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Subject: Re: piece mobility?

Author: Andreas Herrmann

Date: 08:47:46 01/08/04

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On January 08, 2004 at 09:37:59, Tord Romstad wrote:

>On January 08, 2004 at 08:39:24, Andreas Herrmann wrote:
>
>>in my engine, mobility is one of the most powerful parts in the eval. I
>>calculate it from my attack tables.
>
>One of the nice things you get almost for free with attack tables is that it
>is almost trivial to compute safe mobility rather than pseudo-legal mobility.
>
>>Calculating attack tables is very slow, but you can use them for a lot other
>>things.
>
>How slow is the attack table calculation for you?  Do you have a couple of
>test positions we could compare?  In the opening position (which is probably
>not a good position, because all sliding pieces are blocked) I generate my
>16-bit attack tables almost exactly 1000,000 times per second on a PIV 2.4 GHz.
>
>Tord

it's very slow in my engine, it costs me in the most cases about 1 ply. But my
current attack tables, are not very good. I'm generating and using the attack
tables at the moment only in the opening and middle game, but not in the
endgame.
And i calculate only the number of attackers per side and the total attacking
piece value per side, while scanning my piece lists. With my current data, i
can't do for excample SEE in qsearch, or calculate hanging pieces and some other
stuff. So that was the reason for my question to Ed in my other posting, because
i'm looking for another better solution to do SEE and some other things.
Your generating speed with 1 million per second seems realy fast.

Andreas








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