Octochess (new engine)
by Tim Kosse

Octochess is a free open source chess engine distributed under the terms and conditions of the GNU General Public License (GPL).

http://octochess.org/

Octochess r4452 (WB)
http://octochess.org/octochess_msw_r4452.7z

Thanks Tim and also Steve R .

Any idea of the strenght of this engine?

Farbror

@farbrorsniff wrote:Any idea of the strenght of this engine?

Tim Kosse wrote:

Two engines I've extensively tested my engine against are GNU Chess 5.07 and Fruit 2.01. Octochess is able to win against GNU Chess most of the time but so far has only won against Fruit once with the occasional draw. There's plenty of room for improvement though, in particular I've spent almost no time on tuning the evaluation. I've got a framework though to tweak the evaluation terms using a primitive genetic algorithm using the evaluation scores printed by other engines as fitness factor. Octochess' playing style seems strange, near total lack of regard for king safety, definitely one of the things I'd like to look into next.

Thanks Andres

Octochess r4452 win64 Intel JA
http://dl.dropbox.com/u/5047625/octochess-r4452-win64-intel-ja.zip

Jim Ablett wrote:I don't think this will run on any Os earlier than Vista. I saw some Vista/Win7 api-specific calls in the source.

Octochess r4452 JA 64 bit Linux build.
http://dl.dropbox.com/u/5047625/octochess-r4452-linux-ja.zip

Octochess r.4452 JA

Windows/Linux 64

http://dl.dropbox.com/u/5047625/octochess-r4452-ja.zip
http://cl.ly/EphR/octochess-r4452-ja.zip

Octochess r4529 (win64/Linux64) (WB/UCI)

- improved playing strength
- experimental UCI implementation
- many small bugs fixed
- add alternative popcount implemention for systems without POPCOUNT.
- if compiled as 32bit program, clamp transposition table size to 1GB
- some code refactoring

Download:
http://octochess.org/octochess-r4529.7z

Octochess source:
https://svn.filezilla-project.org/svn/chess/

Octochess r4558 JA - compiled from latest src pulled from SVN.
Windows/Linux 32/64 bit
http://dl.dropbox.com/u/5047625/octochess-r4558-ja.zip
http://cl.ly/FhWH/octochess-r4558-ja.zip

Octochess r4632

- CECP and UCI: Number of threads can be set
- CECP and UCI: Size of transposition table can be set
- CECP: Support fixed move time (st command)
- Improved playing strength
- Specialized endgame evaluation
- Many small performance optimizations

http://octochess.org/octochess-r4632.7z

Octochess r4638 (Windows and Linux)

- UCI: Fix quit command not actually quitting
- UCI: After returning bestmove after a go, the move is not actually applied
- UCI: Implement support for the OwnBook option
- UCI: Basic support for the movetime argument to the go command

http://octochess.org/octochess-r4638.7z

OctoChess r.4638 JA (UCI)

Windows/Linux/Android 64/32

http://dl.dropbox.com/u/5047625/octochess-r4638-ja.zip
http://cl.ly/GpgB/octochess-r4638-ja.zip

Octochess Revision r4690 (Windows and Linux)

- Fix evaluation bug and use new eval values
- Fix bug in static exchange evaluation leading to assumed king exchange
- UCI: Fix black increment not being considered in time calculation
- UCI: Handle movestogo argument to the go command
- Fix crash in endgame evaluation
- Fix bug in hash table replacement strategy due to truncation at high search depths
- Use history based move ordering of noncaptures in search
- CECP: Tell user an error if trying to use a POPCNT enabled Octochess on a CPU not supporting that instruction

http://octochess.org/octochess-r4690.7z

OctoChess r.4692 JA (UCI)

Windows/Linux/Android 64/32

https://dl.dropbox.com/u/5047625/octochess-r4692-ja.zip
http://cl.ly/ICOy/octochess-r4692-ja.zip

Octochess r4984
http://octochess.org/octochess-r4984.7z

Octochess r.4984 Android : https://dl.dropbox.com/u/5047625/octochess

Octochess r5132 (WB/UCI)

Windows, Linux, Kindle (Touch, Paperwhite)

- implemented Multi-PV analysis
- in analysis mode, the moves to be searched can be specified
- WB protocol: hint command is now supported, it returns best move from transposition table
- more accurate timekeeping
- handle KRPvKR endgame
- improve KPvK endgame
- adjust scores if stronger side is pawnless
- smaller book format
- fix handling of enpassant in hypothetical positions not reachable in a game from the start position
- fix scaling of scores in opposite-bishop endings
- fixed overflow in evaluation of king attack
- various code cleanup
- faster statistics calculation

http://octochess.org/downloads/octochess-r5132.7z

Octochess r5178
http://octochess.org/downloads/octochess-r5178.7z

- Full support for Fischer Random Chess, aka Chess960
- KBPvPK endgame is handled better
- Fixed too early move counter increment in search
- Fix repetition draw detection after a null-move
- Small improvements to the threading if searching with multiple cores

Octochess r5190 (WB/UCI)

Windows, Linux, Kindle (Touch, Paperwhite)

- fix a bug in the transposition table leading to bogus entries
- do not report f1g1 castling move as ambiguous in Fischer Random Chess with king on f1, rook on g1
- CECP: fix typo in detecting fischerrandom variant
- fix crash on startup if system's default locale is invalid

http://octochess.org/downloads/octochess-r5190.7z

Octochess r7482
http://www.andscacs.com/octochess/octochess.zip