Author: Tony Nichols
Date: 08:31:36 12/03/04
Go up one level in this thread
On December 02, 2004 at 03:53:14, Mike Hood wrote: >On December 01, 2004 at 15:52:03, Tony Nichols wrote: > >>On December 01, 2004 at 15:31:34, John Merlino wrote: >> >>>On December 01, 2004 at 14:42:06, Tony Nichols wrote: >>> >>>>On December 01, 2004 at 14:28:44, John Merlino wrote: >>>> >>>>>On December 01, 2004 at 14:06:54, Tony Nichols wrote: >>>>> >>>>>>On December 01, 2004 at 13:16:06, Dann Corbit wrote: >>>>>> >>>>>>>On December 01, 2004 at 10:13:56, Tony Nichols wrote: >>>>>>> >>>>>>>>I was looking at a study in chessbase 8 that is a mate in three. Unable to solve >>>>>>>>it myself I fired up Shredder 8. To my surprise Shredder claimed it was a mate >>>>>>>>in 5!? Deep Fritz 8 also said mate in 5. When I played the key move both engines >>>>>>>>saw the mate in 2! Other engines found the mate in 3 immediately(Hiarcs 9, Chess >>>>>>>>Tiger 15, Gambit Tiger 2.0, Crafty 19.17 etc.). If someone would tell me how to >>>>>>>>post the position I will. Has anyone else had similiar problems? >>>>>>> >>>>>>>What is the position you are looking at? >>>>>>Hi Dan >>>>>>I don't know how to post the position. If you tell me how I will post it. >>>>>>Regards >>>>>>Tony >>>>>>P.S. it is a study by Milan Vukcevich >>>>> >>>>>You can just describe the position (which pieces are on which squares, and whose >>>>>side to move it is) and somebody else can convert it to the proper format. >>>>> >>>>>Or, if you know how to convert the position into a FEN string, just put a line >>>>>in your post that has a [D] at the beginning and then paste the FEN string >>>>>immediately after it. That will do the trick. >>>>> >>>>>jm >>>>ok here goes [D]3K1B2/2pPPp2/7R/2k2r2/7q/P2Q4/8/8 w - - 0 1 >>>>wKd8,Qd3,Bf8,Rh6,Pa3,d7,e7/bKc5,Qh4,Rf5,Pc7,f7 >>> >>>CM9000 also finds it in a handful of milliseconds. It is possible, since some >>>solution paths require underpromotions (e.g. 1.Ra6 Qc4 2.e8=N+! Kb5 3.Nxc7#), >>>that this could be the reason that some engines don't find the mate in 3. >>> >>>jm >> >> Interestingly enough all my UCI engines find it immediately in Frtiz 8 GUI. >>Only native chessbase engines have a problem. >>Regards Tony > >Tony, you can't generalize by saying native engines don't find the mate in 3. As >you can see below, Shredder 8 and Junior 8 don't find the mate in 3, but Fritz >8, Hiarcs 9 and Tiger 15 do find the mate. It's a common "fault" that Fritz, >Shredder and Junior stop searching for a shorter mate when they've already found >an unavoidable longer mate (although Fritz succeeds in your example). Tiger 15 >doesn't have this "fault", because it keeps on searching after it's already >found a mate. > >================================== > >Analysis by Shredder 8: > >1.Rxh4 > +- (15.33) Depth: 1/1 00:00:00 >1.Rxh4 > +- (27.18) Depth: 1/1 00:00:00 >1.Rxh4 > +- (27.18) Depth: 1/1 00:00:00 >1.Rxh4 Rd5 > +- (27.45) Depth: 2/4 00:00:00 >1.Rxh4 Rf6 > +- (28.09) Depth: 2/4 00:00:00 >1.Rxh4 Kb6 2.e8Q > +- (29.03) Depth: 2/8 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kb3 > +- (39.48) Depth: 2/8 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kb3 > +- (39.48) Depth: 2/8 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kb3 3.e8Q > +- (39.59) Depth: 3/6 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kb3 3.e8Q c6 > +- (39.85) Depth: 4/8 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.e8Q c6 > +- (40.12) Depth: 4/14 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.e8Q c6 4.Qb1 > +- (40.38) Depth: 5/8 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kb3 3.Qb1+ Kc3 4.e8Q c6 > +- (40.88) Depth: 5/9 00:00:00 >1.Qxf5+ Kc4 2.Kxc7 > +- (40.88) Depth: 5/18 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.e8Q Kb3 4.Kxc7 f6 > +- (41.13) Depth: 6/10 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.e8Q Kb2 4.Kxc7 Kb3 > +- (41.63) Depth: 6/10 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Qf3+ Kb2 4.Rh2+ Ka1 5.Qf1# > +- (#150) Depth: 6/18 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Qf3+ Kb2 4.Rh2+ Ka1 5.Qf1# > +- (#5) Depth: 7/12 00:00:00 16kN >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Qf3+ Kb2 4.Rh2+ Ka1 5.Qf1# > +- (#5) Depth: 8/12 00:00:00 21kN >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Qf3+ Kb2 4.Rh2+ Ka1 5.Qf1# > +- (#5) Depth: 9/12 00:00:00 31kN > >========================================= > >Analysis by Fritz 8: > >1.Qxf5+ Kd4 2.Rxh4+ Kc3 3.Qf3+ > +- (#6) Depth: 5/24 00:00:02 1669kN >1.Ra6! > +- (#5) Depth: 5/24 00:00:02 1740kN >1.Ra6 Qg3 2.e8Q+ Qd6 3.Qee3# > +- (#3) Depth: 5/24 00:00:02 1757kN >1.Ra6 Qg3 2.e8Q+ Qd6 3.Qee3# > +- (#3) Depth: 5/24 00:00:02 1760kN > >=========================================== > >Analysis by Hiarcs 9: > >1.Rxh4 Rd5 2.e8Q+ Kc6 > +- (27.16) Depth: 1/10 00:00:00 >1.Qxf5+ > +- (31.50) Depth: 1/10 00:00:00 >1.Qxf5+ Kd4 > +- (31.50) Depth: 1/10 00:00:00 >1.Qxf5+ Kd4 > +- (35.95) Depth: 2/10 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 > +- (35.95) Depth: 2/10 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 > +- (36.24) Depth: 3/11 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Bg7+ Kd2 4.Qf2+ Kd3 5.e8Q c6 > +- (37.74) Depth: 3/15 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Bg7+ Kd2 4.Qf2+ Kd3 5.e8Q c6 > +- (38.28) Depth: 4/16 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Bg7+ Kd2 4.Qf2+ Kd3 5.e8Q c6 > +- (#7) Depth: 4/16 00:00:00 >1.Qxf5+ Kd4 2.Rxh4+ Kc3 3.Qf3+ Kc2 4.Rh2+ Kc1 > +- (#5) Depth: 4/17 00:00:00 >1.Qxf5+ Kd4 2.Rxh4+ Kc3 3.Qf3+ Kc2 > +- (#5) Depth: 5/19 00:00:00 56kN >1.Ra6 Qe1 > +- (#4) Depth: 5/19 00:00:00 65kN >1.Ra6 Rd5 2.Ra5+ Kc6 3.Qa6# > +- (#3) Depth: 5/19 00:00:00 77kN > >========================================= > >Analysis by Junior 8: > >1.a4 Rd5 2.Rxh4 > +- (10.78) Depth: 3 00:00:00 >1.Bg7 Qf4 2.Qc3+ Kb5 3.e8Q > +- (16.89) Depth: 3 00:00:00 1kN >1.Rxh4 Kb6 2.e8Q > +- (26.82) Depth: 3 00:00:00 5kN >1.Qxf5+ Kc4 2.Rxh4+ Kb3 3.Qd3+ Ka2 4.Qc4+ Kxa3 5.e8Q+ > +- (31.87) Depth: 3 00:00:00 12kN >1.Qxf5+! > +- (32.17) Depth: 6 00:00:00 15kN >1.Qxf5+ Kc4 2.Rxh4+ Kb3 3.e8Q f6 4.Qb1+ Kc3 5.Qee1# > +- (#5) Depth: 6 00:00:00 163kN >1.Qxf5+ Kc4 2.Rxh4+ Kb3 3.e8Q f6 4.Qb1+ Kc3 5.Qee1# > +- (#5) Depth: 6 00:00:00 215kN > >======================================= > >Analysis by Chess Tiger 15.0: > >1.Qxf5+ > +- (14.56) Depth: 1 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.e8Q > +- (44.04) Depth: 1 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.e8Q > +- (44.04) Depth: 1 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.e8Q > +- (44.04) Depth: 2 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Qc5+ Kb2 4.e8Q > +- (44.48) Depth: 3 00:00:00 >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Qf3+ Kb2 4.Rh2+ > +- (45.38) Depth: 4 00:00:00 3kN >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Qf3+ Kb2 4.Rh2+ Ka1 > +- (#5) Depth: 4 00:00:00 4kN >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Qf3+ Kb2 4.Rh2+ Ka1 > +- (#5) Depth: 5 00:00:00 10kN >1.Qxf5+ Kc4 2.Rxh4+ Kc3 3.Qf3+ Kb2 4.Rh2+ Ka1 5.Qf1# > +- (#5) Depth: 6 00:00:00 22kN >1.Ra6 Qg5 2.Ra5+ Kb6 3.Qa6# > +- (#3) Depth: 6 00:00:00 55kN Hi Mike I wasn't saying that all CB native engines have this problem,But all engines that have this problem are CB native. Regards Tony
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