Author: Antonio Dieguez
Date: 13:21:11 02/26/02
Go up one level in this thread
On February 26, 2002 at 12:26:11, Vincent Diepeveen wrote: [snip] >>Not exactly. 16 ply to DB is not 16 ply to DF. DF uses null move, and DB did >>not. 16 ply to DB is much deeper than 16 ply to DF. > >first of all it only got 11 to 12 ply. Secondly it is not deeper >at all. it is the same depth. It only means sometimes you *might* >prune away something which DF sees at 12 which DB sees at 11. > >In principle minimax as well as nullmove as well as alfabeta >as well as hashtables give >for a depth n the same score back to the root. > >Nevertheless *no one* is using minimax without alfabeta pruning, >simply because alfabeta is using less nodes to get the same result. > >Alfabeta *might* prune something which minimax doesn't, because of >the qsearch where you prune on beta anyway. what do you mean? alphabeta cuts variants everywere in the tree. If you mean something that causes alphabeta see something different than minimax, prunning in beta in the qsearch isn't anything different than prunning before. >Same is true for nullmove. very different actually, alfabeta is alfabeta. And nullmove is nullmove, where there is a chance to get inferior move to the root and wrong score as you know. I recommend you not support your point with inexactitudes or exaggerations as it is bad for credibility... >In reality the difference between using nullmove and not using it >is many plies. Not a constant number, but it IMPROVES the branching >factor. > >Nowadays nearly no one is not using hashtables+nullmove, without >replacing it by very dubious pruning.
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.