Author: John Merlino
Date: 17:24:19 01/30/02
Go up one level in this thread
On January 30, 2002 at 14:30:32, John Merlino wrote: >On January 30, 2002 at 11:58:49, Andrew Smith wrote: > >>This is an interesting position. In particular, the fourth move in the winning >>line. Qg7 Kh2 f8Q Qb6+ Kh6 *Bc6*. Other moves are possibly winning but 4. Bc6 >>looks to be the best by far. I let gambit tiger analyse this over night, and it >>couldn't come up with 4. Bc6. What do other programs think here on fast >>hardware? Can they find Bc6 in the initial position? >> >>[D]5Q2/5P1b/8/7K/8/1q4k1/1p4B1/8 w - - 0 1 > >Your post is a little confusing, because your line above contains at least two >errors (2...Qb6 is not check, because the White King is on h5, and obviously >3.Kh6 is not a legal move after 2...Qb6). So, here is what I BELIEVE your line >is: > >1.Qg7+ Kh2 >2.f8=Q Qb5+ >3.Kh6 Qb6+ >4.Bc6!? > >If so, then the problem is that, from the initial position, it looks like a >12-ply search is needed to find the win. And, with three queens on the board >(and the potential for a fourth in most PVs) this can take quite some time, as >you have noticed. > >If you move ahead until after 3...Qb6+, it STILL takes CM8000 (on my more and >more ancient PIII-600) over 2 1/2 minutes to find the move: > >Time Depth Score Positions Moves >0:00 1/3 1.82 2124 4.Kxh7 b1=Q+ 5.Kh8 Q6g6 6.Bf3 Qxg7+ > 7.Qxg7 >0:00 1/4 1.84 12795 4.Kxh7 b1=Q+ 5.Kh8 Q6g6 6.Qe5+ > Qg3 7.Qxg3+ Kxg3 8.Qf3+ Kh4 >0:00 2/5 1.72 51470 4.Kxh7 b1=Q+ 5.Kh8 Qb8 6.Bd5 Qxf8+ > 7.Qxf8 Qa1+ 8.Kh7 Qa7+ 9.Kg6 Qg1+ > 10.Kh6 Qg4 >0:02 2/6 1.71 178789 4.Kxh7 b1=Q+ 5.Kh8 Qb8 6.Bd5 Qxf8+ > 7.Qxf8 Qa1+ 8.Kh7 Qa7+ 9.Kg6 Qg1+ > 10.Kh5 Qd1+ 11.Bf3 Qd4 >0:08 3/7 1.72 716546 4.Kxh7 b1=Q+ 5.Kh8 Qb8 6.Bd5 Qxf8+ > 7.Qxf8 Qa1+ 8.Kh7 Qa7+ 9.Kg6 Qg1+ > 10.Kh5 Qg3 11.Kh6 >0:18 4/8 1.71 1617792 4.Kxh7 b1=Q+ 5.Kh8 Qb8 6.Bd5 Qxf8+ > 7.Qxf8 Qb2+ 8.Kg8 Qe5 9.Qf7 Qg5+ > 10.Kh7 Qh4+ 11.Kg6 Qg3+ 12.Kh6 > Qh4+ 13.Kg7 >0:52 5/9 1.70 4681827 4.Kxh7 b1=Q+ 5.Kh8 Qb8 6.Bd5 Qxf8+ > 7.Qxf8 Qb2+ 8.Kg8 Qe5 9.Qf7 Qg5+ > 10.Kh7 Qh4+ 11.Kg6 Qg3+ 12.Kh6 > Qh4+ 13.Kg7 Qg5+ 14.Kf8 >2:38 5/9 10.63 14025528 4.Bc6 Qxc6+ 5.Kxh7 Qe4+ 6.Kh8 Qh4+ > 7.Qh6 Qxh6+ 8.Qxh6+ Kg3 9.Qg7+ > Kf4 10.Qxb2 Ke4 11.Kg7 Kf5 12.Qb5+ > Ke6 13.Kg6 > >By INCREDIBLY rough estimation, I would therefore guess that it would take >approximately 6-7 hours to find 4.Bc6!! from the initial position on my >(slow)machine. I'll let it run overnight and find out. > >Good position! > >jm Ok. Apparently my math is as bad as others' these days.... ;-) CM8000, on a PIII-600, finds 4.Bc6! in just under 29 minutes: Time Depth Score Positions Moves 0:00 1/3 0.80 3868 1.Qg7+ Kh2 2.f8=Q b1=Q 3.Qf4+ Kg1 0:00 1/4 3.19 24774 1.Qg7+ Kh2 2.f8=Q Qb5+ 3.Kh6 Qa6+ 4.Kxh7 Qd3+ 5.Kg8 b1=Q 0:00 2/5 3.08 57828 1.Qg7+ Kh2 2.f8=Q Qb5+ 3.Kh6 Qa6+ 4.Kxh7 b1=Q+ 5.Kh8 Qag6 0:02 3/6 1.90 199374 1.Qg7+ Kh2 2.f8=Q Qb5+ 3.Kg4 Bf5+ 4.Qxf5 Qxf5+ 5.Kxf5 b1=Q+ 6.Be4 Qf1+ 7.Ke6 0:07 4/7 1.84 557895 1.Qg7+ Kh2 2.f8=Q Qb5+ 3.Kh6 Qa6+ 4.Kxh7 b1=Q+ 5.Kh8 Qag6 6.Qe5+ Qg3 7.Qxg3+ Kxg3 8.Qf3+ Kh4 9.Qf4+ Kh5 0:18 5/8 1.84 1562005 1.Qg7+ Kh2 2.f8=Q Qb5+ 3.Kh6 Qa6+ 4.Kxh7 b1=Q+ 5.Kh8 Qag6 6.Qe5+ Qg3 7.Qxg3+ Kxg3 8.Qf3+ Kh4 9.Qf4+ Kh5 1:15 6/9 1.70 6628552 1.Qg7+ Kh2 2.f8=Q Qb5+ 3.Kh6 Qb6+ 4.Kxh7 b1=Q+ 5.Kh8 Qb8 6.Bd5 Qxf8+ 7.Qxf8 Qa1+ 8.Kg8 Qg1+ 9.Kh7 Qa7+ 10.Kg6 Qg1+ 11.Kh6 Qg4 3:05 7/10 1.71 16464515 1.Qg7+ Kh2 2.f8=Q Qb5+ 3.Kh6 Qb6+ 4.Kxh7 b1=Q+ 5.Kh8 Qb8 6.Bd5 Qxf8+ 7.Qxf8 Qa1+ 8.Kh7 Qa7+ 9.Bf7 Qd4 10.Qh6+ Kg3 11.Qg5+ Kf3 12.Kh6 8:11 8/11 1.72 44219863 1.Qg7+ Kh2 2.f8=Q Qb5+ 3.Kh6 Qb6+ 4.Kxh7 b1=Q+ 5.Kh8 Qb8 6.Bd5 Qxf8+ 7.Qxf8 Qa1+ 8.Kh7 Qa7+ 9.Kg6 Qg1+ 10.Kh5 Qd1+ 11.Bf3 Qd4 12.Qg8 Qe5+ 13.Kh6 28:54 9/12 10.61 162039259 1.Qg7+ Kh2 2.f8=Q Qb5+ 3.Kh6 Qb6+ 4.Bc6 Qxc6+ 5.Kxh7 Qe4+ 6.Kh8 Qh4+ 7.Qh6 Qxh6+ 8.Qxh6+ Kg2 9.Qg7+ Kf3 10.Qxb2 Ke4 11.Kg7 Kd5 12.Qb5+ Ke6 13.Kg6 jm
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