shakmaty-syzygy 0.6.0

Probe Syzygy tablebases


A Rust library to probe Syzygy endgame tablebases, based on shakmaty.

Build Status

Syzygy tables allow optimal play under the 50-move rule. Tables are available for positions with up to 6 (and experimentally 7) pieces.


use shakmaty::Chess;
use shakmaty::fen::Fen;
use shakmaty_syzygy::{Tablebase, Wdl, Dtz, Syzygy};

let mut tables = Tablebase::new();

let pos: Chess = "8/8/8/8/B7/N7/K2k4/8 b - - 0 1"

let wdl = tables.probe_wdl(&pos)?;
assert_eq!(wdl, Wdl::Loss);

let dtz = tables.probe_dtz(&pos)?;
assert_eq!(dtz, Dtz(-59));


Read the documentation


  • 0.6.0
    • Update shakmaty to 0.9.0. Minimum Rust version is now 1.27.0.
  • 0.5.2
    • Fix Wdl::from_dtz_after_zeroing(Dtz(100)).
  • 0.5.1
    • Fix out of bounds panic when probing KPPPPPvK.
    • Fix error when first group in giveaway should have had more than two identical pieces.
    • Only 6 pieces supported in antichess variants. Return SyzygyError::TooManyPieces instead of potential panic.
  • 0.5.0
    • More contextual information for errors (table, backtrace, invalid magic header bytes).
    • Update to shakmaty 0.8.
    • Provide a target for cargo fuzz. Fix several panics caused by initializing and probing corrupted tables:
      • Panic when reference pawn is missing.
      • Panic when subtable material is not consistent with first file.
      • Integer overflow when reading symlen.
      • Integer overflow when min_symlen or max_symlen are out of bounds.
      • Integer overflow when computing block_length_size.
      • Stack overflow when recursively reading symlen.
  • 0.4.5
    • Make better use of positioned-io (cursor, remove RandomAccessFile).
  • 0.4.4
    • Remove work around from 0.3.1.
    • Minor internal optimizations and cleanups.
  • 0.4.3
    • Fix DTZ off-by-one in some positions when there is mate in 1.
    • Fix DTZ off-by-one in antichess endgames, when there is a threat to force a capture leading to a blessed loss.
    • Add Tablebase::best_move().
  • 0.4.2
    • Fix DTZ in en passant positions.
    • Minimum Rust version 1.26.0.
    • Use guaranteed lossless versions from u16 to usize.
    • Provide i128 conversions for Wdl and Dtz.
  • 0.4.1
    • Fix debug assertion for Dtz(0).add_plies().
  • 0.4.0
    • Update to shakmaty 0.7, which has bugfixes with regard to insufficient material.
  • 0.3.1
    • Work around compiler bug in release mode.
  • 0.3.0
    • Rename Tablebases to Tablebase.
    • Group file extension and magic as TableType in Syzygy trait.
  • 0.2.2
    • Implement support for wide DTZ values. These are required for some long 7 piece endgames.
    • Fix panic on corrupted table.
  • 0.2.1
    • Should not panic on corrupted tables (even in debug mode).
    • Switch from fnv to fxhash.
  • 0.2.0
    • Replace Wdl::from(dtz) with Wdl::from_dtz_after_zeroing(dtz).
    • Remove isize conversions of Dtz and Wdl.
    • Fix WDL of lone king in atomic chess.
    • Support stable rust.
  • 0.1.4
    • Fix ordering of lead pawns.
  • 0.1.3
    • Add support for Atomic chess and Giveaway.
  • 0.1.2
    • Cosmetic tweak to DTZ in case of mate in 1.
  • 0.1.1
    • Optional serde-1 feature.
    • Add Dtz.add_plies().
  • 0.1.0
    • First release.


Thanks to Ronald de Man for his Syzygy tablebases. The probing code is closely based on his implementation for Stockfish.


shakmaty-syzygy is licensed under the GPL-3.0 (or any later version at your option). See the COPYING file for the full license text.