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Subject: Re: The Null Move Killer Killed (and an announcement)

Author: Stuart Cracraft

Date: 15:28:51 09/30/04

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On September 30, 2004 at 18:04:05, Robert Hyatt wrote:

>On September 30, 2004 at 14:25:34, Stuart Cracraft wrote:
>
>>On September 30, 2004 at 09:35:09, Robert Hyatt wrote:
>>
>>>On September 30, 2004 at 02:53:16, Stuart Cracraft wrote:
>>>
>>>>The null move killed, win-at-chess 141, has itself
>>>>finally been killed, vanquished with the help of
>>>>two board contributors whose combined suggestion
>>>>led to a 17-fold reduction in time-to-solve.
>>>>
>>>>This posting announces those winners. First the
>>>>stats!
>>>>
>>>>Now solved in 5.49 seconds on a P3 @ 1ghz it would be
>>>>solved in under 2 seconds on more modern equipment.
>>>>Formerly it took 95 seconds to solve.
>>>>
>>>>That's good enough for me. And it's good enough to win
>>>>the $50 contest posed recently since it broke the
>>>>10-second-and-under-barrieras posed in the contest
>>>>posting.
>>>>
>>>>The search:
>>>>
>>>>Alpha=-1332 Beta=-531 Maxdepth=9999999 MaxTime=99999
>>>> 1/ 9  g2f1  0.00 -953      511 g2f1 f4d5
>>>>                                g2f1 f4d5
>>>> 2/ 9  g2f1  0.01 -953      884
>>>>                                g2f1 f4d5 c1g5
>>>> 3/12  g2f1  0.06 -953    11929
>>>>                                g2f1 f4d5 c1g5 d5f6
>>>> 4/16  g2f1  0.39 -953    72781
>>>>                                g2f1 f4d5 b3d5 c6d5 f1g2 d6e7
>>>> 5/24> g2f1  3.83 -552   978925
>>>>                                g2f1 b5b4 b3a4 f4d5 f6g5 d5e7
>>>> 5/25  c1f4  5.49 2260  1420038 c1f4 d6f4 h4h5 g6h5 h1h5 f4h6 h5h6 c7g3 g2g3 d7d
>>>>6
>>>>                                c1f4 d6f4 h4h5 g6h5 h1h5 f4h6 h5h6 c7g3 g2g3 d7d
>>>>6
>>>> 6/25  c1f4  6.06 2260  1519145
>>>>                                c1f4 d6f4 h4h5 g6h5 h1h5 f4h6 h5h6 c7g3 g2g3 d7d
>>>>6
>>>>
>>>>And with it the announcement -- because of the contribution
>>>>of Will Singleton in indicating that null move should be
>>>>avoided before leaves in the main search (and the sense
>>>>of a comparison in an old commented out section of the
>>>>code associated with disabled null move verification having been
>>>>intended to do what Will suggested but having been miscoded
>>>>by me and then #ifdefed out months ago) and Uri Blass'
>>>>comments about my recaptures being too free and easy,
>>>>the program went from a total of 95 seconds
>>>>for wac 141 to 5.49 after these two suggestions were
>>>>implemented.
>>>
>>>I doubt null-move is the problem.  I do null-move _everywhere_ and Crafty has no
>>>problem solving wac 141 doing so...
>>>
>>>
>>>>
>>>>So Will and Uri are the winners, if they wish to accept,
>>>>of the divided $50 prize. Because Will's contribution was
>>>>more significant but less work for him and Uri's contribution
>>>>was less significant but with more work for him, but in either
>>>>case without the change from the other's suggestion the result
>>>>would not have been as dramatic getting down to <= 10 seconds
>>>>as stated in the earlier contest challenge a day or two ago,
>>>>the award has been divided in half for the 2 winners.
>>>>
>>>>Will and Uri are welcome to send me, and only if they wish
>>>>to collect, their postal mail addresses, to cracraft@cox.net
>>>>and a check for $25 will be sent out to each.
>>>>
>>>>In the future, more contests will be held like this whenever
>>>>I run into a huge roadblock but I see none looming presently,
>>>>including a rather unusual one that I am not ready to announce.
>>>>
>>>>Thanks everybody for the help on 141 -- and thanks to Will
>>>>Singleton and Uri Blass.
>>>>
>>>>Stuart
>>
>>What is your quiescence like? Do you investigate moves-that-check
>>at the first ply of quiescence?
>
>
>My q-search has _no_ checks or check-evasions whatsoever.  Just captures, and
>the captures have to appear to be at least equal using SEE or they get discarded
>as well...

What if a capture is a check or check evasion? Acceptable?

Stuart




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