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Subject: Re: Simple quad-opteron test

Author: Robert Hyatt

Date: 20:50:42 12/03/03

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On December 03, 2003 at 20:42:57, Jeremiah Penery wrote:

>On December 03, 2003 at 19:54:49, Robert Hyatt wrote:
>
>>On December 03, 2003 at 19:37:13, Jeremiah Penery wrote:
>>
>>>On December 03, 2003 at 16:22:27, Robert Hyatt wrote:
>>>
>>>>On December 03, 2003 at 15:54:45, Tord Romstad wrote:
>>>>
>>>>>On December 03, 2003 at 14:59:03, Robert Hyatt wrote:
>>>>>
>>>>>>=====================10 seconds per position========================
>>>>>>test results summary:
>>>>>>
>>>>>>total positions searched..........         300
>>>>>>number right......................         299
>>>>>
>>>>>That's really impressive, even considering the fast hardware.  The last
>>>>>time I tried, I got 289/300 at 1 second/position, 293/300 at 3 seconds,
>>>>>294/300 at 5 seconds, 295/300 at 10 seconds, and 298/300 at 20 seconds.
>>>>>
>>>>>The remaining two positions, number 100 and 230, are *never* solved.
>>>>>I can let my program analyse for hours, but it still doesn't find
>>>>>the solutions.  In both positions, it thinks it is winning, but
>>>>>never finds the right moves.
>>>>
>>>>I have gotten 230 in the past, but when I made some passed pawn changes of
>>>>some sort, it went away.  But even back then it took several minutes to choose
>>>>the rook toss...
>>>
>>>If you compile with the #define DETECTDRAW it will find almost instantly that
>>>any move other than Rb4 is a blocked position draw. :)
>>
>>Have you tried it already?  I'll give it a whirl tonight when I get home..
>>
>>Although the opteron seems to be down right now.  They were installing a
>>firewall, so I might be dead until tomorrow.
>
>Yes, I wrote that code, remember? :)

Yes I remembered.  :)  I was specifically talking about it with respect to
WAC 230.  I remembered some results from some of those stupid positions
with the pawn locked where one side offers a rook that should not be
taken.  :)

I didn't know it also worked on wac 230.



> This is one position that I initially used
>for testing (among a great many blocked/near blocked positions) to verify that
>it didn't mis-detect.  It's possible that it still does occasionally, but the
>benefit may outweigh that.  The biggest cost is to search speed, but on a huge
>majority of positions the code will have incredibly tiny impact (for instance,
>if there is a knight on the board, the only cost is a single if statement).
>Only on a very small class of positions will very much of the code be used, but
>of course those will be the ones where the code is most helpful. :)



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