Author: Robert Hyatt
Date: 11:42:52 07/15/02
Go up one level in this thread
On July 15, 2002 at 13:30:54, Gian-Carlo Pascutto wrote: >On July 15, 2002 at 13:11:09, Christophe Theron wrote: > >>Why does double null move prove that null move is a correct search method???? >> >>Doing two null moves in a row means going back to standard search (a search not >>involving an illegal move like null move is). >> >>I fail to see how it legitimates null move. > >I think the idea is simply to show that you can nullmove and still >have a correct search. (but only with double nullmove, not single) > >-- >GCP I think the discussion is pointless, myself. Null-move search is _not_ equlvalent to non-null-move search. It demonstrably has more errors due to reducing the depth on many sub-trees. The concept of "correct search" is therefore so abstract as to mean absolutely nothing. double-null eliminates _some_ zugzwang problems, but not _all_. It is obviously impossible to eliminate all of them, particularly when you are whacking 6 plies off the tree depth and then drawing conclusiong about the resulting sub-trees.. The only useful definition of "correct search" would be to somehow prove that a null-move search to depth=D would produce the _same_ move as a non-null-move search to depth=D, for all positions. This is simply not possible.
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.