chorcat/rukh-positions-eval

Distinct positions sampled from rukh-games-1800, keyed by the four-field FEN and joined with Lichess/chess-position-evaluations. One row per position with the best line and every analysed line, for value heads, reward models and preference pairs without running an engine.

Part of Rukh, a chess language model built from scratch as a course on generative and agentic AI. Every derived dataset ships with the exact filters and counts of its manifest.json, so it can be regenerated with rukh data positions and rukh data evals.

Files

File	Bytes	SHA-256
positions-eval.parquet	22138204	8aecea4739b706bb3a9596b3b6d2e57637c6f6aced0e18184818f861a537d9eb

Rows: 488159.

Columns

Column	Description
fen	pieces, side to move, castling rights and en-passant square
game_id	game of the first occurrence
ply	half-move index of the first occurrence
last_move	UCI move that reached the position
result	result of that game
phase	opening (ply <= 10), middlegame (14+ pieces) or endgame
n_seen	occurrences in the sampled games
best_move	first move of the best line for the side to move
cp	centipawns of the best line, from White's point of view
mate	moves to mate of the best line (positive: White mates)
depth	search depth of the best line
knodes	kilonodes searched
pvs	every line as {move, cp, mate, depth}, best first

Provenance and filters

Source: Lichess/standard-chess-games (positions) and Lichess/chess-position-evaluations (evaluations).

{
  "positions": "data/positions/positions.parquet",
  "files_present": [
    0,
    1,
    2,
    3,
    4,
    5,
    6,
    7,
    8,
    9,
    10,
    11,
    12,
    13,
    14,
    15,
    16,
    17,
    18,
    19
  ],
  "files_fetched_now": [
    2,
    3,
    4,
    5,
    6,
    7,
    8,
    9,
    10,
    11,
    12,
    13,
    14,
    15,
    16,
    17,
    18,
    19
  ],
  "n_files": 20,
  "coverage": 0.0976,
  "best_line": "deepest; mate for the mover first; then best cp for the side to move",
  "mate_score": 10000
}

Counts:

{
  "positions": 5000000,
  "evaluated": 488159,
  "lines": 3424866
}

Generated on 2026-09-19 with rukh 0.0.1.

In the course

• Built in M1 · Del PGN al tensor: los labs, the lesson that runs every command behind this repository.
• Measured in the single results table: every stage of the course, the same suite, the same day.
• Bring it to the paths the configs read: uv run rukh pull rukh-positions-eval.

License

CC0 1.0. The games, puzzles and evaluations come from the Lichess open database (https://database.lichess.org, https://huggingface.co/Lichess), published under CC0; the derived files keep that license. Please credit Lichess when you use them.