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Stockfish is a free, powerful UCI chess engine derived from Glaurung 2.1. Stockfish is not a complete chess program and requires a UCI-compatible graphical user interface (GUI) (e.g. XBoard with PolyGlot, Scid, Cute Chess, eboard, Arena, Sigma Chess, Shredder, Chess Partner or Fritz) in order to be used comfortably. Read the documentation for your GUI of choice for information about how to use Stockfish with it. Stockfish is a 11-time winner of the Top Chess Engine Championship. Stockfish is open source (GPLv3 license). That means you can read the code, modify it, and contribute back. You can use Stockfish on your computer or on your iOS or Android device. So you can get world-class chess analysis, wherever you are. The Stockfish engine features two evaluation functions for chess, the classical evaluation based on handcrafted terms, and the NNUE evaluation based on efficiently updatable neural networks.
Features
- The classical evaluation runs efficiently on almost all CPU architectures
- The NNUE evaluation benefits from the vector intrinsics available on most CPUs (sse2, avx2, neon, or similar)
- The Universal Chess Interface (UCI) is a standard protocol used to communicate with a chess engine
- Stockfish implements the majority of it options as described in the UCI protocol
- Developers can see the default values for UCI options available in Stockfish by typing ./stockfish uci in a terminal
- On CPUs supporting modern vector instructions (avx2 and similar), the NNUE evaluation results in much stronger playing strength
Project Samples
