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

Author: Don Dailey

Date: 14:05:13 01/02/98

Go up one level in this thread

On January 02, 1998 at 16:20:29, Amir Ban wrote:

>On January 02, 1998 at 14:59:02, Don Dailey wrote:
>>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.
>You were almost certainly looking at random noise. In a 300 position
>test-suite, I can get the SAME program scoring 3-6 less on its "bad"
>day. Test suites like Louguet are so small that no real significance
>should be attributed to any particular result. Understanding the effects
>of noise is the key to keeping your sanity in this business. Controlling
>it is a different question.
>>>This result came by making only these changes:
>>>  1. correctly evaluate passed pawns based on rank
>>>     (previously, no passed pawn logic)
>An important change for endgames, but cerainly not for the WAC suite.
>>>  2. correctly evaluate doubled pawns
>>>     (previously, penalized 2 pawns on file, but ignored more than 2)
>Isn't this totally insignificant ?
>>>  3. correctly evaluate isolated pawns based on file
>>>     (previously did not take file into account.)
>What's the correct evaluation of isolated pawns based on file ?

He is a thought on the isolated pawn thing.  Like any pawn structure
thing a good program will have different values depending on file
and rank.  For instance a backward 'a' pawn is not nearly as serious
as a backward d or e pawn.

-- Don

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