Arasan 17.3

[jdart]

Arasan 17.3 is available from http://www.arasanchess.org.

Changes in Arasan 17.3 (Sept. 2014):
1) Reduce doubled pawn score in endgame.
2) Fix some bugs involving hash size settings for UCI.
3) Minor changes to outpost scores.
4) Fix a couple bugs in "makebook" program.
5) Some king safety enhancements.
6) Tuning of futility pruning parameters.
7) History pruning disabled.
8) Fixes to history and killer move handling.
9) Simplify capture extension code and disable "easy nove" if
capturing the last piece.
10) Increase see pruning depth to 1.5 ply.

Plus as usual there are book improvements.

In matches against version 17.2, this version scores only a little better. But it is stronger against other programs.

Here for example is a match result against Crafty 24.0 (Linux, blitz 5+3, 1 core, ponder off):

Rank Name Elo + - games score oppo. draws
1 Arasan 17.3 2431 9 8 1200 59% 2369 38%
2 Crafty 24.0 2369 8 9 1200 41% 2431 38%

Note for Arena users: I have probably mentioned this before, but Arena by default sets "-H 32768" as command-line arguments for Arasan. This sets the hash size way too low (the value used to be in kilobytes but for many versions now it is interpreted as a byte value). If you want to set the hash on the command line you can use something like "-H 500M" to set 500MB hash ("G" for gigabyte is accepted, too), or you can just omit the command line and use standard GUI facilities for setting the hash size. (UCI hash options used not to work for setting large hash values but that bug is fixed in this release).

--Jon

[Graham Banks]

Thanks Jon.

[GONeill]

Hi Jon,

Can you please check the compilation of Arasanx-32 as I'm getting an error that 64 bit engines won't run on a 32 bit OS. (Win 7 32bit)?

Many thanks,
Graham

[jdart]

I keep forgetting that the 32-bit compiler on Windows is a whole separate toolchain and so changing the Makefile target is not sufficient.

Should be fixed now. I have re-uploaded the .zip/installer.

--Jon

[Sedat Canbaz]

Arasan 17.3 is available from http://www.arasanchess.org.

Changes in Arasan 17.3 (Sept. 2014):
1) Reduce doubled pawn score in endgame.
2) Fix some bugs involving hash size settings for UCI.
3) Minor changes to outpost scores.
4) Fix a couple bugs in "makebook" program.
5) Some king safety enhancements.
6) Tuning of futility pruning parameters.
7) History pruning disabled.
8) Fixes to history and killer move handling.
9) Simplify capture extension code and disable "easy nove" if
capturing the last piece.
10) Increase see pruning depth to 1.5 ply.

Plus as usual there are book improvements.

In matches against version 17.2, this version scores only a little better. But it is stronger against other programs.

Here for example is a match result against Crafty 24.0 (Linux, blitz 5+3, 1 core, ponder off):

Rank Name Elo + - games score oppo. draws
1 Arasan 17.3 2431 9 8 1200 59% 2369 38%
2 Crafty 24.0 2369 8 9 1200 41% 2431 38%

Note for Arena users: I have probably mentioned this before, but Arena by default sets "-H 32768" as command-line arguments for Arasan. This sets the hash size way too low (the value used to be in kilobytes but for many versions now it is interpreted as a byte value). If you want to set the hash on the command line you can use something like "-H 500M" to set 500MB hash ("G" for gigabyte is accepted, too), or you can just omit the command line and use standard GUI facilities for setting the hash size. (UCI hash options used not to work for setting large hash values but that bug is fixed in this release).

--Jon

Many thanks dear Jon !

Probably in the next days I will test your latest version !

Btw, congrats! to beat Crafty is not so easy as it looks...

Best,
Sedat

[Jamal Bubker]

Thank you Jon