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Subject: Re: Attack information in evaluation and speed

Author: Matthias Gemuh

Date: 14:16:47 05/18/03

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On May 18, 2003 at 09:52:43, JW de Kort wrote:

>Dear friends,
>
>For a long time i have been planning to use attack information in my 0x88 based
>program. Before evaluation starts, my program calculates a table with attack
>information like the one discribed on the internet page of Ed Schroder. The
>result is disaterous: nps count has dropped by 50%! I have taken a look at the
>Sjeng code but as i see it, this must also be a serious reduction of the NPS in
>this program.
>
>Can anybody give me some tips to do this efficiently?
>
>Thanks in advance,
>
>Jan Willem


Hi Jan,
even I will speak, though my BigLion([http://www.gemuh.de]) is bad in
everything.
I use Bitboards and achieve no speed gain in updating.
I hash attack boards and use them in InCheck(), SEE(), MoveGen(), Eval().
They are valid almost everywhere and drop my speed from 230kN/s to 90kN/s !
Playing strength seems unchanged, but advantage is that no piece gets trapped.
Hash hits = 70%, therefore hashing hardly advantageous.
Regards,
Matthias.








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