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Subject: Re: Problem with extending to maxdepth

Author: Albert Bertilsson

Date: 05:46:53 06/26/03

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On June 26, 2003 at 08:30:19, Peter Fendrich wrote:

>On June 26, 2003 at 08:11:23, Albert Bertilsson wrote:
>
>>Hi Everybody!
>>
>>Previously I've used check-extensions, and now I added single-reply extensions.
>>This has given me some problems because it seems that the engine tries to extend
>>to much now! Some positions are just searched to very few plies. I guess it has
>>to do with one side only having one move to do (single-reply) and the other side
>>constantly checking, and this makes the search go deep immediatly and not
>>returning until searching to max depth or getting 3-fold repetition.
>>
>>I've solved this temporarily by only allowing to extend at most Depth plies, so
>>when searching to ply 6 maximum search depth should be 12 plies. Anybody have a
>>better idea?
>
>One way to deal with it is to use "fractions of ply". Let's say you search to
>depth=6 and calling search(depth-1,....) you would instead search to depth=600
>(for instance) and doing search(depth-100,...)
>Now you can extend for instance 90 and acter a while you can't go deeper.
>With this method you can also get more reasonable values for less important
>extensions.
Seems like a good solution, specially if I add more extensions later. Although
I'd still like to figure out some clever way to figure out when to stop
extending, to allow extending when it's leading to something good.
>
>/Peter
>
>>Forgive me for interrupting the other threads with this computer chess related
>>question. This is still the computer chess forum?
>
>:-)
>
>>/Regards Albert



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