Here comes AviChess, a Winboard/Xboard compatible freeware chess engine written in C. This is an entirely original work, apart from the Mersenne/Twister random generator used to make AviChess vary its play. Sources should compile under Windows or Linux without problem.

AviChess runs in 5 different modes depending on compile option used:
None Console mode
/D or -D PERFT Console perft mode
/D or -D SEED Console mode with initial seed for random generator
/D WINBOARD Winboard mode (Windows)
-D XBOARD Xboard mode (Linux)

See program usage for needed parameters in console mode (just run AviChess with no parameters).

In perft mode, AviChess will read test data from the perftsuite.epd file if it exists, otherwise it will run from the initial position. Sometimes AviChess will give different numbers from those provided in the perftsuite file because legal draws are detected by AviChess in perft mode as it is done in other modes. Indeed I would greatly appreciate if anyone could confirm those numbers.

12/12/2009 Version 0.6 main features:
- Iterative deepening
- Alpha/Beta pruning
- Principal variation search
- Evaluation based on material and mobility

29/12/2009 Version 0.7 main new features:
- Aspiration window
- Evaluation now based on material value and position
- Winboard/Xboard logo

31/01/2010 Version 0.8 main new features:
- Some code and data structures optimization
- Winboard/Xboard incremental clock mode management (used to crash in previous versions, thanks to John Boyd for having discovered the issue!)
- King safety

26/03/2010 Version 0.9 main new features:
- Winboard/Xboard incremental clock mode 1 x management (used to crash in previous versions)
- Pawn structure
- Winboard Move Now
- Embryon of configuration file

17/04/2010 Version 0.9a (released after BotF/OpenWar/WBEC test tournaments) main new features:
- Fixed false draw claim by insufficient material when KNkn remaining
- Fixed Winboard/Xboard result not sent when not on move
- Fixed Winboard/Xboard clock management when less time than expected remains
- Fixed console seed mode under Windows (now included in package)
- Pawn structure removed (not efficient)
- Small adjustments to evaluation function
- 2 parameters now in configuration file!

27/05/2010 Version 0.9b main new features:
- Some code and data structures optimization
- Added time management for human player in console mode
- Small adjustments to evaluation function

perftsuite.epd file downloaded from Mediocre chess engine website, thanks to Jonatan Pettersson!

Windows binaries provided:
avichess.exe Console mode
avichess_perft.exe Console perft mode
avichess_seed.exe Console mode with initial seed for random generator
avichess_winboard.exe Winboard mode

Have fun!

Download AviChess 0.6
Download AviChess 0.7
Download AviChess 0.8
Download AviChess 0.9
Download AviChess 0.9a
Download AviChess 0.9b

Michel Gaillard (France) -