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

Author: Stuart Cracraft

Date: 11:03:48 01/02/98

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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.

--Stuart



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