Computer Chess Club Archives




Subject: Re: Confusion on Null Move

Author: Inmann Werner

Date: 06:44:24 02/10/99

Go up one level in this thread

>I would think that null move would be useful when you get a cutoff. If you can
>refute my move and even if I make two moves in a row, you can still refute it,
>then I have picked a really lousy move. But in this case, you already have a
>cutoff, so why search deeper on it. I think I must be missing something here.
I think you talk about different things.

At each position, first a null move is done and then the search for this null
move goes only 2 plys less than normal search. You need this search to get a
evaluation. This search nearly costs nothing because of the potential increasing
of the search tree in deeper searches and you spare two plies!
After this you have a evaluation of the null move and if it ist >=beta, you
cut off the hole search below. You do not have to search any other move in this
position because this position is plunder and you never should have reached it.
And this really cuts of much, because most of the searched positions are


This page took 0.03 seconds to execute

Last modified: Thu, 07 Jul 11 08:48:38 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.