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Subject: Re: Secrets of Rybka and Fruit from my point of view

Author: Brian Richardson

Date: 18:01:00 12/15/05

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On December 15, 2005 at 20:03:47, Sergei S. Markoff wrote:

>>Really? Just the line from fruit:eval.c:
>>
>>  eval = ((opening * (256 - phase)) + (endgame * phase)) / 256;
>
>No. Not just this line, but the concept and well tuning.
>
>>I find that VERY hard to believe. That concept has been around a
>>very long-time.
>
>Really? Where it was introduced by the first time?

Don't know about the first time, but GNUChess (v4) uses the same approach,
albeit only for some king eval terms, and many programs scale things by
material, although not necessarily as nicely as Fruit does.

>
>There was a lot of material-dependent evaluatation factors, but its was tuned
>independently. The result for the most engines that used this approach was bad
>consolidation ability.
>
>>We need specifics. I see nothing special about Fruit 2.1 evaluation
>>to explain the strength.
>
>Lets experiment with it. It's easy to remake Fruit search to make it same to the
>Crafty's.



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