Author: Uri Blass
Date: 23:46:18 01/10/04
Go up one level in this thread
On January 11, 2004 at 00:07:22, Mike Byrne wrote: >On January 10, 2004 at 20:23:32, Bob Durrett wrote: > >>On January 10, 2004 at 18:29:20, Mike Byrne wrote: >> >>>On January 10, 2004 at 17:47:25, Drexel,Michael wrote: >>> >>>>On January 10, 2004 at 17:22:53, Kurt Utzinger wrote: >>>> >>>>>On January 10, 2004 at 15:29:16, David Dahlem wrote: >>>>> >>>>>>White to move and draw. Which engines can find it? >>>>>> >>>>>>[D]3B4/1r2p3/r2p1p2/bkp1P1p1/1p1P1PPp/p1P1K2P/PPB5/8 w - - 0 1 >>>>>> >>>>>>1. Ba4+ Kxa4 2. b3+ Kb5 3. c4+ Kc6 4. d5+ Kd7 5. e6+ Kxd8 6. f5 1/2-1/2 >>>>>> >>>>>>Regards >>>>>>Dave >>>>> >>>>>Crafty_1908 WB2: (P4 1.8/32 MB hash) >>>>> 3 00:00 -4.04 1. c4+ Kxc4 2. Bd3+ Kd5 3. Bxa6 cxd4+ 4. Kd3 >>>>> 4 00:00 -4.01 1. c4+ Kxc4 2. Bd3+ Kd5 3. Bxa6 cxd4+ 4. Kd3 Ra7 >>>>> 4 00:00 -3.64 1. Ba4+!! >>>>> 4 00:00 0.00 1. Ba4+ Kxa4 2. b3+ Kb5 3. c4+ Kc6 4. d5+ Kd7 5. e6+ Kxd8 6. >>>>>f5 >>>>> 5 00:00 0.00 1. Ba4+ Kxa4 2. b3+ Kb5 3. c4+ Kc6 4. d5+ Kd7 5. e6+ Kxd8 6. >>>>>f5 Rba7 >>>>> 6 00:00 0.00 1. Ba4+ Kxa4 2. b3+ Kb5 3. c4+ Kc6 4. d5+ Kd7 5. e6+ Kxd8 6. >>>>>f5 Rba7 7. Kf3 >>>>> 7 00:01 0.00 1. Ba4+ Kxa4 2. b3+ Kb5 3. c4+ Kc6 4. d5+ Kd7 5. e6+ Kxd8 6. >>>>>f5 Rba7 7. Kf3 Rc6 >>>>> 8 00:01 0.00 1. Ba4+ Kxa4 2. b3+ Kb5 3. c4+ Kc6 4. d5+ Kd7 5. e6+ Kxd8 6. >>>>>f5 Rba7 7. Kf3 Rc6 8. Ke4 >>>>> 9 00:01 0.00 1. Ba4+ Kxa4 2. b3+ Kb5 3. c4+ Kc6 4. d5+ Kd7 5. e6+ Kxd8 6. >>>>>f5 Rba7 7. Kf3 Rc6 8. Ke4 Rb6 >>>>>10 00:03 0.00 1. Ba4+ Kxa4 2. b3+ Kb5 3. c4+ Kc6 4. d5+ Kd7 5. e6+ Kxd8 6. >>>>>f5 Rba7 7. Kf3 Rc6 8. Ke4 Rb6 9. Kf3 >>>>>11 00:08 0.00 1. Ba4+ Kxa4 2. b3+ Kb5 3. c4+ Kc6 4. d5+ Kd7 5. e6+ Kxd8 6. >>>>>f5 Rba7 7. Kf3 Rc6 8. Ke4 Rb6 9. Kf3 Rc6 >>>>>12 00:11 0.00 1. Ba4+ Kxa4 2. b3+ Kb5 3. c4+ Kc6 4. d5+ Kd7 5. e6+ Kxd8 6. >>>>>f5 Rba7 7. Kf3 Rc6 8. Ke4 Rb6 9. Kf3 Rc6 >>>> >>>>Interesting. Crafty 19.06 can't find 1.Ba4+. >>>> >>>>Michael >>>> >>>>New game >>>>3B4/1r2p3/r2p1p2/bkp1P1p1/1p1P1PPp/p1P1K2P/PPB5/8 w - - 0 1 >>>> >>>>Analysis by Crafty 19.06: >>>> >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Bxa6 cxd4+ >>>> -+ (-4.45) Depth: 1/18 00:00:00 >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Bxa6 cxd4+ >>>> -+ (-4.45) Depth: 1/18 00:00:00 >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Bxa6 cxd4+ >>>> -+ (-4.45) Depth: 2/18 00:00:00 >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Bxa6 cxd4+ >>>> -+ (-4.45) Depth: 2/18 00:00:00 >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Bxa6 cxd4+ >>>> -+ (-4.45) Depth: 2/18 00:00:00 >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Bxa6 cxd4+ 4.Kd3 >>>> -+ (-4.28) Depth: 3/19 00:00:00 >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Bxa6 cxd4+ 4.Kd3 Ra7 >>>> -+ (-4.25) Depth: 4/19 00:00:00 >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Be4+ Ke6 4.f5+ Kd7 5.Bxb7 axb2 6.Bxa6 b1Q 7.Bxa5 dxe5 >>>>8.dxc5 Qxa2 >>>> -+ (-5.36) Depth: 5/23 00:00:00 >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Be4+ Ke6 4.f5+ Kd7 5.Bxb7 axb2 6.Bxa6 b1Q 7.Bxa5 dxe5 >>>>8.dxc5 Qxa2 >>>> -+ (-5.36) Depth: 6/24 00:00:00 392kN >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Be4+ Ke6 4.f5+ Kd7 5.Bxb7 axb2 6.Bxa6 b1Q 7.Bxa5 dxe5 >>>>8.dxc5 Qxa2 >>>> -+ (-5.36) Depth: 7/26 00:00:01 806kN >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Be4+ Ke6 4.Bxb7 gxf4+ 5.Kxf4 dxe5+ 6.dxe5 Ra7 7.Bxa5 >>>>axb2 8.Bc8+ Kd5 9.Bb6 b1Q 10.Bxa7 Qxa2 >>>> -+ (-5.73) Depth: 8/27 00:00:04 2236kN >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Be4+ Ke6 4.f5+ Kd7 5.Bxb7 cxd4+ 6.Kxd4 dxe5+ 7.Kc5 Ra7 >>>>8.bxa3 Bxd8 9.Bc6+ Kc7 10.axb4 Rxa2 >>>> -+ (-6.00) Depth: 9/28 00:00:08 5405kN >>>>1.c4+ Kxc4 2.Bd3+ Kd5 3.Be4+ Ke6 4.f5+ Kf7 5.Bxb7 axb2 6.Bxa6 b1Q 7.Bxa5 Qxa2 >>>>8.e6+ Kf8 9.Bb6 Qxa6 10.dxc5 dxc5 11.Bxc5 >>>> -+ (-6.55) Depth: 10/30 00:00:31 21256kN >>> >>>It becomes a block pawn position, so when crafty is compiled with /DDETECTDRAW, >>>it will find it. >> >>Would somebody who is familiar with Crafty's /DDETECTDRAW code please tell >>everybody WHY is works [in plain English, please]? What is special about that >>code which almost every other chess programmer has failed to put into his/her >>engines? What does that code do [other than produce the correct move] which is >>unique? >> >>Bob D. > >A picture is worth a thousand words, play the best moves for the above position >and take a look at the ending position. > >[d]3k4/1r2p3/r2pPp2/b1pP1Pp1/1pP3Pp/pP2K2P/P7/8 b - - 0 6 > >the code simply identifies a locked position where the K is safely behind bars >(pawns) , i.e., the game must be drawn. The question is if it does not detect draw in wrong cases(for example if black has a queen instead of a bishop. Uri
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