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Subject: Re: Which engines can solve this? (Crafty 19.08)

Author: Mike Byrne

Date: 06:08:55 01/11/04

Go up one level in this thread


On January 11, 2004 at 02:46:18, Uri Blass wrote:

>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


New game
3k4/1r2p3/r2pPp2/q1pP1Pp1/1pP3Pp/pP2K2P/P7/8 b - - 0 1

Analysis by Crafty 19.08 SE:

6...Qa4 7.bxa4 b3 8.axb3 Rxb3+ 9.Ke4 Rxh3 10.a5 Rxa5
  -+  (-23.39)   Depth: 8   00:00:00  101kN
6...Qa4
  -+  (-23.79)   Depth: 9   00:00:00  112kN
6...Qa4 7.bxa4 b3 8.axb3 Rxb3+ 9.Ke4 Rxh3 10.a5 Rh1 11.Kd3 Rxa5
  -+  (-23.89)   Depth: 9   00:00:00  114kN
6...Qa4 7.bxa4 b3 8.axb3 Rxb3+ 9.Ke4 Rxh3 10.a5 Rh1 11.Kd3 Rxa5
  -+  (-23.89)   Depth: 9   00:00:00  255kN
6...Qa4 7.bxa4 b3 8.axb3 Rxb3+ 9.Ke4 Rxh3 10.a5 Rh1 11.Kf3 Rxa5
  -+  (-23.99)   Depth: 10   00:00:00  285kN
6...Qa4 7.bxa4 b3 8.axb3 Rxb3+ 9.Ke4 Rxh3 10.a5 Rh1 11.Kf3 Rxa5
  -+  (-23.99)   Depth: 10   00:00:01  566kN
6...Qa4
  -+  (-24.39)   Depth: 11   00:00:01  573kN
6...Qa4 7.bxa4 b3 8.axb3 Rxb3+ 9.Kf2 Rab6 10.Ke2 Rb2+ 11.Kf3 R6b3+ 12.Ke4 Re2#
  -+  (-#7)   Depth: 11   00:00:11  6025kN
6...Qa4 7.bxa4 b3 8.axb3 Rxb3+ 9.Kf2 Rab6 10.Ke2 Rb2+ 11.Kf3 R6b3+ 12.Ke4 Re2#
  -+  (-#7)   Depth: 11   00:00:13  7559kN
6...Qa4 7.bxa4 b3 8.axb3 Rxb3+ 9.Kf2 Rab6 10.Ke2 Rb2+ 11.Kf3 R6b3+ 12.Ke4 Re2#
  -+  (-#7)   Depth: 12   00:00:50  27457kN

(Byrne, Secane, PA USA 11.01.2004)

not in this case ..you put any type of piece (Queen, light square bishop or
knight) that can a  force a win and it will see it



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