Author: Robert Hyatt
Date: 14:59:55 11/15/01
Go up one level in this thread
On November 15, 2001 at 16:47:57, Antonio Dieguez wrote: >I would like to know why they work for you (if). > >I have tried doing a null window search in the first root move with (prev_score, >prev_score+1), to decide if to research up or down. But that is not better than >just a (prev_score-window,prev_score+window), is that normal? I mean, if not >even that works well for me why should I think MTD will? >What do you get if you do the first thing mentioned? > >And do many null window searches in the tree have never worked very well for me. >No more than 1% or 2% gain. Even only using them when there are ht move of exact >score and the window is very big I have that 1% or something. I have heard PVS >is a lot better than alphabeta(with small and nulls windows in the root of >cors), yea sure... > >What difference you get using pvs or using alphabeta with aspiration search? I use both PVS _and_ aspiration. I set an aspiration window at the root before I call Search(), and I use PVS inside the search everywhere. PVS will generally reduce the tree size by around 10%. Less if the program changes its mind at the root a lot since it has to re-search those things twice. It might be more than 10% for positions where you _never_ change your mind or fail high. > >Well, am sorry to bother you. Be well...
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.