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Subject: Re: History Heuristic

Author: Sune Fischer

Date: 04:35:03 03/17/04

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On March 17, 2004 at 06:53:44, Peter Fendrich wrote:

>>I scale it down by a factor 8 when the entries hit a certain limit, ie.
>>
>>if (hist[index]>X)
>>  for (i...)
>>     hist[i]=hist_seed[i]+(hist[i]>>3);
>
>
>This doesn't make sense to me. Maybe you meant to have the for-stmt before the
>if-stmt? That's what I have tested a few times but without the hist_seed thing.

It's a form of normalizing the table, if you scale you must scale everything
otherwise only the best entries gets cut down and not the bad ones.

>Is it a random seed and does that really help?

It's not random, I just give a small static bonus for pawns to 7th and such so
they don't zero out completely, seems those will always be interesting moves.

>I have similar results as you but with much less differences than you between
>the different frequencies. Without any seed though.

-S.



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