Stockfish (chess)

Stockfish
Developer(s)The Stockfish developers[1]
Initial releaseNovember 2, 2008; 16 years ago (2008-11-02)
Stable release
17 / September 6, 2024; 2 months ago (2024-09-06)
Repository
Written inC++
Operating systemMicrosoft Windows
macOS
Linux
iOS
Android
TypeChess engine
LicenseGPL-3.0-or-later[2]
Websitestockfishchess.org Edit this on Wikidata
This article is part of the series on
Chess programming
Board representations
Evaluation functions
Graph and tree search algorithms
Chess computers
Chess engines

Stockfish is a free and open-source chess engine, available for various desktop and mobile platforms. It can be used in chess software through the Universal Chess Interface.

Stockfish has been one of the best chess engines in the world for several years;[3][4][5] it has won all main events of the Top Chess Engine Championship (TCEC) and the Chess.com Computer Chess Championship (CCC) since 2020 and, as of October 2024, is the strongest CPU chess engine in the world with an estimated Elo rating of 3642, in a time control of 40/15 (15 minutes to make 40 moves), according to CCRL.[6]

The Stockfish engine was developed by Tord Romstad, Marco Costalba, and Joona Kiiski, and was derived from Glaurung, an open-source engine by Tord Romstad released in 2004. It is now being developed and maintained by the Stockfish community.[7]

Stockfish historically used only a classical hand-crafted function to evaluate board positions, but with the introduction of the efficiently updatable neural network (NNUE) in August 2020, it adopted a hybrid evaluation system that primarily used the neural network and occasionally relied on the hand-crafted evaluation.[8][9][10] In July 2023, Stockfish removed the hand-crafted evaluation and transitioned to a fully neural network-based approach.[11][12]

  1. ^ "List of Stockfish authors". github.com/official-stockfish/Stockfish. Archived from the original on 13 July 2018. Retrieved 3 July 2023.
  2. ^ "Stockfish GPLv3 license". github.com/official-stockfish/Stockfish. Archived from the original on 15 November 2022. Retrieved 20 July 2020.
  3. ^ Strogatz, Steven (2018-12-26). "One Giant Step for a Chess-Playing Machine". The New York Times. ISSN 0362-4331. Archived from the original on 2022-01-04. Retrieved 2024-02-08.
  4. ^ Gibbs, Samuel (2017-12-07). "AlphaZero AI beats champion chess program after teaching itself in four hours". The Guardian. ISSN 0261-3077. Archived from the original on 2020-12-07. Retrieved 2024-02-08.
  5. ^ Perez-Rey, Lisandro (2023-08-12). "Why AI Chess Bots Are Virtually Unbeatable (ft. GothamChess)". Wired. Archived from the original on 2024-02-15. Retrieved 2024-02-08.
  6. ^ "CCRL 40/15 - Index". computerchess.org.uk. Archived from the original on 2024-07-18. Retrieved 2024-09-29.
  7. ^ "Engine authors". Stockfish. Archived from the original on 17 February 2014. Retrieved 3 July 2023.
  8. ^ "Introducing NNUE Evaluation". Stockfish. Archived from the original on 14 May 2024. Retrieved 14 May 2024.
  9. ^ "Add NNUE evaluation". GitHub. Retrieved 14 May 2024.
  10. ^ "NNUE evaluation threshold". GitHub. Archived from the original on 14 May 2024. Retrieved 14 May 2024.
  11. ^ "Remove classical evaluation". GitHub. Archived from the original on 16 May 2024. Retrieved 14 May 2024.
  12. ^ Cite error: The named reference Stockfish 16.1 was invoked but never defined (see the help page).