Fairy-Stockfish 14.0.1 XQ

This release is specifically for providing built-in NNUE networks for Xiangqi and Janggi, so that the NNUE evaluation can be used without the need for any additional downloads or configuration. This release of course still supports all other variants, but for those you can also use the smaller standard releases without built-in NNUE.

With NNUE evaluation, playing strength for Xiangqi and Janggi is far surpassing classical Fairy-Stockfish, and reaching super-human level. See the test results below for comparison against Fairy-Stockfish without NNUE.

Xiangqi

STC (10''+0.1'')

ELO: 541.10 +-95.1 (95%) LOS: 100.0%
Total: 200 W: 184 L: 1 D: 15

LTC (30''+0.3'')

ELO: 541.10 +-107.7 (95%) LOS: 100.0%
Total: 200 W: 186 L: 3 D: 11

Janggi

STC (10''+0.1'')

ELO: 350.27 +-73.4 (95%) LOS: 100.0%
Total: 200 W: 172 L: 19 D: 9

LTC (30''+0.3'')

ELO: 297.95 +-67.2 (95%) LOS: 100.0%
Total: 200 W: 167 L: 28 D: 5

Files of the release

• The .nnue files do not need to be downloaded. They are only included in the release so that the build can be reproduced from source if desired.
• .exe are Windows executables, the files without extensions are Linux binaries.
• Use bmi2 versions for best performance on modern hardware, or fairy-stockfish-largeboard_x86-64.exe for best compatibility.
• This release does not contain non-largeboard binaries, since they would not support Xiangqi and Janggi.

Fairy-Stockfish 14

This release significantly enhances support for NNUE evaluation, switching to a new network architecture and enabling to use it for much more variants including all major regional variants (Xiangqi, Shogi, Janggi, Makruk). As of the time of this release only a few networks are available yet, but many more are about to come. Also see the NNUE overview and patreon.

New

• NNUE generalizations in order to support most variants
  • Basically works with any piece types, board size, and pieces in hand
  • Only remaining limitation is that both sides need to have exactly one king each
• Variants
  • Sho Shogi
  • Opulent

Improvements

• Merged new stronger NNUE architecture from official Stockfish (HalfKP->HalfKAv2).
• Extended range for UCI_Elo, so weaker levels can be selected.

Fixes

• Fixed evaluation bug for extinction variants with piece drops

Files of the release

• .exe are Windows executables, the files without extensions are Linux binaries.
• Versions containing largeboard have support for board sizes >8x8 (e.g., Xiangqi, Shogi), the others are faster but have only variants <=8x8.
• Use bmi2 versions for best performance on modern hardware, or fairy-stockfish-largeboard_x86-64.exe for best compatibility.
• The variants.ini contains documentation and examples how to configure user-defined variants and pieces.

Thanks to all code contributors, fishtest contributors, and supporters for their contributions to this release.

Fairy-Stockfish 13.1

This release adds support for up to 26 custom piece types per user-defined variant.

New

• Custom piece types
  • Piece movements are defined using Betza notation.
  • See the variants.ini for details on defining custom pieces.
• New base piece movements
  • Nightrider
  • Diagonal cannon
  • Grasshopper
  • Limited distance sliders
• Variants
  • Nightrider
  • Grasshopper
  • TenCubed
  • Yari, Tori, and Okisaki shogi

Improvements

• Small speed improvements for all variants
• Significant playing strength improvement in bughouse against human opponents by considering drops of pieces from anticipated piece flow.

Fixes

• Fix atomic castling rules for one corner case to ensure compatibility with lichess rules.
• Use correct rank numbering for en passant field in Grand chess FENs in CECP protocol.
• Disambiguate castling moves in variants where the king only moves one square to castle.

Files of the release

• .exe are Windows executables, the files without extensions are Linux binaries.
• Versions containing largeboard have support for board sizes >8x8 (e.g., Xiangqi, Shogi), the others are faster but have less variants.
• Use bmi2 versions for best performance on modern hardware, or fairy-stockfish-largeboard_x86-64.exe for best compatibility.
• The variants.ini contains documentation and examples how to configure user-defined variants and pieces.

Thanks to all code contributors, fishtest contributors, and supporters for their contributions to this release.

Fairy-Stockfish 13

This release contains a large number of new features, improvements, and bugfixes. The biggest change is the support of NNUE evaluation for chess, shogi, and several other variants. Furthermore, due to the addition of atomic chess, Fairy-Stockfish now supports all lichess variants.

New

• NNUE evaluation
  • Chess
  • Shogi
  • Chess variants (list)
• Variants
  • Atomic
  • Coregal
  • Maharajah and the sepoys
• Pondering in CECP/xboard protocol
• UCI-cyclone protocol for Xiangqi

Improvements

• Merged all changes from official Stockfish up to SF13 release.
• Speed improvements leading to better performance for a large number of variants
• >100 Elo playing strength improvements for horde, antichess, and losers chess
• Significant playing strength improvements when using NNUE evaluation for some variants, e.g., Shogi, King of the Hill, Atomic, Minixiangqi, and more. See the variant NNUE overview and Patreon for more info.

Fixes

• Fix castling for several 960 variants
• Resolve time losses when using USI protocol
• Remove spaces from option names in USI protocol
• Proper error message for illegal moves in CECP

Files of the release

• .exe are Windows executables, the files without extensions are Linux binaries.
• Versions containing largeboard have support for board sizes >8x8 (e.g., Xiangqi, Shogi), the others are faster but have less variants.
• Use bmi2 versions for best performance on modern hardware, or fairy-stockfish-largeboard_x86-64.exe for best compatibility.
• The variants.ini contains documentation and examples how to configure user-defined variants.

Thanks to all code contributors, fishtest contributors, and supporters for their contributions to this release. Particular credits to @tttak for contributing the shogi NNUE support.

Fairy-Stockfish 11.2

This release has a main focus on improving playing strength for a variety of games, along with a few feature additions and bugfixes.

New

• Variants
  • Armageddon
  • Ataxx
  • Game of the Amazons (not part of official build)

Improvements

• Significant playing strength improvements, especially for Antichess, Shogi, Makruk, Janggi, S-Chess, and more
• Merged all pre-NNUE changes from official Stockfish
• Force adjudication in CECP for better compatibility with Winboard/XBoard

Fixes

• More robust handling of passing moves in CECP

Files of the release

• .exe are Windows executables, the files without extensions are Linux binaries.
• Versions containing largeboard have support for board sizes >8x8, the others are faster but have less variants.
• Use bmi2 versions for best performance on modern hardware, or fairy-stockfish-largeboard_x86-64.exe for best compatibility.

Thanks to all contributors of code, CPU time, and donations.

Fairy-Stockfish 11.1

This release adds support for Janggi (장기, Korean chess), along with several improvements and bugfixes.

New

• Variants
  • Janggi (Korean Chess)
  • Makpong
  • Three Kings
  • Koedem
• Variant configuration options
  • Mobility area per piece type
  • Janggi related rules (passing, palace moves, bikjang)
  • piece drop restrictions
  • piece count for extinction variants
• Variant configuration checker
  • automatically identifies errors in variant configuration files

Improvements

• Significant improvement of Winboard/XBoard compatibility by highlighting legal moves
• Playing strength improvements, especially for extinction, nCheck, and capture the flag variants
• More partner communication in bughouse
• Extended range of available skill levels

Fixes

• Prohibit Sittuyin promotions that attack pieces
• Disable Makruk counting in presence of unpromoted pawns
• Start ASEAN counting at one
• Correct SFEN parsing for pieces in hand
• Use seconds as time unit for st command
• Clear search state on new in CECP protocol
• Prevent race condition in communication of holdings in bughouse

Thanks to all CPU contributors, and to @Fulmene for code contributions.

Files of the release

• .exe are Windows executables, the files without extensions are Linux binaries.
• Versions containing largeboard have support for board sizes >8x8, the others are faster but have less variants.
• Use bmi2 versions for best performance on modern hardware, or fairy-stockfish-largeboard_x86-64.exe for best compatibility.

Fairy-Stockfish 11

This release includes Windows and Linux binaries for the large-board version supporting board sizes up to 12x10 and the faster normal version for board sizes up to 8x8, along with a variants.ini for examples and documentation of user-defined variants.

New

• Variants
  • Bughouse
  • Knightmate
  • Suicide
  • Nocastle
  • Supply chess
• Variant configuration options
  • royal non-king pieces
  • prohibit checks by piece drops
  • allow pawn drops in promotion zone
• Tsume mode
  • allows to solve (Shogi) Tsume/mate problems

Improvements

• Much improved XBoard/WinBoard compatibility for custom variants
• Merged recent changes from official Stockfish
• Various playing strength improvements
• Improved compatibility with Shogi GUIs

Fixes

• Endgame evaluation fix for large-board version
• Case-insensitive parsing of piece types from variant configuration
• XBoard checkbox options use integer instead of boolean values

Fairy-Stockfish 10.4

This release includes Windows and Linux binaries for the large-board version supporting board sizes up to 12x10 and the faster normal version for board sizes up to 8x8. Furthermore, it includes a variants.ini for examples and documentation of user-defined variants.

New

• Variants
  • Xiangqi
  • Manchu
  • Minixiangqi
  • Centaur
  • New Zealand
• Protocols
  • CECP/XBoard
  • UCCI
• Piece types
  • Soldier, Horse, Elephant, Banner
  • Rookni, Kniroo
  • Centaur

Improvements

• Improved XBoard/WinBoard compatibility for custom variants
• Playing strength improvements for drop variants and hoppelpoppel
• Improved output of board representaton of d command in CLI
• Reduced memory consumption (of continuation history)
• Merged recent changes from official Stockfish

Fixes

• Fixed illegal moves in displayed principal variation
• Fixed move generation for shako

Fairy-Stockfish 10.3

This release includes Windows and Linux binaries for the normal version supporting variants up to 8x8 board size and the large-board version supporting board sizes up to 12x10. Furthermore, it includes a variants.ini for examples and documentation of user-defined variants.

New

• User-defined variants
  • Variants can now be added at runtime via a configuration file, without the need to recompile the program.
  • A sample variants.ini including some documentation is attached to the release.
• Many new pre-defined variants. Major additions:
  • S-Chess
  • Ouk Chatrang (Cambodian chess)
  • Grand
  • Gothic
  • Shako

Improvements

• Various variant-specific playing strength improvements
  • Playing strength is improved in almost all supported variants.
  • Especially big improvements (>100 Elo) for drop and Losing chess variants, as well as Three-check, Horde and Racing Kings
• Merged recent changes from official Stockfish
• Reduced memory consumption

Fixes

• Resolved issue with mingw compilation
• Multiple fixes for pseudo-legal move validation leading to more stable and faster search
• Removed potential undefined behavior in drop variants

Fairy-Stockfish 10.2

First release based on development version after Stockfish 10. Includes normal and large-board version for windows and linux.