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Subject: Re: Self-test and others rating stuffs...

Author: Don Dailey

Date: 11:59:02 01/02/98

Go up one level in this thread

On January 02, 1998 at 14:03:48, Stuart Cracraft wrote:

>Perhaps not directly related but I'll share this anyway...
>My experience in adding knowledge to the evaluation function
>and its relation to test results is that pure tests like
>Win-at-Chess and other tactically-based tests, including
>rating tests that are more tactical (like Kaufman's) suffer for
>more evaluation knowledge but that non-tactical tests may benefit.
>A recent result was that correcting some pawn structure logic
>in a program that was mis-evaluating passed/doubled/isolated
>pawns dropped the Win-at-Chess score by about 2.66% in total
>problems solved but raised the Louguet rating by 45 ELO points.
>At the same time the Louguet result went up 45 points the
>Kaufman result went down 24 points.
>This result came by making only these changes:
>  1. correctly evaluate passed pawns based on rank
>     (previously, no passed pawn logic)
>  2. correctly evaluate doubled pawns
>     (previously, penalized 2 pawns on file, but ignored more than 2)
>  3. correctly evaluate isolated pawns based on file
>     (previously did not take file into account.)
>I'd recommend using extensive positional/endgame tests, not just
>tactical suites.

Yes, of course.  My opinion has always been than tactical sets do not
predict chess strength very well at all.  I think it goes way beyond
just the extra speed you lose for adding evaluation.  I whole lot of
nice tactical algorithms I've used in the past (often extensions) were
dropped from the program despite the fact they looked so good on
tactical problem sets because they in fact weakened the program.

And this had nothing to do with evaluation speed.

-- Don

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