Stockfish 19
Official release version of Stockfish 19
Bench: 2497913
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Stockfish 19
Today, we have the pleasure of announcing Stockfish 19, a new major
release. As always, you can freely download it at
[stockfishchess.org/download][1] and use it as a drop-in replacement in
the [GUI of your choice][2] to benefit from stronger play and more
accurate analysis.
Whether you can spare hours or days of CPU time, your help matters for
the ongoing development of Stockfish. Find out how you can contribute at
[stockfishchess.org/get-involved][3]. Join our [Discord server][4] to
get in touch with the community of developers and users of the project!
Quality of Chess Play
In tests against Stockfish 18, this new release brings an Elo gain of
[up to 44 points][5], and wins [more than three times as many game
pairs][6] as it loses.
Stockfish continues to set the standard for engine strength. Against the
strongest competition, it consistently secures the top spot in engine
championships, continuing to [dominate the field][7].
Update Highlights
Universal Binaries
We have transitioned to universal binaries for our releases, simplifying
the download process. These universal binaries automatically detect the
features of your CPU and run the optimal code, eliminating the need to
manually choose between AVX2, AVX-512, etc.
Upgraded NNUE Architecture and Training
This release introduces the SFNNv16 network architecture, reducing
binary size by removing redundant threat features while increasing
strength by introducing new pawn-pair features. The secondary neural
network, introduced in Stockfish 16.1, has been retired, enhancing
strength in positions where the small net previously underperformed.
The training process has been further improved with the introduction of
new techniques, such as Quantization-Aware Training (QAT), and further
parameter tweaks. These techniques have been applied to hundreds of
billions of training positions, all of which have been consistently
rescored using a strong [Leela][8] net.
Expanded Platform Support
We have added native support for RISC-V (RVV) and LoongArch (LSX/LASX),
1GB Linux huge pages, as well as WebAssembly targets. The shared-memory
implementation for Linux, macOS, and BSD was also overhauled.
Strict Position Validation
We have implemented stricter validation for board positions, FEN
strings, and UCI commands. The engine will now output an `info string
CRITICAL ERROR` followed by the exact command and the reason it failed,
and then immediately terminate the process. A good GUI will ensure you
never encounter these errors.
Thank You
The Stockfish project builds on a thriving community of enthusiasts
(thanks to 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 16.4k stars that light up
our GitHub project. Thank you for your support and encouragement – your
recognition means a lot to us. Programmers can contribute to the project
either directly to [Stockfish][9] (C++), to [Fishtest][10] (HTML, CSS,
JavaScript, and Python), to our trainer [nnue-pytorch][11] (C++ and
Python), or to our [website][12] (HTML, CSS/SCSS, and JavaScript).
The Stockfish team
[1]: https://stockfishchess.org/download
[2]: https://official-stockfish.github.io/docs/stockfish-wiki/Download-and-usage.html#download-a-chess-gui
[3]: https://stockfishchess.org/get-involved/
[4]: https://discord.gg/GWDRS3kU6R
[5]: https://tests.stockfishchess.org/tests/view/6a85df4c5b1b38ebda864ccd
[6]: https://tests.stockfishchess.org/tests/view/6a85df595b1b38ebda864ccf
[7]: https://en.wikipedia.org/wiki/Stockfish_(chess)#Competition_results
[8]: https://lczero.org/
[9]: https://github.com/official-stockfish/Stockfish
[10]: https://github.com/official-stockfish/fishtest
[11]: https://github.com/official-stockfish/nnue-pytorch
[12]: https://github.com/official-stockfish/stockfish-web