Chiron 4 released

Chiron 4 is about 70 points stronger than Chiron 3.

Here’s a list of the main changes:
– improved automatic tuning of the evaluation
– improved evaluation of passed pawns, mobility, opposite bishops endings
– improved forward pruning in the search
– improved LazySMP for parallel search
– support for Windows Processor Groups (more than 64 threads can now be used)
– NUMA optimization (new UCI and Winboard options “NUMA”)
– minor speed optimizations
– fixed a pondering bug
– fixed two time management bugs under the Winboard protocol

Chiron 4 is available for Windows and Android.
Buyers of the Windows version will also receive a code to get the Android one for free.

Chiron 2/3 Customers can buy Chiron 4 with a discount through the link they have reiceved. Whoever has bought Chiron 3 in the last month will receive Chiron 4 for free.

Chiron wins IGT 2016

Chiron has won the 2016 edition of the International Gsei Tournament. The playing venue should have been at Il Capisterium in Norcia but, because of the earthquake that struck the area, the tournament was held at Accademia Scacchistica Romana in Rome, on September 10-11. There were ten participants, the time control was 30′ + 10″ for 7 rounds. Chiron finished ahead of Booot by half a point. You can read more on G6’s site. Thanks to Jeroen Noomen who provided the opening book for Chiron.

Chiron 3.01 released

Chiron 3.01 is a bugfix version.
There was a bug that would often make Chiron crash when Syzygy bases were used.

Thanks to Antonello R. and Christian G. for reporting and helping with testing.

Chiron 3 released

Chiron 3 is about 60 points stronger than Chiron 2.

Now also available on Android:

Here’s a short list of changes:
– improved search (better parameters for pruning and move ordering)
– improved evaluation (in particular mobility and king safety)
– tuning of the evaluation
– new parallel search
– added support for Syzygybases
– added option “Tablebases Probe Depth” (default=6, lower it if you have a SSD)
– 6 pieces Scorpio bitbases can now be probed
– improved time management
– fixed a time management bug for X moves in Y minutes time controls (thanks to Gabor Szots)
– added option “Blockage Detection” to enable/disable pawn blockage detection
– added again support for CTG books

It comes with an improved Polyglot opening book developed by Arturo Ochoa.

Who has bought Chiron 2 in the last month will receive Chiron 3 for free.
Past Customers can buy it with a discount through the link received in an email.

Chiron in Ubisoft’s Watch Dogs

Chiron has been chosen by Ubisoft for the chess mini game in its highly anticipated open world action game Watch Dogs. The player controls Aiden Pearce, a grey hat hacker obsessed with security and surveillance, and can play throughout the Chicago area normal chess games or try to solve puzzles to increase Aiden’s focus skill.
Of course, given the wide audience, a highly modified reduced strength version of Chiron was used.



Here are a couple of chess related screenshots from the game.

New Book for Chiron 2

Arturo Ochoa has made and kindly offered an opening book for Chiron 2 customers.
It is a wide balanced Polyglot book (~76MB) made from a selection of human and computer games from 2013. You should have received an email with a link to download it.

My thanks to Arturo and my best wishes for Christmas!

Chiron 2 released

Chiron 2 is about 40 Elo points stronger than Chiron 1.5 thanks to improvements in both search and evaluation functions.
Parallel search and time management have been improved too.
Several ChironBitbases have been integrated in the executable:
as well as 4 tablebases: KPK, KRK, KQK and KPKP with rammed pawns.
Besides that, some bugs have been fixed:
– Chiron would often crash with multi-socket systems
– Gaviota tablebases were rarely probed

I would like to thank Martin Thoresen and Ingo Bauer that have helped with testing.

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.