zurichess neuchatel - preview release

[brtzsnr]

Hi, all!

This is a preview release for the next version of my engine Zurichess.

You can get the binaries from here:
http://www.zurichess.xyz/zurichess-master-darwin-amd64
http://www.zurichess.xyz/zurichess-master-linux-amd64
http://www.zurichess.xyz/zurichess-mast ... -amd64.exe
but you should also check the sources at:
https://bitbucket.org/zurichess/zurichess/overview

Visit the website in the signature for older releases.

This is a preview release to find bugs that might have been overlooked by my tests. As usual, the engine should not crash on valid input and should be able to solve simple mates/positions. I expect ~50 Elo improvement so please let me know if you think you found a regression.

Do not use these binaries for any rating list or more extensive tests. I'll release new binaries when I'm happy with the quality of the code.

Regards,

[MikeB]

Hi, all!

This is a preview release for the next version of my engine Zurichess.

You can get the binaries from here:
http://www.zurichess.xyz/zurichess-master-darwin-amd64
http://www.zurichess.xyz/zurichess-master-linux-amd64
http://www.zurichess.xyz/zurichess-mast ... -amd64.exe
but you should also check the sources at:
https://bitbucket.org/zurichess/zurichess/overview

Visit the website in the signature for older releases.

This is a preview release to find bugs that might have been overlooked by my tests. As usual, the engine should not crash on valid input and should be able to solve simple mates/positions. I expect ~50 Elo improvement so please let me know if you think you found a regression.

Do not use these binaries for any rating list or more extensive tests. I'll release new binaries when I'm happy with the quality of the code.

Regards,

I expect ~50 Elo improvement

sweet!

keep up the good work!

[Jamal Bubker]

Thank you very much Alexandru !

A very nice improvement

[brtzsnr]

I did a bunch of cleanups and and uploaded new binaries. This is very likely the last binary update, but please wait until I tag the stable version.

Nobody has reported any issue so far which is encouraging. I expect to release the new version Friday or Saturday if no new issues are uncovered.

[brtzsnr]

Hi, everyone!

I decided to release the new version. Get the fresh&stable binaries from http://www.zurichess.xyz/

Linux AMD64: https://bitbucket.org/zurichess/zuriche ... inux-amd64
Windows AMD64: https://bitbucket.org/zurichess/zuriche ... -amd64.exe
As always the sources can be downloaded from https://bitbucket.org/zurichess/zurichess/overview . I encourage you to browse and to compile the sources.

I expect the neuchatel version to be about 60 Elo stronger than the luzern version. Of course, selfplay often exaggerates the improvements so you results may vary.

A lot of effort was wasted on improving the evaluation. In the end improving the search resulted in the most Elo gain. The detailed list of changes is as follows:

Code: Select all

Improve evaluation:
    Evaluate king-queen tropism.
    Evaluate rammed pawns on 2nd and 3rd rank.
Improve search:
    Implement SEE based LMR.
    Implement SEE based leaf pruning.
    Tweak limits for FP and LMR.
    Time control tweaks and simplificats.
    History heuristic accounts for the depth of the move.
Some small additions to public API
    PawnPromotionSquare returns the promotion square of a pawn.
    RammedPawns returns rammed pawns on 2nd and 3rd rank for white and 6th and 6th rank for black.
Fix a late end game bug in which PV did not have a root move.
Score was halved to be a bit more realistic.
Reduce the number of illegal moves generated when in check.
Usual code clean ups, speed ups and bug fixes.

For those who care about the code size, this version is 54 lines smaller.

Code: Select all

$ git diff --shortstat official/release.luzern 
 25 files changed, 459 insertions(+), 513 deletions(-)

Many thanks to everyone who tested the previous and the prerelease versions. Without your feedback and tests this new release wouldn't have been possible.

[cdani]

Nice advance. Congratulations!

[Pierre Bourget]

What version to use with Intel i7 ?

[Damir]

how strong is Zurichess ?

[brtzsnr]

What version to use with Intel i7 ?

linux-amd64 or windows-amd64. amd64 (aka x86-64) refers to the instruction set.

[brtzsnr]

how strong is Zurichess ?

Strong enough to beat Stockfish 1 in 30 games.

Luzern version is about 2790 on CCRL 40/40. It has adjustable playing strength if you want to play a game against this engine.