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Subject: Re: Initial Position Search Nodes

Author: Dan Newman

Date: 18:03:18 10/09/00

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On October 09, 2000 at 17:45:16, Steve Maughan wrote:

>Dan,
>
>Thanks for the input.  Your stats would indicate that my hash table / move
>ordering is to blame - this is helpful.  I'll take a look.  Looks as though you
>have created a fast program!
>
>Thanks again,
>
>Steve

I just read Vincent's post above where he turned off his hash move and got
very little difference.  I tried the same thing and got the same result.
I went from 2.94 to 3.24 seconds (1.27 to 1.36 Mnodes).  So I take back
my hash move sugestion.  I guess that internal iterative deepening really
works :).

Dang.  I commented out my IID and the node count only rose to 1.49 Mnodes.
I tried to comment out my SEE, but that breaks something...  I guess the
only thing I can think of that makes a really huge difference is the
null-move heuristic.

That did the trick.  With the null-move off I get 12 Mnodes...

-Dan.

>
>>Mine (Shrike) is doing this in just under 3s (1.27M nodes) on a P3/600.
>>It's getting about a 35% hit rate on the hash table, so this may well
>>be the problem.  Those hash table moves are really important in getting
>>good move ordering (and a low branching factor).
>>
>>I also keep stats on the fraction of cutoffs from the first move tried
>>and the fraction that are from hash table moves.  In this case I'm
>>getting 92% of the cutoffs from the first move and 25% from the hash table.
>>
>>-Dan.



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