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Subject: Re: Attack Table Question

Author: martin fierz

Date: 15:16:37 03/22/04

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On March 22, 2004 at 03:40:57, Daniel Shawul wrote:

>Hello
>
>I have decided to use attack tables. I just did
>a rough implementation of it at the beginning of the eval
>according to Ed's paper. The problem is the thing dropped the nodecount
>by almost 40% .  Initial position nodecount was 800000 and now it is 500000.
>Do incremental move attack tables help? And how do i update the table? It seems
>very difficult to update a sliding move and other special cases.
>
>thanks
>daniel

hi daniel,

i use attack tables in my engine, however they are quite different than those
described by ed (and probably much inferior :-) )
i also don't do incremental updates, and compute them from scratch at each node,
even at leaf nodes, which is very expensive and the main reason that my engine
is so awfully slow.
of course i would also like to make an incremental update of that table, but i
decided against such an attempt because i couldn't figure out how to do it - or
rather, i devised a scheme for incremental updating which was so horribly
complicated that i decided not to use it - i'd rather have a slow engine with
little bugs and good maintainability than a fast engine with many bugs and low
maintainability :-)
the main question you have to answer is "what do i get from my attack tables to
justify the extreme drop in NPS?". the answer for me is that my crappy SEE uses
those attack tables, and my evaluation uses them too, specially for kingsafety.

if you can justify it right now, you can always switch to incremental updating
if you find a sensible way of doing this...

cheers
  martin



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