Today, we have the pleasure to announce Stockfish 17.1. As always, you can freely download it at stockfishchess.org/download and use it in the GUI of your choice. Join our Discord server 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 17.1 shows a consistent improvement in performance, with an Elo gain of up to 20 points and winning close to 2 times more game pairs than it loses.| Stockfish Blog on Stockfish - Strong open-source chess engine
Today we have the pleasure to announce a new major release of Stockfish. As always, you can freely download it at stockfishchess.org/download and use it in the GUI of your choice. Don’t forget to join our Discord server to get in touch with the community of developers and users of the project! Quality of chess play In tests against Stockfish 16, this release brings an Elo gain of up to 46 points and wins up to 4.| Stockfish Blog on Stockfish - Strong open-source chess engine
Today, we have the pleasure to announce Stockfish 16.1. As always, you can freely download it at stockfishchess.org/download and use it in the GUI of your choice. Don’t forget to join our Discord server 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 than it loses.| Stockfish Blog on Stockfish - Strong open-source chess engine
A new major release of Stockfish is now available at stockfishchess.org/download. Quality of chess play Stockfish continues to demonstrate its ability to discover superior moves with remarkable speed. In self-play against Stockfish 15, this new release gains up to 50 Elo and wins up to 12 times more game pairs than it loses. In major chess engine tournaments, Stockfish reliably tops the rankings winning the TCEC season 24 Superfinal, Swiss, Fischer Random, and Double Random Chess tournaments ...| Stockfish Blog on Stockfish - Strong open-source chess engine
Today, we have the pleasure to announce Stockfish 15.1. As usual, downloads will be freely available at stockfishchess.org/download 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 pr...| Stockfish Blog on Stockfish - Strong open-source chess engine
More than one year ago, leading developers of the chess engine Stockfish, Tord Romstad and Stéphane Nicolet, with broad support from the development community, filed suit against ChessBase GmbH before the District Court Munich I (Az. 42 0 9765/21) to enforce the GNU General Public License v3 (GPL) license termination provision, claiming repeated violation of the license conditions by ChessBase with their products Fat Fritz 2 and Houdini 6. We are pleased to announce that we have found an agr...| Stockfish Blog on Stockfish - Strong open-source chess engine
As announced nearly one year ago, leading Stockfish developers have filed suit against ChessBase to enforce their license termination after repeated copyright violation by ChessBase. The court hearing in the case Tord Romstad and Stéphane Nicolet vs. ChessBase GmbH will take place soon. In recent months, we have presented to the court detailed evidence that the ChessBase products Houdini 6 and Fat Fritz 2 have copied extensive parts of the Stockfish code base authored by the plaintiffs and t...| Stockfish Blog on Stockfish - Strong open-source chess engine
A new major release of Stockfish is now available at https://stockfishchess.org Stockfish 15 continues to push the boundaries of chess, providing unrivalled analysis and playing strength. In our testing, Stockfish 15 is ahead of Stockfish 14 by 36 Elo points and wins nine times more game pairs than it loses. Improvements to the engine have made it possible for Stockfish to end up victorious in tournaments at all sorts of time controls ranging from bullet to classical and even at Fischer rando...| Stockfish Blog on Stockfish - Strong open-source chess engine
Today, we have the pleasure to announce Stockfish 14.1. As usual, downloads will be freely available at stockfishchess.org/download. With Stockfish 14.1 our users get access to the strongest chess engine available today. In the period leading up to this release, Stockfish convincingly won several chess engine tournaments, including the TCEC 21 superfinal, the TCEC Cup 9, and the Computer Chess Championship for Fischer Random Chess (Chess960). In the latter tournament, Stockfish was undefeated...| Stockfish Blog on Stockfish - Strong open-source chess engine
Today, we have the pleasure to announce Stockfish 14. As usual, downloads will be freely available at stockfishchess.org/download. The engine is now significantly stronger than just a few months ago, and wins four times more game pairs than it loses against the previous release version. Stockfish 14 is now at least 400 Elo ahead of Stockfish 7, a top engine in 2016. During the last five years, Stockfish has thus gained about 80 Elo per year.| Stockfish Blog on Stockfish - Strong open-source chess engine
It is our pleasure to release Stockfish 13 to chess fans worldwide. As usual, downloads are freely available at stockfishchess.org/download/ The Stockfish project builds on a thriving community of enthusiasts 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 thank them all! The good news first: from now on, our users can expect more frequent high-quality releases of Stockfish!| Stockfish Blog on Stockfish - Strong open-source chess engine
Stockfish is an open-source project, sharing and freely distributing the code, tools and data needed to deliver this chess engine. We do this because we are convinced that open software and open data are key ingredients to make rapid progress, and thus for the benefit of our users. The recent progress in playing strength of Stockfish confirms the path taken. We proudly provide the tools for free chess analysis to millions of users, with countless titled players using Stockfish for their prepa...| Stockfish Blog on Stockfish - Strong open-source chess engine
It is our pleasure to release Stockfish 12 to users worldwide. Downloads are freely available at https://stockfishchess.org/download/ This version 12 of Stockfish plays significantly stronger than any of its predecessors. In a match against Stockfish 11, Stockfish 12 will typically win at least ten times more game pairs than it loses. This jump in strength, visible in regular progression tests during development, results from the introduction of an efficiently updatable neural network (NNUE) ...| Stockfish Blog on Stockfish - Strong open-source chess engine
As of August 6, the efficiently updatable neural network (NNUE) evaluation has landed in the Stockfish repo! What is NNUE? Both the NNUE and the classical evaluations are available, and can be used to assign a value to a position that is later used in alpha-beta (PVS) search to find the best move. The classical evaluation computes this value as a function of various chess concepts, handcrafted by experts, tested and tuned using fishtest.| Stockfish Blog on Stockfish - Strong open-source chess engine
It is our pleasure to release Stockfish 11 to our fans and supporters. Downloads are freely available at http://stockfishchess.org/download/ This version 11 of Stockfish is 50 Elo stronger than the last version, and 150 Elo stronger than the version which famously lost a match to AlphaZero two years ago. This makes Stockfish the strongest chess engine running on your smartphone or normal desktop PC, and we estimate that on a modern four cores CPU, Stockfish 11 could give 1:1000 time odds to t...| Stockfish Blog on Stockfish - Strong open-source chess engine
Official release version of Stockfish 10. Downloads are available at http://stockfishchess.org/download/ This is also the 10th anniversary version of the Stockfish project, which started exactly ten years ago! I wish to extend a huge thank you to all contributors and authors in our amazing community :-) SF 10 improves by about 50 ELO in self-play compared to SF 9. Bench: 3939338| Stockfish Blog on Stockfish - Strong open-source chess engine
I am pleased to announce that Stockfish 9 is out. You can download the offical builds from here https://stockfishchess.org/download/ I would like to thank all the amazing people that made this release possible. All our testers and our developers, all the people that donate CPU time through fishtest (thank you! You are amazing) and a special thank to Daylen, our webmaster, and to the people contributing to the final optimized builds:| Stockfish Blog on Stockfish - Strong open-source chess engine
Stockfish 8 is out! This is the result of the effort of many people along many months: it has been a huge and hard effort and I would like to thank all the testers for their relentless patience, determination and creativity. I would like to thank all the people supporting us with CPU time (we don’t ask nor accept donations so if you want to support us then donating CPU time through fishtest is the way to go and we greatly appreciate that).| Stockfish Blog on Stockfish - Strong open-source chess engine
Stockfish 7 is out! This release is around 60 ELO stronger than Stockfish 6 in self play. SMP algorithm has been changed from YBW to Lazy SMP. Gary Linscott is now officially listed as a co-author. Download it from https://stockfishchess.org/download/.| Stockfish Blog on Stockfish - Strong open-source chess engine
Stockfish 6 is now available! This release adds support for Syzygy endgame tablebases, and is 50 ELO stronger than Stockfish 5 in self play. We recommend that you download Syzygy bases via torrent from here: http://oics.olympuschess.com/tracker/index.php Stockfish 6 binaries are available here: http://stockfishchess.org/download/| Stockfish Blog on Stockfish - Strong open-source chess engine
Stockfish 5 is now available! This is the version that won TCEC Season 6 but without table-bases. From SF DD released at end of November of last year a lot of work has been done: 44 files changed, 2272 insertions(+), 2764 deletions(-) By many contributors both in patches: Arjun Temurnikar Chris Cain Daylen Yang Gary Linscott Henri Wiechers H. Felix Wittmann Jean-Francois Romang Jerry Donald Joerg Oster Jonathan Calovski Joona Kiiski Joseph Hellis Leonid Pechenik Lucas Braesch Marco Costalba M...| Stockfish Blog on Stockfish - Strong open-source chess engine
This is a new release of Stockfish after the last TCEC season. It is almost the same version that played the superfinal against Komodo. Download Browse the source code For people compiling themselves, please verify signature is correct running ‘stockfish bench’ from a terminal window. At the end of the run, searched nodes shall be 8596156 Diffs from last version is: 32 files changed, 966 insertions(+), 1257 deletions(-) So 291 lines of code less but should be quite stronger than version 4.| Stockfish Blog on Stockfish - Strong open-source chess engine
Stockfish 4 has been released. You can download at http://stockfishchess.org/ or browse the sources at https://github.com/mcostalba/Stockfish Diffs from last version is: 43 files changed, 1534 insertions(+), 1703 deletions(-) So 169 lines of code less but should be quite stronger than version 3. For interested people here is the breakdown of lines count. Language files blank comment code C++ 20 2110 1619 5772 C/C++ Header 21 636 570 1558 SUM: 41 2746 2189 7330| Stockfish Blog on Stockfish - Strong open-source chess engine
This is Stockfish 3. The big news of this version, and the reason why we have bumped version number to 3 is not due to ELO increase (that anyhow should be interesting) nor to some cool feature, but it is due to the new super awesome testing framework that Gary setup and currently runs on http://tests.stockfishchess.org/ This is really a new beginning for Stockfish development. A development that now is fully open and in just few weeks has already attract many people willing to test their idea...| Stockfish Blog on Stockfish - Strong open-source chess engine
This version fixes a Chess960 bug. It also has an ELO increase: https://github.com/mcostalba/Stockfish/commit/fdbe8006e058f3d2852117045be51b8841daa16f Stockfish bench signature is 5423738.| Stockfish Blog on Stockfish - Strong open-source chess engine
44 files changed, 3486 insertions(+), 3778 deletions(-) ELO increase is very limited, it is mainly a minor release to flush the accumulated work. From the user point of view the biggest thing is that SF should not crash anymore even with many threads because a nasty SMP bug causing a rare but repetitive crash has been fixed. Marco| Stockfish Blog on Stockfish - Strong open-source chess engine
The 64-bit Windows compiles are built with GCC instead of Intel, so there is a 5-6% speed increase. Very few code changes: it should be a bit faster and a bug is fixed where Stockfish in some (rare) positions erroneously moves immediately without thinking. Stockfish’s new signature is: 5447426 Marco| Stockfish Blog on Stockfish - Strong open-source chess engine
This version fixes the time management issue. The signature is 5457475. Marco Update Jan 6, 2012: Stockfish 2.2.1 has been reposted to fix a compatibility issue with SSE4.2 Phenom processors. Update Jan 7, 2012: Stockfish 2.2.1 for Android has been reposted to fix an issue in engine tournaments.| Stockfish Blog on Stockfish - Strong open-source chess engine
To start the new year with a fresh new base I’d like to release Stockfish 2.2. This should be really a small improvement ELO wise, I have tested it against SF 2.1.1 JA and in single core I got +10 ELO, we think in multi core we should gain some more, but remain anyhow around +20 ELO maximum. Not a lot for 6 months of work but at least the readability of code base has greatly improved and also shrinked in size of almost 900 lines:| Stockfish Blog on Stockfish - Strong open-source chess engine
This is a maintenance release to fix the book reading issue reported by some users. As an added benefit, Jim’s build should be now a little faster on Intel CPU (4% on 64-bit and almost 6% on 32-bit). This is a non functional change release so there is no need to retest Stockfish for people who have already done so; for people who still to test we suggest to use this one because it should be a bit faster on Intel hardware.| Stockfish Blog on Stockfish - Strong open-source chess engine
This is Stockfish 2.1. Diff stats from 2.0.1 says: 54 files changed, 4138 insertions(+), 5656 deletions(-) So more than 1500 lines of code removed for this release. In this release a new skill level facility has been introduced. Stockfish can be set to skill level 20 (default) to play at maximum strength or, through setting the “Skill Level” UCI option, can be lowered until 0 when should be beatable even by weak players.| Stockfish Blog on Stockfish - Strong open-source chess engine
This is a maintenance release. No functional change and no ELO increase from 2.0. Main fixes are: Fix a crash in multi-pv analysis Fix Chess960 support| Stockfish Blog on Stockfish - Strong open-source chess engine
Stockfish is a strong and open-source chess engine.| Stockfish
Updates from the Stockfish team.| Stockfish