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Subject: Re: Nullmove: when to avoid it?

Author: Severi Salminen

Date: 03:05:38 02/28/01

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On February 28, 2001 at 05:56:36, Leen Ammeraal wrote:

>I am not sure about when to avoid nullmoves.
>I omit it:
>a. when in check
>b. when there are less than 5 pieces (including pawns) on the board
>c. when the last move was a nullmove
>d. at the root node
>Should I also omit it in some other cases,
>for example, when any hashmove (even with a low draft) was found,
>or when beta = alpha + 1?

I avoid it also when it seems that this node is futile: material+MARGIN<=alpha.
It saved a few nodes and it seems to be quite sound assumption.


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