Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: new tablebase probe code in Crafty

Author: Robert Hyatt

Date: 18:51:28 07/16/99

Go up one level in this thread


On July 16, 1999 at 14:58:58, José de Jesús García Ruvalcaba wrote:

>On July 16, 1999 at 14:06:09, Robert Hyatt wrote:
>
>>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
>
>	Does it mean that egtb.cpp has been modified?
>José.


No.  egtb.cpp has nothing to do with this.  This is an internal Crafty issue,
and doesn't bother Eugene's code at all...



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.