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Subject: Re: SEE functions

Author: David Rasmussen

Date: 13:31:01 11/25/02

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On November 25, 2002 at 15:16:35, Andreas Guettinger wrote:

>On November 25, 2002 at 14:17:38, Robert Hyatt wrote:
>
>>
>>Crafty's is not bad.  This is a classic trade-off issue.  It could easily be
>>made more
>>accurate.  IE not using absolute-pinned pieces and so forth.  But the question
>>becomes,
>>does the cost of the extra accuracy result in tree sizes that are small enough
>>that the
>>savings offsets the added computational cost...
>>
>>It's easy to make it more accurate.  But the question is, "is it worth it?"
>

We're not just talking tree sizes here, are we? See below.

>
>I would say no. The differences between MVV/LVA are already not that big, so
>even if the SEE is not the most accuratest, if it is only used for move
>ordering, that doesn't really. More important is that it is fast and only
>executed when necessary.
>

For move ordering, Crafty's is probably fine. That is, I don't think that there
is a lot to gain in move ordering and therefore tree size, by a more accurate
SEE. But SEE is also, in Crafty at least, and in Chezzz (which uses a
SEE-function similar to Crafty's), used to throw out apparently futile captures.
If the SEE isn't good enough, this will lead to tactical problems, by throwing
out what seems to be a futile capture, but isn't. I asked my original question
with that aspect in mind. How safe is it to throw a capture out, using Crafty's
SEE?

/David



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