{
  "architecture": "ChessTransformer200M",
  "params": "~204M",
  "vocab_version": "compact",
  "config": {
    "encoder_dim": 256,
    "encoder_type": "fused",
    "encoder_conv_blocks": 2,
    "normalize_stm": false,
    "hidden_dim": 1024,
    "num_layers": 16,
    "num_heads": 16,
    "ffn_ratio": 4,
    "dropout": 0.1,
    "policy_head_dim": 512,
    "value_hidden": 512,
    "use_pos_embed": true,
    "n_ctx_tokens": 4,
    "value_head_type": "cls",
    "n_value_classes": 3,
    "use_swiglu": false,
    "use_rel_bias": false,
    "gradient_checkpointing": false,
    "full_dim_attention": false
  },
  "training": {
    "experiment": "exp189_200m_maxelo_policy",
    "base_model": "avewright/chess-transformer-200m-compact-soft",
    "soft_data": "avewright/exp186-sf-multipv-2m + avewright/exp190-phase-deep-soft",
    "latest_step": 2851,
    "best_metric_blended_top1": 0.3965625,
    "inference": "policy argmax (no MCTS)"
  },
  "elo_eval": {
    "estimated_elo": 1700,
    "bracket": [
      1500,
      1800
    ],
    "protocol": "elo_eval_latest.py vs SF18 UCI_LimitStrength, openings x colors, syzygy+book"
  }
}