Author: José Carlos
Date: 16:32:02 08/06/04
Go up one level in this thread
On August 06, 2004 at 08:44:32, Tord Romstad wrote: >A basic question from a PVS newbie: > >How much of an improvement should I expect to see when I introduce aspiration >windows in a PVS search? When using an aspiration window of +- 0.5 pawns, >I don't see any improvement at all compared to a window of +- INFINITY. In >most positions, the node counts differ by just a couple of % (and the version >with aspiration is not always the fastest). > >Is this what I should expect, or should I start looking for a bug? > >Tord I've always had aspiration and every try to remove it has been bad for me. I guess, considering most other results, that I must have something incorrectly implemented regarding mate scores and hash table, but I've never found exactly what I do wrong. My aspiration is also a bit sophisticated (!= good). I adjust the size of the window dinamically, either the first search and the researches (for fail high or fail low). I try to get rid of mates unless there's no other chance. For example, in case of a very big fail high, instead of setting beta = +INFINITY, I first try beta = bigger than any score except mate in max. It works for me, but as I said, I believe I have a problem elsewhere. José C.
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.