Author: Robert Hyatt
Date: 07:17:19 11/17/97
Go up one level in this thread
On November 17, 1997 at 08:10:51, Alessandro Damiani wrote:
>Hello!
>
>Before searching the null-move or doing any form of forward pruning, I
>think it should be faster if we test whether evaluate(position)>=beta.
>Since I own a slow machine (MC68020) I would like to know how it works
>with deep search (in the middle game). Any comments?
>
>Bye
>
>Alessandro
would be very dangerous. I assume you mean something like this:
if (evaluate() >= beta) return(beta);
.. do null-move search here ...
The problem with this is that a null-move search is more conservative,
in that *at least* we get to the capture search to see if something is
hanging badly. The above would have *severe* horizon effects. IE
imagine a case where my opponent sacrificed a rook for a mating attack.
I'm a rook up, so the above test would succeed and I'd quit and not
notice
I'm getting mated, only that I am a rook ahead. But the roof would fall
in
later of course...
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