Author: Sanjiv Karnataki
Date: 08:06:45 02/29/00
Go up one level in this thread
On February 29, 2000 at 08:39:14, Robert Hyatt wrote: >On February 29, 2000 at 03:19:00, Bas Hamstra wrote: > >>On February 29, 2000 at 01:34:48, Sanjiv Karnataki wrote: >> >>>Hi All, >>> >>>I just finished reading Ernest Heinz's article on the subject and I had a >>>question about the code sample. It uses a routine called "try_null" that is not >>>given in the article and the only thing the article says is "tries to avoid >>>superfluous null-move searches that do not really promise to cut off as decided >>>by the function try_null" >>> >>>Does anyone know how that decision could be made? I was thinking of trying it in >>>my program. >>> >>>Thank you >>> >>>Sanjiv. >> >>For instance if material is more than PawnValue below Alpha,chances are there >>will be no cutoff. Not perferct of course. > > >Also the hash table trick (used in crafty and many other null-move programs) >can be used. If you get a hit on the hash table, but the depth is not deep >enough to let you take the true score of cutoff score, it still might be good >enough to prove that a null-move search won't fail high (see search.c in Crafty >source, look for "avoid_null". Then look at hash.c to see how this gets set to >disable a null move at this position.) I had a question about that: Crafty also hashes the threat flag if the null move failed low to mate-in-N. Why does it not use that in hash.c also to avoid null move? Thank you. Sanjiv.
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.