Author: Robert Hyatt
Date: 12:42:03 09/11/99
Go up one level in this thread
On September 11, 1999 at 11:42:29, Ed Schröder wrote: >>Posted by Robert Hyatt on September 11, 1999 at 10:19:19: >> >>In Reply to: Re: Interesting mate test for hashing posted by Ed Schröder on >>September 11, 1999 at 01:43:12: >> >>On September 11, 1999 at 01:43:12, Ed Schröder wrote: >> >>> >>>Do not underestimate the idea that in case there is no bestmove from the >>>hash table you do a full static evaluation of all nodes first and based >>>on that you pick the bestmove as being the first move you are going to >>>search for this (new) depth. The very early Rebel's (1981) worked that >>>way and I remember (although the system is very time consuming) it was >>>superior to all other systems I tried. >>> >> >>I'm not underestimating it. I was simply saying that this approach can >>be applied when the position is encountered and there is no 'best move' >>in the hash table. Rather than doing it when the hash entry is stored, >>and we are not even sure that this hash entry will ever be used again or >>that it won't be overwritten before it is needed. > >Right. > >>>I later removed the system because hash tables + bestmove was more powerful >>>at least for Rebel. But I wouldn't exclude the possibility such a system >>>can have a positive effect on the speed of the search. >>> >>>Actually I didn't remove the system but I replaced it with a faster one >>>that is: >>> >>>- generate all legal moves; >>>- for all moves do a (very) quick evaluation; >>>- sort all moves based on the quick evaluation. >>> >>>This (move ordering) system (for Rebel) is still superior. >>> >>>Ed >> >> >>Do you use killers, history, etc? > >Just the normal stuff. > >Order... > >- hash table move >- winning captures (ordered by expected material gain) >- promotion >- equal captures (QxQ etc) >- killers (4 of them) >- remaining moves ordered by the intelligent move generator > >The Killer History from Jonathan Schaefer gave no improvement for me. > >Ed It probably won't help if you keep 4 killers. I didn't find any improvement in Cray Blitz either... but I did even more with killers. I tried the current ply killers then the killers from _other_ plies if they were legal... adding history did nothing for me... I probably ought to re-check Crafty again as it might be extra overhead for nothing now...
This page took 0.01 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.