top of page

Stockfish 15.1 released

The strongest Stockfish has seen the light of day :)

Within the MCERL games, the results achieved by the 20221202 development version of Stockfish left no doubt - we are dealing with the strongest incarnation of this chess engine. And indeed, after a few days this very version was renamed Stockfish 15.1.

Source: MCERL (ongoing)

Stockfish 15.1 compiled for Macs is noticeably stronger than its predecessor.

The 600 games this engine has played is not a small number, but it is not a lot either (e.g., 10000), so please consider the results as its approximate strength.

Here's what the developers wrote in releasing Stockfish 15.1


Today, we have the pleasure to announce Stockfish 15.1.

As usual, downloads will be freely available at

Elo gain and competition results With this release, version 5 of the NNUE neural net architecture has been introduced, and the training data has been extended to include Fischer random chess (FRC) positions. As a result, Elo gains are largest for FRC, reaching up to 50 Elo for doubly randomized FRC (DFRC). More importantly, also for standard chess this release progressed and will win two times more game pairs than it loses against Stockfish 15. Stockfish continues to win in a dominating way all chess engine tournaments, including the TCEC Superfinal, Cup, FRC, DFRC, and Swiss as well as the CCC Bullet, Blitz, and Rapid events.

New evaluation This release also introduces a new convention for the evaluation that is reported by search. An evaluation of +1 is now no longer tied to the value of one pawn, but to the likelihood of winning the game. With a +1 evaluation, Stockfish has now a 50% chance of winning the game against an equally strong opponent. This convention scales down evaluations a bit compared to Stockfish 15 and allows for consistent evaluations in the future.

ChessBase settlement In this release period, the Stockfish team has successfully enforced its GPL license against ChessBase. This has been an intense process that included filing a lawsuit, a court hearing, and finally negotiating a settlement that established that ChessBase infringed on the license by not distributing the Stockfish derivatives Fat Fritz 2 and Houdini 6 as free software, and that ensures ChessBase will respect the Free Software principles in the future. This settlement has been covered by major chess sites (see e.g. and, and we are proud that it has been hailed as a ‘historic violation settlement’ by the Software Freedom Conservancy.

Thank you The Stockfish project builds on a thriving community of enthusiasts (thanks everybody!) that contribute their expertise, time, and resources to build a free and open-source chess engine that is robust, widely available, and very strong. We invite our chess fans to join the fishtest testing framework and programmers to contribute to the project. The Stockfish team


* Feel free to download Stockfish.

Android – Compiled by Stockfish Developers & Archimedes

Download 7Z • 67.15MB

Linux ARM – Compiled by Darius

Download 7Z • 21.93MB

Linux 64-bit – Compiled by Stockfish Developers

Download 7Z • 22.67MB

Mac Apple Silicon & Intel – Compiled by Darius

Download 7Z • 22.26MB
Download 7Z • 22.09MB

Windows 32-bit – Compiled by Darius

Download 7Z • 22.44MB

Windows 64-bit – Compiled by Stockfish Developers

Download 7Z • 23.08MB


All archives were created using the multiplatform open-source archiver 7-Zip.

If you need a tool to unzip a 7-Zip archive, feel free to download it from the Files section.



bottom of page