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Subject: Re: evaluation tuning tricks

Author: Uri Blass

Date: 07:44:57 03/17/04

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On March 17, 2004 at 09:55:59, Fabien Letouzey wrote:

>On March 17, 2004 at 09:52:27, Tord Romstad wrote:
>>On March 17, 2004 at 04:58:06, Peter Alloysius wrote:
>>>what are tricks for evaluation tuning so that it could
>>>search less nodes?
>>An easy way to reduce your tree size enormously is to evaluate all
>>positions to the value 0.  You will get beta cutoffs at the first move
>>everywhere in the tree, therefore the tree will be extremely small.  Your
>>move ordering will always be perfect, and the simple evaluation function
>>will certainly boost your nodes/second count.  :-)
>>Seriously, I don't think tuning the evaluation is the right way to go
>>in order to reduce the tree size.  You should rather concentrate on
>>making the evaluation function as accurate as possible, and look for
>>improvements in your search and move ordering when trying to reduce the
>>size of your tree.
>No offense Tord, but I don't understand  why programmers think the move ordering
>is "perfect" if a fail-high move is found first 100% of the time.  The size of
>subtrees is a very important matter in programs with many extensions/reductions.

I never was interested in the % of first fail high.

If I do a change in the search and test it(including change in move ordering) I
use test positions and test if it is better or worse in solving them.


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