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Subject: Re: Question to Robert Hyatt

Author: Robert Hyatt

Date: 08:33:40 05/02/01

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On May 01, 2001 at 18:21:08, Graham Laight wrote:

>
>
>This represents a major flaw in modern chess programs with their relatively
>simple eval functions.
>
>They have to accurately evaluate up to a million NPS (single processor). This
>represents a node every 1000 clock cycles - and this can ONLY be done in a
>relatively simple way. In many positions, the quick eval is enough - but in many
>other positions - it just isn't. Sometimes, you'll get lucky and get the right
>eval for the wrong reasons. Other times, you'll have the reasons roughly correct
>- and still deliver the wrong eval.


This is not quite accurate.  In the case of Crafty, it will do about 1/2
million nodes per second on a 1ghz processor.  That 1ghz processor executes
2 or 3 instructions per clock cycle.  In Crafty's case, the instructions per
node turns into more like 4000-6000, rather than 1000.  When you factor in the
unique way bitboards can answer evaluation questions (ie is this pawn passed
takes 1 operation) this turns into closer to 10,000 instructions per node...

Also, I don't think today's evaluations are "simple".  I'm a pretty decent
chess player and there is very little that I know that Crafty doesn't, in terms
of general chess knowledge about evaluating positions.  There are some things I
know based on experience that are hard to code of course...  but general
positional skills are not bad.




>
>As for getting "every positional factor in the position", as you've said above -
>I think we're talking new technology. Something better than a top human, I
>think.
>
>I believe it would be possible, with today's technology, to set up a system that
>could, somehow, automatically tease out the major positional factors from every
>position in the Chessbase database. This would make for a superb chess position
>evaluator.
>
>-g


I don't think this is possible, until a human can do it himself...





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