metadata

license: cc0-1.0
tags:
  - chess
  - lichess
  - stockfish

Dataset Card for the Stockfish Evaluations

A dataset of chess positions evaluated with various flavours of Stockfish running within user browsers. Produced by, and for, the Lichess analysis board. Evaluations are formatted as JSON; one position per line.

The schema of a position looks like this:

{
  "fen": "8/8/2B2k2/p4p2/5P1p/Pb6/1P3KP1/8 w - -",
  "depth": 42,
  "evaluation": 5.64,
  "best_move": "Kg1",
  "best_line": "Kg1 Ke6 Kh2 Kd6 Be8 Kc5 Kh3 Kd6 Bb5 Ke7"
}

fen: string, the position FEN only contains pieces, active color, castling rights, and en passant square.
depth: int, the depth reached by the engine.
evaluation: string, the evaluation for the given FEN/board state.
best_move: string, the first move of the best_line, in SAN format.
best_line: string, the first principal variation for the given highest available depth, in SAN format.