Author: Heiner Marxen
Date: 10:48:43 05/15/04
Go up one level in this thread
On May 15, 2004 at 13:16:33, Heiner Marxen wrote: >On May 15, 2004 at 13:09:01, F. Huber wrote: > >>On May 15, 2004 at 12:35:31, F. Huber wrote: >> >>>On May 15, 2004 at 11:34:04, Heiner Marxen wrote: >>>> >>>>According to Chest this actually is a mate in 9: >>>> >>>>PV: Qc7 Bf6 Rxe7+ Bxe7 Re3 Qf1+ Kxf1 Re6 Qc8+ Bd8 Rxe6+ fxe6 Qd7+ Kf8 Nxe6+ Kg8 >>>>Qg7# >>>> >>>>I didn't ask for a solution tree, but the "refutation table" shows: >>>>refu 43: Qc7 Bf6 [ 7-] >>>>solu 1: Bxd4+ [ 6+] >>>>solu 2: Qf1+ [ 6+] >>>>solu 3: Bh6 [ 1+] >>>>solu 4: Re6 [ 1+] >>>>solu 5: Rg6 [ 1+] >>>>solu 6: Qc4 [ 1+] >>>>solu 7: Qxc5 [ 1+] >>>>solu 8: h4 [ 1+] >>>>solu 9: Rg8 [ 1+] >>>>solu 10: Rf8 [ 1+] >>>>solu 11: Rh7 [ 1+] >>>>solu 12: Rhh6 [ 1+] >>>>solu 13: Rf6 [ 1+] >>>>solu 14: Rdh6 [ 1+] >>>>solu 15: f6 [ 1+] >>>>solu 16: e6 [ 6+] >>>>solu 17: e5 [ 6+] >>>>solu 18: b6 [ 1+] >>>>solu 19: Bf6 [ 8+] >>>>solu 20: Bf8 [ 4+] >>>>solu 21: Kf8 [ 2+] >>>>solu 22: Be5 [ 6+] >>>>solu 23: Rd7 [ 2+] >>>>solu 24: Rd8 [ 1+] >>>>solu 25: Qb6 [ 1+] >>>>solu 26: Qe2 [ 6+] >>>>solu 27: Qd3 [ 1+] >>>>solu 28: Qa6 [ 1+] >>>>solu 29: Qa5 [ 1+] >>>>solu 30: Qxb4 [ 1+] >>>>solu 31: Qa4 [ 1+] >>>>So, Bf6 appears to be the best answer, all other moves result in shorter mates. >>>> >>>>Since it starts with a quiet move, it is hard to find, of course. >>>>[Chest needed 1 hour with 100MB hash on an Athlon 1500+] >>>> >>>>Cheers, >>>>Heiner >>> >>>Hello Heiner, >>> >>>what I´m missing in your refutation list is the black castling!? >>>(after 1.Qc7 black has actually 32 moves) >>> >>>Maybe you forgot the castling right when copying the FEN string (?), >>>this was the FEN in the original posting: >>> >>>4k2r/1p2ppb1/2pr4/QqNp1P1p/1P1P4/2P2R2/P5PP/4R1K1 w k - 0 1 >>> >>>Eventually exactly this 1... 0-0 would be the only defence against 1.Qc7 - >>>Chest is just calculating on this position on my faster desktop, and I´m >>>really curious about the result ... >>> >>>Best regards, >>>Franz. >> >>Yes, exactly this black castling was the _key_ move - >>here is Chest´s result: >> >>ChestUCI Ver.3.5 UCI1: >> >>CPU: Pentium-4 2.66GHz >>FEN: 4k2r/1p2ppb1/2pr4/QqNp1P1p/1P1P4/2P2R2/P5PP/4R1K1 w k - >>Suche nach Matt in 9 ... (Hash=384MB) >>Suche abgeschlossen ... (Zeit=2029.28s) >>Kein Matt in 9 gefunden ! (33:49) >> >>Best regards, >>Franz. > >Yes, you are right. Sorry for the confusion. >My current version has a bug (I have made substantial changes recently). >Now searching for the problem cause... Ok, found the problem... had to exchange to assignments. Used a negative array index and thus clobbered the castling rights. The problem applies only to my recently changed development version, all published versions do not suffer from this. Thanks Franz, for pointing out the problem! Cheers, Heiner
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