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Subject: Re: Speaking of the Thesis by Marcel van Kervinck (hopefully no storms)...

Author: Robert Hyatt

Date: 13:17:10 09/06/02

Go up one level in this thread


On September 06, 2002 at 16:03:42, Sune Fischer wrote:

>On September 06, 2002 at 15:46:53, Tony Werten wrote:
>
>>On September 06, 2002 at 14:45:11, Dann Corbit wrote:
>>
>>>Did anyone notice his cutoff idea in the evaluation function?
>>>
>>>It seems to me to be a very good idea, and I don't know if others have tried it
>>>out.
>>>
>>>Basically, it consists of three modes with two early exits...
>>>
>>>1. If the material + structure score alone is dominant enough, it exits right
>>>away.
>>>2. Otherwise, it processes the piece list.  If that score is dominant, it exits.
>>>3. Otherwise, it does a full board control scan for all 64 squares.
>>>
>>>It is described starting on page 62 under the section "3.3.2 Multi Staged
>>>Design"
>>>He gets roughly 71% evals returning in stage #1, 13% in stage #2 and 7% in stage
>>>#3.
>>>
>>>It seems like it might be a big win to do it that way.
>>
>>It's called lazy eval and is not a good idea. The times it is wrong happen to be
>>the important ones.
>
>I think you can do it safely.
>If your positional score can't get higher than x, and your material score is
>already larger than beta+x, then what do you win by doing a full eval?
>
>This is how I use it now, of course I have simple eval, but even with a
>complicated one I would sum up the (few) big factors first and try the same.
>
>-S.
>
>
>
>>Tony


I do it in stages.  Material + big window.

material + big score stuff + smaller window.

Finally do entire eval.  The last part of the eval, the individual piece
stuff, is really a number cruncher and even if I have to do the big score
stuff like passed pawns, I can generally avoid going thru all the piece
loops doing that stuff...



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