![]() Official release version of Stockfish 16.1 Bench: 1303971 --- Stockfish 16.1 Today, we have the pleasure to announce Stockfish 16.1. As always, you can freely download it at https://stockfishchess.org/download and use it in the GUI of your choice[1]. Don't forget to join our Discord server[2] to get in touch with the community of developers and users of the project! *Quality of chess play* In our testing against its predecessor, Stockfish 16.1 shows a notable improvement in performance, with an Elo gain of up to 27 points and winning over 2 times more game pairs[3] than it loses. *Update highlights* *Improved evaluation* - Updated neural network architecture: The neural network architecture has undergone two updates and is currently in its 8th version[4]. - Removal of handcrafted evaluation (HCE): This release marks the removal of the traditional handcrafted evaluation and the transition to a fully neural network-based approach[5]. - Dual NNUE: For the first time, Stockfish includes a secondary neural network[6], used to quickly evaluate positions that are easily decided. *UCI Options removed* `Use NNUE` and `UCI_AnalyseMode`[7] have been removed as they no longer had any effect. `SlowMover`[8] has also been removed in favor of `Move Overhead`. *More binaries* We now offer 13 new binaries. These new binaries include `avx512`, `vnni256`, `vnni512`, `m1-apple-silicon`, and `armv8-dotprod`, which take advantage of specific CPU instructions for improved performance. For most users, using `sse41-popcnt` (formerly `modern`), `avx2`, or `bmi2` should be enough, but if your CPU supports these new instructions, feel free to try them! *Development changes* - Updated testing book: This new book[9], now derived exclusively from the open Lichess database[10], is 10 times larger than its predecessor, and has been used to test potential improvements to Stockfish over the past few months. - Consolidation of repositories: Aiming to simplify access to our resources, we have moved most Stockfish-related repositories into the official Stockfish organization[11] on GitHub. - Growing maintainer team: We welcome Disservin[12] to the team of maintainers of the project! This extra pair of hands will ensure the lasting success of Stockfish. *Thank you* The Stockfish project builds on a thriving community of enthusiasts (thanks everybody!) who contribute their expertise, time, and resources to build a free and open-source chess engine that is robust, widely available, and very strong. We would like to express our gratitude for the 10k stars[13] that light up our GitHub project! Thank you for your support and encouragement – your recognition means a lot to us. We invite our chess fans to join the Fishtest testing framework[14], and programmers to contribute to the project either directly to Stockfish[15] (C++), to Fishtest[16] (HTML, CSS, JavaScript, and Python), to our trainer nnue-pytorch[17] (C++ and Python), or to our website[18] (HTML, CSS/SCSS, and JavaScript). The Stockfish team [1] https://github.com/official-stockfish/Stockfish/wiki/Download-and-usage#download-a-chess-gui [2] https://discord.gg/GWDRS3kU6R [3] https://tests.stockfishchess.org/tests/view/65d666051d8e83c78bfddbd8 [4] https://github.com/official-stockfish/nnue-pytorch/blob/master/docs/nnue.md#sfnnv8-architecture [5] https://github.com/official-stockfish/Stockfish/commit/af110e0 [6] https://github.com/official-stockfish/Stockfish/commit/584d9ef [7] https://github.com/official-stockfish/Stockfish/commit/c53d2ec [8] https://github.com/official-stockfish/Stockfish/commit/536d692 [9] https://github.com/official-stockfish/books/commit/426eca4 [10] https://database.lichess.org/ [11] https://github.com/official-stockfish/ [12] https://github.com/Disservin [13] https://github.com/official-stockfish/Stockfish/stargazers [14] https://github.com/official-stockfish/fishtest/wiki/Running-the-worker [15] https://github.com/official-stockfish/Stockfish [16] https://github.com/official-stockfish/fishtest [17] https://github.com/official-stockfish/nnue-pytorch [18] https://github.com/official-stockfish/stockfish-web |
||
---|---|---|
.github | ||
scripts | ||
src | ||
tests | ||
.clang-format | ||
.git-blame-ignore-revs | ||
.gitignore | ||
AUTHORS | ||
CITATION.cff | ||
CONTRIBUTING.md | ||
Copying.txt | ||
README.md | ||
Top CPU Contributors.txt |
Stockfish
A free and strong UCI chess engine.
Explore Stockfish docs »
Report bug
·
Open a discussion
·
Discord
·
Blog
Overview
Stockfish is a free and strong UCI chess engine derived from Glaurung 2.1 that analyzes chess positions and computes the optimal moves.
Stockfish does not include a graphical user interface (GUI) that is required to display a chessboard and to make it easy to input moves. These GUIs are developed independently from Stockfish and are available online. Read the documentation for your GUI of choice for information about how to use Stockfish with it.
See also the Stockfish documentation for further usage help.
Files
This distribution of Stockfish consists of the following files:
-
README.md, the file you are currently reading.
-
Copying.txt, a text file containing the GNU General Public License version 3.
-
AUTHORS, a text file with the list of authors for the project.
-
src, a subdirectory containing the full source code, including a Makefile that can be used to compile Stockfish on Unix-like systems.
-
a file with the .nnue extension, storing the neural network for the NNUE evaluation. Binary distributions will have this file embedded.
Contributing
See Contributing Guide.
Donating hardware
Improving Stockfish requires a massive amount of testing. You can donate your hardware resources by installing the Fishtest Worker and viewing the current tests on Fishtest.
Improving the code
In the chessprogramming wiki, many techniques used in Stockfish are explained with a lot of background information. The section on Stockfish describes many features and techniques used by Stockfish. However, it is generic rather than focused on Stockfish's precise implementation.
The engine testing is done on Fishtest. If you want to help improve Stockfish, please read this guideline first, where the basics of Stockfish development are explained.
Discussions about Stockfish take place these days mainly in the Stockfish Discord server. This is also the best place to ask questions about the codebase and how to improve it.
Compiling Stockfish
Stockfish has support for 32 or 64-bit CPUs, certain hardware instructions, big-endian machines such as Power PC, and other platforms.
On Unix-like systems, it should be easy to compile Stockfish directly from the
source code with the included Makefile in the folder src
. In general, it is
recommended to run make help
to see a list of make targets with corresponding
descriptions. An example suitable for most Intel and AMD chips:
cd src
make -j profile-build ARCH=x86-64-avx2
Detailed compilation instructions for all platforms can be found in our documentation. Our wiki also has information about the UCI commands supported by Stockfish.
Terms of use
Stockfish is free and distributed under the GNU General Public License version 3 (GPL v3). Essentially, this means you are free to do almost exactly what you want with the program, including distributing it among your friends, making it available for download from your website, selling it (either by itself or as part of some bigger software package), or using it as the starting point for a software project of your own.
The only real limitation is that whenever you distribute Stockfish in some way, you MUST always include the license and the full source code (or a pointer to where the source code can be found) to generate the exact binary you are distributing. If you make any changes to the source code, these changes must also be made available under GPL v3.