Author: Omid David Tabibi
Date: 08:41:30 06/15/04
Go up one level in this thread
On June 15, 2004 at 07:48:48, Tony Werten wrote: >On June 15, 2004 at 04:52:53, Omid David Tabibi wrote: > >>On June 14, 2004 at 21:45:44, Anthony Cozzie wrote: >> >>>On June 14, 2004 at 20:12:09, Omid David Tabibi wrote: >>> >>>>On June 14, 2004 at 19:20:57, Anthony Cozzie wrote: >>>> >>>>>On June 14, 2004 at 16:31:17, Jaime Benito de Valle Ruiz wrote: >>>>> >>>>>>[d]8/8/1p4p1/p5kp/Pp1QP1Pq/1P6/6K1/8 w - - 0 62 >>>>>> >>>>>>White moves and wins! >>>>>>Can your engine find the right answer and give the proper "crushing" score >>>>>>(around 9 pawns!) along with a proper PV? How long does it take? >>>>>>Mine doesn't find anything after a long long time (over an hour), but with >>>>>>null-move disabled, it takes only a few seconds to show the full PV. >>>>>>(Some engines find the right answer, but with a small score, an absurd PV, and >>>>>>they change their mind some plies later) >>>>>> >>>>>>In this position the black king is in a very delicate position: After a couple >>>>>>of moves, if the black queen moves, white checkmates inmediately, so both kings >>>>>>and queens must remain still while pawns play on their own. >>>>>> >>>>>>Any good suggestion to avoid this problem with null-move? >>>>>> >>>>>>Regards, >>>>>> >>>>>> Jaime >>>>> >>>>>Zappa doesn't get it either (gxh5 @ 15 ply after 1 minute). Zappa relies on >>>>>double nullmove for zugzwang avoidance. This works find for positions with 1 >>>>>zugzwang, but in this position black gets hit with about 10 of them :) >>>> >>>>Ehem, ehem, heard about verified null-move pruning? :) >>>> >>>> >>>>> >>>>>anthony >>> >>> >>>It's a possibility. If I understand it correctly verifications performed >>>nonrecursively. >> >>The original formulation had problems with detecting several zugzwangs in a >>line, and I think it might have failed to find the correct move here. One of the >>things I changed in the new formulation is to make the algorithm find as many >>zugzwangs there might be along a line. > >Did you split black and white zugzwangs now ? I'm not quite sure what you mean, but the algorithm works the same for both white and black :) > >Tony > >> >> >>> >>>Right now, my goals are "Deep Zappa" aka "ParZappa" aka "Zappa-NUMA" aka "Zappa" >>>and the autotuning stuff; when I get some free time I'll try to give it a shot. >>> >>>Oh, and I have to rewrite my eval again. >>> >>>anthony
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