Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Null move???

Author: Robert Hyatt

Date: 19:12:15 02/04/99

Go up one level in this thread


On February 04, 1999 at 19:10:24, Greg Lazarou wrote:

>I read with interest the Null move discussion below, and it sounds like it is
>obvious to everybody else on that thread but can somebody explain what exactly
>is the idea of the null move algorithm and why it speeds the search?
>
>Greg


Simple explanation...  if you could make two moves in a row at one place in
a game, of your choice, you could be world champion with no problems.  Two
moves in a row is a crushing advantage.  In chess... suppose you reach a
position where it is your move, and your opponent says "I pass, move again".
You do, but you can't do anything good.  In such a case, you could rightfully
say 'my position sucks'.

That is how null move goes...  in the chess tree you try a null move and see
if your opponent can do anything to you.  If not, you 'fail high' there and
say 'your position sucks, try something else.'  And since the two-moves-in-a-row
is such a big advantage, we can search the resulting tree to a shallower-than-
normal depth which saves a lot of time...



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.