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Subject: Re: New crap statement ?

Author: Miguel A. Ballicora

Date: 17:55:33 09/26/01

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On September 26, 2001 at 19:18:18, Gian-Carlo Pascutto wrote:

>On September 26, 2001 at 19:03:12, Miguel A. Ballicora wrote:
>
>>One of the big problems of alpha-beta is that the machine is quite
>>stupid to determine how to traverse the tree and how to prune (pruning is not
>>part of the pure alpha-beta actually).
>
>Hmm?
>
>I'd say beta cutoffs are a perfect example of pruning.
>
>Not sure what you mean by 'pure alpha-beta' though

No null-move, not futility-cuttofs, no forward pruning of any kind,
no extensions etc. Any sort of trick that affect the shape of the tree.
i.e. speculative tricks.

>Making something faster (in terms of nodes) than alpha-beta with
>perfect move ordering is simply impossible unless you start doing
>tricks with the hashtable (and try to reach the real minimal graph
>instead of the minimal tree).

You do it actually with null-move, so it is not impossible.

Besides, why are you assuming that the programs nowadays have a perfect
move ordering? in fact, it is good but still there is a lot of garbage
that can be thrown out, even if the ratio of cutoffs is >90% since that
10 % is propagated across the tree.

Regards,
Miguel


>If alphabeta is the wrong answer, you were asking the wrong question.
>
>--
>GCP



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