TJchess

TJchess is an engine that plays normal chess, Fischer random, crazyhouse, loop chess, and bughouse. Playing strength for normal chess is around rating 2300-2400 on CCRL.

Features:

• plays standard chess
• opening book
• hash table
• pondering
• plays Chess960 / Fischer Random
• can offer draw by agreement and accept draw offers (WB only)
• plays crazyhouse variant (WB only)
• plays loop chess (similar to crazyhouse) variant (WB only)
• plays bughouse variant (WB only, currently only in private versions, playing at ICC and FICS)
• resigns automatically (WB only)
• analysis mode (WB only)

TJchess Version History: (some minor changes are not listed)

6/20/2006:  Version 0.49:

• Initial public version

12/31/2006:  Version 0.78:

• fixed pondering bugs that caused losses on time
• added piece square tables
• opening book support for crazyhouse
• improved hash table usage
• move sorting improvements, killer moves
• IID (internal iterative deepening)

11/11/2007:  Version 0.96:

• extension on single reply
• nullmove now works correctly
• SEE (static exchange evaluation)
• hash table size is configurable

07/21/2008:  Version 0.121:

• added pawn hash table
• evaluation now accounts for bishop pair
• added some limited endgame knowledge
• time management changes
• move sorting improvements
• report score for self in thinking output, instead of score for white
• added UCI version

04/08/2011:  Version 1.0:

• WinBoard protocol changes:
• - support WinBoard “memory” command
• - added some options to WinBoard engine menu
• - improved draw claim handling
• - support “level” command during game
• UCI version can now ponder under polyglot
• time management improved
• mobility term added to evaluation
• crazyhouse evaluation improved
• improved crazyhouse opening book is available
• added chess960 / FRC support (crazyhouse960 is also possible)
• implemented late move reductions
• .ini file handling changed.  new engine is no longer compatible with old TJchess.ini files.

04/25/2011: Version 1.01:

• fixed a couple chess960 / FRC bugs (mostly affecting UCI chess960 mode)

02/12/2012: Version 1.1:

• fixed hash table usage bug
• added aspiration windows
• time management should be improved for conventional time control
• added support for loop chess variant (similar to crazyhouse)
• crazyhouse/loop chess only: further improved late move reductions
• code is now cross platform and can be compiled for Windows/Linux/Android
• started using profile guided optimization (pgo)
• added 64-bit versions (only a small speed gain over 32-bit)
• WinBoard protocol change: support “st” command
• UCI protocol changes:
• - support “movetime” command
• - support “depth” command
• - improved compliance to UCI spec (e.g. whitespace handling, case insensitivity)