Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Endgame position

Author: Kai Skibbe

Date: 09:23:37 05/12/98

Go up one level in this thread


On May 12, 1998 at 07:05:53, Howard Exner wrote:

>On May 12, 1998 at 01:17:08, Kai Skibbe wrote:
>
>>The following position is from a game between
>>Rebel 9.0 28 MB HT and Fritz 5.03 64MB HT on
>>a PC with a AMD K6-200.
>>
>>WKh3, Rh6, Pg3,g2
>>BKc5, Rb6, Ph7
>>White to move
>>
>>Rebel 9.0 as white was unable to find the winning
>>exchange Rxb6 in 5 minutes. He played Rxh7 and after
>>some moves the game became a draw.
>>I have tested the same position with Shredder 2.0 64MB
>>and Genius 5.0 32 MB. Both programs didn´t see the winning
>>exchange in 10 minutes and played the same move as
>>Rebel (Rxh7).
>>I´m not sure if the game could be a win for white after
>>Rxh7, but after Rxb6 the win should be clear.
>>
>>Does any chessprogram play the move Rxb6 and see the win ?
>>The evaluation should be at least 4 pawn, if the program
>>has understood the position.
>>
>>Why is this position so difficult for programs ?
>
>Both moves, Rxb6 and Rxh7 will win. In the Rxh7 line the
>black king is too far away and will be cut off by white's
>Rook (Rd7).
>
>Could you post the remainder of the game ? I'd like to see
>how Fritz managed to draw this. I've seen Rebel routinely
>win these kinds of positions when the king is cut off.

Here is the rest of the game after the position
Rebel 9.0 28MB - Fritz 5.03 64MB
59. Rxh7	Kd5
60. g4		Ke5
61. g5		Kf5
62. Kh4		Rb1
63. Rf7+	Kg6
64. Rf6+	Kg7
65. Rd6		Rh1+
66. Kg3		Rg1
67. Rb6		Kf7
68. Kf3		Rc1
69. Kg4		Rd1
70. Rc6		Kg7
71. Ra6		Rc1
72. g3		Rf1
73. Ra7+	Kg6
74. Ra4		Rd1
75. Ra6+	Rg7

At this point I stopped the game. IMO there is no win for white.

I have tested the position after 59. Rxb6  Kxb6. From this position
all programs play the correct moves ( 60. Kg4 or g4 ).

BTW CM 5500 and CM5555 find the move Rxb6 instantly, but the evaluation
is only
about +1.8 pawns. So they both have not seen a promoted pawn.




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.