Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Endgame Position : Is this a win for Black or a draw?

Author: Enrique Irazoqui

Date: 11:05:14 01/04/03

Go up one level in this thread


On January 04, 2003 at 13:48:22, Omid David Tabibi wrote:

>On January 04, 2003 at 11:47:36, Enrique Irazoqui wrote:
>
>>On January 04, 2003 at 10:58:00, Roy Brunjes wrote:
>>
>>>
>>>I have been studying the following position, with the help of various programs,
>>>and I am not sure if this is a win for Black.  This position was declared a win
>>>for Black by some training software I am using.  The commentator there says that
>>>after:
>>>
>>> 1. Kg3     Kc2
>>> 2. Kxh3    Kxb2
>>> 3. Kh4     Kxa2
>>>
>>>    "White needs 8 moves to queen and Black needs only 4"
>>>
>>>The commentator then goes on to say that if instead of 1. Kg3, white tries 1.
>>>b4, that 1. ... Kc4! follows and the game is over.
>>>
>>>However, as you can see from the pgn I post below, after I forced the first move
>>>on each side (1. Kg3 Kc2) Chess Tiger 14 plays 2. b4 and the game seems to be a
>>>much tougher win for Black, if indeed a win still exists.  Odd how the
>>>commentator sees 1. b4  but not the possiblity of 2. b4 after the Black King has
>>>gone too far "south" to provide the same defense it could a move earlier.  By
>>>the way, Tiger wanted to play 1... Ke3 instead of 1. ... Kc2.  Given a bit more
>>>time, Tiger switches to Ke2 with the following played in the 30+30 shootout I am
>>>running: 1. Kg3 Ke2 2. a3 h2 3. Kxh2 Kxf3 4. Kg1 Kxf4 and the eval is hugely in
>>>Black's favor.  So it would appear that 1. ... Ke2 is superior to the
>>>commentator's suggested 1. ... Kc2.
>>>
>>>I post below the analysis of Chess Tiger 14 (48 MB hash) generated by the H8 GUI
>>>option "shootout" with a time control of 10 minutes + 15 seconds per move
>>>increment on my 1.6 GHz laptop.  Tiger seemed to average about 20-25 seconds per
>>>move at this time control.
>>>
>>>Tiger is a respectable endgame player and it can only see a draw after many
>>>moves.  Is Tiger right?  I am running the shootout again, this time with 30
>>>minutes + 30 seconds per move increment to see if additional time makes any
>>>difference in the result.
>>>
>>>Here is the diagram ...
>>>
>>>[D] 8/8/6p1/1p3p2/5P2/3k1P1p/PP3K2/8 w
>>>
>>>And here is the 10+15 shootout output from Chess Tiger 14.0 on my P4 1.6 GHz
>>>laptop using 48 MB for hash:
>>>
>>>1. Kg3 Kc2 2. b4 Kd3 3. a4 bxa4 4. b5 a3 5. b6 a2 6. b7 a1=Q 7. b8=Q Qe1+ 8.
>>>Kxh3 Ke3 9. Qe5+ Kf2 10. Kh4 Qh1+ 11. Kg5 Qh5+ 12. Kf6 Kxf3 13. Qd6 Qg4 14. Qd2
>>>Qxf4 15. Qd1+ Kg2 16. Qc2+ Qf2 17. Qc6+ Kh2 18. Qb7 g5 19. Kxg5 f4 20. Qh7+ Kg2
>>>21. Qe4+ f3 22. Kf6 Qb2+ 23. Kf5 Qe2 24. Qg4+ Kf1 25. Kf4 f2 26. Qg6 Qc4+ 27.
>>>Kg3 Qc3+ 28. Kh2 Qc7+ 29. Kh3 Qc8+ 30. Kg3 Qb8+ 31. Kh3 Qh8+ 32. Kg3 Qe5+ 33.
>>>Kh3 Qe3+ 34. Kh2 Qf4+ 35. Kh3 Qf3+ 36. Kh2 Qd5 37. Qb1+ Ke2 38. Qb2+ Qd2 39.
>>>Qe5+ Qe3 40. Qb2+ Ke1 41. Qb1+ Kd2 42. Qa2+ 1/2-1/2
>>>
>>>It appears to me that the commentator missed an important continuation for both
>>>sides:
>>>
>>>    A.   1. ... Ke2 appears superior to 1. ... Kc2
>>>    B.   After 1. Kg2 Kc2 it appears that 2. b4! draws
>>>
>>>What do you folks think?  What do your programs think?  Thanks for your help!
>>>
>>>Roy
>>
>>Hi Roy,
>>
>>I don't see how it could be a draw.
>>
>>
>>8/8/6p1/1p3p2/5P2/3k1P1p/PP3K2/8 w - - 0 1
>>
>>Analysis by Fritz 8:
>>
>>1.Kg3 Ke3 2.b4
>>  -+  (-3.06)   Depth: 7/11   00:00:00  10kN
>>1.Kg3!
>>  -+  (-2.78)   Depth: 8/17   00:00:00  14kN
>>1.Kg3 Ke2 2.a3 h2
>>  -+  (-2.59)   Depth: 8/17   00:00:00  16kN
>>1.Kg3--
>>  -+  (-2.87)   Depth: 9/14   00:00:00  20kN
>>1.Kg3 Ke2 2.a3 h2 3.Kg2 h1Q+ 4.Kxh1 Kxf3 5.Kg1 Kxf4 6.Kf2 g5 7.b3 Ke4
>>  -+  (-4.72)   Depth: 9/34   00:00:00  42kN, tb=4
>>1.Kg3!
>>  -+  (-4.44)   Depth: 10/24   00:00:00  59kN, tb=4
>>1.Kg3!
>>  -+  (-4.16)   Depth: 10/24   00:00:00  63kN, tb=4
>>1.Kg3!
>>  -+  (-3.59)   Depth: 10/24   00:00:00  68kN, tb=4
>>1.Kg3 Ke2 2.b4 Ke3 3.a3 h2 4.Kxh2 Kxf4 5.Kg2
>>  -+  (-2.50)   Depth: 10/26   00:00:00  76kN, tb=4
>>1.Kg3--
>>  -+  (-2.81)   Depth: 11/22   00:00:00  85kN, tb=4
>>1.Kg3 Ke2 2.a3 h2 3.Kxh2 Kxf3 4.b3 Kxf4 5.a4 bxa4 6.bxa4 Ke5 7.a5 Kd6
>>  -+  (-2.94)   Depth: 11/34   00:00:00  154kN, tb=5
>>1.Kg3--
>>  -+  (-3.22)   Depth: 12/28   00:00:00  169kN, tb=6
>>1.Kg3 Ke2 2.a3 h2 3.Kg2 h1Q+ 4.Kxh1
>>  -+  (-3.28)   Depth: 12/31   00:00:00  219kN, tb=12
>>1.Kg3 Ke2 2.a3 h2 3.Kg2 h1Q+ 4.Kxh1 Kxf3 5.b3 Kxf4
>>  -+  (-3.28)   Depth: 13/25   00:00:00  318kN, tb=19
>>1.Kg3--
>>  -+  (-3.56)   Depth: 14/27   00:00:01  440kN, tb=46
>>1.Kg3 Ke3 2.a3 h2 3.Kxh2 Kxf3 4.b3 Kxf4 5.Kg1 Ke4 6.a4 b4 7.Kf2 g5
>>  -+  (-3.81)   Depth: 14/42   00:00:01  543kN, tb=63
>>1.Kg3--
>>  -+  (-4.09)   Depth: 15/25   00:00:02  640kN, tb=95
>>1.Kg3 Ke3 2.a3 h2 3.Kxh2 Kxf3 4.b3 Kxf4 5.Kg1 Ke4 6.a4 b4 7.Kf1
>>  -+  (-4.12)   Depth: 15/35   00:00:03  908kN, tb=170
>>1.Kg3 Ke3 2.a3 h2 3.Kxh2 Kxf3 4.b3 Kxf4 5.Kg1 Ke4 6.Kf1 g5 7.a4
>>  -+  (-4.22)   Depth: 16/29   00:00:04  1254kN, tb=381
>>1.Kg3 Ke3 2.a3 h2 3.Kxh2 Kxf3 4.Kg1 Kxf4 5.Kf2 Ke4 6.b3 g5 7.Kg2 f4
>>  -+  (-4.37)   Depth: 17/32   00:00:07  1934kN, tb=855
>>1.Kg3--
>>  -+  (-4.66)   Depth: 18/31   00:00:09  2507kN, tb=1374
>>1.Kg3 Ke3 2.a3 h2 3.Kxh2 Kxf3 4.Kg1 Kxf4 5.Kf2 g5 6.b3 g4 7.Kg2 Ke5
>>  -+  (-4.69)   Depth: 18/40   00:00:12  3718kN, tb=2066
>>1.Kg3--
>>  -+  (-4.97)   Depth: 19/34   00:00:16  4972kN, tb=2994
>>1.Kg3 Ke3 2.a3 h2 3.Kxh2 Kxf3 4.Kg1 Kxf4 5.Kf2 g5 6.b3 g4 7.Kg2 Ke5
>>  -+  (-5.34)   Depth: 19/43   00:00:22  7563kN, tb=4909
>>1.Kg3 Ke3 2.a3 h2 3.Kxh2 Kxf3 4.Kg1 Kxf4 5.Kf2 g5 6.b3 g4 7.Kg2 Ke5
>>  -+  (-5.34)   Depth: 20/36   00:00:33  10416kN, tb=7951
>>1.Kg3--
>>  -+  (-5.62)   Depth: 21/39   00:00:45  15682kN, tb=13627
>>1.Kg3 Ke3 2.a3 h2 3.Kxh2 Kxf3 4.Kg1 Kxf4 5.Kf2 g5 6.b3 g4 7.Kg2 Ke3
>>  -+  (-9.09)   Depth: 21/56   00:01:24  31600kN, tb=26421
>>1.Kg3 Ke3 2.a3 h2 3.Kxh2 Kxf3 4.Kg1 Kxf4 5.Kf2 g5 6.b3 g4 7.Kg2 Ke3
>>  -+  (-9.09)   Depth: 22/42   00:02:07  46375kN, tb=41661
>>1.Kg3--
>>  -+  (-9.37)   Depth: 23/45   00:03:24  87234kN, tb=80090
>>1.Kg3 Ke3 2.a3 h2 3.Kxh2 Kxf3 4.Kg1 Kxf4 5.Kf2 Ke4 6.Ke2 f4 7.b3 f3+ 8.Kf1 g5
>>9.Kf2 g4
>>  -+  (-9.50)   Depth: 23/50   00:04:50  131320kN, tb=130794
>>
>>(Irazoqui, MyTown 04.01.2003)
>
>
>Yes, that position is indeed a win for black. But generally, one should always
>take computers' endgame analysis with a grain of salt.

A few kilos.

>The following position should be "closely" familiar to you :-)

5 meters close? :)

Enrique

>
>[D] 4k3/2p5/1p2p1p1/p1p1P1P1/P1P3p1/1P6/5PK1/8 b - - 0 28
>
>Deep Fritz - Kramnik,V
>4k3/2p5/1p2p1p1/p1p1P1P1/P1P3p1/1P6/5PK1/8 b - - 0 1
>
>Analysis by Fritz 7:
>
>28...Kd7 29.Kg3 c6 30.Kxg4 Ke7 31.Kf4 Kf8 32.Ke4 Ke8 33.Ke3 Ke7
>  ±  (1.19)   Depth: 12/19   00:00:00  94kN
>28...Kd7 29.Kg3 c6 30.Kxg4 Ke7 31.Kf4 Kf8 32.Ke4
>  ±  (1.19)   Depth: 13/19   00:00:00  148kN
>28...Kd7 29.Kg3 c6 30.Kxg4 Ke7 31.Kf4 Kf8 32.Ke4
>  ±  (1.19)   Depth: 14/21   00:00:00  239kN
>28...Kd7 29.Kg3 c6 30.Kxg4 Ke7 31.Kf4 Kf8 32.Ke4
>  ±  (1.19)   Depth: 15/23   00:00:01  386kN
>28...Kd7 29.Kg3 c6 30.Kxg4 Ke7 31.Kf4 Kf8 32.Ke4
>  ±  (1.19)   Depth: 16/27   00:00:02  609kN
>28...Kd7 29.Kg3 c6 30.Kxg4 Ke7 31.Kf4 Kf8 32.Ke4
>  ±  (1.19)   Depth: 17/31   00:00:03  1034kN
>28...Kd7 29.Kg3 c6 30.Kxg4 Ke7 31.Kf4 Kf8 32.Ke4
>  ±  (1.19)   Depth: 18/31   00:00:05  1588kN
>28...Kd7 29.Kg3 c6 30.Kxg4 Ke7 31.Kf4 Kf8 32.Ke4
>  ±  (1.19)   Depth: 19/33   00:00:09  2543kN
>28...Kd7 29.Kg3 c6 30.Kxg4 Ke7 31.Kf4 Kf8 32.Ke4
>  ±  (1.19)   Depth: 20/36   00:00:16  4231kN
>28...Kd7 29.Kg3 c6 30.Kxg4 Ke7 31.Kf4 Kf8 32.Ke4
>  ±  (1.19)   Depth: 21/38   00:00:27  7182kN
>28...Kd7 29.Kg3 c6 30.Kxg4 Ke7 31.Kf4 Kf8
>  ±  (1.19)   Depth: 22/39   00:00:48  12441kN
>
>(David Tabibi, Tel-Aviv 04.01.2003)



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.