Author: Enrique Irazoqui
Date: 13:12:13 02/02/01
Go up one level in this thread
On February 02, 2001 at 15:25:13, Uri Blass wrote: >On February 02, 2001 at 08:40:06, Enrique Irazoqui wrote: > >>On February 02, 2001 at 07:47:52, Heiner Marxen wrote: >> >>>On February 01, 2001 at 17:47:23, Ignacio Santos Crespo wrote: >>> >>>>On January 31, 2001 at 11:25:25, Enrique Irazoqui wrote: >>>> >>>>>On January 31, 2001 at 10:25:50, Heiner Marxen wrote: >>>>> >>>>>>On January 30, 2001 at 17:15:45, Olaf Jenkner wrote: >>>>>> >>>>>>>Perhaps I had in mind this problem what is easily to prove that there is >>>>>>>no shorter mate. >>>>>>> >>>>>>>Pervakow/Sum. #46 >>>>>>>[D]2N5/p4P2/p4RqP/P2krb2/5RNK/2PPBnP1/3P1pP1/5Q2 w - - 1 0 >>>>>> >>>>>>Yes, that can be. Much to my own surprise Chest really proves this >>>>>>as a mate in 46 moves, and needs just 8.2 seconds (K7/600) for it. >>>>>>It gives the following PV: >>>>>> >>>>>> 1. gxf3 Qh5+ >>>>>> 2. Kxh5 Bg6+ >>>>>> 3. Kxg6 Rg5+ >>>>>> 4. Kh7 Rg7+ >>>>>> 5. Kh8 Rh7+ >>>>>> 6. Kg8 Rh8+ >>>>>> 7. Kg7 Rh7+ >>>>>> 8. Kf8 Rh8+ >>>>>> 9. Ke7 Re8+ >>>>>>10. Kd7 Rd8+ >>>>>>11. Kc7 Rd7+ >>>>>>12. Kb8 Rb7+ >>>>>>13. Ka8 Rb8+ >>>>>>14. Kxa7 Rb7+ >>>>>>15. Kxa6 Ra7+ >>>>>>16. Kb5 Rxa5+ >>>>>>17. Kb4 Rb5+ >>>>>>18. Ka3 Rb3+ >>>>>>19. Ka2 Rb2+ >>>>>>20. Ka1 Ra2+ >>>>>>21. Kb1 Rb2+ >>>>>>22. Kc1 Rb1+ >>>>>>23. Kc2 Rb2+ >>>>>>24. Kd1 Rb1+ >>>>>>25. Ke2 Re1+ >>>>>>26. Kxf2 Re2+ >>>>>>27. Kg1 Rg2+ >>>>>>28. Kh1 Rg1+ >>>>>>29. Kh2 Rh1+ >>>>>>30. Kg2 Rg1+ >>>>>>31. Kh3 Rxg3+ >>>>>>32. Kh4 Rh3+ >>>>>>33. Kg5 Rh5+ >>>>>>34. Kg6 Rg5+ >>>>>>35. Kh7 Rg7+ >>>>>>36. Kh8 Rh7+ >>>>>>37. Kg8 Rh8+ >>>>>>38. Kg7 Rh7+ >>>>>>39. Kg6 Rg7+ >>>>>>40. Kh5 Rg5+ >>>>>>41. Kh4 Rh5+ >>>>>>42. Kg3 Rh3+ >>>>>>43. Kf2 Rxf3+ >>>>>>44. Ke2 Rf2+ >>>>>>45. Nxf2 Ke5 >>>>>>46. R4f5# >>>>>> >>>>>>I even had to increase the maximal allowed depth in Chest (formerly 30). >>>>>>Quite an exceptional position! >>>>>> >>>>>>Can the playing programs solve this, also? I suspect so. >>>>> >>>>>92 plies? You must be kidding. They pick gxf3 instantly with a huge score, but >>>>>no mate. I only tried Deep Fritz, Gambit Tiger and Shredder 5, but I don't think >>>>>any playing program will see it. >>>>> >>>>>Enrique >>>>> >>>>>>Heiner >>>> >>>>On my Pentium 166 after 2... Bg6+, Junior 6 (with 15 Mb. hash) say mate in 42 >>>>(6´2") >>> >>>While I'm pleased to hear that a program solved this one, from the above >>>I believe "mate in 44" would be correct, not "mate in 42". Can you show >>>us a PV? I would like to check it. Someone errs, and I'd like to know who. >>> >>>Heiner >> >>Junior 6 says mate in 42 after 2... Bg6+ in 55 seconds on a P750, 128MB hash, >>see below. I find very impressive that a playing program can see so far ahead >>and so quickly. I'm trying from the initial position with Deep Junior, but after >>14 hours it doesn't see the mate yet. > > >What was the depth of Deep Junior after 14 hours. Difficult to say. The PV showed ply 45 already computed after 10 hours and 40 minutes, but the search window said ply 48 and stayed like this for seven more hours. Then I stopped it because I needed the machine for something else. >I know that it has no chance to see mate in 46 if the depth is not close to 46 >so you can guess if it has a chance to see the mate by looking at the depth of >it and at the branching factor. Branching factor was very low, between 2 and 3 for the last plies. So maybe it was close to see the mate when I stopped it. That's what I waited for during 7 hours. :( Enrique >>Enrique >> >>2N5/p4P2/p4RbP/P2kr2K/5RN1/2PPBPP1/3P1p2/5Q2 w - - 0 1 >> >>Analysis by Junior 6.0: >> >>3.Kxg6 Rg5+ >> +- (34.96) Depth: 3 00:00:00 >>3.Kxg6 Rg5+ >> +- (34.96) Depth: 6 00:00:00 >>3.Kxg6 Rg5+ >> +- (34.96) Depth: 9 00:00:00 2kN >>3.Kxg6 Rg5+ >> +- (34.96) Depth: 12 00:00:00 5kN >>3.Kxg6! >> +- (35.26) Depth: 15 00:00:00 20kN >>3.Kxg6! >> +- (35.56) Depth: 18 00:00:00 71kN >>3.Kxg6 Rg5+ 4.Kh7 Rg7+ 5.Kh8 Rh7+ 6.Kg8 Rh8+ 7.Kg7 Rh7+ 8.Kf8 Rh8+ 9.Ke7 Re8+ >>10.Kd7 Rd8+ 11.Kc7 Rd7+ 12.Kb8 >> +- (27.69) Depth: 21 00:00:00 211kN >>3.Kxg6! >> +- (27.99) Depth: 24 00:00:00 296kN >>3.Kxg6! Rg5+ 4.Kh7 Rg7+ 5.Kh8 Rh7+ 6.Kg8 Rh8+ 7.Kg7 Rh7+ 8.Kf8 Rh8+ 9.Ke7 Re8+ >>10.Kd7 Rd8+ 11.Kc7 Rd7+ 12.Kb8 >> +- (32.02) Depth: 24 00:00:00 392kN >>3.Kxg6! >> +- (32.32) Depth: 27 00:00:01 790kN >>3.Kxg6 Rg5+ 4.Kh7 Rg7+ 5.Kh8 Rh7+ 6.Kg8 Rh8+ 7.Kg7 Rh7+ 8.Kf8 Rh8+ 9.Ke7 Re8+ >>10.Kd7 Rd8+ 11.Kc7 Rd7+ 12.Kb8 >> +- (32.32) Depth: 30 00:00:02 1089kN >>3.Kxg6 Rg5+ 4.Kh7 Rg7+ 5.Kh8 Rh7+ 6.Kg8 Rh8+ 7.Kg7 Rh7+ 8.Kf8 Rh8+ 9.Ke7 Re8+ >>10.Kd7 Rd8+ 11.Kc7 Rd7+ 12.Kb8 >> +- (24.40) Depth: 33 00:00:03 2227kN >>3.Kxg6! >> +- (24.70) Depth: 36 00:00:04 2379kN >>3.Kxg6! Rg5+ 4.Kh7 Rg7+ 5.Kh8 Rh7+ 6.Kg8 Rh8+ 7.Kg7 Rh7+ 8.Kf8 Rh8+ 9.Ke7 Re8+ >>10.Kd7 Rd8+ 11.Kc7 Rd7+ 12.Kb8 >> +- (25.16) Depth: 36 00:00:04 2608kN >>3.Kxg6! >> +- (25.46) Depth: 38 00:00:05 2897kN >>3.Kxg6! Rg5+ 4.Kh7 Rg7+ 5.Kh8 Rh7+ 6.Kg8 Rh8+ 7.Kg7 Rh7+ 8.Kf8 Rh8+ 9.Ke7 Re8+ >>10.Kd7 Rd8+ 11.Kc7 Rd7+ 12.Kb8 >> +- (28.35) Depth: 38 00:00:06 3153kN >>3.Kxg6! >> +- (28.65) Depth: 40 00:00:08 4369kN >>3.Kxg6! Rg5+ 4.Kh7 Rg7+ 5.Kh8 Rh7+ 6.Kg8 Rh8+ 7.Kg7 Rh7+ 8.Kf8 Rh8+ 9.Ke7 Re8+ >>10.Kd7 Rd8+ 11.Kc7 Rd7+ 12.Kb8 >> +- (32.74) Depth: 40 00:00:11 6960kN >>3.Kxg6! >> +- (33.04) Depth: 42 00:00:16 9629kN >>3.Kxg6! >> +- (33.34) Depth: 44 00:00:23 14185kN >>3.Kxg6! Rg5+ 4.Kh7 Rg7+ 5.Kh8 Rh7+ 6.Kg8 Rh8+ 7.Kg7 Rh7+ 8.Kf8 Rh8+ 9.Ke7 Re8+ >>10.Kd7 Rd8+ 11.Kc7 Rd7+ 12.Kb8 >> +- (#42) Depth: 44 00:00:55 40825kN >>3.Kxg6! Rg5+ 4.Kh7 Rg7+ 5.Kh8 Rh7+ 6.Kg8 Rh8+ 7.Kg7 Rh7+ 8.Kf8 Rh8+ 9.Ke7 Re8+ >>10.Kd7 Rd8+ 11.Kc7 Rd7+ 12.Kb8 >> +- (#42) Depth: 44 00:00:55 40825kN > >I believe chest and not Junior. >I know that Junior can be wrong in the number of moves. > >Junior has also a stalemate bug that can cause it to see mate when there is a >stalemate combination. >This is the reason that I did not think to try Junior in the original position. > >In this case it seems that another bug is the reason for seeing a shorter mate. > >Here is an example for the bug that I talk about. >[D]6r1/7k/Q7/8/7K/7B/8/6qq w - - 0 1 > >Junior cannot find Qh6+ because of the bug and plays Qd3+ with mate in 5 against >itself. > >Uri
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