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Subject: Re: not using nullmove? [generalized null move]

Author: Bruce Cleaver

Date: 14:13:03 02/15/04

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On February 15, 2004 at 14:21:25, Christophe Theron wrote:

>On February 14, 2004 at 20:15:58, Bruce Cleaver wrote:
>>"Why not use a logarithmic scale based on the difference between the best
>>possible move and the move under consideration?"
>>Ron Rivest (he is the "R" in the RSA encryption algorithm) wrote a chess
>>algorithm called min-max approximation, which computes the first derivative
>>(really!!) of the score's change as a means to shape the search.  It has
>>somewhat the same flavor as your idea.
>>It is really beautiful, but has two flaws:  it is a best-first searcher
>>(therefore exponential in memory), and heavily involves floating-point calcs.
>>The first objection can be overcome in the standard way, but not the second.
>I see a third conceptual flaw: it's not intuitive. I don't see this idea as
>trying to mimic a human chess player's thinking process.
>Even MTD(f) seems more intuitive than this.
>If I had to try new ideas, I would not go into that direction.
>    Christophe

Rivest explains that the idea is to expand the node whose change in evaluation
(if any) will have the most effect upon the root node score.  It *does* take a
different frame of mind than alpha-beta or any of its variants.

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