompt": "FEN: r1bqrnk1/1p3ppp/pb6/3PP3/3p1P2/3P2P1/PP1BQ1BP/2R2RK1 w - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: c1 white rook; f1 white rook; g1 white king; a2 white pawn; b2 white pawn; d2 white bishop; e2 white queen; g2 white bishop; h2 white pawn; d3 white pawn; g3 white pawn; f4 white pawn; d5 white pawn; e5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "c1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "e2", "piece": "white queen"}, {"square": "g2", "piece": "white bishop"}, {"square": "h2", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "d5", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "c1", "piece": "white rook"}, {"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white king"}, {"square": "a2", "piece": "white pawn"}, {"square": "b2", "piece": "white pawn"}, {"square": "d2", "piece": "white bishop"}, {"square": "e2", "piece": "white queen"}, {"square": "g2", "piece": "white bishop"}, {"square": "h2", "piece": "white pawn"}, {"square": "d3", "piece": "white pawn"}, {"square": "g3", "piece": "white pawn"}, {"square": "f4", "piece": "white pawn"}, {"square": "d5", "piece": "white pawn"}, {"square": "e5", "piece": "white pawn"}]}}
{"example_id": "rules_01926", "split": "rules", "task_type": "piece_legal_moves", "fen": "5r2/1p4pk/p2p3p/2qPp3/2PbP3/1P1B3P/P3R1P1/3Q3K w - - 5 31", "prompt": "FEN: 5r2/1p4pk/p2p3p/2qPp3/2PbP3/1P1B3P/P3R1P1/3Q3K w - - 5 31\nWhat legal moves does the piece on c4 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "c4", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "c4", "piece": "pawn"}}
{"example_id": "rules_01927", "split": "rules", "task_type": "check_detection", "fen": "r7/6P1/3k4/5K2/6R1/8/8/8 b - -", "prompt": "FEN: r7/6P1/3k4/5K2/6R1/8/8/8 b - -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01928", "split": "rules", "task_type": "captures", "fen": "7k/5Bp1/2Q4p/8/8/8/8/6K1 w - -", "prompt": "FEN: 7k/5Bp1/2Q4p/8/8/8/8/6K1 w - -\nList all capture moves available.", "gold_answer": "c6h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01929", "split": "rules", "task_type": "special_rules", "fen": "7r/p2k1p2/1nn1r2p/q2pP2P/1bpP4/4BN2/PPQN3R/1K4R1 b - - 3 26", "prompt": "Given FEN: 7r/p2k1p2/1nn1r2p/q2pP2P/1bpP4/4BN2/PPQN3R/1K4R1 b - - 3 26\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01930", "split": "rules", "task_type": "legality_check", "fen": "4r1k1/pp2rpp1/2p2n1p/3pq3/6b1/2PQP3/PPB2PPP/2KR2NR b - - 1 18", "prompt": "FEN: 4r1k1/pp2rpp1/2p2n1p/3pq3/6b1/2PQP3/PPB2PPP/2KR2NR b - - 1 18\nIs the move b2e5 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "b2e5", "_legality_check_reason_label": "wrong_side_piece", "move": "b2e5", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01931", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "1r3rk1/pp3pp1/1n2p2p/1b2P3/1P2N2P/P4N2/5PPK/R3R3 w - - 1 26", "prompt": "FEN: 1r3rk1/pp3pp1/1n2p2p/1b2P3/1P2N2P/P4N2/5PPK/R3R3 w - - 1 26\nList pseudo-legal moves from a1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from a1: a1a2 a1b1 a1c1 a1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01932", "split": "rules", "task_type": "piece_legal_filter", "fen": "4kbnr/2p4p/1p2b1p1/p2pp3/7P/2P3P1/PPQ1PPB1/RN2K1NR w KQ - 0 19", "prompt": "FEN: 4kbnr/2p4p/1p2b1p1/p2pp3/7P/2P3P1/PPQ1PPB1/RN2K1NR w KQ - 0 19\nFor the piece on b1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from b1: b1a3 b1d2.\nLegal: b1a3 b1d2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01933", "split": "rules", "task_type": "king_safety_filter", "fen": "r2q1rk1/pp1n1pbp/2p1pnp1/2Pp4/3P4/2NQPN2/PP1B1PPP/R4RK1 b - -", "prompt": "FEN: r2q1rk1/pp1n1pbp/2p1pnp1/2Pp4/3P4/2NQPN2/PP1B1PPP/R4RK1 b - -\nFor move a7a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a7a5.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "a7a5", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a7a5", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01934", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "3r3r/5kpp/4qp2/3p4/Pb6/3Q1PB1/1P3P1P/5RK1 b - - 1 27", "prompt": "FEN: 3r3r/5kpp/4qp2/3p4/Pb6/3Q1PB1/1P3P1P/5RK1 b - - 1 27\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: b4 black bishop; d5 black pawn; e6 black queen; f6 black pawn; f7 black king; g7 black pawn; h7 black pawn; d8 black rook; h8 black rook.\nMoves by piece:\nb4 black bishop: b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7 b4f8\nd5 black pawn: d5d4\ne6 black queen: e6a6 e6b6 e6c6 e6c8 e6d6 e6d7 e6e1 e6e2 e6e3 e6e4 e6e5 e6e7 e6e8 e6f5 e6g4 e6h3\nf6 black pawn: f6f5\nf7 black king: f7e7 f7e8 f7f8 f7g8\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\nd8 black rook: d8a8 d8b8 d8c8 d8d6 d8d7 d8e8 d8f8 d8g8\nh8 black rook: h8e8 h8f8 h8g8\nAll legal moves: b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7 b4f8 d5d4 d8a8 d8b8 d8c8 d8d6 d8d7 d8e8 d8f8 d8g8 e6a6 e6b6 e6c6 e6c8 e6d6 e6d7 e6e1 e6e2 e6e3 e6e4 e6e5 e6e7 e6e8 e6f5 e6g4 e6h3 f6f5 f7e7 f7e8 f7f8 f7g8 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"b4": ["b4a3", "b4a5", "b4c3", "b4c5", "b4d2", "b4d6", "b4e1", "b4e7", "b4f8"], "d5": ["d5d4"], "e6": ["e6a6", "e6b6", "e6c6", "e6c8", "e6d6", "e6d7", "e6e1", "e6e2", "e6e3", "e6e4", "e6e5", "e6e7", "e6e8", "e6f5", "e6g4", "e6h3"], "f6": ["f6f5"], "f7": ["f7e7", "f7e8", "f7f8", "f7g8"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "d8": ["d8a8", "d8b8", "d8c8", "d8d6", "d8d7", "d8e8", "d8f8", "d8g8"], "h8": ["h8e8", "h8f8", "h8g8"]}, "_legal_moves_by_piece_moves": "b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7 b4f8 d5d4 d8a8 d8b8 d8c8 d8d6 d8d7 d8e8 d8f8 d8g8 e6a6 e6b6 e6c6 e6c8 e6d6 e6d7 e6e1 e6e2 e6e3 e6e4 e6e5 e6e7 e6e8 e6f5 e6g4 e6h3 f6f5 f7e7 f7e8 f7f8 f7g8 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"b4": ["b4a3", "b4a5", "b4c3", "b4c5", "b4d2", "b4d6", "b4e1", "b4e7", "b4f8"], "d5": ["d5d4"], "e6": ["e6a6", "e6b6", "e6c6", "e6c8", "e6d6", "e6d7", "e6e1", "e6e2", "e6e3", "e6e4", "e6e5", "e6e7", "e6e8", "e6f5", "e6g4", "e6h3"], "f6": ["f6f5"], "f7": ["f7e7", "f7e8", "f7f8", "f7g8"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "d8": ["d8a8", "d8b8", "d8c8", "d8d6", "d8d7", "d8e8", "d8f8", "d8g8"], "h8": ["h8e8", "h8f8", "h8g8"]}, "legal_moves": "b4a3 b4a5 b4c3 b4c5 b4d2 b4d6 b4e1 b4e7 b4f8 d5d4 d8a8 d8b8 d8c8 d8d6 d8d7 d8e8 d8f8 d8g8 e6a6 e6b6 e6c6 e6c8 e6d6 e6d7 e6e1 e6e2 e6e3 e6e4 e6e5 e6e7 e6e8 e6f5 e6g4 e6h3 f6f5 f7e7 f7e8 f7f8 f7g8 g7g5 g7g6 h7h5 h7h6 h8e8 h8f8 h8g8"}}
{"example_id": "rules_01935", "split": "rules", "task_type": "ray_walk", "fen": "r6k/6pp/p2pbpq1/1p2p3/8/4PN1P/PPP1QRP1/R5K1 w - - 1 24", "prompt": "FEN: r6k/6pp/p2pbpq1/1p2p3/8/4PN1P/PPP1QRP1/R5K1 w - - 1 24\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 empty; e1 empty; f1 empty; g1 white king: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1 a1d1 a1e1 a1f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01936", "split": "rules", "task_type": "legal_moves", "fen": "4r3/4bkp1/3q1p1p/1Q1p4/3P4/1P5P/P3RP1P/4R1K1 w - - 1 32", "prompt": "FEN: 4r3/4bkp1/3q1p1p/1Q1p4/3P4/1P5P/P3RP1P/4R1K1 w - - 1 32\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b3b4 b5a4 b5a5 b5a6 b5b4 b5b6 b5b7 b5b8 b5c4 b5c5 b5c6 b5d3 b5d5 b5d7 b5e8 e1a1 e1b1 e1c1 e1d1 e1f1 e2b2 e2c2 e2d2 e2e3 e2e4 e2e5 e2e6 e2e7 f2f3 f2f4 g1f1 g1g2 g1h1 h3h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01937", "split": "rules", "task_type": "legal_moves", "fen": "r1bqk1nr/ppp2p2/2nbp2p/1N1p2p1/3P1B2/P4N2/1PPQPPPP/R3KB1R w KQkq - 0 8", "prompt": "FEN: r1bqk1nr/ppp2p2/2nbp2p/1N1p2p1/3P1B2/P4N2/1PPQPPPP/R3KB1R w KQkq - 0 8\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a1a2 a1b1 a1c1 a1d1 a3a4 b2b3 b2b4 b5a7 b5c3 b5c7 b5d6 c2c3 c2c4 d2a5 d2b4 d2c1 d2c3 d2d1 d2d3 d2e3 e1c1 e1d1 e2e3 e2e4 f3e5 f3g1 f3g5 f3h4 f4d6 f4e3 f4e5 f4g3 f4g5 g2g3 g2g4 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01938", "split": "rules", "task_type": "side_piece_inventory", "fen": "7k/2p5/1p1p3q/pPnPp3/P1P1Pn2/5Q1P/2B3rK/5RN1 w - - 3 31", "prompt": "FEN: 7k/2p5/1p1p3q/pPnPp3/P1P1Pn2/5Q1P/2B3rK/5RN1 w - - 3 31\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: f1 white rook; g1 white knight; c2 white bishop; h2 white king; f3 white queen; h3 white pawn; a4 white pawn; c4 white pawn; e4 white pawn; b5 white pawn; d5 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white knight"}, {"square": "c2", "piece": "white bishop"}, {"square": "h2", "piece": "white king"}, {"square": "f3", "piece": "white queen"}, {"square": "h3", "piece": "white pawn"}, {"square": "a4", "piece": "white pawn"}, {"square": "c4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}, {"square": "b5", "piece": "white pawn"}, {"square": "d5", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "f1", "piece": "white rook"}, {"square": "g1", "piece": "white knight"}, {"square": "c2", "piece": "white bishop"}, {"square": "h2", "piece": "white king"}, {"square": "f3", "piece": "white queen"}, {"square": "h3", "piece": "white pawn"}, {"square": "a4", "piece": "white pawn"}, {"square": "c4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}, {"square": "b5", "piece": "white pawn"}, {"square": "d5", "piece": "white pawn"}]}}
{"example_id": "rules_01939", "split": "rules", "task_type": "piece_legal_moves", "fen": "8/4r1k1/1R5p/6pP/6P1/5P2/5K2/8 b - -", "prompt": "FEN: 8/4r1k1/1R5p/6pP/6P1/5P2/5K2/8 b - -\nWhat legal moves does the piece on g5 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "g5", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "g5", "piece": "pawn"}}
{"example_id": "rules_01940", "split": "rules", "task_type": "check_detection", "fen": "5k2/p4p1p/1pn1p1p1/2p5/4NP2/5KP1/PPP4P/8 w - - 2 27", "prompt": "FEN: 5k2/p4p1p/1pn1p1p1/2p5/4NP2/5KP1/PPP4P/8 w - - 2 27\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01941", "split": "rules", "task_type": "captures", "fen": "3n4/ppp4p/5kp1/4Np2/3P4/2P5/PP3R1P/2K1R3 w - - 3 25", "prompt": "FEN: 3n4/ppp4p/5kp1/4Np2/3P4/2P5/PP3R1P/2K1R3 w - - 3 25\nList all capture moves available.", "gold_answer": "e5g6 f2f5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01942", "split": "rules", "task_type": "special_rules", "fen": "6bk/6bp/8/pp2pnN1/2p1B3/2P4P/P2r1PP1/4R1K1 w - - 0 37", "prompt": "Given FEN: 6bk/6bp/8/pp2pnN1/2p1B3/2P4P/P2r1PP1/4R1K1 w - - 0 37\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01943", "split": "rules", "task_type": "legality_check", "fen": "8/2Pb3k/6p1/3P3p/4pP2/7P/6P1/6K1 w - - 1 42", "prompt": "FEN: 8/2Pb3k/6p1/3P3p/4pP2/7P/6P1/6K1 w - - 1 42\nIs the move g2g4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "g2g4", "_legality_check_reason_label": "legal", "move": "g2g4", "legality_reason_label": "legal"}}
{"example_id": "rules_01944", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2k4r/p6p/2bq2p1/p2rp1B1/2Rb3P/P7/3Q1PP1/2R3K1 b - -", "prompt": "FEN: 2k4r/p6p/2bq2p1/p2rp1B1/2Rb3P/P7/3Q1PP1/2R3K1 b - -\nList pseudo-legal moves from d4.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from d4: d4a1 d4b2 d4b6 d4c3 d4c5 d4e3 d4f2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "d4", "diagnostic": true, "hard_gate": false, "source_square": "d4"}}
{"example_id": "rules_01945", "split": "rules", "task_type": "piece_legal_filter", "fen": "rn6/1b1p4/p1p1pkp1/8/3P3p/2PB3P/PP3PP1/R4RK1 w - - 0 21", "prompt": "FEN: rn6/1b1p4/p1p1pkp1/8/3P3p/2PB3P/PP3PP1/R4RK1 w - - 0 21\nFor the piece on a1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from a1: a1b1 a1c1 a1d1 a1e1.\nLegal: a1b1 a1c1 a1d1 a1e1.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01946", "split": "rules", "task_type": "king_safety_filter", "fen": "2k3r1/ppp2p1p/2n5/3p1p2/3P3P/N1P2P1R/PPK3N1/R7 w - - 1 22", "prompt": "FEN: 2k3r1/ppp2p1p/2n5/3p1p2/3P3P/N1P2P1R/PPK3N1/R7 w - - 1 22\nFor move a1b1, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a1b1.\nPseudo-legal: yes.\nKing safe after move: yes.\nFinal: legal; legal.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a1b1", "_king_safety_filter_reason_label": "legal", "_king_safety_filter_is_legal": true, "diagnostic": true, "hard_gate": false, "move": "a1b1", "legality_reason_label": "legal", "expected_is_legal": true}}
{"example_id": "rules_01947", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqkb1r/pp2pp1p/2np1p2/1Bp5/8/3P1N2/PPP2PPP/R1BQK2R w KQkq -", "prompt": "FEN: r1bqkb1r/pp2pp1p/2np1p2/1Bp5/8/3P1N2/PPP2PPP/R1BQK2R w KQkq -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; c1 white bishop; d1 white queen; e1 white king; h1 white rook; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; h2 white pawn; d3 white pawn; f3 white knight; b5 white bishop.\nMoves by piece:\na1 white rook: a1b1\nc1 white bishop: c1d2 c1e3 c1f4 c1g5 c1h6\nd1 white queen: d1d2 d1e2\ne1 white king: e1d2 e1e2 e1f1 e1g1\nh1 white rook: h1f1 h1g1\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: c2c3 c2c4\nf2 white pawn: no legal moves\ng2 white pawn: g2g3 g2g4\nh2 white pawn: h2h3 h2h4\nd3 white pawn: d3d4\nf3 white knight: f3d2 f3d4 f3e5 f3g1 f3g5 f3h4\nb5 white bishop: b5a4 b5a6 b5c4 b5c6\nAll legal moves: a1b1 a2a3 a2a4 b2b3 b2b4 b5a4 b5a6 b5c4 b5c6 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c2c4 d1d2 d1e2 d3d4 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1d2", "d1e2"], "e1": ["e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "d3": ["d3d4"], "f3": ["f3d2", "f3d4", "f3e5", "f3g1", "f3g5", "f3h4"], "b5": ["b5a4", "b5a6", "b5c4", "b5c6"]}, "_legal_moves_by_piece_moves": "a1b1 a2a3 a2a4 b2b3 b2b4 b5a4 b5a6 b5c4 b5c6 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c2c4 d1d2 d1e2 d3d4 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1"], "c1": ["c1d2", "c1e3", "c1f4", "c1g5", "c1h6"], "d1": ["d1d2", "d1e2"], "e1": ["e1d2", "e1e2", "e1f1", "e1g1"], "h1": ["h1f1", "h1g1"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": ["c2c3", "c2c4"], "f2": [], "g2": ["g2g3", "g2g4"], "h2": ["h2h3", "h2h4"], "d3": ["d3d4"], "f3": ["f3d2", "f3d4", "f3e5", "f3g1", "f3g5", "f3h4"], "b5": ["b5a4", "b5a6", "b5c4", "b5c6"]}, "legal_moves": "a1b1 a2a3 a2a4 b2b3 b2b4 b5a4 b5a6 b5c4 b5c6 c1d2 c1e3 c1f4 c1g5 c1h6 c2c3 c2c4 d1d2 d1e2 d3d4 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4"}}
{"example_id": "rules_01948", "split": "rules", "task_type": "ray_walk", "fen": "r1bqk2r/ppppnppp/2n5/2PN4/2P5/1P2P3/P4PBP/R1BQK2R b KQkq -", "prompt": "FEN: r1bqk2r/ppppnppp/2n5/2PN4/2P5/1P2P3/P4PBP/R1BQK2R b KQkq -\nWalk each ray for the slider on a8: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a8 black rook.\nRay N: edge.\nRay E: b8 empty; c8 black bishop: own piece (stop, excluded).\nRay S: a7 black pawn: own piece (stop, excluded).\nRay W: edge.\nMoves from rays: a8b8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_ray_walk_square": "a8", "diagnostic": true, "hard_gate": false, "source_square": "a8"}}
{"example_id": "rules_01949", "split": "rules", "task_type": "legal_moves", "fen": "r1bqkb1r/p1ppp1pp/1pn2n2/3P1p2/2P5/4PQ2/PP3PPP/RNB1KBNR b KQkq -", "prompt": "FEN: r1bqkb1r/p1ppp1pp/1pn2n2/3P1p2/2P5/4PQ2/PP3PPP/RNB1KBNR b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a7a5 a7a6 a8b8 b6b5 c6a5 c6b4 c6b8 c6d4 c6e5 c8a6 c8b7 d7d6 e7e5 e7e6 e8f7 f5f4 f6d5 f6e4 f6g4 f6g8 f6h5 g7g5 g7g6 h7h5 h7h6 h8g8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01950", "split": "rules", "task_type": "legal_moves", "fen": "r4b2/2p1n3/2ppRNkr/q4bNp/3B1P1P/pPPQ2P1/P7/2K4R b - -", "prompt": "FEN: r4b2/2p1n3/2ppRNkr/q4bNp/3B1P1P/pPPQ2P1/P7/2K4R b - -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a5a4 a5a6 a5a7 a5b4 a5b5 a5b6 a5c3 a5c5 a5d5 a5e5 a8a6 a8a7 a8b8 a8c8 a8d8 a8e8 c6c5 d6d5 e7c8 e7d5 e7g8 f5d3 f5e4 f8g7 g6g7 h6h7 h6h8", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01951", "split": "rules", "task_type": "side_piece_inventory", "fen": "5r2/2p1kr1p/ppnp1p2/3p4/P3P3/N1P5/4KRPP/1R6 w - - 0 26", "prompt": "FEN: 5r2/2p1kr1p/ppnp1p2/3p4/P3P3/N1P5/4KRPP/1R6 w - - 0 26\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: white.\nPieces: b1 white rook; e2 white king; f2 white rook; g2 white pawn; h2 white pawn; a3 white knight; c3 white pawn; a4 white pawn; e4 white pawn.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "white", "_side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "e2", "piece": "white king"}, {"square": "f2", "piece": "white rook"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white knight"}, {"square": "c3", "piece": "white pawn"}, {"square": "a4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}], "diagnostic": true, "hard_gate": false, "side_to_move": "white", "side_piece_inventory": [{"square": "b1", "piece": "white rook"}, {"square": "e2", "piece": "white king"}, {"square": "f2", "piece": "white rook"}, {"square": "g2", "piece": "white pawn"}, {"square": "h2", "piece": "white pawn"}, {"square": "a3", "piece": "white knight"}, {"square": "c3", "piece": "white pawn"}, {"square": "a4", "piece": "white pawn"}, {"square": "e4", "piece": "white pawn"}]}}
{"example_id": "rules_01952", "split": "rules", "task_type": "piece_legal_moves", "fen": "4k2r/4nppp/r1p1q3/2b3B1/1n2P3/2N2N2/1P3PPP/R2Q1RK1 b k - 3 16", "prompt": "FEN: 4k2r/4nppp/r1p1q3/2b3B1/1n2P3/2N2N2/1P3PPP/R2Q1RK1 b k - 3 16\nWhat legal moves does the piece on f7 have?", "gold_answer": "f7f5 f7f6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "f7", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f7", "piece": "pawn"}}
{"example_id": "rules_01953", "split": "rules", "task_type": "check_detection", "fen": "2kr1bnr/ppq2ppp/2n5/3pP3/6b1/4PN2/PPP2PPP/RN1QKB1R w KQ -", "prompt": "FEN: 2kr1bnr/ppq2ppp/2n5/3pP3/6b1/4PN2/PPP2PPP/RN1QKB1R w KQ -\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01954", "split": "rules", "task_type": "captures", "fen": "r2q1rk1/pp1b1pbp/2nppnp1/2p5/4PPP1/3P2NP/PPP3B1/RNBQ1RK1 b - - 1 10", "prompt": "FEN: r2q1rk1/pp1b1pbp/2nppnp1/2p5/4PPP1/3P2NP/PPP3B1/RNBQ1RK1 b - - 1 10\nList all capture moves available.", "gold_answer": "f6e4 f6g4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01955", "split": "rules", "task_type": "special_rules", "fen": "2kr3Q/ppp2p1p/8/8/2P2pq1/1P4P1/P4PKP/3RR3 w - - 9 33", "prompt": "Given FEN: 2kr3Q/ppp2p1p/8/8/2P2pq1/1P4P1/P4PKP/3RR3 w - - 9 33\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01956", "split": "rules", "task_type": "legality_check", "fen": "r5k1/p1pbqpp1/2pp3p/2r1P3/8/1B3Q1P/PP3PP1/3RR1K1 b - - 0 20", "prompt": "FEN: r5k1/p1pbqpp1/2pp3p/2r1P3/8/1B3Q1P/PP3PP1/3RR1K1 b - - 0 20\nIs the move c5d5 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c5d5", "_legality_check_reason_label": "legal", "move": "c5d5", "legality_reason_label": "legal"}}
{"example_id": "rules_01957", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "8/r1k5/1p3p2/rPp1pP1p/2P1P1pP/pR1P2P1/R7/1K1B4 w - - 18 56", "prompt": "FEN: 8/r1k5/1p3p2/rPp1pP1p/2P1P1pP/pR1P2P1/R7/1K1B4 w - - 18 56\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a1 b1b2 b1c1 b1c2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01958", "split": "rules", "task_type": "piece_legal_filter", "fen": "3r3k/1p4b1/2p4p/2P2p1Q/1P2p3/4P1qP/6P1/3RR1K1 b - -", "prompt": "FEN: 3r3k/1p4b1/2p4p/2P2p1Q/1P2p3/4P1qP/6P1/3RR1K1 b - -\nFor the piece on g3, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from g3: g3b8 g3c7 g3d6 g3e1 g3e3 g3e5 g3f2 g3f3 g3f4 g3g2 g3g4 g3g5 g3g6 g3h2 g3h3 g3h4.\nLegal: g3b8 g3c7 g3d6 g3e1 g3e3 g3e5 g3f2 g3f3 g3f4 g3g2 g3g4 g3g5 g3g6 g3h2 g3h3 g3h4.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_filter_square": "g3", "diagnostic": true, "hard_gate": false, "source_square": "g3"}}
{"example_id": "rules_01959", "split": "rules", "task_type": "king_safety_filter", "fen": "3r2k1/1q2n2p/2brp1p1/1pQ1Np2/4PP2/3P4/2R2NPP/4R1K1 b - -", "prompt": "FEN: 3r2k1/1q2n2p/2brp1p1/1pQ1Np2/4PP2/3P4/2R2NPP/4R1K1 b - -\nFor move g8f7, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: g8f7.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "g8f7", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "g8f7", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01960", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "5rk1/N2nbppp/1pr1p3/p2p4/3P4/8/PP3PPP/R1B2RK1 b - - 1 17", "prompt": "FEN: 5rk1/N2nbppp/1pr1p3/p2p4/3P4/8/PP3PPP/R1B2RK1 b - - 1 17\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a5 black pawn; d5 black pawn; b6 black pawn; c6 black rook; e6 black pawn; d7 black knight; e7 black bishop; f7 black pawn; g7 black pawn; h7 black pawn; f8 black rook; g8 black king.\nMoves by piece:\na5 black pawn: a5a4\nd5 black pawn: no legal moves\nb6 black pawn: b6b5\nc6 black rook: c6c1 c6c2 c6c3 c6c4 c6c5 c6c7 c6c8 c6d6\ne6 black pawn: e6e5\nd7 black knight: d7b8 d7c5 d7e5 d7f6\ne7 black bishop: e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7g5 e7h4\nf7 black pawn: f7f5 f7f6\ng7 black pawn: g7g5 g7g6\nh7 black pawn: h7h5 h7h6\nf8 black rook: f8a8 f8b8 f8c8 f8d8 f8e8\ng8 black king: g8h8\nAll legal moves: a5a4 b6b5 c6c1 c6c2 c6c3 c6c4 c6c5 c6c7 c6c8 c6d6 d7b8 d7c5 d7e5 d7f6 e6e5 e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7g5 e7h4 f7f5 f7f6 f8a8 f8b8 f8c8 f8d8 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a5": ["a5a4"], "d5": [], "b6": ["b6b5"], "c6": ["c6c1", "c6c2", "c6c3", "c6c4", "c6c5", "c6c7", "c6c8", "c6d6"], "e6": ["e6e5"], "d7": ["d7b8", "d7c5", "d7e5", "d7f6"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6", "e7d8", "e7f6", "e7g5", "e7h4"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "f8": ["f8a8", "f8b8", "f8c8", "f8d8", "f8e8"], "g8": ["g8h8"]}, "_legal_moves_by_piece_moves": "a5a4 b6b5 c6c1 c6c2 c6c3 c6c4 c6c5 c6c7 c6c8 c6d6 d7b8 d7c5 d7e5 d7f6 e6e5 e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7g5 e7h4 f7f5 f7f6 f8a8 f8b8 f8c8 f8d8 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a5": ["a5a4"], "d5": [], "b6": ["b6b5"], "c6": ["c6c1", "c6c2", "c6c3", "c6c4", "c6c5", "c6c7", "c6c8", "c6d6"], "e6": ["e6e5"], "d7": ["d7b8", "d7c5", "d7e5", "d7f6"], "e7": ["e7a3", "e7b4", "e7c5", "e7d6", "e7d8", "e7f6", "e7g5", "e7h4"], "f7": ["f7f5", "f7f6"], "g7": ["g7g5", "g7g6"], "h7": ["h7h5", "h7h6"], "f8": ["f8a8", "f8b8", "f8c8", "f8d8", "f8e8"], "g8": ["g8h8"]}, "legal_moves": "a5a4 b6b5 c6c1 c6c2 c6c3 c6c4 c6c5 c6c7 c6c8 c6d6 d7b8 d7c5 d7e5 d7f6 e6e5 e7a3 e7b4 e7c5 e7d6 e7d8 e7f6 e7g5 e7h4 f7f5 f7f6 f8a8 f8b8 f8c8 f8d8 f8e8 g7g5 g7g6 g8h8 h7h5 h7h6"}}
{"example_id": "rules_01961", "split": "rules", "task_type": "ray_walk", "fen": "2q5/6pk/1P5p/8/5p2/3p4/1R1K3P/8 w - - 1 42", "prompt": "FEN: 2q5/6pk/1P5p/8/5p2/3p4/1R1K3P/8 w - - 1 42\nWalk each ray for the slider on b2: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: b2 white rook.\nRay N: b3 empty; b4 empty; b5 empty; b6 white pawn: own piece (stop, excluded).\nRay E: c2 empty; d2 white king: own piece (stop, excluded).\nRay S: b1 empty; edge.\nRay W: a2 empty; edge.\nMoves from rays: b2a2 b2b1 b2b3 b2b4 b2b5 b2c2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "b2", "diagnostic": true, "hard_gate": false, "source_square": "b2"}}
{"example_id": "rules_01962", "split": "rules", "task_type": "legal_moves", "fen": "r1bnkbnr/1pp2ppp/p7/4P1N1/4p3/2P5/PP3PPP/RNB1KB1R b KQkq - 1 7", "prompt": "FEN: r1bnkbnr/1pp2ppp/p7/4P1N1/4p3/2P5/PP3PPP/RNB1KB1R b KQkq - 1 7\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 a8b8 b7b5 b7b6 c7c5 c7c6 c8d7 c8e6 c8f5 c8g4 c8h3 d8c6 d8e6 e4e3 e8d7 e8e7 f7f5 f7f6 f8a3 f8b4 f8c5 f8d6 f8e7 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01963", "split": "rules", "task_type": "legal_moves", "fen": "8/p7/kp6/3R3r/2P5/6rP/P7/R5K1 w - - 0 38", "prompt": "FEN: 8/p7/kp6/3R3r/2P5/6rP/P7/R5K1 w - - 0 38\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: g1f1 g1f2 g1h1 g1h2", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01964", "split": "rules", "task_type": "side_piece_inventory", "fen": "2k1r2r/pp1n1p2/2p2p2/6p1/3P3P/bP4B1/P1P5/1K1R1B1R b - - 0 24", "prompt": "FEN: 2k1r2r/pp1n1p2/2p2p2/6p1/3P3P/bP4B1/P1P5/1K1R1B1R b - - 0 24\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: a3 black bishop; g5 black pawn; c6 black pawn; f6 black pawn; a7 black pawn; b7 black pawn; d7 black knight; f7 black pawn; c8 black king; e8 black rook; h8 black rook.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_games", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "a3", "piece": "black bishop"}, {"square": "g5", "piece": "black pawn"}, {"square": "c6", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "f7", "piece": "black pawn"}, {"square": "c8", "piece": "black king"}, {"square": "e8", "piece": "black rook"}, {"square": "h8", "piece": "black rook"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "a3", "piece": "black bishop"}, {"square": "g5", "piece": "black pawn"}, {"square": "c6", "piece": "black pawn"}, {"square": "f6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "f7", "piece": "black pawn"}, {"square": "c8", "piece": "black king"}, {"square": "e8", "piece": "black rook"}, {"square": "h8", "piece": "black rook"}]}}
{"example_id": "rules_01965", "split": "rules", "task_type": "piece_legal_moves", "fen": "r1bqk2r/ppp2pp1/2np1n1p/2b1p3/1PB1P3/P2P1N1P/2P2PP1/RNBQK2R b KQkq - 0 7", "prompt": "FEN: r1bqk2r/ppp2pp1/2np1n1p/2b1p3/1PB1P3/P2P1N1P/2P2PP1/RNBQK2R b KQkq - 0 7\nWhat legal moves does the piece on h6 have?", "gold_answer": "h6h5", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "h6", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "h6", "piece": "pawn"}}
{"example_id": "rules_01966", "split": "rules", "task_type": "check_detection", "fen": "2kr3r/pp5p/1bp1Bp1B/4n3/4P3/7P/PPP3P1/2KR1R2 b - - 5 18", "prompt": "FEN: 2kr3r/pp5p/1bp1Bp1B/4n3/4P3/7P/PPP3P1/2KR1R2 b - - 5 18\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Check.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01967", "split": "rules", "task_type": "captures", "fen": "6k1/1rp3pp/8/6R1/4p1n1/1P6/P3K3/8 b - - 2 33", "prompt": "FEN: 6k1/1rp3pp/8/6R1/4p1n1/1P6/P3K3/8 b - - 2 33\nList all capture moves available.", "gold_answer": "b7b3", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01968", "split": "rules", "task_type": "special_rules", "fen": "6r1/pp4kp/2pb3n/3p4/3P4/2P1R1PP/PPBN2P1/5RK1 b - - 6 28", "prompt": "Given FEN: 6r1/pp4kp/2pb3n/3p4/3P4/2P1R1PP/PPBN2P1/5RK1 b - - 6 28\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01969", "split": "rules", "task_type": "legality_check", "fen": "q4r1k/2pbbppp/Q2p1n2/8/P3P3/2P1BN2/3N1PPP/1R4K1 w - -", "prompt": "FEN: q4r1k/2pbbppp/Q2p1n2/8/P3P3/2P1BN2/3N1PPP/1R4K1 w - -\nIs the move b1f1 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legality_check_move": "b1f1", "_legality_check_reason_label": "legal", "move": "b1f1", "legality_reason_label": "legal"}}
{"example_id": "rules_01970", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "2R1r1k1/p7/1p2pp1Q/3pq3/7p/8/P4PP1/6K1 w - -", "prompt": "FEN: 2R1r1k1/p7/1p2pp1Q/3pq3/7p/8/P4PP1/6K1 w - -\nList pseudo-legal moves from g1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from g1: g1f1 g1h1 g1h2", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_pseudo_legal_moves_square": "g1", "diagnostic": true, "hard_gate": false, "source_square": "g1"}}
{"example_id": "rules_01971", "split": "rules", "task_type": "piece_legal_filter", "fen": "r1bqkb1r/5ppp/4pn2/1p2N3/3p4/3B1Q2/PP3PPP/R1B1K2R b KQkq - 1 13", "prompt": "FEN: r1bqkb1r/5ppp/4pn2/1p2N3/3p4/3B1Q2/PP3PPP/R1B1K2R b KQkq - 1 13\nFor the piece on e8, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from e8: e8d7 e8e7.\nLegal: e8e7.\nRejected: e8d7 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_openings", "is_chess960": false, "_piece_legal_filter_square": "e8", "diagnostic": true, "hard_gate": false, "source_square": "e8"}}
{"example_id": "rules_01972", "split": "rules", "task_type": "king_safety_filter", "fen": "1br2rk1/1b2qp2/p4Pn1/1p1p2Q1/3p1P1N/1B5P/PP4PK/3RR3 b - -", "prompt": "FEN: 1br2rk1/1b2qp2/p4Pn1/1p1p2Q1/3p1P1N/1B5P/PP4PK/3RR3 b - -\nFor move g6e5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: g6e5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; pinned_piece_exposes_king.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_king_safety_filter_move": "g6e5", "_king_safety_filter_reason_label": "pinned_piece_exposes_king", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "g6e5", "legality_reason_label": "pinned_piece_exposes_king", "expected_is_legal": false}}
{"example_id": "rules_01973", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "6k1/5p1n/B3p3/3pP1p1/6P1/q7/4K3/7R b - - 6 46", "prompt": "FEN: 6k1/5p1n/B3p3/3pP1p1/6P1/q7/4K3/7R b - - 6 46\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: black.\nPieces: a3 black queen; d5 black pawn; g5 black pawn; e6 black pawn; f7 black pawn; h7 black knight; g8 black king.\nMoves by piece:\na3 black queen: a3a1 a3a2 a3a4 a3a5 a3a6 a3b2 a3b3 a3b4 a3c1 a3c3 a3c5 a3d3 a3d6 a3e3 a3e7 a3f3 a3f8 a3g3 a3h3\nd5 black pawn: d5d4\ng5 black pawn: no legal moves\ne6 black pawn: no legal moves\nf7 black pawn: f7f5 f7f6\nh7 black knight: h7f6 h7f8\ng8 black king: g8f8 g8g7 g8h8\nAll legal moves: a3a1 a3a2 a3a4 a3a5 a3a6 a3b2 a3b3 a3b4 a3c1 a3c3 a3c5 a3d3 a3d6 a3e3 a3e7 a3f3 a3f8 a3g3 a3h3 d5d4 f7f5 f7f6 g8f8 g8g7 g8h8 h7f6 h7f8", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a3": ["a3a1", "a3a2", "a3a4", "a3a5", "a3a6", "a3b2", "a3b3", "a3b4", "a3c1", "a3c3", "a3c5", "a3d3", "a3d6", "a3e3", "a3e7", "a3f3", "a3f8", "a3g3", "a3h3"], "d5": ["d5d4"], "g5": [], "e6": [], "f7": ["f7f5", "f7f6"], "h7": ["h7f6", "h7f8"], "g8": ["g8f8", "g8g7", "g8h8"]}, "_legal_moves_by_piece_moves": "a3a1 a3a2 a3a4 a3a5 a3a6 a3b2 a3b3 a3b4 a3c1 a3c3 a3c5 a3d3 a3d6 a3e3 a3e7 a3f3 a3f8 a3g3 a3h3 d5d4 f7f5 f7f6 g8f8 g8g7 g8h8 h7f6 h7f8", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a3": ["a3a1", "a3a2", "a3a4", "a3a5", "a3a6", "a3b2", "a3b3", "a3b4", "a3c1", "a3c3", "a3c5", "a3d3", "a3d6", "a3e3", "a3e7", "a3f3", "a3f8", "a3g3", "a3h3"], "d5": ["d5d4"], "g5": [], "e6": [], "f7": ["f7f5", "f7f6"], "h7": ["h7f6", "h7f8"], "g8": ["g8f8", "g8g7", "g8h8"]}, "legal_moves": "a3a1 a3a2 a3a4 a3a5 a3a6 a3b2 a3b3 a3b4 a3c1 a3c3 a3c5 a3d3 a3d6 a3e3 a3e7 a3f3 a3f8 a3g3 a3h3 d5d4 f7f5 f7f6 g8f8 g8g7 g8h8 h7f6 h7f8"}}
{"example_id": "rules_01974", "split": "rules", "task_type": "ray_walk", "fen": "3r2k1/5rb1/p3Q1p1/PpB5/8/2P2p2/1P2K3/6R1 w - - 0 48", "prompt": "FEN: 3r2k1/5rb1/p3Q1p1/PpB5/8/2P2p2/1P2K3/6R1 w - - 0 48\nWalk each ray for the slider on g1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: g1 white rook.\nRay N: g2 empty; g3 empty; g4 empty; g5 empty; g6 black pawn: capture (stop, included).\nRay E: h1 empty; edge.\nRay S: edge.\nRay W: f1 empty; e1 empty; d1 empty; c1 empty; b1 empty; a1 empty; edge.\nMoves from rays: g1a1 g1b1 g1c1 g1d1 g1e1 g1f1 g1g2 g1g3 g1g4 g1g5 g1g6 g1h1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "g1", "diagnostic": true, "hard_gate": false, "source_square": "g1"}}
{"example_id": "rules_01975", "split": "rules", "task_type": "legal_moves", "fen": "r1b2rk1/ppp2pbp/4p1p1/1P6/8/5N2/1PN2PPP/2B1K2R w K - 1 19", "prompt": "FEN: r1b2rk1/ppp2pbp/4p1p1/1P6/8/5N2/1PN2PPP/2B1K2R w K - 1 19\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: b2b3 b2b4 b5b6 c1d2 c1e3 c1f4 c1g5 c1h6 c2a1 c2a3 c2b4 c2d4 c2e3 e1d1 e1d2 e1e2 e1f1 e1g1 f3d2 f3d4 f3e5 f3g1 f3g5 f3h4 g2g3 g2g4 h1f1 h1g1 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01976", "split": "rules", "task_type": "legal_moves", "fen": "1rb2rk1/1p2qpp1/p1np3p/4p3/2B1P3/4QN2/PPP2PPP/3R1RK1 w - - 0 15", "prompt": "FEN: 1rb2rk1/1p2qpp1/p1np3p/4p3/2B1P3/4QN2/PPP2PPP/3R1RK1 w - - 0 15\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a2a3 a2a4 b2b3 b2b4 c2c3 c4a6 c4b3 c4b5 c4d3 c4d5 c4e2 c4e6 c4f7 d1a1 d1b1 d1c1 d1d2 d1d3 d1d4 d1d5 d1d6 d1e1 e3a3 e3a7 e3b3 e3b6 e3c1 e3c3 e3c5 e3d2 e3d3 e3d4 e3e1 e3e2 e3f4 e3g5 e3h6 f1e1 f3d2 f3d4 f3e1 f3e5 f3g5 f3h4 g1h1 g2g3 g2g4 h2h3 h2h4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01977", "split": "rules", "task_type": "side_piece_inventory", "fen": "rn1q1rk1/ppp2pbp/3pb1p1/5p2/2PP4/4PNP1/PP1N1PBP/R2QK2R b KQ -", "prompt": "FEN: rn1q1rk1/ppp2pbp/3pb1p1/5p2/2PP4/4PNP1/PP1N1PBP/R2QK2R b KQ -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: f5 black pawn; d6 black pawn; e6 black bishop; g6 black pawn; a7 black pawn; b7 black pawn; c7 black pawn; f7 black pawn; g7 black bishop; h7 black pawn; a8 black rook; b8 black knight; d8 black queen; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "f5", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "e6", "piece": "black bishop"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black bishop"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "f5", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "e6", "piece": "black bishop"}, {"square": "g6", "piece": "black pawn"}, {"square": "a7", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "c7", "piece": "black pawn"}, {"square": "f7", "piece": "black pawn"}, {"square": "g7", "piece": "black bishop"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "b8", "piece": "black knight"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01978", "split": "rules", "task_type": "piece_legal_moves", "fen": "r4rk1/1p3pp1/p3pb1N/2p5/P3b3/2P1P2N/1P4PP/R4RK1 b - - 0 22", "prompt": "FEN: r4rk1/1p3pp1/p3pb1N/2p5/P3b3/2P1P2N/1P4PP/R4RK1 b - - 0 22\nWhat legal moves does the piece on e4 have?", "gold_answer": "No legal moves.", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_moves_square": "e4", "_piece_legal_moves_piece": "bishop", "diagnostic": true, "hard_gate": false, "source_square": "e4", "piece": "bishop"}}
{"example_id": "rules_01979", "split": "rules", "task_type": "check_detection", "fen": "8/2r1p3/1k1p2p1/1q5p/5P2/2Q3PP/P3R2K/8 b - - 0 46", "prompt": "FEN: 8/2r1p3/1k1p2p1/1q5p/5P2/2Q3PP/P3R2K/8 b - - 0 46\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01980", "split": "rules", "task_type": "captures", "fen": "1r3rk1/5ppp/1p6/pPbp4/P2B4/4P1P1/3N1PK1/R3R3 b - - 0 23", "prompt": "FEN: 1r3rk1/5ppp/1p6/pPbp4/P2B4/4P1P1/3N1PK1/R3R3 b - - 0 23\nList all capture moves available.", "gold_answer": "c5d4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01981", "split": "rules", "task_type": "special_rules", "fen": "1r1q1rk1/p1p2pB1/2p2Pb1/3pP1Qp/3P4/8/PP4PP/R5K1 b - -", "prompt": "Given FEN: 1r1q1rk1/p1p2pB1/2p2Pb1/3pP1Qp/3P4/8/PP4PP/R5K1 b - -\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01982", "split": "rules", "task_type": "legality_check", "fen": "r1b2rk1/1p3pp1/p1p4p/4B2n/8/1P1P1N1P/1PP2PP1/R3R1K1 w - - 0 20", "prompt": "FEN: r1b2rk1/1p3pp1/p1p4p/4B2n/8/1P1P1N1P/1PP2PP1/R3R1K1 w - - 0 20\nIs the move c2c4 legal?", "gold_answer": "Yes, legal. Reason: legal.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "c2c4", "_legality_check_reason_label": "legal", "move": "c2c4", "legality_reason_label": "legal"}}
{"example_id": "rules_01983", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rr4k1/5pbp/2p1q1p1/p7/5PR1/P1PPB3/1P1Q3P/2K3R1 w - - 3 25", "prompt": "FEN: rr4k1/5pbp/2p1q1p1/p7/5PR1/P1PPB3/1P1Q3P/2K3R1 w - - 3 25\nList pseudo-legal moves from c1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from c1: c1b1 c1c2 c1d1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "c1", "diagnostic": true, "hard_gate": false, "source_square": "c1"}}
{"example_id": "rules_01984", "split": "rules", "task_type": "piece_legal_filter", "fen": "8/7K/5k2/8/7P/4Q3/P7/8 w - - 9 67", "prompt": "FEN: 8/7K/5k2/8/7P/4Q3/P7/8 w - - 9 67\nFor the piece on h7, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from h7: h7g6 h7g7 h7g8 h7h6 h7h8.\nLegal: h7g8 h7h6 h7h8.\nRejected: h7g6 king_would_be_in_check; h7g7 king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "h7", "diagnostic": true, "hard_gate": false, "source_square": "h7"}}
{"example_id": "rules_01985", "split": "rules", "task_type": "king_safety_filter", "fen": "8/8/6p1/4np1p/4k3/6P1/8/3R2K1 b - - 9 53", "prompt": "FEN: 8/8/6p1/4np1p/4k3/6P1/8/3R2K1 b - - 9 53\nFor move e4d3, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: e4d3.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; king_would_be_in_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "e4d3", "_king_safety_filter_reason_label": "king_would_be_in_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "e4d3", "legality_reason_label": "king_would_be_in_check", "expected_is_legal": false}}
{"example_id": "rules_01986", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r1bqr1k1/p3bpp1/2p2n1p/3p2B1/8/2NB1Q1P/PPP2PP1/R3R1K1 w - -", "prompt": "FEN: r1bqr1k1/p3bpp1/2p2n1p/3p2B1/8/2NB1Q1P/PPP2PP1/R3R1K1 w - -\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: a1 white rook; e1 white rook; g1 white king; a2 white pawn; b2 white pawn; c2 white pawn; f2 white pawn; g2 white pawn; c3 white knight; d3 white bishop; f3 white queen; h3 white pawn; g5 white bishop.\nMoves by piece:\na1 white rook: a1b1 a1c1 a1d1\ne1 white rook: e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1f1\ng1 white king: g1f1 g1h1 g1h2\na2 white pawn: a2a3 a2a4\nb2 white pawn: b2b3 b2b4\nc2 white pawn: no legal moves\nf2 white pawn: no legal moves\ng2 white pawn: g2g3 g2g4\nc3 white knight: c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4\nd3 white bishop: d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 d3g6 d3h7\nf3 white queen: f3d1 f3d5 f3e2 f3e3 f3e4 f3f4 f3f5 f3f6 f3g3 f3g4 f3h5\nh3 white pawn: h3h4\ng5 white bishop: g5c1 g5d2 g5e3 g5f4 g5f6 g5h4 g5h6\nAll legal moves: a1b1 a1c1 a1d1 a2a3 a2a4 b2b3 b2b4 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 d3g6 d3h7 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1f1 f3d1 f3d5 f3e2 f3e3 f3e4 f3f4 f3f5 f3f6 f3g3 f3g4 f3h5 g1f1 g1h1 g1h2 g2g3 g2g4 g5c1 g5d2 g5e3 g5f4 g5f6 g5h4 g5h6 h3h4", "metric_type": "text_exact_match", "metadata": {"source": "lichess_evals", "is_chess960": false, "_legal_moves_by_piece_grouped": {"a1": ["a1b1", "a1c1", "a1d1"], "e1": ["e1b1", "e1c1", "e1d1", "e1e2", "e1e3", "e1e4", "e1e5", "e1e6", "e1e7", "e1f1"], "g1": ["g1f1", "g1h1", "g1h2"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": [], "f2": [], "g2": ["g2g3", "g2g4"], "c3": ["c3a4", "c3b1", "c3b5", "c3d1", "c3d5", "c3e2", "c3e4"], "d3": ["d3a6", "d3b5", "d3c4", "d3e2", "d3e4", "d3f1", "d3f5", "d3g6", "d3h7"], "f3": ["f3d1", "f3d5", "f3e2", "f3e3", "f3e4", "f3f4", "f3f5", "f3f6", "f3g3", "f3g4", "f3h5"], "h3": ["h3h4"], "g5": ["g5c1", "g5d2", "g5e3", "g5f4", "g5f6", "g5h4", "g5h6"]}, "_legal_moves_by_piece_moves": "a1b1 a1c1 a1d1 a2a3 a2a4 b2b3 b2b4 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 d3g6 d3h7 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1f1 f3d1 f3d5 f3e2 f3e3 f3e4 f3f4 f3f5 f3f6 f3g3 f3g4 f3h5 g1f1 g1h1 g1h2 g2g3 g2g4 g5c1 g5d2 g5e3 g5f4 g5f6 g5h4 g5h6 h3h4", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"a1": ["a1b1", "a1c1", "a1d1"], "e1": ["e1b1", "e1c1", "e1d1", "e1e2", "e1e3", "e1e4", "e1e5", "e1e6", "e1e7", "e1f1"], "g1": ["g1f1", "g1h1", "g1h2"], "a2": ["a2a3", "a2a4"], "b2": ["b2b3", "b2b4"], "c2": [], "f2": [], "g2": ["g2g3", "g2g4"], "c3": ["c3a4", "c3b1", "c3b5", "c3d1", "c3d5", "c3e2", "c3e4"], "d3": ["d3a6", "d3b5", "d3c4", "d3e2", "d3e4", "d3f1", "d3f5", "d3g6", "d3h7"], "f3": ["f3d1", "f3d5", "f3e2", "f3e3", "f3e4", "f3f4", "f3f5", "f3f6", "f3g3", "f3g4", "f3h5"], "h3": ["h3h4"], "g5": ["g5c1", "g5d2", "g5e3", "g5f4", "g5f6", "g5h4", "g5h6"]}, "legal_moves": "a1b1 a1c1 a1d1 a2a3 a2a4 b2b3 b2b4 c3a4 c3b1 c3b5 c3d1 c3d5 c3e2 c3e4 d3a6 d3b5 d3c4 d3e2 d3e4 d3f1 d3f5 d3g6 d3h7 e1b1 e1c1 e1d1 e1e2 e1e3 e1e4 e1e5 e1e6 e1e7 e1f1 f3d1 f3d5 f3e2 f3e3 f3e4 f3f4 f3f5 f3f6 f3g3 f3g4 f3h5 g1f1 g1h1 g1h2 g2g3 g2g4 g5c1 g5d2 g5e3 g5f4 g5f6 g5h4 g5h6 h3h4"}}
{"example_id": "rules_01987", "split": "rules", "task_type": "ray_walk", "fen": "1rb1k2r/1p2ppbp/p2p1np1/3q4/8/1P2B3/P1P2PPP/R2QR1K1 w k - 0 17", "prompt": "FEN: 1rb1k2r/1p2ppbp/p2p1np1/3q4/8/1P2B3/P1P2PPP/R2QR1K1 w k - 0 17\nWalk each ray for the slider on a1: list every square until a blocker, capture, or the board edge, then list the resulting moves.\n\nAnswer format: return a \"Piece:\" line, one \"Ray <direction>:\" line per ray in the listed order, and a final \"Moves from rays:\" line with space-separated UCI moves or \"none\".", "gold_answer": "Piece: a1 white rook.\nRay N: a2 white pawn: own piece (stop, excluded).\nRay E: b1 empty; c1 empty; d1 white queen: own piece (stop, excluded).\nRay S: edge.\nRay W: edge.\nMoves from rays: a1b1 a1c1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_ray_walk_square": "a1", "diagnostic": true, "hard_gate": false, "source_square": "a1"}}
{"example_id": "rules_01988", "split": "rules", "task_type": "legal_moves", "fen": "r2qkbnr/1pp2ppp/p1n1p3/3p1b2/2PP4/PQN2N2/1P2PPPP/R1B1KB1R b KQkq -", "prompt": "FEN: r2qkbnr/1pp2ppp/p1n1p3/3p1b2/2PP4/PQN2N2/1P2PPPP/R1B1KB1R b KQkq -\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: black.\nLegal moves: a6a5 a8a7 a8b8 a8c8 b7b5 b7b6 c6a5 c6a7 c6b4 c6b8 c6d4 c6e5 c6e7 d5c4 d8b8 d8c8 d8d6 d8d7 d8e7 d8f6 d8g5 d8h4 e6e5 e8d7 e8e7 f5b1 f5c2 f5d3 f5e4 f5g4 f5g6 f5h3 f7f6 f8a3 f8b4 f8c5 f8d6 f8e7 g7g5 g7g6 g8e7 g8f6 g8h6 h7h5 h7h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01989", "split": "rules", "task_type": "legal_moves", "fen": "8/p5p1/6P1/2p3bP/p2k4/K7/8/8 w - - 4 47", "prompt": "FEN: 8/p5p1/6P1/2p3bP/p2k4/K7/8/8 w - - 4 47\nList all legal moves.\n\nAnswer format: return exactly two lines: \"Side to move: <white|black>.\" then \"Legal moves: <space-separated UCI moves>\".", "gold_answer": "Side to move: white.\nLegal moves: a3a2 a3a4 a3b2 h5h6", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01990", "split": "rules", "task_type": "side_piece_inventory", "fen": "r1bq1rk1/1p1nb1pp/p2p4/3P1p2/PPN1p3/8/2P1BPPP/R1BQR1K1 b - -", "prompt": "FEN: r1bq1rk1/1p1nb1pp/p2p4/3P1p2/PPN1p3/8/2P1BPPP/R1BQR1K1 b - -\nList the side-to-move pieces and their squares.", "gold_answer": "Side to move: black.\nPieces: e4 black pawn; f5 black pawn; a6 black pawn; d6 black pawn; b7 black pawn; d7 black knight; e7 black bishop; g7 black pawn; h7 black pawn; a8 black rook; c8 black bishop; d8 black queen; f8 black rook; g8 black king.", "metric_type": "side_piece_inventory", "metadata": {"source": "lichess_evals", "is_chess960": false, "_side_piece_inventory_side": "black", "_side_piece_inventory": [{"square": "e4", "piece": "black pawn"}, {"square": "f5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black bishop"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}], "diagnostic": true, "hard_gate": false, "side_to_move": "black", "side_piece_inventory": [{"square": "e4", "piece": "black pawn"}, {"square": "f5", "piece": "black pawn"}, {"square": "a6", "piece": "black pawn"}, {"square": "d6", "piece": "black pawn"}, {"square": "b7", "piece": "black pawn"}, {"square": "d7", "piece": "black knight"}, {"square": "e7", "piece": "black bishop"}, {"square": "g7", "piece": "black pawn"}, {"square": "h7", "piece": "black pawn"}, {"square": "a8", "piece": "black rook"}, {"square": "c8", "piece": "black bishop"}, {"square": "d8", "piece": "black queen"}, {"square": "f8", "piece": "black rook"}, {"square": "g8", "piece": "black king"}]}}
{"example_id": "rules_01991", "split": "rules", "task_type": "piece_legal_moves", "fen": "r4r2/ppp2pk1/2np2q1/2b1p3/2B1P1Q1/2PP4/PP1N1PPP/R3K2R w KQ -", "prompt": "FEN: r4r2/ppp2pk1/2np2q1/2b1p3/2B1P1Q1/2PP4/PP1N1PPP/R3K2R w KQ -\nWhat legal moves does the piece on f2 have?", "gold_answer": "f2f3 f2f4", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false, "_piece_legal_moves_square": "f2", "_piece_legal_moves_piece": "pawn", "diagnostic": true, "hard_gate": false, "source_square": "f2", "piece": "pawn"}}
{"example_id": "rules_01992", "split": "rules", "task_type": "check_detection", "fen": "2kr1r2/pp3ppp/2q1bp2/8/Pnp1P3/5N2/1P3PPP/RQ2KB1R w KQ - 6 15", "prompt": "FEN: 2kr1r2/pp3ppp/2q1bp2/8/Pnp1P3/5N2/1P3PPP/RQ2KB1R w KQ - 6 15\nDetect the game state: check, checkmate, stalemate, or none.", "gold_answer": "Normal position -- no check, checkmate, or stalemate.", "metric_type": "check_state", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01993", "split": "rules", "task_type": "captures", "fen": "rn1qkbnr/ppp1pppp/8/3p1b2/1PP5/8/PB1PPPPP/RN1QKBNR b KQkq -", "prompt": "FEN: rn1qkbnr/ppp1pppp/8/3p1b2/1PP5/8/PB1PPPPP/RN1QKBNR b KQkq -\nList all capture moves available.", "gold_answer": "d5c4 f5b1", "metric_type": "uci_set_jaccard", "metadata": {"source": "lichess_evals", "is_chess960": false}}
{"example_id": "rules_01994", "split": "rules", "task_type": "special_rules", "fen": "5Q2/1pkr1p2/1np2p2/p7/P7/1B6/1PP5/1K5R w - - 0 33", "prompt": "Given FEN: 5Q2/1pkr1p2/1np2p2/p7/P7/1B6/1PP5/1K5R w - - 0 33\nList any special moves available (castling, en passant, promotion).", "gold_answer": "No special moves available.", "metric_type": "special_rules", "metadata": {"source": "lichess_games", "is_chess960": false}}
{"example_id": "rules_01995", "split": "rules", "task_type": "legality_check", "fen": "4k3/pp5R/8/2P5/P3n3/1P2n3/6KP/4r3 w - - 5 44", "prompt": "FEN: 4k3/pp5R/8/2P5/P3n3/1P2n3/6KP/4r3 w - - 5 44\nIs the move e1a3 legal?", "gold_answer": "No, illegal. Reason: wrong side piece.", "metric_type": "legality_check", "metadata": {"source": "lichess_games", "is_chess960": false, "_legality_check_move": "e1a3", "_legality_check_reason_label": "wrong_side_piece", "move": "e1a3", "legality_reason_label": "wrong_side_piece"}}
{"example_id": "rules_01996", "split": "rules", "task_type": "piece_pseudo_legal_moves", "fen": "rn1qk1nr/pp1b1pbp/3pp1p1/1B6/5P2/5N2/PPPP2PP/RNBQK2R w KQkq - 2 7", "prompt": "FEN: rn1qk1nr/pp1b1pbp/3pp1p1/1B6/5P2/5N2/PPPP2PP/RNBQK2R w KQkq - 2 7\nList pseudo-legal moves from b1.\n\nAnswer format: return exactly \"Pseudo-legal moves from <square>: <space-separated UCI moves>\".", "gold_answer": "Pseudo-legal moves from b1: b1a3 b1c3", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_pseudo_legal_moves_square": "b1", "diagnostic": true, "hard_gate": false, "source_square": "b1"}}
{"example_id": "rules_01997", "split": "rules", "task_type": "piece_legal_filter", "fen": "1kr4r/p2p2p1/b3p2p/q7/1pP1N3/1Q1R1P1P/6P1/7K w - - 7 31", "prompt": "FEN: 1kr4r/p2p2p1/b3p2p/q7/1pP1N3/1Q1R1P1P/6P1/7K w - - 7 31\nFor the piece on h1, split pseudo-legal moves into legal and rejected moves with rejection reasons.\n\nAnswer format: return exactly three lines starting \"Pseudo-legal from\", \"Legal:\", and \"Rejected:\". Rejected entries must be \"<uci> <reason_label>\" separated by semicolons, or \"none\" when no moves are rejected.", "gold_answer": "Pseudo-legal from h1: h1g1 h1h2.\nLegal: h1g1 h1h2.\nRejected: none.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_piece_legal_filter_square": "h1", "diagnostic": true, "hard_gate": false, "source_square": "h1"}}
{"example_id": "rules_01998", "split": "rules", "task_type": "king_safety_filter", "fen": "rn2kbnr/1bq4p/p2p4/1pp1p1pQ/4P2B/2PPN1P1/PP3PBP/R3K2R b KQkq - 1 14", "prompt": "FEN: rn2kbnr/1bq4p/p2p4/1pp1p1pQ/4P2B/2PPN1P1/PP3PBP/R3K2R b KQkq - 1 14\nFor move a6a5, decide whether king safety allows it.\n\nAnswer format: return exactly four lines starting \"Move:\", \"Pseudo-legal:\", \"King safe after move:\", and \"Final:\".", "gold_answer": "Move: a6a5.\nPseudo-legal: yes.\nKing safe after move: no.\nFinal: illegal; does_not_resolve_check.", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_king_safety_filter_move": "a6a5", "_king_safety_filter_reason_label": "does_not_resolve_check", "_king_safety_filter_is_legal": false, "diagnostic": true, "hard_gate": false, "move": "a6a5", "legality_reason_label": "does_not_resolve_check", "expected_is_legal": false}}
{"example_id": "rules_01999", "split": "rules", "task_type": "legal_moves_by_piece", "fen": "r2q2k1/6p1/p1bnN2n/1p2p2Q/3pP3/P2P2N1/1P4B1/3R1rK1 w - - 0 27", "prompt": "FEN: r2q2k1/6p1/p1bnN2n/1p2p2Q/3pP3/P2P2N1/1P4B1/3R1rK1 w - - 0 27\nGroup all legal moves by side-to-move piece.\n\nAnswer format: include \"Side to move:\", \"Pieces:\", \"Moves by piece:\", one line per side-to-move piece, and \"All legal moves:\".", "gold_answer": "Side to move: white.\nPieces: d1 white rook; g1 white king; b2 white pawn; g2 white bishop; a3 white pawn; d3 white pawn; g3 white knight; e4 white pawn; h5 white queen; e6 white knight.\nMoves by piece:\nd1 white rook: d1f1\ng1 white king: g1f1 g1h2\nb2 white pawn: no legal moves\ng2 white bishop: g2f1\na3 white pawn: no legal moves\nd3 white pawn: no legal moves\ng3 white knight: g3f1\ne4 white pawn: no legal moves\nh5 white queen: no legal moves\ne6 white knight: no legal moves\nAll legal moves: d1f1 g1f1 g1h2 g2f1 g3f1", "metric_type": "text_exact_match", "metadata": {"source": "lichess_games", "is_chess960": false, "_legal_moves_by_piece_grouped": {"d1": ["d1f1"], "g1": ["g1f1", "g1h2"], "b2": [], "g2": ["g2f1"], "a3": [], "d3": [], "g3": ["g3f1"], "e4": [], "h5": [], "e6": []}, "_legal_moves_by_piece_moves": "d1f1 g1f1 g1h2 g2f1 g3f1", "diagnostic": true, "hard_gate": false, "legal_moves_by_piece": {"d1": ["d1f1"], "g1": ["g1f1", "g1h2"], "b2": [], "g2": ["g2f1"], "a3": [], "d3": [], "g3": ["g3f1"], "e4": [], "h5": [], "e6": []}, "legal_moves": "d1f1 g1f1 g1h2 g2f1 g3f1"}}