Released 4 months ago on January 14, 2012
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
Released 4 months ago on January 6, 2012
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.
Released 4 months ago on December 29, 2011
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:
42 files changed, 3853 insertions(+), 4729 deletions(-)
This is just an “Happy New Year” release, nothing more.
It is important that the below signature matches in all the platforms:
stockfish bench signature is: 5457475
Thanks a lot and Happy New 2012 to everybody!
Marco
Update Dec 30, 2011: We are having some issues compiling for Windows. For those who downloaded the Mac version yesterday, the final 2.2 release may be different.
Update Dec 31, 2011: Stockfish 2.2 for all platforms is now available!
Released 1 year ago on May 8, 2011
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.
Released 1 year ago on May 4, 2011
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. Implementation of skill levels has been developed around an idea from Heinz van Saanen and is time control and CPU speed independent: you can set skill level at 4 and SF will play with the same strength both on a cell phone at 1’ per game or on a super quad-core machine at 120’+30” TC.
Also of note, “seldepth” UCI info is now correctly implemented and maximum number of threads has been raised from 16 to 32.
For people compiling themselves, Stockfish 2.1’s signature is 6487630. It means that running from command line ‘stockfish bench’ you should get at the end 6487630 searched nodes. If this does not happen please report back; it means SF is miscompiled.
We would like to thank Heinz, Onno, Justin, BB+ and Fruity for their contributions in ideas and useful suggestions, and of course, a big thank you to Jim for its usual kind help.
Have fun.
Stockfish Team
