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Subject: Re: TranspositionTables and NULL-move

Author: Renze Steenhuisen

Date: 03:06:35 03/10/04

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On March 10, 2004 at 05:56:46, Michel Langeveld wrote:

>On March 10, 2004 at 05:45:47, Renze Steenhuisen wrote:
>> [SNIPPED]
>
>Hi Renze,
>
>Do you use also the best_move in the hashtable?

Hi Michel!

Right now, I do not yet use the best_move yet, but that will be done in about an
hour from now. I will run the same tests again.

>I don't store Nullmove search results in Nullmover too.
>It costs me extra nodes to do it. Also in Olithink and TSCPGothic I found
>similiair behaviour.
>
>I think the reason is that you you fill your hashtable to save something that is
>cheap to calculate (do_nullmove, restore_nullmove and a function call). With
>saving this you throw something out of the hash what is more valuable probably.
>
>Michel

This could indeed be the reason, but I observed very different behaviour for my
program when having different sized TT's. The behaviour of the version that
stores the NULL-move results is very much influenced by the size of the TT,
while the version without the NULL-move results being stored is performing
better with increasing TT-size (32, 64 and 128Meg).
On the other hand, the NULL-move storing version is faster (and expands less
nodes) when using 64 MegaByte... (Could it be the magic number?)

Cheers!

Renze



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