Author: Robert Hyatt
Date: 11:41:48 10/01/04
Go up one level in this thread
On October 01, 2004 at 12:21:51, Stuart Cracraft wrote: >On September 30, 2004 at 20:00:57, Robert Hyatt wrote: > >>On September 30, 2004 at 18:28:51, Stuart Cracraft wrote: >> >>>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 >> >> >>Yes, but Crafty doesn't notice this nor handle it differently as they are "just >>captures" in the q-search... q-search doesn't detect mate stalemate or draw at >>all either... > >How about check? I assume you don't hand off an incheck position to >quiesce, saving the function call and keeping it investigated by >the main search for one ply extension only at all places in the tree. That is why I extend on _giving_ check rather than on _escaping_ check. Therefore I will _never_ drop into the q-search with the side on move in check, unless I have extended so far that I don't extend the check a full ply... There I just accept the errors since most likely a capture of the checking piece will be the only valid move anyway... > >But in quiescence what if you end up in check? What then? I ignore it. If I can capture the checking piece, or if the king can capture any piece to move out of check, it'll do so. Otherwise it will have to stand pat... > >Stuart
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