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The Sinobyl Chess Engine

A chess program written by Eric Oldre.

License

Sinobyl is free for personal use.

Download

• Sinobyl 1.5 (Released 1/14/06 - renamed 11/29/08) 
• Sinobyl 1.4 (Released 12/23/05) 
• End-game bitbase files for use with Sinobyl 1.4 and up (Developed by Daniel Shawul) 
• Sinobyl 1.3 (Released 7/1/05) 
• Sinobyl 1.2 (Released 1/1/05)

What happened to the chess engine named Latista

Sinobyl is the same engine as Latista was, it has just been renamed. Why? Because Sinobyl Is Not Owned BY Latista Technologies LLC.

How do I play?

Sinobyl supports the xboard chess engine protocol. This means that you need a graphical user interface (GUI) in order to be able to play against it. Examples of some interfaces that you can use to play Latista are:

• Winboard
• Arena

Sinobyl also plays on the Free Internet Chess Server (FICS) whenever my computer is free. It plays under the handle "Murderhole". It has a rating of about 2100.

What has changed since 1.4?

• Sinobyl nows uses more agressive null move pruning. R=3, with a verification search in the endgame
• The evaluation function has been tweaked with a few special cases. Other parts have been simplified to make a more smooth transition from the middle to end game.
• New configuration option: [book]selectivity. The higher the number the "closer to the vest" Sinobyl will play during the opening. With a value of 100 it will always play the most popular move in it's book.
• New configuration option: [logging]createlogfile (1 or 0). Now you have the option to not create a log file and conserve hard disk space.
• Changes to the way Sinobyl handles searching on a "ponderhit". It will now simply continue the ponder search, instead of restarting. This should increase it effectiveness in game with pondering on.

How do I use the endgame bitbases?

1. Download the endgame bitbase dll and data files.
2. Put the files in a directory on your PC. Put both the dll and data files in the same directory.
3. Edit the Sinobyl.ini file, enter the location of the files in the [egbb] section under "path".

How does Sinobyl work?

board representation: Sinobyl is a chess engine built on the concept of rotated bitboards, a concept developed by Robert Hyatt. Information about them can be found at http://www.cis.uab.edu/info/faculty/hyatt/pubs.html search features: Sinobyl uses a Alpha-Beta search algorithim with several enhancements which include:

• Iterative deepening.
• Aspiration window.
• Null move cutoffs
• Quiesent search (captures and promotions only)
• Move ordering by:
  • Hash table entries
  • Internal Iterative deepening
  • Static exchange evaluation
  • Killer moves
• Fractional extensions for:
  • Checks
  • Pawn to 7th rank.
• Evaluation features:
  • Material
  • Pawn hash table
  • Piece square table
  • Piece activity
  • Pawn shelter for king
  • King safety
  • Pawn Races
  • Development

What can I expect in future releases?

There are many improvements that I'd like to make in future releases.

• Configurable hash table size.
• Configurable evaluation and search parameters.
• Hopefully, much stronger play.
• Improved king-safety.

Special thanks to

• The members of the computer chess club.
• All the directors of winboard engine tournaments.
• Daniel Shawul for developing the shared endgame bitbase library.