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Subject: Re: Extended futility prunning not working

Author: Pallav Nawani

Date: 11:53:03 08/04/04

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On August 03, 2004 at 15:04:54, Cesar Contreras wrote:

>Hi
>
>I'm working on extended futility prunning and it's not working, it seems to make
>a node reduction, but it plays worse than without it.
>
>My question is, do any of you have seen good improvement using extended futility
>prunning?
>
>what normal futility margin do you use?
>what extended futility margin do you use?
>
>Thank you.

Works very well for me (Natwarlal). I think I am getting a ply extra depth from
Futility pruning/reductions. But this could just be because I have very bad
moveordering (50% first move cutoff rate).

Where pruning really shines is in endgame. I get 2-5 extra plies because of the
(heavy?) pruning I do, some times even more.

Pruning hurts tactical strength a bit, especially for a simple program like
mine.

Source for my program, is available, you can look at it if you like. Also, you
can turn futility on/off or change pruning margins from the config file,
Natwarlal.ini.

Hth,
Pallav




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