Computer Chess Club Archives


Search

Terms

Messages

Subject: new tablebase probe code in Crafty

Author: Robert Hyatt

Date: 11:06:09 07/16/99


Ok...

  For all you whiners, naggers, complainers, grumblers, bellyachers, and other
lazy bums that won't pony up and buy a 6gig disk, the endgame database probe
idea of your dreams is now ready for testing.  :)

A crafty user (I won't mention names, but it is in the comments in main.c if
you are really interested) submitted some code that looked ok.  It is now in
the just released version 16.13...

Here is what it does.

If the initial position is a mate in N (tablebase hit), then for each move,
a probe is done.  If the move is not mate in N-1, then that move is excluded
from the set of moves to search.  This leaves non-tablebase moves, one of which
_must_ lead to a mate in N-1.  We now hope Crafty can find it via a search.

I had to further modify iterate.c, as with the submitted code, crafty would
still think it was in a tablebase position, and stop the search after 4 plies.

Now you can download the files of your choice with pawns, without having to
grab the promotion cases.  It is _still_ probably better to have them, but
at least it will now avoid most of the ugly draws that could happen without
them using the old approach.

Reports of success or failure always welcome...

Bob



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.