Prompt:
Position (FEN): r3k2r/1b3p2/4qP1p/p2pP1p1/1ppP3P/2P2NK1/PP1NQ3/R7 b kq - 2 28
Show me the board.


Prompt:
Here is the current board:
8 . . . . . . . .
7 . . . . . . . .
6 p . . . . K . .
5 . . . . . . . .
4 P . . . . . . .
3 . k . . . . . .
2 . . . . . . . .
1 . . . . . . . .
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 2
Fullmove number: 58

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.


Prompt:
FEN: r7/pkp5/1p3QNp/8/1P6/2P3P1/P2P1PbP/R1K2R2 w - - 1 29
What piece is on a2?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: rn2kb1N/pp3Bpp/3q4/2p1n3/6N1/3P2P1/PPP4P/R1B1KR2 b q - 6 21
What is the material count for both sides?

White (13 pieces): 2 bishops, 1 king, 2 knights, 6 pawns, 2 rooks. Black (11 pieces): 1 bishop, 1 king, 2 knights, 5 pawns, 1 queen, 1 rook. Material is equal.


Prompt:
FEN: rn1qkb1r/pp2pppp/2p2n2/5b2/2pP1B2/2N1P3/PP3PPP/R2QKBNR w KQkq -
What is on f2?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: r1bq1rk1/1p2bppp/2nppn2/p5B1/4P3/1NN5/PPPQ1PPP/2KR1B1R w - -
What is the compressed FEN row for rank 4?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: r6r/pQkn2b1/5p2/N6B/3P4/2N5/PPP3PP/4RbK1 b - - 0 23
For square a2, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

a2: file=a; rank=2; fen_row_from_top=7; file_index=1


Prompt:
FEN: rn1B1rk1/p5pp/2p5/1p1n4/8/1BP3P1/PP3PP1/R2bR1K1 w - - 0 18
Compressed rank 2 row: PP3PP1
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 4 row before: N2Pp2n
File g changes from 1 to P. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


r2qkb1r/ppp3pp/8/3p4/2n2B2/8/PP3PPP/RN1QK2R w KQkq - 0 12

Prompt:
Board FEN before: r2qkb1r/ppp3pp/8/3p4/2n2B2/8/PP3PPP/RN1QK2R
Apply square edits: f4 B->1; d6 1->B
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: r2qkb1r/ppp3pp/3B4/3p4/2n5/8/PP3PPP/RN1QK2R


Prompt:
Starting FEN: 4r1k1/1p1n1pp1/1b5p/p1p5/3p1N2/P2P1NPP/1PP3P1/R5K1 w - - 2 23
Move: f4g6
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: f4=white knight; g6=empty.
Squares: f4 white knight->empty; g6 empty->white knight.
Ranks: rank 4 f N->1; rank 6 g 1->N.


Prompt:
Starting FEN: r1b1k1r1/1pq2pp1/p2ppb1p/2n5/3NPPP1/2N4Q/PPP3BP/2KR3R w q - 0 1
Move: d4b3
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: white
Castling rights: q
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: white knight d4b3.
Lookup: d4=white knight; b3=empty.
Squares: d4 white knight->empty; b3 empty->white knight.
Ranks: rank 4 d N->1; rank 3 b 1->N.
Result FEN: r1b1k1r1/1pq2pp1/p2ppb1p/2n5/4PPP1/1NN4Q/PPP3BP/2KR3R b q - 1 1


Prompt:
Starting FEN: 2kr3r/ppp1p3/6pp/3b1pN1/6n1/1P1P4/PR1P1PPP/4R1K1 w - - 0 18
Move: b2c2
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 18

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 2 PR1P1PPP->P1RP1PPP.
Result FEN: 2kr3r/ppp1p3/6pp/3b1pN1/6n1/1P1P4/P1RP1PPP/4R1K1 b - - 1 18


Prompt:
Starting FEN: r1b1kb1r/pppp1ppp/5n2/4q3/8/P3P3/1PP1BPPP/RNBQK2R b KQkq - 2 7
After the moves h7h6, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: KQkq
En passant: none
Halfmove clock: 2
Fullmove number: 7

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: r1b1kb1r/pppp1pp1/5n1p/4q3/8/P3P3/1PP1BPPP/RNBQK2R w KQkq - 0 8


Prompt:
FEN: 8/2p1QN1p/2B1bnp1/3r4/6kP/2P5/3NPP2/R3K1R1 b Q - 1 34
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=e1; queen=e7; rook=a1,g1; bishop=c6; knight=d2,f7; pawn=e2,f2,c3,h4.
Black inventory: king=g4; queen=none; rook=d5; bishop=e6; knight=f6; pawn=g6,c7,h7.


Prompt:
FEN: 3r3k/p2bR2p/3p4/1ppP1p2/5n2/P1N2B1P/1PP2KP1/8 w - - 1 27
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=0; rook=1; bishop=1; knight=1; pawn=6.
Black counts: king=1; queen=0; rook=1; bishop=1; knight=1; pawn=6.


Prompt:
FEN: 2b5/5pp1/pp2kn1p/3p4/5B2/P3PP2/1P1KB1PP/8 w - - 0 27
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=0; rook=0; bishop=6; knight=0; pawn=6; total=12.
Black values: king=0; queen=0; rook=0; bishop=3; knight=3; pawn=6; total=12.


Prompt:
FEN: 6k1/1p4b1/p1q1p2p/3pP3/P2P3p/6B1/1P2Q1PK/2r5 w - - 0 29
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=h2; queen=e2; rook=none; bishop=g3; knight=none; pawn=b2,g2,a4,d4,e5 | black king=g8; queen=c6; rook=c1; bishop=g7; knight=none; pawn=h4,d5,a6,e6,h6,b7
Counts: white king=1; queen=1; rook=0; bishop=1; knight=0; pawn=5 | black king=1; queen=1; rook=1; bishop=1; knight=0; pawn=6
Values: white total=17; black total=23
Balance: Black is up 6 point(s) of material.


Prompt:
Starting FEN: 8/8/8/8/8/2K5/8/1k2R3 b - - 0 1
After the moves b1a2 e1c1, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".


Prompt:
Position (FEN): r2qkbnr/pp3p1p/2b1p1p1/2ppP3/8/1P1P4/PBP1QPPP/RN2K1NR b KQkq - 0 8
Show me the board.


Prompt:
Here is the current board:
8 . . . . . . . .
7 . . . . . . . .
6 . . . . . . K .
5 . . . . . . p .
4 . . k . B b P .
3 . . . . . P . .
2 . . . . . . . .
1 . . . . . . . .
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 24
Fullmove number: 78

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.


Prompt:
FEN: r1bqkbnr/ppp2ppp/2n5/8/3p4/1P3N2/PBPPPPPP/RN1QKB1R b KQkq - 1 5
What piece is on h2?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: r2qkbnr/ppp2ppp/8/4p3/Q1BnP3/2N2P2/PP3P1P/R1B1K2R b KQkq - 1 8
What is the material count for both sides?

White (13 pieces): 2 bishops, 1 king, 1 knight, 6 pawns, 1 queen, 2 rooks. Black (14 pieces): 1 bishop, 1 king, 2 knights, 7 pawns, 1 queen, 2 rooks. Black is up 1 point(s) of material.


Prompt:
FEN: 2q3k1/1p1nb1pn/p2p3p/3Pp3/1P2N3/P1Q2N2/1B3PPP/6K1 b - - 1 25
What is on g7?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: r1bq1rk1/ppp2ppp/5n2/3p4/3NP3/3P3P/PPP1BKP1/R1BQ1R2 b - - 1 11
What is the compressed FEN row for rank 5?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: 2rqkb1r/3n1ppp/p2pb3/1p1Np1Pn/4P3/1N2BP2/PPPQ3P/2KR1B1R w k -
For square a1, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

a1: file=a; rank=1; fen_row_from_top=8; file_index=1


Prompt:
FEN: rnbqkbnr/p1pp2pp/4p3/1p3p2/8/4PN2/PPPPBPPP/RNBQ1RK1 b kq - 1 4
Compressed rank 3 row: 4PN2
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 3 row before: 3P4
File b changes from 1 to P. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


2rnqr2/2p1n1bk/b2pP1pp/p7/Pp1P1N2/4BN2/1PBQ1PP1/2R1R1K1 b - -

Prompt:
Board FEN before: 2rnqr2/2p1n1bk/b2pP1pp/p7/Pp1P1N2/4BN2/1PBQ1PP1/2R1R1K1
Apply square edits: h7 k->1; h8 1->k
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 2rnqr1k/2p1n1b1/b2pP1pp/p7/Pp1P1N2/4BN2/1PBQ1PP1/2R1R1K1


Prompt:
Starting FEN: r3kbnr/2qp1ppp/p1b1p3/1p6/3p1N2/P2P1B2/1PP2PPP/R1BQ1RK1 w kq - 3 13
Move: f4h3
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: f4=white knight; h3=empty.
Squares: f4 white knight->empty; h3 empty->white knight.
Ranks: rank 4 f N->1; rank 3 h 1->N.


Prompt:
Starting FEN: r1b1k1nr/pppp1ppp/2n5/b3Pq2/2B5/1Qp2N2/P4PPP/RNB2RK1 w kq - 0 1
Move: b3b6
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: white
Castling rights: kq
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: white queen b3b6.
Lookup: b3=white queen; b6=empty.
Squares: b3 white queen->empty; b6 empty->white queen.
Ranks: rank 3 b Q->1; rank 6 b 1->Q.
Result FEN: r1b1k1nr/pppp1ppp/1Qn5/b3Pq2/2B5/2p2N2/P4PPP/RNB2RK1 b kq - 1 1


Prompt:
Starting FEN: 2kr1bnr/pp3ppp/1qn1p3/4Pb2/2Bp4/2N1BN2/PP3PPP/R2Q1RK1 w - - 0 1
Move: c3a4
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 3 2N1BN2->4BN2; rank 4 2Bp4->N1Bp4.
Result FEN: 2kr1bnr/pp3ppp/1qn1p3/4Pb2/N1Bp4/4BN2/PP3PPP/R2Q1RK1 b - - 1 1


Prompt:
Starting FEN: 5b2/5pk1/1n4p1/pN1p2P1/3P4/P4N2/5PK1/8 b - - 0 1
After the moves f8c5, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".


Prompt:
FEN: 8/3k4/8/4Q3/5K2/8/8/7b w - -
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=f4; queen=e5; rook=none; bishop=none; knight=none; pawn=none.
Black inventory: king=d7; queen=none; rook=none; bishop=h1; knight=none; pawn=none.


Prompt:
FEN: 4r3/ppRb2pp/3k1p2/8/4PN2/3PP2P/PP4P1/1K6 w - - 9 24
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=0; rook=1; bishop=0; knight=1; pawn=7.
Black counts: king=1; queen=0; rook=1; bishop=1; knight=0; pawn=5.


Prompt:
FEN: 1nbqk2r/1pp2ppp/4pn2/1P1p4/1P1P1B2/8/4PPPP/Q3KBNR b Kk -
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=9; rook=5; bishop=6; knight=3; pawn=7; total=30.
Black values: king=0; queen=9; rook=5; bishop=3; knight=6; pawn=7; total=30.


Prompt:
FEN: 8/5b2/5k2/7Q/4K3/8/8/8 w - -
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=e4; queen=h5; rook=none; bishop=none; knight=none; pawn=none | black king=f6; queen=none; rook=none; bishop=f7; knight=none; pawn=none
Counts: white king=1; queen=1; rook=0; bishop=0; knight=0; pawn=0 | black king=1; queen=0; rook=0; bishop=1; knight=0; pawn=0
Values: white total=9; black total=3
Balance: White is up 6 point(s) of material.


Prompt:
Starting FEN: 4rrk1/ppq3p1/3b1n1p/3p4/3n4/1BP1B2P/PP1Q2P1/R4R1K w - - 0 20
After the moves b3d5 f8f7 h1g1, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 20

Answer format: return exactly "Result FEN: <complete six-field FEN>".


Prompt:
Position (FEN): r1bq1rk1/4bpp1/7p/p3P3/1p1pP1n1/1P1P2P1/PB2N1BP/R2Q1RK1 w - - 1 19
Show me the board.


Prompt:
Here is the current board:
8 . n r . k . n .
7 . p . . . p p .
6 . . b . P . . r
5 q . . p P . N .
4 . b . P . . P .
3 p P N Q . . . .
2 P . . B B . K .
1 . . R . . R . .
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.


Prompt:
FEN: r1b2k1r/pp1p1ppp/5q2/1p6/3p4/2P5/PP3PPP/RN1QR1K1 b - -
What piece is on h7?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: r3kbnr/6pp/b3pq2/1N1p4/p7/2P5/P1nPQPPP/R1BK2NR b kq - 2 14
What is the material count for both sides?

White (13 pieces): 1 bishop, 1 king, 2 knights, 6 pawns, 1 queen, 2 rooks. Black (13 pieces): 2 bishops, 1 king, 2 knights, 5 pawns, 1 queen, 2 rooks. Black is up 2 point(s) of material.


Prompt:
FEN: r2q1rk1/ppb3p1/2ppp2p/4n3/2P1nB2/P1N4P/1P1QBPP1/R3R1K1 w - - 0 17
What is on e1?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: 2r1r1k1/1bqp1pbp/pp3np1/4p3/1PPn4/2NP1NP1/Q2BPPBP/1RR3K1 b - -
What is the compressed FEN row for rank 8?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: 8/8/6p1/1R6/K5QP/5P2/5k2/8 w - - 8 57
For square d4, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

d4: file=d; rank=4; fen_row_from_top=5; file_index=4


Prompt:
FEN: rn2kb1r/pb6/1pp1pq1p/8/3P1n2/3B3Q/PPN2PPP/R1B2RK1 w kq - 0 18
Compressed rank 2 row: PPN2PPP
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


r1bq1rk1/pppp1ppp/2n2n2/2b1p3/2B1P3/2PP1N2/PP1N1PPP/R1BQK2R b KQ -

Prompt:
Rank 4 row before: 2B1P3
File d changes from 1 to b. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: 2k5/ppp2p1p/3b4/8/5pR1/3P4/PPPBr2q/3R1K2
Apply square edits: c7 p->1; c5 1->p
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 2k5/pp3p1p/3b4/2p5/5pR1/3P4/PPPBr2q/3R1K2


Prompt:
Starting FEN: 6k1/p4p1p/b5p1/7q/P3B3/6K1/5PPP/1R6 b - - 4 33
Move: a6c4
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: a6=black bishop; c4=empty.
Squares: a6 black bishop->empty; c4 empty->black bishop.
Ranks: rank 6 a b->1; rank 4 c 1->b.


Prompt:
Starting FEN: r1br2k1/ppq1ppbp/2np1np1/8/4PP2/1NN1B3/PPP1B1PP/R2Q1RK1 w - - 0 1
Move: a2a4
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: white pawn a2a4.
Lookup: a2=white pawn; a4=empty.
Squares: a2 white pawn->empty; a4 empty->white pawn.
Ranks: rank 2 a P->1; rank 4 a 1->P.
Result FEN: r1br2k1/ppq1ppbp/2np1np1/8/P3PP2/1NN1B3/1PP1B1PP/R2Q1RK1 b - - 0 1


Prompt:
Starting FEN: r3r1k1/ppp1qppp/3p4/3P4/3p4/3P4/PPP1QPPP/R4RK1 w - - 0 14
Move: e2g4
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 14

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 2 PPP1QPPP->PPP2PPP; rank 4 3p4->3p2Q1.
Result FEN: r3r1k1/ppp1qppp/3p4/3P4/3p2Q1/3P4/PPP2PPP/R4RK1 b - - 1 14


Prompt:
Starting FEN: 8/2R1bp2/1p4k1/4P2p/1p4pP/1P4P1/r5K1/2R5 w - - 0 36
After the moves g2g1, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 36

Answer format: return exactly "Result FEN: <complete six-field FEN>".


Prompt:
FEN: r2q1rk1/pbpnbp1p/1p1pp1p1/8/2PP4/2PBPN1P/P1Q2PP1/1RB2RK1 b - - 0 12
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=g1; queen=c2; rook=b1,f1; bishop=c1,d3; knight=f3; pawn=a2,f2,g2,c3,e3,h3,c4,d4.
Black inventory: king=g8; queen=d8; rook=a8,f8; bishop=b7,e7; knight=d7; pawn=b6,d6,e6,g6,a7,c7,f7,h7.


Prompt:
FEN: rnbqk2r/ppp2p2/5n1p/3p2p1/1b1P4/2N1P1B1/PP3PPP/R2QKBNR b KQkq -
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=1; rook=2; bishop=2; knight=2; pawn=7.
Black counts: king=1; queen=1; rook=2; bishop=2; knight=2; pawn=7.


Prompt:
FEN: r2q1k1r/pp1b2pp/1b2pn2/1P1pQ3/8/2PB4/P4PPP/RNB1K2R w KQ -
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=9; rook=10; bishop=6; knight=3; pawn=6; total=34.
Black values: king=0; queen=9; rook=10; bishop=6; knight=3; pawn=6; total=34.


Prompt:
FEN: R7/P5k1/6P1/8/8/r3K3/8/8 w - -
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=e3; queen=none; rook=a8; bishop=none; knight=none; pawn=g6,a7 | black king=g7; queen=none; rook=a3; bishop=none; knight=none; pawn=none
Counts: white king=1; queen=0; rook=1; bishop=0; knight=0; pawn=2 | black king=1; queen=0; rook=1; bishop=0; knight=0; pawn=0
Values: white total=7; black total=5
Balance: White is up 2 point(s) of material.


Prompt:
Starting FEN: rnbqkb1r/1pp2ppp/5n2/p7/1P1p4/P4N2/1BPP1PPP/RN1QKB1R w KQkq - 0 1
After the moves f3h4 c8g4 c2c4, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: KQkq
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: rn1qkb1r/1pp2ppp/5n2/p7/1PPp2bN/P7/1B1P1PPP/RN1QKB1R b KQkq c3 0 2


Prompt:
Position (FEN): rnb1kb1r/ppppqpp1/5n1p/4p3/2B1P3/1P3N2/PBPP1PPP/RN1QK2R b KQkq - 2 5
Show me the board.

8 r n b . k b . r
7 p p p p q p p .
6 . . . . . n . p
5 . . . . p . . .
4 . . B . P . . .
3 . P . . . N . .
2 P B P P . P P P
1 R N . Q K . . R
  a b c d e f g h


Prompt:
Here is the current board:
8 . . k . . . . .
7 . . . . . Q . p
6 . . n . . p . .
5 b . . . . . . .
4 . . . . . . . .
3 . . . . . . P .
2 . . . . . P . P
1 . . . . . . K .
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.


Prompt:
FEN: r7/8/5ppk/2R1p3/rP3PP1/P3R1K1/8/8 w - -
What piece is on e3?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: 1r6/3k2pp/p4n2/8/P1pPP3/5P2/1r3NPP/R4K1R w - -
What is the material count for both sides?

White (10 pieces): 1 king, 1 knight, 6 pawns, 2 rooks. Black (8 pieces): 1 king, 1 knight, 4 pawns, 2 rooks. White is up 2 point(s) of material.


Prompt:
FEN: r1b2rk1/2p1qpb1/pp1p2np/3P2p1/4P3/2NBB3/PPPQ1RPP/5RK1 b - -
What is on g5?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: 4Rrk1/p1p3pp/1p6/3r1p2/8/2P4P/PP4P1/R5K1 w - - 4 26
What is the compressed FEN row for rank 6?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: r1bqr1k1/ppp1bp1p/2np1npB/4p3/2B1P3/2PP1Q2/PP3PPP/RN2K1NR w KQ - 5 9
For square b7, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

b7: file=b; rank=7; fen_row_from_top=2; file_index=2


Prompt:
FEN: 3rk1nr/p4ppp/q7/8/1b1Q4/2N5/PP3PPP/R3K2R w KQk - 1 17
Compressed rank 4 row: 1b1Q4
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


rnb1kbnr/pp1p1ppp/2p2q2/4p3/2B1P3/8/PPPPQPPP/RNB1K1NR w KQkq - 2 4

Prompt:
Rank 1 row before: RNB1K1NR
File e changes from K to 1. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: 4rr1k/p5p1/3Q3p/2p5/PpB1b3/4B1PP/2q3P1/R3R1K1
Apply square edits: e3 B->1; d2 1->B
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 4rr1k/p5p1/3Q3p/2p5/PpB1b3/6PP/2qB2P1/R3R1K1


Prompt:
Starting FEN: r2qkb1r/pb1n1ppp/1p2pn2/8/3p4/2PB1NN1/PP3PPP/R1BQ1RK1 w kq - 0 11
Move: h2h4
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: h2=white pawn; h4=empty.
Squares: h2 white pawn->empty; h4 empty->white pawn.
Ranks: rank 2 h P->1; rank 4 h 1->P.


Prompt:
Starting FEN: 1q2rrk1/1p2bpp1/pBppnn1p/2P2Q2/NP6/P5P1/4PPBP/R2R2K1 b - - 0 19
Move: b8a8
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 19

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: black queen b8a8.
Lookup: b8=black queen; a8=empty.
Squares: b8 black queen->empty; a8 empty->black queen.
Ranks: rank 8 b q->1; rank 8 a 1->q.
Result FEN: q3rrk1/1p2bpp1/pBppnn1p/2P2Q2/NP6/P5P1/4PPBP/R2R2K1 w - - 1 20


Prompt:
Starting FEN: r1bqkbnr/1p1p2pp/p1n1pp2/2p5/4P3/1PN2N2/PBPP1PPP/R2QKB1R w KQkq - 0 6
Move: f1c4
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: white
Castling rights: KQkq
En passant: none
Halfmove clock: 0
Fullmove number: 6

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 1 R2QKB1R->R2QK2R; rank 4 4P3->2B1P3.
Result FEN: r1bqkbnr/1p1p2pp/p1n1pp2/2p5/2B1P3/1PN2N2/PBPP1PPP/R2QK2R b KQkq - 1 6


Prompt:
Starting FEN: r3kbnr/pppb2pp/2n1pq2/3P1p2/2N5/5NP1/PP2PPBP/R1BQ1RK1 b kq - 0 9
After the moves c6a5, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: kq
En passant: none
Halfmove clock: 0
Fullmove number: 9

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: r3kbnr/pppb2pp/4pq2/n2P1p2/2N5/5NP1/PP2PPBP/R1BQ1RK1 w kq - 1 10


Prompt:
FEN: 8/1N4k1/3Q4/8/8/4K3/8/8 w - -
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=e3; queen=d6; rook=none; bishop=none; knight=b7; pawn=none.
Black inventory: king=g7; queen=none; rook=none; bishop=none; knight=none; pawn=none.


Prompt:
FEN: 8/8/8/8/4prkp/8/6RK/4B3 b - - 1 63
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=0; rook=1; bishop=1; knight=0; pawn=0.
Black counts: king=1; queen=0; rook=1; bishop=0; knight=0; pawn=2.


Prompt:
FEN: 8/8/pk6/2pK4/PpP5/1P6/8/8 w - -
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=0; rook=0; bishop=0; knight=0; pawn=3; total=3.
Black values: king=0; queen=0; rook=0; bishop=0; knight=0; pawn=3; total=3.


Prompt:
FEN: 8/6kp/5p2/2n2P2/6KP/8/8/8 b - - 3 46
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=g4; queen=none; rook=none; bishop=none; knight=none; pawn=h4,f5 | black king=g7; queen=none; rook=none; bishop=none; knight=c5; pawn=f6,h7
Counts: white king=1; queen=0; rook=0; bishop=0; knight=0; pawn=2 | black king=1; queen=0; rook=0; bishop=0; knight=1; pawn=2
Values: white total=2; black total=5
Balance: Black is up 3 point(s) of material.


Prompt:
Starting FEN: 5r1r/ppqkb1p1/2npp2p/2p5/2N1nB2/2PP4/PP3PPP/R2QK2R w KQ - 0 16
After the moves e1e2 e6e5 g2g3, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: KQ
En passant: none
Halfmove clock: 0
Fullmove number: 16

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: 5r1r/ppqkb1p1/2np3p/2p1p3/2N1nB2/2PP2P1/PP2KP1P/R2Q3R b - - 0 17


Prompt:
Position (FEN): 2kr3r/ppp1q1pp/2n2p1n/2B1p3/2B1P3/2P2N1P/PP2Q1P1/R3K2R b KQ - 0 17
Show me the board.


Prompt:
Here is the current board:
8 r . b k . . n b
7 p p p . . . . p
6 q . n . p . . .
5 . . . . . . . B
4 . . . . . P . .
3 N P P . B . P .
2 P . . . . . . P
1 . . . R . R K .
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 6
Fullmove number: 20

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.


Prompt:
FEN: r3kb1r/pp3ppp/2n5/5b2/2P1n3/4BN2/PP1N1PPP/R2K1B1R b kq -
What piece is on f2?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: r6r/1pkn1ppp/p3b3/4p3/6P1/2P1B2P/P1P2PB1/R4RK1 w - -
What is the material count for both sides?

White (11 pieces): 2 bishops, 1 king, 6 pawns, 2 rooks. Black (11 pieces): 1 bishop, 1 king, 1 knight, 6 pawns, 2 rooks. Material is equal.


Prompt:
FEN: 2kr2nr/pbp2ppp/3q4/4p3/2B5/P7/2QN1PPP/R4RK1 w - - 1 17
What is on e1?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: 2r1r2k/p4ppp/2q5/1ppN1P2/2P5/3P1Q2/Pb4PP/4RRK1 w - - 0 21
What is the compressed FEN row for rank 4?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: r2qk2r/ppp2ppp/2nb1n2/4pb2/4P3/2PP4/PP1BB1PP/RN1QK1NR b KQkq - 0 8
For square d5, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

d5: file=d; rank=5; fen_row_from_top=4; file_index=4


Prompt:
FEN: r1b1kbnr/pppp1pp1/2n4p/8/2BNP2q/8/PPP2PPP/RNBQK2R w KQkq - 1 6
Compressed rank 7 row: pppp1pp1
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 6 row before: p5kp
File g changes from k to 1. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


rn2k2r/ppp2pp1/3bbn2/3pp3/4P3/3P2PP/PPP3P1/R1B1KBNR b KQkq - 0 11

Prompt:
Board FEN before: rn2k2r/ppp2pp1/3bbn2/3pp3/4P3/3P2PP/PPP3P1/R1B1KBNR
Apply square edits: b8 n->1; a6 1->n
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: r3k2r/ppp2pp1/n2bbn2/3pp3/4P3/3P2PP/PPP3P1/R1B1KBNR


Prompt:
Starting FEN: 2k4r/pppr2pp/8/2b2pN1/2Bp1n2/5P2/PPP2P1P/1K1RR3 w - - 4 17
Move: b2b4
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: b2=white pawn; b4=empty.
Squares: b2 white pawn->empty; b4 empty->white pawn.
Ranks: rank 2 b P->1; rank 4 b 1->P.


Prompt:
Starting FEN: 3r4/b1B4p/8/5k2/8/5B2/6KP/8 b - - 0 1
Move: f5f6
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: black king f5f6.
Lookup: f5=black king; f6=empty.
Squares: f5 black king->empty; f6 empty->black king.
Ranks: rank 5 f k->1; rank 6 f 1->k.
Result FEN: 3r4/b1B4p/5k2/8/8/5B2/6KP/8 w - - 1 2


Prompt:
Starting FEN: 3r4/p1N1k1p1/7p/2B5/2p5/2N5/PPn2PPP/3R2K1 b - - 0 23
Move: e7f6
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 23

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 7 p1N1k1p1->p1N3p1; rank 6 7p->5k1p.
Result FEN: 3r4/p1N3p1/5k1p/2B5/2p5/2N5/PPn2PPP/3R2K1 w - - 1 24


Prompt:
Starting FEN: 1r2k1nr/pb1p2pp/1pnb4/2p2p2/3P1P2/1P4P1/P1PQPNBP/q1B2K1R b k - 1 13
After the moves h7h6, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: k
En passant: none
Halfmove clock: 1
Fullmove number: 13

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: 1r2k1nr/pb1p2p1/1pnb3p/2p2p2/3P1P2/1P4P1/P1PQPNBP/q1B2K1R w k - 0 14


Prompt:
FEN: 2q3k1/2bn1pp1/5n1p/Bp1p4/3Pp3/1N2P2P/5PP1/Q1N3K1 w - - 1 28
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=g1; queen=a1; rook=none; bishop=a5; knight=c1,b3; pawn=f2,g2,e3,h3,d4.
Black inventory: king=g8; queen=c8; rook=none; bishop=c7; knight=f6,d7; pawn=e4,b5,d5,h6,f7,g7.


Prompt:
FEN: 5r1k/3Q2pp/3p2n1/1p1P2N1/8/1B2P2P/PP4PK/4q3 b - - 0 26
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=1; rook=0; bishop=1; knight=1; pawn=6.
Black counts: king=1; queen=1; rook=1; bishop=0; knight=1; pawn=4.


Prompt:
FEN: 2r1k1nr/pp2bpp1/1q2p3/4P1BP/1n1p1P1P/2N2Q2/PPP3B1/2KR3R w k -
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=9; rook=10; bishop=6; knight=3; pawn=7; total=35.
Black values: king=0; queen=9; rook=10; bishop=3; knight=6; pawn=6; total=34.


Prompt:
FEN: r2q1rk1/1p4pp/p1npb2n/4pp2/2P1P3/2NQ4/PPN1BPPP/3R1RK1 b - -
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=g1; queen=d3; rook=d1,f1; bishop=e2; knight=c2,c3; pawn=a2,b2,f2,g2,h2,c4,e4 | black king=g8; queen=d8; rook=a8,f8; bishop=e6; knight=c6,h6; pawn=e5,f5,a6,d6,b7,g7,h7
Counts: white king=1; queen=1; rook=2; bishop=1; knight=2; pawn=7 | black king=1; queen=1; rook=2; bishop=1; knight=2; pawn=7
Values: white total=35; black total=35
Balance: Material is equal.


Prompt:
Starting FEN: 3r2k1/p5p1/1bprp1Np/5p2/1n6/1K3B2/6PP/2BR1R2 b - - 1 33
After the moves c6c5 f3h5 d6d7, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 1
Fullmove number: 33

Answer format: return exactly "Result FEN: <complete six-field FEN>".


Prompt:
Position (FEN): 6k1/6p1/2N4p/8/5pR1/7P/r4rPK/8 b - - 1 37
Show me the board.


Prompt:
Here is the current board:
8 r . b q . . . r
7 . . p p b k p p
6 p . . . . . . .
5 . p n . R . . .
4 . . . . . . . .
3 . . . . . . . .
2 P P P P . P P P
1 R N B Q . . K .
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.

r1bq3r/2ppbkpp/p7/1pn1R3/8/8/PPPP1PPP/RNBQ2K1 w - - 0 1


Prompt:
FEN: 8/3k2pR/2p5/2PnP3/r1NK4/8/8/8 b - -
What piece is on d4?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: rnr3k1/1R3pp1/p2ppq1p/2b5/2P5/1N2B1P1/P1P2PKP/3Q1R2 b - -
What is the material count for both sides?

White (12 pieces): 1 bishop, 1 king, 1 knight, 6 pawns, 1 queen, 2 rooks. Black (12 pieces): 1 bishop, 1 king, 1 knight, 6 pawns, 1 queen, 2 rooks. Material is equal.


Prompt:
FEN: r1bqkb1r/ppp2ppp/2n2n2/8/3N4/8/PPP2PPP/R1BQKBNR w KQkq - 1 9
What is on b7?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: 8/5ppk/6n1/1R4Pp/2p3b1/p7/PbB1N1P1/5K2 b - -
What is the compressed FEN row for rank 5?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: 8/p1p5/8/5p1p/6k1/1P6/2K3RP/4N3 b - - 2 35
For square b5, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

b5: file=b; rank=5; fen_row_from_top=4; file_index=2


Prompt:
FEN: rnb1k2r/pp1pppbp/5np1/2q5/2P5/4PN2/PP1B1PPP/RN1QKB1R w KQkq -
Compressed rank 7 row: pp1pppbp
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".

rank 7: a=p; b=p; c=1; d=p; e=p; f=p; g=b; h=p


Prompt:
Rank 5 row before: PbKp2pp
File c changes from K to 1. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: 8/pK6/P2p4/8/3k4/2p5/2P5/8
Apply square edits: d4 k->1; d5 1->k
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 8/pK6/P2p4/3k4/8/2p5/2P5/8


Prompt:
Starting FEN: r3r1k1/1b1n3p/pp2pqp1/2pP1p2/2P5/1P1B1N1P/PQ3PP1/R2R2K1 w - -
Move: a1b1
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: a1=white rook; b1=empty.
Squares: a1 white rook->empty; b1 empty->white rook.
Ranks: rank 1 a R->1; rank 1 b 1->R.


Prompt:
Starting FEN: r5k1/1p2q2p/1P1p2pB/1QpPpP2/8/7P/5PP1/1R4K1 b - - 0 29
Move: e7e8
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 29

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: black queen e7e8.
Lookup: e7=black queen; e8=empty.
Squares: e7 black queen->empty; e8 empty->black queen.
Ranks: rank 7 e q->1; rank 8 e 1->q.
Result FEN: r3q1k1/1p5p/1P1p2pB/1QpPpP2/8/7P/5PP1/1R4K1 w - - 1 30


Prompt:
Starting FEN: 4r2k/p1n3p1/6pp/8/2QP1Pq1/2P3P1/P2B3P/1R4K1 b - - 0 1
Move: e8b8
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 8 4r2k->1r5k.
Result FEN: 1r5k/p1n3p1/6pp/8/2QP1Pq1/2P3P1/P2B3P/1R4K1 w - - 1 2


Prompt:
Starting FEN: rnbq1rk1/pp2ppbp/5np1/2p5/4p3/3P1NP1/PPPN1PBP/R1BQ1RK1 w - - 0 1
After the moves f3d4, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: rnbq1rk1/pp2ppbp/5np1/2p5/3Np3/3P2P1/PPPN1PBP/R1BQ1RK1 b - - 1 1


Prompt:
FEN: 1r1r4/p4k2/3b2p1/5p2/2P1p3/2Bn4/P1KP4/5RR1 b - - 1 34
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=c2; queen=none; rook=f1,g1; bishop=c3; knight=none; pawn=a2,d2,c4.
Black inventory: king=f7; queen=none; rook=b8,d8; bishop=d6; knight=d3; pawn=e4,f5,g6,a7.


Prompt:
FEN: 8/p4kpp/2p1p3/1p6/2B5/8/PP3PPP/3K4 w - - 0 22
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=0; rook=0; bishop=1; knight=0; pawn=5.
Black counts: king=1; queen=0; rook=0; bishop=0; knight=0; pawn=6.


Prompt:
FEN: r5nr/pp2kQpp/1q2pp2/1b1pN3/3p4/PP1P4/3N1PPP/R3K2R b KQ -
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=9; rook=10; bishop=0; knight=6; pawn=6; total=31.
Black values: king=0; queen=9; rook=10; bishop=3; knight=3; pawn=8; total=33.


Prompt:
FEN: rn5r/pp3k2/2pPn3/7p/3P4/8/PPP2PPP/2KR3R b - - 1 20
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=c1; queen=none; rook=d1,h1; bishop=none; knight=none; pawn=a2,b2,c2,f2,g2,h2,d4,d6 | black king=f7; queen=none; rook=a8,h8; bishop=none; knight=e6,b8; pawn=h5,c6,a7,b7
Counts: white king=1; queen=0; rook=2; bishop=0; knight=0; pawn=8 | black king=1; queen=0; rook=2; bishop=0; knight=2; pawn=4
Values: white total=18; black total=20
Balance: Black is up 2 point(s) of material.


Prompt:
Starting FEN: r4rk1/pbqnppbp/3p2p1/1B6/1P1PP3/B1P2QNP/5PP1/R4RK1 w - - 3 17
After the moves g3h1 c7c3, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 3
Fullmove number: 17

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: r4rk1/pb1nppbp/3p2p1/1B6/1P1PP3/B1q2Q1P/5PP1/R4RKN w - - 0 18


Prompt:
Position (FEN): 4r3/1kq2p2/4r1p1/3PPb1p/p1p4P/PpP3KP/1P2R3/4R3 b - - 0 45
Show me the board.


Prompt:
Here is the current board:
8 r . . . . k . r
7 p p p . . p p p
6 . . . . . . . .
5 . . b n Q . . .
4 . . B . . . . q
3 . . P P . P . .
2 P P . . . . . P
1 R N B . K . . R
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: KQ
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.

r4k1r/ppp2ppp/8/2bnQ3/2B4q/2PP1P2/PP5P/RNB1K2R w KQ - 0 1


Prompt:
FEN: r1b1k1nr/ppp2ppp/2n5/3qp3/1b1P4/2N1PN2/PP3PPP/R1BQKB1R b KQkq - 0 6
What piece is on a7?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: 4k2r/6R1/5p2/4p3/b3N2p/q4N1P/P2K4/2R5 b k - 3 35
What is the material count for both sides?

White (7 pieces): 1 king, 2 knights, 2 pawns, 2 rooks. Black (7 pieces): 1 bishop, 1 king, 3 pawns, 1 queen, 1 rook. Black is up 2 point(s) of material.


Prompt:
FEN: 8/8/4R3/8/1k1K4/8/8/8 w - -
What is on d4?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: r1bqkb1r/pp1npppp/2Bp4/4P3/3Q4/5N2/PPP2PPP/RNB1K2R b KQkq -
What is the compressed FEN row for rank 8?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: r3kbnr/pp2pp1p/2n3p1/1Bpq4/6b1/2P2N2/PP1P1PPP/RNBQ1RK1 w kq -
For square e1, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

e1: file=e; rank=1; fen_row_from_top=8; file_index=5


Prompt:
FEN: r4r1k/5pp1/p7/1p6/1P1nBPq1/P6R/6PP/R5K1 b - - 1 27
Compressed rank 2 row: 6PP
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 4 row before: 8
File f changes from 1 to P. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: 4R3/2B2k2/p6p/1p6/8/5P1P/6PK/8
Apply square edits: b5 p->1; b4 1->p
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 4R3/2B2k2/p6p/8/1p6/5P1P/6PK/8


Prompt:
Starting FEN: 3r1r2/pppk4/2nqpbQR/3p2p1/3P4/P1P1B3/2P1PPB1/R3K3 w Q - 3 21
Move: e3c1
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: e3=white bishop; c1=empty.
Squares: e3 white bishop->empty; c1 empty->white bishop.
Ranks: rank 3 e B->1; rank 1 c 1->B.


Prompt:
Starting FEN: 8/8/2k5/8/p6R/4P3/P2B1PP1/R3KBN1 w Q - 0 1
Move: h4d4
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: white
Castling rights: Q
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: white rook h4d4.
Lookup: h4=white rook; d4=empty.
Squares: h4 white rook->empty; d4 empty->white rook.
Ranks: rank 4 h R->1; rank 4 d 1->R.
Result FEN: 8/8/2k5/8/p2R4/4P3/P2B1PP1/R3KBN1 b Q - 1 1


Prompt:
Starting FEN: 5R2/8/3k4/8/8/4K3/8/7R w - - 0 1
Move: e3d3
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".


Prompt:
Starting FEN: 4r1k1/5p2/1pn3p1/1Bp3Bq/6p1/8/Pb3PPP/2QR2K1 w - - 0 1
After the moves b5c4, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".


Prompt:
FEN: rn1qkb1r/pp3ppp/2p1b3/1B6/3P4/4pN2/PPP3PP/RN1Q1RK1 w kq -
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=g1; queen=d1; rook=a1,f1; bishop=b5; knight=b1,f3; pawn=a2,b2,c2,g2,h2,d4.
Black inventory: king=e8; queen=d8; rook=a8,h8; bishop=e6,f8; knight=b8; pawn=e3,c6,a7,b7,f7,g7,h7.


Prompt:
FEN: k2r1r2/P1R5/3Q3p/1q1P2p1/P7/3p1P1b/5P1P/7K w - - 0 28
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=1; rook=1; bishop=0; knight=0; pawn=6.
Black counts: king=1; queen=1; rook=2; bishop=1; knight=0; pawn=3.


Prompt:
FEN: 5k2/R5pp/7n/8/1P1p1P2/5K1P/3r4/8 b - - 0 38
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=0; rook=5; bishop=0; knight=0; pawn=3; total=8.
Black values: king=0; queen=0; rook=5; bishop=0; knight=3; pawn=3; total=11.


Prompt:
FEN: rnb2rk1/p4pp1/2p1pq1p/1p6/1PpP4/1PN1PN2/5PPP/R2QKB1R w KQ - 0 11
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=e1; queen=d1; rook=a1,h1; bishop=f1; knight=c3,f3; pawn=f2,g2,h2,b3,e3,b4,d4 | black king=g8; queen=f6; rook=a8,f8; bishop=c8; knight=b8; pawn=c4,b5,c6,e6,h6,a7,f7,g7
Counts: white king=1; queen=1; rook=2; bishop=1; knight=2; pawn=7 | black king=1; queen=1; rook=2; bishop=1; knight=1; pawn=8
Values: white total=35; black total=33
Balance: White is up 2 point(s) of material.


Prompt:
Starting FEN: 6k1/4qp1p/1p2p1p1/p2bN3/Pn1Pp3/BP2P3/5PPP/1Q4K1 b - - 1 26
After the moves g8h8 h2h3 h7h5, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 1
Fullmove number: 26

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: 7k/4qp2/1p2p1p1/p2bN2p/Pn1Pp3/BP2P2P/5PP1/1Q4K1 w - - 0 28


Prompt:
Position (FEN): r1b2rk1/ppp3pp/8/3P4/1q1PnB2/4P3/P1Q2PPP/2RK1B1R b - -
Show me the board.


Prompt:
Here is the current board:
8 r . . q . r k .
7 p b p p b p p p
6 n p . . p n . .
5 . . . . . . B .
4 . . P P . . . .
3 P . N . P N . .
2 . P . . . P P P
1 R . . Q K B . R
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: KQ
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.

r2q1rk1/pbppbppp/np2pn2/6B1/2PP4/P1N1PN2/1P3PPP/R2QKB1R w KQ - 0 1


Prompt:
FEN: r1bqkb1r/pppp2pp/2n5/4NP1n/4pPP1/8/PPPP3P/RNBQKB1R w KQkq -
What piece is on g7?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: r3kq1r/pp1b2p1/5p1p/1Q2p3/N1Bp3B/8/PP4PP/4R1K1 w kq - 2 20
What is the material count for both sides?

White (10 pieces): 2 bishops, 1 king, 1 knight, 4 pawns, 1 queen, 1 rook. Black (12 pieces): 1 bishop, 1 king, 7 pawns, 1 queen, 2 rooks. Black is up 2 point(s) of material.


Prompt:
FEN: r2k1b1r/p1pp2pp/b7/8/4R3/8/PPP2PPP/RNBQ2K1 b - - 0 12
What is on g7?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: r1bq1rk1/3n1ppp/3bp3/1p1p4/p1pPPP2/P1P5/1PBNQ1PP/R1B2R1K w - - 0 16
What is the compressed FEN row for rank 3?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: r2qk2r/pb3p1p/1p2p1pb/n2pPn2/5P2/BPPB1NP1/2NPQ2P/R3K2R w KQkq -
For square b2, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

b2: file=b; rank=2; fen_row_from_top=7; file_index=2


Prompt:
FEN: r4rk1/ppR2ppp/2n1q3/8/5Q2/2P3P1/P1PR1PKP/8 b - - 0 23
Compressed rank 5 row: 8
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 3 row before: pK5P
File h changes from P to 1. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: r1b2R2/ppk5/3p2p1/2p1b2p/2B5/2PP4/PP4PP/4R2K
Apply square edits: f8 R->1; f3 1->R
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: r1b5/ppk5/3p2p1/2p1b2p/2B5/2PP1R2/PP4PP/4R2K


Prompt:
Starting FEN: Qn2r1r1/2pk4/Bp2pB2/3pP3/3q2p1/7P/5P2/1R4K1 w - - 2 34
Move: b1b5
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: b1=white rook; b5=empty.
Squares: b1 white rook->empty; b5 empty->white rook.
Ranks: rank 1 b R->1; rank 5 b 1->R.


Prompt:
Starting FEN: 8/8/8/R7/3K4/1R6/2k5/8 w - - 0 1
Move: a5a4
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: white rook a5a4.
Lookup: a5=white rook; a4=empty.
Squares: a5 white rook->empty; a4 empty->white rook.
Ranks: rank 5 a R->1; rank 4 a 1->R.
Result FEN: 8/8/8/8/R2K4/1R6/2k5/8 b - - 1 1


Prompt:
Starting FEN: 3r4/p7/5pp1/1pp2b1p/2k2N1P/2P2P2/P2B1KPR/3R4 b - - 3 28
Move: f5e4
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 3
Fullmove number: 28

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 5 1pp2b1p->1pp4p; rank 4 2k2N1P->2k1bN1P.
Result FEN: 3r4/p7/5pp1/1pp4p/2k1bN1P/2P2P2/P2B1KPR/3R4 w - - 4 29


Prompt:
Starting FEN: 3r1rk1/pp2ppbp/3q2p1/1Bpb4/5n2/PP2Q3/R2P1PPP/1NB1R1K1 b - - 10 17
After the moves f7f6, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 10
Fullmove number: 17

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: 3r1rk1/pp2p1bp/3q1pp1/1Bpb4/5n2/PP2Q3/R2P1PPP/1NB1R1K1 w - - 0 18


Prompt:
FEN: 6k1/3N4/6BK/8/8/8/8/8 w - -
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=h6; queen=none; rook=none; bishop=g6; knight=d7; pawn=none.
Black inventory: king=g8; queen=none; rook=none; bishop=none; knight=none; pawn=none.


Prompt:
FEN: 8/P7/2b2p1p/2K2Pp1/6P1/7k/4B3/8 b - - 1 55
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=0; rook=0; bishop=1; knight=0; pawn=3.
Black counts: king=1; queen=0; rook=0; bishop=1; knight=0; pawn=3.


Prompt:
FEN: rn3r2/5p1k/p4q1p/3p1np1/Np3Q2/1P3N1P/P1PP1PP1/R4RK1 w - - 0 21
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=9; rook=10; bishop=0; knight=6; pawn=7; total=32.
Black values: king=0; queen=9; rook=10; bishop=0; knight=6; pawn=6; total=31.


Prompt:
FEN: r1b1k1nr/pp1p1p1p/2p1n3/2Q1P3/2B5/2N5/PPP3PP/R4RK1 b kq -
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=g1; queen=c5; rook=a1,f1; bishop=c4; knight=c3; pawn=a2,b2,c2,g2,h2,e5 | black king=e8; queen=none; rook=a8,h8; bishop=c8; knight=e6,g8; pawn=c6,a7,b7,d7,f7,h7
Counts: white king=1; queen=1; rook=2; bishop=1; knight=1; pawn=6 | black king=1; queen=0; rook=2; bishop=1; knight=2; pawn=6
Values: white total=31; black total=25
Balance: White is up 6 point(s) of material.


Prompt:
Starting FEN: 8/8/8/8/Q7/3k4/8/4K3 w - - 0 1
After the moves a4b3 d3e4 b3b7, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".


Prompt:
Position (FEN): r1bqk3/ppp2pBp/4p3/1PPp4/5nn1/4P3/3N1P1P/R2QKBNR b KQq - 0 14
Show me the board.


Prompt:
Here is the current board:
8 r n b q k b . r
7 . p . p . p p p
6 . . p . . n . .
5 p . . . . . . .
4 . . P . P p . .
3 . . N P . . . .
2 P P . . . . P P
1 R . B Q K B N R
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: KQkq
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.

rnbqkb1r/1p1p1ppp/2p2n2/p7/2P1Pp2/2NP4/PP4PP/R1BQKBNR w KQkq - 0 1


Prompt:
FEN: r1b1r1k1/pp3p2/7Q/2pq2p1/1nNp1b2/3P4/PPP2BPP/1K1R2NR b - - 6 18
What piece is on b4?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: rnbqkb1r/pp2pppp/5n2/2pP4/8/2N2N2/PP1PPPPP/R1BQKB1R b KQkq -
What is the material count for both sides?

White (16 pieces): 2 bishops, 1 king, 2 knights, 8 pawns, 1 queen, 2 rooks. Black (15 pieces): 2 bishops, 1 king, 2 knights, 7 pawns, 1 queen, 2 rooks. White is up 1 point(s) of material.


Prompt:
FEN: rn3rk1/1bp2pp1/p4b1p/1p1P4/4BN2/q1P4P/PN1Q1PP1/R1R3K1 b - - 5 20
What is on a5?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: 8/1p4p1/2k2p1p/5P2/4P1PP/3K4/8/8 w - -
What is the compressed FEN row for rank 4?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: r2q1rk1/3bpnbp/p2p1pp1/1ppP4/2P1PP1P/2BB2N1/PPQ3P1/4RRK1 w - -
For square f8, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

f8: file=f; rank=8; fen_row_from_top=1; file_index=6


Prompt:
FEN: 8/5K2/2pk4/6P1/8/8/8/8 w - -
Compressed rank 2 row: 8
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 5 row before: 8
File e changes from 1 to B. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: 1r4k1/1b1R1p1p/4p1p1/1pp1P3/p7/P7/BPP1NP1P/6K1
Apply square edits: g8 k->1; g7 1->k
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 1r6/1b1R1pkp/4p1p1/1pp1P3/p7/P7/BPP1NP1P/6K1


Prompt:
Starting FEN: r2q1k2/p7/2p2n1r/7p/2BQ2P1/7P/PP6/4RRK1 w - - 1 25
Move: h3h4
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: h3=white pawn; h4=empty.
Squares: h3 white pawn->empty; h4 empty->white pawn.
Ranks: rank 3 h P->1; rank 4 h 1->P.


Prompt:
Starting FEN: 5K2/P7/8/8/6k1/5b2/7p/8 w - - 0 52
Move: a7a8n
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 52

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: white pawn a7a8n. Promotes to white knight.
Lookup: a7=white pawn; a8=empty.
Squares: a7 white pawn->empty; a8 empty->white knight.
Ranks: rank 7 a P->1; rank 8 a 1->N.
Result FEN: N4K2/8/8/8/6k1/5b2/7p/8 b - - 0 52


Prompt:
Starting FEN: r1bq2rk/1p1p4/p1n1pPQp/3n4/4N3/1N1B4/PPPb2PP/R4R1K w - - 0 1
Move: a2a4
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 2 PPPb2PP->1PPb2PP; rank 4 4N3->P3N3.
Result FEN: r1bq2rk/1p1p4/p1n1pPQp/3n4/P3N3/1N1B4/1PPb2PP/R4R1K b - - 0 1


Prompt:
Starting FEN: r2q1rk1/1p3p1p/2bpp1p1/p1n1b3/2P1P3/1PN2P2/P2Q1BPP/1R1R1BK1 b - - 0 1
After the moves d8c7, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: r4rk1/1pq2p1p/2bpp1p1/p1n1b3/2P1P3/1PN2P2/P2Q1BPP/1R1R1BK1 w - - 1 2


Prompt:
FEN: 2r2rk1/5pbp/p2q2p1/1pNp1b2/1P1PPp2/P4P2/3NQ1PP/R1R3K1 b - - 0 23
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=g1; queen=e2; rook=a1,c1; bishop=none; knight=d2,c5; pawn=g2,h2,a3,f3,b4,d4,e4.
Black inventory: king=g8; queen=d6; rook=c8,f8; bishop=f5,g7; knight=none; pawn=f4,b5,d5,a6,g6,f7,h7.


Prompt:
FEN: r4rk1/pp1n1ppp/1q1bpn2/3p2B1/3P4/2P2N2/PPQ2PPP/RN3RK1 w - - 5 11
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=1; rook=2; bishop=1; knight=2; pawn=7.
Black counts: king=1; queen=1; rook=2; bishop=1; knight=2; pawn=7.


Prompt:
FEN: 8/8/8/4p1p1/8/5P2/4k3/6K1 w - -
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=0; rook=0; bishop=0; knight=0; pawn=1; total=1.
Black values: king=0; queen=0; rook=0; bishop=0; knight=0; pawn=2; total=2.


Prompt:
FEN: r1b2r1k/1q2bppp/pp2p2B/4n3/3N4/2N3R1/PPP2PPP/3R2K1 w - -
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=g1; queen=none; rook=d1,g3; bishop=h6; knight=c3,d4; pawn=a2,b2,c2,f2,g2,h2 | black king=h8; queen=b7; rook=a8,f8; bishop=e7,c8; knight=e5; pawn=a6,b6,e6,f7,g7,h7
Counts: white king=1; queen=0; rook=2; bishop=1; knight=2; pawn=6 | black king=1; queen=1; rook=2; bishop=2; knight=1; pawn=6
Values: white total=25; black total=34
Balance: Black is up 9 point(s) of material.


Prompt:
Starting FEN: r5k1/p2R1ppp/1p2p3/1P2P3/P7/5PPP/1Bn3K1/8 w - - 2 36
After the moves b2d4 a8c8 d4b6, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 2
Fullmove number: 36

Answer format: return exactly "Result FEN: <complete six-field FEN>".


Prompt:
Position (FEN): 1nr2k2/5pp1/p2p3p/1b1B4/1Q5N/4K1P1/5P1P/7R b - - 0 29
Show me the board.


Prompt:
Here is the current board:
8 . . k r . b . r
7 p p p . . p p p
6 . . n . b . . .
5 q . . . . . N .
4 . . . p . . . .
3 . . . . . N . .
2 P P P . . P P P
1 R . B Q R . K .
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.

2kr1b1r/ppp2ppp/2n1b3/q5N1/3p4/5N2/PPP2PPP/R1BQR1K1 w - - 0 1


Prompt:
FEN: r1bq1rk1/4Bpbp/3p2p1/2pP4/1n6/pPpP1N1P/P1B2PP1/R2QR1K1 b - -
What piece is on d5?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: rn1qkb1r/ppp2ppp/4pn2/5b2/2B5/P1N2N1P/1PPP1PP1/R1BQK2R b KQkq -
What is the material count for both sides?

White (15 pieces): 2 bishops, 1 king, 2 knights, 7 pawns, 1 queen, 2 rooks. Black (15 pieces): 2 bishops, 1 king, 2 knights, 7 pawns, 1 queen, 2 rooks. Material is equal.


Prompt:
FEN: rnb1kb1r/pp3ppp/5n2/2pp4/3P1B2/4PN2/Pq1N1PPP/R2QKB1R w KQkq -
What is on e6?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: 6k1/1p3pp1/p3p2p/3pP1PP/1b3P2/7K/4R1B1/r5q1 b - - 0 32
What is the compressed FEN row for rank 4?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: r3k2r/pp1nbppp/2p2n2/7q/3N4/1BPP1P1b/PP2Q2P/RNB1K2R w KQkq - 1 13
For square c4, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

c4: file=c; rank=4; fen_row_from_top=5; file_index=3


Prompt:
FEN: 2r2rk1/pp4pp/2b2p2/3pp3/8/1N2bN2/PPP3PP/1K1R1R2 w - - 4 19
Compressed rank 5 row: 3pp3
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 7 row before: p1p2k2
File d changes from 1 to r. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: 8/8/1K6/3k4/2q5/2b5/8/8
Apply square edits: b6 K->1; a7 1->K
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".


Prompt:
Starting FEN: rnbq1rk1/ppp1bppp/5n2/4p3/3N1P2/2N5/PPP3PP/R1BQKB1R w KQ - 0 8
Move: h2h3
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: h2=white pawn; h3=empty.
Squares: h2 white pawn->empty; h3 empty->white pawn.
Ranks: rank 2 h P->1; rank 3 h 1->P.


Prompt:
Starting FEN: 3r2k1/p4ppp/8/4P3/2PB4/1P2P1P1/P1r1N2P/R3K3 b - - 0 1
Move: c2d2
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: black rook c2d2.
Lookup: c2=black rook; d2=empty.
Squares: c2 black rook->empty; d2 empty->black rook.
Ranks: rank 2 c r->1; rank 2 d 1->r.
Result FEN: 3r2k1/p4ppp/8/4P3/2PB4/1P2P1P1/P2rN2P/R3K3 w - - 1 2


Prompt:
Starting FEN: 1n1q1rk1/r3ppbp/p2p1Bp1/1p6/3NP3/P1P5/1P3PPP/RN1Q1RK1 b - - 0 14
Move: d8c8
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 14

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 8 1n1q1rk1->1nq2rk1.
Result FEN: 1nq2rk1/r3ppbp/p2p1Bp1/1p6/3NP3/P1P5/1P3PPP/RN1Q1RK1 w - - 1 15


Prompt:
Starting FEN: 6k1/4pp2/3p2p1/8/2p1P3/3n1RPP/1r6/5BK1 b - - 0 1
After the moves b2b5, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".


Prompt:
FEN: 3qk1r1/pbr1bppp/2p2n2/5N2/N2p4/1P6/2PPQPPP/R1B1R1K1 b - - 0 16
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=g1; queen=e2; rook=a1,e1; bishop=c1; knight=a4,f5; pawn=c2,d2,f2,g2,h2,b3.
Black inventory: king=e8; queen=d8; rook=c7,g8; bishop=b7,e7; knight=f6; pawn=d4,c6,a7,f7,g7,h7.


Prompt:
FEN: 5r2/p4p2/1p3k2/4pp1R/2P5/1P3B2/P2r2P1/5RK1 w - - 4 31
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=0; rook=2; bishop=1; knight=0; pawn=4.
Black counts: king=1; queen=0; rook=2; bishop=0; knight=0; pawn=5.


Prompt:
FEN: 6k1/5p1p/4r1p1/4P3/4K3/5P2/3R3P/8 w - -
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=0; rook=5; bishop=0; knight=0; pawn=3; total=8.
Black values: king=0; queen=0; rook=5; bishop=0; knight=0; pawn=3; total=8.


Prompt:
FEN: 8/8/pp1k4/3p2p1/1P3p2/P1R5/4r1PK/8 w - - 0 41
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=h2; queen=none; rook=c3; bishop=none; knight=none; pawn=g2,a3,b4 | black king=d6; queen=none; rook=e2; bishop=none; knight=none; pawn=f4,d5,g5,a6,b6
Counts: white king=1; queen=0; rook=1; bishop=0; knight=0; pawn=3 | black king=1; queen=0; rook=1; bishop=0; knight=0; pawn=5
Values: white total=8; black total=10
Balance: Black is up 2 point(s) of material.


Prompt:
Starting FEN: rnbqk1nr/pp2ppb1/3p2pp/2p5/3PP2B/2P2N2/PP3PPP/RN1QKB1R b KQkq - 0 1
After the moves f7f6 h4g5, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: KQkq
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: rnbqk1nr/pp2p1b1/3p1ppp/2p3B1/3PP3/2P2N2/PP3PPP/RN1QKB1R b KQkq - 1 2


Prompt:
Position (FEN): r2qk1nr/ppp2ppp/1bnp4/4p3/1P2P3/1BP2b1P/P2P1PP1/RNBQK2R w KQkq -
Show me the board.


Prompt:
Here is the current board:
8 . . . . . r . .
7 . . . . . . . .
6 . . . . . . . .
5 . . . . B K . .
4 . . . . . . . .
3 . R . p k P . .
2 . . . . . . . .
1 . . . . . . . .
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.


Prompt:
FEN: r2q3r/pb1k4/1p1b1p2/2p1pB2/1BP3Pp/4P3/PP2QPP1/2KR3R b - - 3 18
What piece is on f6?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: rnb1k2r/pp2npbp/2pp1qp1/4p3/4P3/2NP1NQ1/PPP2PPP/R1B1KB1R w KQkq - 0 8
What is the material count for both sides?

White (16 pieces): 2 bishops, 1 king, 2 knights, 8 pawns, 1 queen, 2 rooks. Black (16 pieces): 2 bishops, 1 king, 2 knights, 8 pawns, 1 queen, 2 rooks. Material is equal.


Prompt:
FEN: 2krr3/pp1n3p/2pb1pp1/8/4PP2/6N1/PPP2P1P/4RRK1 w - - 0 18
What is on a8?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: 2rr2k1/p4qb1/1p1p2pp/4p3/2P5/1PN1Q1P1/P4P1P/2RR2K1 b - -
What is the compressed FEN row for rank 4?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: 8/p1pk2r1/4bb2/2Q5/4p2P/1P2P3/P1PP4/5K2 b - -
For square a7, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

a7: file=a; rank=7; fen_row_from_top=2; file_index=1


Prompt:
FEN: 3r2k1/1p1nqppp/1p3n2/4p3/1p2P3/2r3PP/1Q1NBP2/R1B2RK1 w - -
Compressed rank 1 row: R1B2RK1
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 4 row before: 1q6
File b changes from q to 1. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: 4Rbk1/5p1p/1p4p1/pP6/P2q4/6P1/5P1P/1bR2BK1
Apply square edits: e8 R->1; c8 1->R
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 2R2bk1/5p1p/1p4p1/pP6/P2q4/6P1/5P1P/1bR2BK1


Prompt:
Starting FEN: rnb1kbnr/p1p1pppp/8/1P1q4/2pP4/4P3/1P3PPP/RNBQKBNR b KQkq - 0 5
Move: d5g5
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: d5=black queen; g5=empty.
Squares: d5 black queen->empty; g5 empty->black queen.
Ranks: rank 5 d q->1; rank 5 g 1->q.


Prompt:
Starting FEN: rn1q1rk1/pb2bpp1/1p2pn1p/3P4/3P3B/2NB1N2/PPQ2PPP/R3K2R b KQ - 0 11
Move: d8d7
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: black
Castling rights: KQ
En passant: none
Halfmove clock: 0
Fullmove number: 11

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: black queen d8d7.
Lookup: d8=black queen; d7=empty.
Squares: d8 black queen->empty; d7 empty->black queen.
Ranks: rank 8 d q->1; rank 7 d 1->q.
Result FEN: rn3rk1/pb1qbpp1/1p2pn1p/3P4/3P3B/2NB1N2/PPQ2PPP/R3K2R w KQ - 1 12


Prompt:
Starting FEN: 1r2r2k/p1p1nRbp/B2q2p1/8/Q2PP3/2P5/PP1B2PP/5RK1 b - - 2 23
Move: d6d5
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 2
Fullmove number: 23

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 6 B2q2p1->B5p1; rank 5 8->3q4.
Result FEN: 1r2r2k/p1p1nRbp/B5p1/3q4/Q2PP3/2P5/PP1B2PP/5RK1 w - - 3 24


Prompt:
Starting FEN: rnbqk1nr/ppp3pp/3bp3/3pNp2/3P1B2/8/PPP1PPPP/RN1QKB1R w KQkq - 0 1
After the moves d1d2, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: KQkq
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: rnbqk1nr/ppp3pp/3bp3/3pNp2/3P1B2/8/PPPQPPPP/RN2KB1R b KQkq - 1 1


Prompt:
FEN: 8/8/5K2/4q3/4k3/8/8/8 w - - 7 67
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=f6; queen=none; rook=none; bishop=none; knight=none; pawn=none.
Black inventory: king=e4; queen=e5; rook=none; bishop=none; knight=none; pawn=none.


Prompt:
FEN: 6k1/7p/6pP/1p4K1/1P3P2/P1B5/2b5/8 w - -
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=0; rook=0; bishop=1; knight=0; pawn=4.
Black counts: king=1; queen=0; rook=0; bishop=1; knight=0; pawn=3.


Prompt:
FEN: 2kr1b1r/ppp3p1/2n1ppp1/3q4/3P1P2/2P1BN1P/PP4P1/R2Q1RK1 w - - 0 14
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=9; rook=10; bishop=3; knight=3; pawn=7; total=32.
Black values: king=0; queen=9; rook=10; bishop=3; knight=3; pawn=7; total=32.


Prompt:
FEN: 8/8/3R4/1K6/8/2k5/8/8 b - -
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=b5; queen=none; rook=d6; bishop=none; knight=none; pawn=none | black king=c3; queen=none; rook=none; bishop=none; knight=none; pawn=none
Counts: white king=1; queen=0; rook=1; bishop=0; knight=0; pawn=0 | black king=1; queen=0; rook=0; bishop=0; knight=0; pawn=0
Values: white total=5; black total=0
Balance: White is up 5 point(s) of material.


Prompt:
Starting FEN: 8/pp6/5p1p/8/5NP1/k7/P4b1P/1K6 w - - 0 1
After the moves f4d5 f2e1 d5f6, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".


Prompt:
Position (FEN): 8/p5p1/1pp2p1p/3k4/P2PN1P1/6PP/1P3K2/8 w - - 1 33
Show me the board.


Prompt:
Here is the current board:
8 R . . . . . . .
7 . . . . . . . .
6 . B . . k . p p
5 . . . . . p . .
4 . . p . . K . P
3 . . . . . . . .
2 . . . . . . . .
1 . . . . . . . .
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 1
Fullmove number: 53

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.


Prompt:
FEN: 8/2R5/6k1/4rp1p/8/7P/5PP1/5K2 b - - 1 46
What piece is on g6?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: 8/pp4k1/2p1b1p1/4p3/5r2/2P2B1R/PP3P2/2K5 w - - 3 31
What is the material count for both sides?

White (7 pieces): 1 bishop, 1 king, 4 pawns, 1 rook. Black (8 pieces): 1 bishop, 1 king, 5 pawns, 1 rook. Black is up 1 point(s) of material.


Prompt:
FEN: 4r3/kp3r2/p1pQNP2/P1RpB1P1/3P2P1/4KR1P/8/4q3 w - - 14 48
What is on f6?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: r3k1nr/pp1bn1bp/q2p1pp1/2pPp3/P1P1P3/1PN2N1P/3B1PP1/1R1QKB1R b Kkq - 0 17
What is the compressed FEN row for rank 7?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: 1r1r2k1/4bppp/8/pP2P3/3p1P2/7P/2P3P1/R1K4R b - - 0 25
For square c2, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

c2: file=c; rank=2; fen_row_from_top=7; file_index=3


Prompt:
FEN: r1bq1rk1/2p1npp1/pbnp3p/1p5Q/3PP3/1B3N2/PP3PPP/RNB2RK1 b - - 1 12
Compressed rank 7 row: 2p1npp1
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 4 row before: 2P3Q1
File f changes from 1 to q. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: 8/1kp4p/1p4p1/p3Pp2/2r1bB2/PK6/2P4P/4R3
Apply square edits: c4 r->1; c6 1->r
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 8/1kp4p/1pr3p1/p3Pp2/4bB2/PK6/2P4P/4R3


Prompt:
Starting FEN: 2k2b2/p5p1/1pp1q1pp/3PPn2/N2P4/1P1QB2P/P5P1/6K1 b - - 0 26
Move: c6c5
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: c6=black pawn; c5=empty.
Squares: c6 black pawn->empty; c5 empty->black pawn.
Ranks: rank 6 c p->1; rank 5 c 1->p.


Prompt:
Starting FEN: 4k2r/4bppp/8/3p4/1B6/3n1N2/5PPP/1R4K1 w k - 0 26
Move: h2h3
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: white
Castling rights: k
En passant: none
Halfmove clock: 0
Fullmove number: 26

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: white pawn h2h3.
Lookup: h2=white pawn; h3=empty.
Squares: h2 white pawn->empty; h3 empty->white pawn.
Ranks: rank 2 h P->1; rank 3 h 1->P.
Result FEN: 4k2r/4bppp/8/3p4/1B6/3n1N1P/5PP1/1R4K1 b k - 0 26


Prompt:
Starting FEN: r4rk1/4q2p/pn1p2p1/2pPp3/Pp2P3/1B2Q1Nn/1PP2PK1/2R2R2 b - - 1 22
Move: f8e8
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 1
Fullmove number: 22

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 8 r4rk1->r3r1k1.
Result FEN: r3r1k1/4q2p/pn1p2p1/2pPp3/Pp2P3/1B2Q1Nn/1PP2PK1/2R2R2 w - - 2 23


Prompt:
Starting FEN: rnbq1rk1/ppp2pbp/5np1/4p1B1/4P3/2P5/PP1N1PPP/R2QKBNR w KQ - 0 1
After the moves g5f4, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: KQ
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: rnbq1rk1/ppp2pbp/5np1/4p3/4PB2/2P5/PP1N1PPP/R2QKBNR b KQ - 1 1


Prompt:
FEN: r1b3k1/pp5p/3ppqp1/4n3/2P1P3/8/P3B1PP/1R1Q2K1 w - - 0 20
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=g1; queen=d1; rook=b1; bishop=e2; knight=none; pawn=a2,g2,h2,c4,e4.
Black inventory: king=g8; queen=f6; rook=a8; bishop=c8; knight=e5; pawn=d6,e6,g6,a7,b7,h7.


Prompt:
FEN: rnbqkbnr/pp1ppppp/8/2p1P3/8/8/PPPP1PPP/RNBQKBNR w KQkq - 0 3
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=1; rook=2; bishop=2; knight=2; pawn=8.
Black counts: king=1; queen=1; rook=2; bishop=2; knight=2; pawn=8.


Prompt:
FEN: r2qk2r/ppp2ppp/2n1pn2/8/1bBP4/2N1BP2/PP3PPP/R2Q1RK1 w kq - 4 9
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=9; rook=10; bishop=6; knight=3; pawn=7; total=35.
Black values: king=0; queen=9; rook=10; bishop=3; knight=6; pawn=7; total=35.


Prompt:
FEN: r1b1kbnr/ppp1pppp/2n5/q2P4/8/2N5/PP2PPPP/R1BQKBNR b KQkq - 0 5
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=e1; queen=d1; rook=a1,h1; bishop=c1,f1; knight=g1,c3; pawn=a2,b2,e2,f2,g2,h2,d5 | black king=e8; queen=a5; rook=a8,h8; bishop=c8,f8; knight=c6,g8; pawn=a7,b7,c7,e7,f7,g7,h7
Counts: white king=1; queen=1; rook=2; bishop=2; knight=2; pawn=7 | black king=1; queen=1; rook=2; bishop=2; knight=2; pawn=7
Values: white total=38; black total=38
Balance: Material is equal.


Prompt:
Starting FEN: r1b1r2k/pp1nnQp1/4p3/3pP1N1/1b1q1P2/2N2R2/PP4PP/R1B3K1 w - - 0 1
After the moves f3e3 e7c6 g5f3, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: r1b1r2k/pp1n1Qp1/2n1p3/3pP3/1b1q1P2/2N1RN2/PP4PP/R1B3K1 b - - 3 2


Prompt:
Position (FEN): r1b1k2r/pp2bppp/1q3n2/2pp2B1/8/2PBPN2/PPQ2PPP/R3K2R b KQkq -
Show me the board.


Prompt:
Here is the current board:
8 . . r . k b n r
7 p . . n p p . .
6 . p . . . . . p
5 . . . . . . . .
4 . . . P . B . .
3 . . K . . N P .
2 P P . . . P . P
1 . R . . . B . R
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: k
En passant: none
Halfmove clock: 1
Fullmove number: 17

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.


Prompt:
FEN: 2kr1b1r/pppbqppp/2n2n2/8/3p4/3P1NP1/PP2PPBP/RNBQ1RK1 w - - 5 10
What piece is on a2?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: 6k1/5p1p/6p1/4N3/8/8/3K1PPP/8 b - - 1 36
What is the material count for both sides?

White (5 pieces): 1 king, 1 knight, 3 pawns. Black (4 pieces): 1 king, 3 pawns. White is up 3 point(s) of material.


Prompt:
FEN: r3k2r/1p2bppp/p7/2p1N3/P3P3/5K2/1P3PPP/2RR4 b kq - 2 20
What is on f7?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: 3r1r1k/p2q3p/1pp2b2/5p2/1PPP1p2/PNN2Q2/B4P2/5KR1 w - - 4 33
What is the compressed FEN row for rank 3?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: 3r1r2/pQ2kpp1/2B4p/q1b1p3/4p1PP/4B3/PPP2P2/2K3R1 b - -
For square g4, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

g4: file=g; rank=4; fen_row_from_top=5; file_index=7


Prompt:
FEN: r2q1rk1/pp2p1b1/3p2pp/5b1n/3B4/2P5/PP2BPPP/RN1QR1K1 b - - 0 14
Compressed rank 8 row: r2q1rk1
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 8 row before: r5rk
File a changes from r to 1. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: 8/8/7p/1p4p1/1P3p2/P1k1N2P/1b4P1/5K2
Apply square edits: f1 K->1; e2 1->K
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 8/8/7p/1p4p1/1P3p2/P1k1N2P/1b2K1P1/8


Prompt:
Starting FEN: r1bq1rk1/p4p2/1p3R1p/6p1/4P3/1P1P4/PB2B1PP/R4QK1 w - - 0 19
Move: d3d4
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: d3=white pawn; d4=empty.
Squares: d3 white pawn->empty; d4 empty->white pawn.
Ranks: rank 3 d P->1; rank 4 d 1->P.


Prompt:
Starting FEN: r2q4/pp1kb2Q/2n1p1r1/3pPpN1/8/2P5/PP3PPP/R1B1R1K1 b - - 0 1
Move: d8e8
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: black queen d8e8.
Lookup: d8=black queen; e8=empty.
Squares: d8 black queen->empty; e8 empty->black queen.
Ranks: rank 8 d q->1; rank 8 e 1->q.
Result FEN: r3q3/pp1kb2Q/2n1p1r1/3pPpN1/8/2P5/PP3PPP/R1B1R1K1 w - - 1 2


Prompt:
Starting FEN: 4rrk1/pp3ppp/8/2p5/2PpP3/1P1B2Qq/P4P2/4RRK1 b - - 1 23
Move: e8b8
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 1
Fullmove number: 23

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 8 4rrk1->1r3rk1.
Result FEN: 1r3rk1/pp3ppp/8/2p5/2PpP3/1P1B2Qq/P4P2/4RRK1 w - - 2 24


Prompt:
Starting FEN: rn1qk2r/pbpp1ppp/1p2p3/3PP3/1bP1n3/2N5/PP3PPP/R1BQKBNR w KQkq - 0 1
After the moves e1e2, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: KQkq
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: rn1qk2r/pbpp1ppp/1p2p3/3PP3/1bP1n3/2N5/PP2KPPP/R1BQ1BNR b kq - 1 1


Prompt:
FEN: r1bq1rk1/1p3ppp/p1n2n2/2b2P2/4p3/3BPQ2/PPPB2PP/2KR2NR w - - 0 12
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=c1; queen=f3; rook=d1,h1; bishop=d2,d3; knight=g1; pawn=a2,b2,c2,g2,h2,e3,f5.
Black inventory: king=g8; queen=d8; rook=a8,f8; bishop=c5,c8; knight=c6,f6; pawn=e4,a6,b7,f7,g7,h7.


Prompt:
FEN: r1bqk2r/pppp1ppp/3b1n2/4P3/4P3/P1N5/1PP2PPP/R1BQKB1R b KQkq -
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=1; rook=2; bishop=2; knight=1; pawn=8.
Black counts: king=1; queen=1; rook=2; bishop=2; knight=1; pawn=7.


Prompt:
FEN: r1b5/1p3k2/p4pp1/2Pp3p/7P/1P5N/2n2PP1/RN4K1 w - -
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=0; rook=5; bishop=0; knight=6; pawn=5; total=16.
Black values: king=0; queen=0; rook=5; bishop=3; knight=3; pawn=6; total=17.


Prompt:
FEN: rnb1k2r/pp3ppp/3p4/q3p3/2B5/2n1PN2/PPP3PP/R2Q1RK1 w kq - 0 10
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=g1; queen=d1; rook=a1,f1; bishop=c4; knight=f3; pawn=a2,b2,c2,g2,h2,e3 | black king=e8; queen=a5; rook=a8,h8; bishop=c8; knight=c3,b8; pawn=e5,d6,a7,b7,f7,g7,h7
Counts: white king=1; queen=1; rook=2; bishop=1; knight=1; pawn=6 | black king=1; queen=1; rook=2; bishop=1; knight=2; pawn=7
Values: white total=31; black total=35
Balance: Black is up 4 point(s) of material.


Prompt:
Starting FEN: 1k4rr/1bq2pp1/pp6/2bPpP1n/2p1P1Qp/2P5/PBB2NPP/4RRK1 w - - 0 1
After the moves g4d1 c5b4, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: 1k4rr/1bq2pp1/pp6/3PpP1n/1bp1P2p/2P5/PBB2NPP/3QRRK1 w - - 2 2


Prompt:
Position (FEN): 2r5/4P3/8/3P1p2/5Pp1/P2KP3/6k1/7R b - - 0 60
Show me the board.


r1bqk1nr/pp1ppp1p/2N3p1/8/4P3/8/PPPb1PPP/R2QKB1R w KQkq - 0 8

Prompt:
Here is the current board:
8 r . b q k . n r
7 p p . p p p . p
6 . . N . . . p .
5 . . . . . . . .
4 . . . . P . . .
3 . . . . . . . .
2 P P P b . P P P
1 R . . Q K B . R
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: KQkq
En passant: none
Halfmove clock: 0
Fullmove number: 8

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.


Prompt:
FEN: 2b1r3/3knQ2/p1p1B3/2P3B1/4P2P/3P1Pq1/6P1/5RK1 b - - 0 30
What piece is on f7?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: rn2kb1r/ppp2p1p/3p1np1/4p3/2B1P3/2NP3P/PPP2PP1/R1B1K2R b KQkq - 0 8
What is the material count for both sides?

White (14 pieces): 2 bishops, 1 king, 1 knight, 8 pawns, 2 rooks. Black (14 pieces): 1 bishop, 1 king, 2 knights, 8 pawns, 2 rooks. Material is equal.


Prompt:
FEN: rn4k1/p4p1p/1pp3p1/6N1/3P2b1/1BPq4/P5PP/1R3K1R w - - 2 21
What is on b6?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: 8/p7/P7/5k2/5p1p/7P/5K2/8 w - - 3 47
What is the compressed FEN row for rank 1?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: 8/8/7p/6q1/8/3K4/7k/8 b - - 3 68
For square h2, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

h2: file=h; rank=2; fen_row_from_top=7; file_index=8


Prompt:
FEN: r1bqk2r/pp3pp1/2nb1n2/2p3p1/2Pp4/1P1P3P/PB2BP2/RN1QK1NR w KQkq - 0 11
Compressed rank 7 row: pp3pp1
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 5 row before: 2p1pP2
File a changes from 1 to B. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


2rqkb1r/3b1ppp/p1n1p3/1p1pPn2/3P4/P1N1BN2/1PB2PPP/R2Q1RK1 b k - 3 14

Prompt:
Board FEN before: 2rqkb1r/3b1ppp/p1n1p3/1p1pPn2/3P4/P1N1BN2/1PB2PPP/R2Q1RK1
Apply square edits: c6 n->1; e7 1->n
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 2rqkb1r/3bnppp/p3p3/1p1pPn2/3P4/P1N1BN2/1PB2PPP/R2Q1RK1


Prompt:
Starting FEN: 2b5/1p6/p4k2/2PB2pp/1P1K4/8/6PP/8 w - -
Move: d4d3
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: d4=white king; d3=empty.
Squares: d4 white king->empty; d3 empty->white king.
Ranks: rank 4 d K->1; rank 3 d 1->K.


Prompt:
Starting FEN: 4k3/1N6/3K2p1/6N1/8/8/8/8 w - - 0 1
Move: g5e6
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: white knight g5e6.
Lookup: g5=white knight; e6=empty.
Squares: g5 white knight->empty; e6 empty->white knight.
Ranks: rank 5 g N->1; rank 6 e 1->N.
Result FEN: 4k3/1N6/3KN1p1/8/8/8/8/8 b - - 1 1


Prompt:
Starting FEN: 3rk2r/Qb1n1pp1/1p1p1q1p/1BbPp3/4P3/5N2/PP3PPP/RN3RK1 b k - 0 13
Move: c5e3
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: black
Castling rights: k
En passant: none
Halfmove clock: 0
Fullmove number: 13

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 5 1BbPp3->1B1Pp3; rank 3 5N2->4bN2.
Result FEN: 3rk2r/Qb1n1pp1/1p1p1q1p/1B1Pp3/4P3/4bN2/PP3PPP/RN3RK1 w k - 1 14


Prompt:
Starting FEN: rnb2rk1/pp1pppbp/3n2p1/1q6/3P1B2/P4N2/4BPPP/2RQ1K1R w - - 0 1
After the moves f3h4, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: rnb2rk1/pp1pppbp/3n2p1/1q6/3P1B1N/P7/4BPPP/2RQ1K1R b - - 1 1


Prompt:
FEN: r1b2rk1/pppp1ppp/1bn3n1/4P1Pq/4Q2P/2N1PN2/PPPB1P2/R3KB1R w KQ -
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=e1; queen=e4; rook=a1,h1; bishop=f1,d2; knight=c3,f3; pawn=a2,b2,c2,f2,e3,h4,e5,g5.
Black inventory: king=g8; queen=h5; rook=a8,f8; bishop=b6,c8; knight=c6,g6; pawn=a7,b7,c7,d7,f7,g7,h7.


Prompt:
FEN: r1bqkb1r/4p2p/p1p2p2/3p1np1/3P4/4PNB1/PP3PPP/RN1Q1RK1 w kq -
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=1; rook=2; bishop=1; knight=2; pawn=7.
Black counts: king=1; queen=1; rook=2; bishop=2; knight=1; pawn=7.


Prompt:
FEN: 1k6/4Q3/8/2N5/3K4/8/8/8 w - -
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=9; rook=0; bishop=0; knight=3; pawn=0; total=12.
Black values: king=0; queen=0; rook=0; bishop=0; knight=0; pawn=0; total=0.


Prompt:
FEN: 3q1r1k/r1n1bppp/4p3/pb1pP3/1p1P2Q1/1P1BB1P1/P1R2P1P/1NR3K1 w - -
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=g1; queen=g4; rook=c1,c2; bishop=d3,e3; knight=b1; pawn=a2,f2,h2,b3,g3,d4,e5 | black king=h8; queen=d8; rook=a7,f8; bishop=b5,e7; knight=c7; pawn=b4,a5,d5,e6,f7,g7,h7
Counts: white king=1; queen=1; rook=2; bishop=2; knight=1; pawn=7 | black king=1; queen=1; rook=2; bishop=2; knight=1; pawn=7
Values: white total=35; black total=35
Balance: Material is equal.


Prompt:
Starting FEN: r3kb1r/pppn1ppp/8/1q2p1P1/4p3/P3P2P/3B1P2/Q3K2R w kq - 1 16
After the moves a1d4 d7b6, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: kq
En passant: none
Halfmove clock: 1
Fullmove number: 16

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: r3kb1r/ppp2ppp/1n6/1q2p1P1/3Qp3/P3P2P/3B1P2/4K2R w kq - 3 17


Prompt:
Position (FEN): rnb1r1k1/ppb2pp1/2pq1n2/3p4/1P1P2Pp/P1N1PP2/4N1BP/R1BQ1RK1 w - -
Show me the board.


r2q1rk1/pp2bppp/2n5/2pp3n/8/3PPbPP/PPP1B1K1/R1BNQ2R w - - 0 15

Prompt:
Here is the current board:
8 r . . q . r k .
7 p p . . b p p p
6 . . n . . . . .
5 . . p p . . . n
4 . . . . . . . .
3 . . . P P b P P
2 P P P . B . K .
1 R . B N Q . . R
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 15

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.


Prompt:
FEN: r3r3/pb3kpp/1ppBp3/8/2B4P/2P5/P1P2PP1/2KRR3 w - - 6 19
What piece is on d1?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: 8/p1k5/8/4K3/6P1/1b6/3p4/7R b - -
What is the material count for both sides?

White (3 pieces): 1 king, 1 pawn, 1 rook. Black (4 pieces): 1 bishop, 1 king, 2 pawns. White is up 1 point(s) of material.


Prompt:
FEN: 1r3rk1/p1q1ppbp/B5p1/5b2/8/Q1P1BP2/PP4PP/2KR3R w - -
What is on b7?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: 8/5k2/1p1r1bp1/p1pp3p/7P/2P3P1/PP3P2/3BR1K1 w - - 0 35
What is the compressed FEN row for rank 1?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: rn2kbnr/pp2p1p1/2pqp3/3p3p/3P2PP/3Q1P2/PPP5/RNB1K1NR w KQkq -
For square e2, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

e2: file=e; rank=2; fen_row_from_top=7; file_index=5


Prompt:
FEN: 6k1/8/8/3p3p/1P3Q1P/2P5/6K1/8 w - -
Compressed rank 1 row: 8
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


r2qk2r/ppp1nppp/4pn2/3p1b2/2PP4/2N1PN2/PP3PPP/R2QKB1R w KQkq -

Prompt:
Rank 2 row before: PP3PPP
File g changes from P to 1. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: 3r2k1/6Pp/p1b1p3/1p2n3/4P3/2P3P1/P4P2/4R1K1
Apply square edits: g1 K->1; g2 1->K
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 3r2k1/6Pp/p1b1p3/1p2n3/4P3/2P3P1/P4PK1/4R3


Prompt:
Starting FEN: r3k3/ppq4p/n2p1n2/2p5/2P3b1/P4NP1/1P2PPBP/R2QK2R w KQq - 2 14
Move: b2b4
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: b2=white pawn; b4=empty.
Squares: b2 white pawn->empty; b4 empty->white pawn.
Ranks: rank 2 b P->1; rank 4 b 1->P.


Prompt:
Starting FEN: 2rqnrk1/pp3ppp/1b1p4/3p4/4PQ2/3B1P2/Pn2NP1P/R5RK w - - 0 1
Move: f4f5
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: white queen f4f5.
Lookup: f4=white queen; f5=empty.
Squares: f4 white queen->empty; f5 empty->white queen.
Ranks: rank 4 f Q->1; rank 5 f 1->Q.
Result FEN: 2rqnrk1/pp3ppp/1b1p4/3p1Q2/4P3/3B1P2/Pn2NP1P/R5RK b - - 1 1


Prompt:
Starting FEN: 4k2r/1b4pp/2n1pp2/1p6/3P4/1P1pPN2/3B1PPP/3K3R b k - 0 1
Move: e8e7
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: black
Castling rights: k
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 8 4k2r->7r; rank 7 1b4pp->1b2k1pp.
Result FEN: 7r/1b2k1pp/2n1pp2/1p6/3P4/1P1pPN2/3B1PPP/3K3R w - - 1 2


Prompt:
Starting FEN: rnbqkb1r/ppp2ppp/3n4/8/2BQ4/5N2/PPP2PPP/RNB1K2R b KQkq - 0 1
After the moves d8e7, what is the resulting position?
State needed for full FEN:
Side to move: black
Castling rights: KQkq
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: rnb1kb1r/ppp1qppp/3n4/8/2BQ4/5N2/PPP2PPP/RNB1K2R w KQkq - 1 2


Prompt:
FEN: 8/2R4p/1R3Bk1/4p3/8/4PP2/4b1PP/7K w - - 3 39
List the material inventory by side and piece type.

Answer format: return exactly two lines starting "White inventory:" and "Black inventory:".

White inventory: king=h1; queen=none; rook=b6,c7; bishop=f6; knight=none; pawn=g2,h2,e3,f3.
Black inventory: king=g6; queen=none; rook=none; bishop=e2; knight=none; pawn=e5,h7.


Prompt:
FEN: r4rk1/ppp3pp/1q3n2/4pN2/3pPn2/1P1P1R1P/P1PNQ1B1/5RK1 w - - 1 22
Count each piece type for both sides.

Answer format: return exactly two lines starting "White counts:" and "Black counts:".

White counts: king=1; queen=1; rook=2; bishop=1; knight=2; pawn=6.
Black counts: king=1; queen=1; rook=2; bishop=0; knight=2; pawn=7.


Prompt:
FEN: r1bq1rk1/pp2n1bp/2n1ppp1/2Pp4/1P6/P3PNP1/1B1N1PBP/R2QK2R b KQ - 0 12
Convert the piece counts into material value totals.

Answer format: return exactly two lines starting "White values:" and "Black values:".

White values: king=0; queen=9; rook=10; bishop=6; knight=6; pawn=7; total=38.
Black values: king=0; queen=9; rook=10; bishop=6; knight=6; pawn=7; total=38.


Prompt:
FEN: 8/8/8/8/3k4/1K6/8/1R6 w - -
Trace inventory, counts, values, and material balance.

Answer format: return exactly four lines starting "Inventory:", "Counts:", "Values:", and "Balance:".

Inventory: white king=b3; queen=none; rook=b1; bishop=none; knight=none; pawn=none | black king=d4; queen=none; rook=none; bishop=none; knight=none; pawn=none
Counts: white king=1; queen=0; rook=1; bishop=0; knight=0; pawn=0 | black king=1; queen=0; rook=0; bishop=0; knight=0; pawn=0
Values: white total=5; black total=0
Balance: White is up 5 point(s) of material.


Prompt:
Starting FEN: r3kbnr/pbppqppp/1pn1p3/8/3PP3/2NB1N2/PPP2PPP/R1BQK2R w KQkq - 4 6
After the moves c1e3 e7f6, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: KQkq
En passant: none
Halfmove clock: 4
Fullmove number: 6

Answer format: return exactly "Result FEN: <complete six-field FEN>".

Result FEN: r3kbnr/pbpp1ppp/1pn1pq2/8/3PP3/2NBBN2/PPP2PPP/R2QK2R w KQkq - 6 7


Prompt:
Position (FEN): r1bqr1k1/pp1n1ppp/5p2/2bQ4/2P5/5N2/PP2BPPP/R1B2RK1 w - -
Show me the board.


rnb2bnr/pppp2pp/5k2/4N3/8/8/PPqPQPPP/RNB1K2R w KQ - 1 7

Prompt:
Here is the current board:
8 r n b . . b n r
7 p p p p . . p p
6 . . . . . k . .
5 . . . . N . . .
4 . . . . . . . .
3 . . . . . . . .
2 P P q P Q P P P
1 R N B . K . . R
  a b c d e f g h
Write the FEN for this position.
State needed for full FEN:
Side to move: white
Castling rights: KQ
En passant: none
Halfmove clock: 1
Fullmove number: 7

Answer format: return exactly one complete six-field FEN, with no prefix and no explanation.


Prompt:
FEN: 3Rbk2/r1q2ppp/4p3/p7/2p4Q/2P2B1P/5PP1/6K1 w - - 2 31
What piece is on h4?

Answer format: for a square query, return only the piece name or empty; do not include the square. For a locate query, return only space-separated squares.


Prompt:
FEN: 2kbb1r1/1pp3B1/p6p/3r1p2/1P6/2P2N1P/P4PP1/R3R1K1 b - -
What is the material count for both sides?

White (11 pieces): 1 bishop, 1 king, 1 knight, 6 pawns, 2 rooks. Black (10 pieces): 2 bishops, 1 king, 5 pawns, 2 rooks. White is up 1 point(s) of material.


Prompt:
FEN: 6k1/5pp1/4n2p/1p6/5P2/1r1N1KPP/8/8 w - - 2 42
What is on c1?

Answer format: return exactly "<square>=<piece>" or "<square>=empty".


Prompt:
FEN: r2qkb1r/1p3ppp/p1n1p3/3n4/3P4/2N2b1P/PP3PP1/R1BQRBK1 w kq -
What is the compressed FEN row for rank 2?

Answer format: return exactly "rank N: <compressed FEN row>".


Prompt:
FEN: r1bqkb1r/p4ppp/1nn1p3/2ppP3/1pPP4/6P1/PP1NNPBP/R1BQ1RK1 b kq -
For square c6, give the FEN row-from-top and file index.

Answer format: return exactly "<square>: file=<file>; rank=<rank>; fen_row_from_top=<1-8>; file_index=<1-8>".

c6: file=c; rank=6; fen_row_from_top=3; file_index=3


Prompt:
FEN: 5rk1/R5b1/2Bp1Bpp/5q2/2p1N1b1/2P5/3Q2P1/6K1 b - -
Compressed rank 5 row: 5q2
Expand it into file cells a through h.

Answer format: return exactly "rank N: a=<cell>; b=<cell>; ...; h=<cell>".


Prompt:
Rank 4 row before: 4Pb1B
File b changes from 1 to q. Rewrite the compressed row.

Answer format: return exactly "rank N: <before-row> -> <after-row>".


Prompt:
Board FEN before: 8/Nk6/1p6/5R2/5Rp1/P7/1P3PP1/6K1
Apply square edits: f5 R->1; g5 1->R
Return the resulting board FEN only.

Answer format: return exactly "Result board FEN: <piece-placement-field>".

Result board FEN: 8/Nk6/1p6/6R1/5Rp1/P7/1P3PP1/6K1


Prompt:
Starting FEN: 1k1r3r/pbq4p/4B1p1/2p1np2/4p3/1QB1P2P/PP4P1/R4RK1 b - -
Move: c7g7
List the square lookups and rank edits.

Answer format: return exactly three lines starting "Lookup:", "Squares:", and "Ranks:"; do not include Result FEN.

Lookup: c7=black queen; g7=empty.
Squares: c7 black queen->empty; g7 empty->black queen.
Ranks: rank 7 c q->1; rank 7 g 1->q.


Prompt:
Starting FEN: 8/8/8/8/8/2k2N2/8/3BK3 b - - 0 1
Move: c3b2
Use square lookups and rank edits to assemble the resulting full FEN.
State needed for full FEN:
Side to move: black
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: include the edit trace and exactly one final line "Result FEN: <complete six-field FEN>".

Move 1: black king c3b2.
Lookup: c3=black king; b2=empty.
Squares: c3 black king->empty; b2 empty->black king.
Ranks: rank 3 c k->1; rank 2 b 1->k.
Result FEN: 8/8/8/8/8/5N2/1k6/3BK3 w - - 1 2


Prompt:
Starting FEN: 1r4k1/p4p1p/3p2P1/2nPP2P/2q5/8/K1PR1Q2/6R1 w - - 0 1
Move: a2a3
Rewrite the affected compressed FEN rank rows and give Result FEN.
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 1

Answer format: first line starts "Rows:" and final line is "Result FEN: <complete six-field FEN>".

Rows: rank 2 K1PR1Q2->2PR1Q2; rank 3 8->K7.
Result FEN: 1r4k1/p4p1p/3p2P1/2nPP2P/2q5/K7/2PR1Q2/6R1 b - - 1 1


Prompt:
Starting FEN: 3rk3/p7/1p1P1p2/2b1P3/2R5/2P4P/P6K/3R4 w - - 0 36
After the moves d1d2, what is the resulting position?
State needed for full FEN:
Side to move: white
Castling rights: none
En passant: none
Halfmove clock: 0
Fullmove number: 36

Answer format: return exactly "Result FEN: <complete six-field FEN>".