TalkChess.com

[Peter Österlund]

Hi,

My new UCI chess engine "Texel" is now available for download from http://web.comhem.se/petero2home/texel101.zip

Texel is derived from my old engine CuckooChess. In fact, Texel 1.00 was functionally equivalent to an unreleased version of CuckooChess. The main difference is that Texel is written in C++11 instead of java.

The program is licensed under GNU GPLv3. The zip archive contains source code and binaries for linux 64-bit and 32-bit (Fedora 16, untested on other distributions) and windows 64-bit and 32-bit (tested on Windows 7 64-bit and Windows Vista 32-bit.)

In theory it should be possible to compile the program on any platform that has a C++11 compiler, because the source code does not contain any platform-specific code. In practice it is still quite hard to find good C++11 compilers. I have used gcc 4.6.3 in linux and Visual Studio 2012 beta in Windows.

Changes compared to CuckooChess 1.12:

* Ported from Java to C++. About twice as fast as a result.
* Made node counters 64-bit to avoid overflow in long searches.
* Fixed handling of UCI "searchmoves" command.
* Added evaluation term to avoid walking into wrong corner in KRKB endings.
* Implemented reverse futility pruning.
* Implemented late move pruning.
* Made strength setting between 0% and 10% even weaker. 0% now plays random legal moves and 10% corresponds to the old 0% setting.
* Replaced cuckoo hashing with a more cache-friendly alternative.
* Try harder not to lose on time in really short time control games.
* Implemented passed pawn race evaluation.
* Increased passed pawn bonus for pawns on rank 6 and 7.

Texel scores about 70% (+140 elo) against CuckooChess 1.13a8 (unreleased) on my 64-bit linux computer at short time control (60 moves in 8 seconds), but I would be very surprised if the difference is that big at longer time controls against different engines.
_________________
Peter Osterlund - peterosterlund2@gmail.com
http://web.comhem.se/petero2home