Chiron 1.5 released

Chiron 1.5 is about 30 Elo points stronger than Chiron 1.1a thanks to improvements in both search and evaluation functions.
Some ChironBitbases (.cbb) are included: KPK, KPPK, KPKP, KQKP, KPPKP.
The min split depth for parallel search can now be chosen automatically by setting the UCI option “Minimum Split Depth” to 0 or by setting “minsplitdepth” in chiron.ini to “auto”. It is already so by default.
Besides that, some minor bugs have been fixed:
– pawn blockage code was not handling correctly en-passant captures (thanks to R. Vida)
– hash table memory allocation was not working correctly when more than 2GB was set

Chiron wins CCT14

Chiron has won the Computer Chess Tournament 14. The tournament, a 7 rounds Swiss, was organized by Peter Skinner and played online on February 25-26 on the Internet Chess Club. Time control was 50’+3″. There were 18 participants. Chiron finished first, one full point ahead of Komodo and Pandix. Thanks to Gary Belton for the book preparation and for his powerful i7 3930k Chiron ran on.

Chiron 1.1a released

Chiron 1.1a is a bugfix version. Unfortunately there were still some bugs that needed to be fixed. Therefore, there are neither strength improvements nor new features.
Once again, thanks to all the users that reported bugs and helped with testing.
In particular these bugs have been fixed:
– tablebases mating problem
– parallel search was not working properly on multi-cpu systems
– pawn blockage detection function could make Chiron crash or score incorrectly some positions
– detection of number of cpu/cores was still wrong with some Intel cpu
– wrong pv output on fail highs

I take this opportunity to wish you a Merry Christmas and a Happy New Year!

Chiron 1.1 released

Chiron 1.1 is a bugfix version. There are neither strength improvements nor new features.
Thanks to all the users that reported bugs and helped with testing.
In particular these bugs have been fixed:
– crashes when probing Nalimov tablebases and Shawul bitbases during parallel search
– incorrect parsing of UCI options regarding tablebases
– incorrect behaviour with UCI fixed depth search and infinite analysis
– disabling of the book after the first game with Chessbase GUIs
– wrong mate announcement with Winboard protocol when Chiron mates with black
– resigning after 6 moves with Winboard protocol when playing with Arena
– wrong castling with some Chess960 positions that lead to blunders and/or crashes
– wrong detection of the number of cpu and cores with Intel processors