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Subject: Re: Evaluation in REBEL (hanging pieces)

Author: Ed Schröder

Date: 01:43:31 01/11/03

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On January 10, 2003 at 16:57:28, Tony Werten wrote:

>Hi Ed,
>I noticed: You tell how to detect hanging pieces in evaluation, but you don't
>tell what you do with them for evaluation.


It is simply bad to give a penalty for hanging pieces, the error margin is too
high. What you can do is add a bonus if you have 2 or more threats, consider the

[d]rnb1kb1r/pppp1ppp/3qpn2/4P3/5P2/3P1N2/PPP3PP/RNBQKB1R b KQkq -

White has 2 threats,

T1=D6=8 (8 is the expected material gain)
T2=F6=2 (2 is the expected material gain)

A bonus for the second threat (T2) is given as follows:


  int TABLE [] = { 0,25,50,75,100,100,100,100,100,100,100..... };

Meaning that for the above situation a bonus of 0.50 is given. It is assumed
black can only save one piece.

For reasons I can't remember anymore I have zeroed this table (meaning no bonus)
some 8-12 years ago. I am testing it right now because of your question, so far
it is doing better than the default settings.

Thanks Tony!




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