Author: Dieter Buerssner
Date: 16:56:43 08/16/04
Go up one level in this thread
On August 16, 2004 at 15:20:06, Uri Blass wrote:
>On August 16, 2004 at 14:48:51, martin fierz wrote:
>
>>On August 16, 2004 at 08:46:12, Vincent Lejeune wrote:
>>
>>>I found this position here http://www.fierz.ch/pontresina.htm , after I searched
>>>10 min with no board and then 10 with a board and then 20 with chessengine, I
>>>gave up ... is this position buggy ??
>>>
>>>pasting :
>>>
>>> A cool (and very instructive) position which occurred in round 5: black to move
>>>and win! This one is harder than you think :-)
>>>Click here for a hint!
>>>The obvious 1... c4+ only draws. To win, you need to know something about
>>>'corresponding squares'.
>>>
>>>[d]8/8/4p2p/1kp1P1p1/1p4P1/1P1K2P1/7P/8 b - - 0 1
>>
>>hi vincent,
>>
>>as far as i am aware, this position is quite correct. computers have trouble
>>with it, that is true...
>>
>>cheers
>> martin
>
>As far as I can see 20 minutes with chess engine and fast hardware should be
>enough at least if you choose the right engine and the right hardware.
>
>Here is some analysis on A3000(512 mbytes hash)
Seems, you did not use bitbases. With them, you should see a rather convincing
score faster. On my slower hardware with the same engine:
151584039 2:35.1 2.83 19t 1...Kb6 2.Ke3 Kb7 3.Kd3 Kc7 4.Ke3 Kb6 5.Ke4 Kc6
6.h3H Kc7H 7.Kd3H Kb7H 8.Ke3H Kb6H 9.h4H Kb5H
10.Ke4H c4H 11.bxc4+H Kxc4H 12.Ke3H b3H 13.Kd2H
Kb4H 14.Kd3H gxh4H 15.Ke3H Ka3H 16.Kd3H b2H
17.Ke2H b1=QH 18.g5H {HT}
157279773 2:42.0 2.84 19t+ 1...Ka5 2.Kd2 c4 3.bxc4 b3 4.Kc3 Ka4 5.Kb2 Kb4
6.c5 Kxc5 7.Kxb3 Kd4 8.Kc2 Ke4 9.Kd2 Kf3 10.Kd3
Kxg4 11.Kd4 Kf5 12.Kd3 Kxe5 13.Kc2 Ke4 14.Kb1
e5 15.Kb2 Kf3 16.Kb3 g4 17.Kc3 e4 18.Kb3 h5
19.Kc4 Kg2 20.Kd5 {80}
162510060 2:48.6 3.23 19++ 1...Ka5 2.Kd2 c4 3.bxc4 b3 4.Kc3 Ka4 5.Kb2 Kb4
6.c5 Kxc5 7.Kxb3 Kd4 8.Kc2 Ke4 9.Kd2 Kf3 10.Kd3
Kxg4 11.Kd4 Kf5 12.Kc3 h5 13.Kb3 Kxe5 14.Kb2 h4
15.g4 Ke4 16.Kc3 Kf3 17.Kb3 h3 18.Kb2 e5 19.Ka1
Kxg4 20.Kb2H Kf4H 21.Kc3H g4H 22.Kd3H {160}
169901780 2:57.8 4.23 19++ 1...Ka5 2.Kd2 c4 3.bxc4 b3 4.Kc3 Ka4 5.Kb2 Kb4
6.c5 Kxc5 7.Kxb3 Kd4 8.Kc2 Ke4 9.Kd2 Kf3 10.Kd3
Kxg4 11.Kd4 h5 12.Kc5 Kf5 13.Kd6 g4 14.Kc6 Kxe5
15.Kc7 Kd5 16.Kd7 e5 17.Kd8 e4 18.Kc8 h4 19.Kb8
hxg3 20.Kc7 {160}
177193974 3:06.3 4.32 19t 1...Ka5 2.Kd2 c4 3.bxc4 b3 4.Kc3 Ka4 5.Kb2 Kb4
6.c5 Kxc5 7.Kxb3 Kd4 8.Kc2 Ke4 9.Kc3 Kf3 10.Kc4
Kxg4 11.Kc5H Kf5H 12.Kc4H h5H 13.Kb3H Kxe5H
14.Kc4H Ke4H 15.Kb4H Kf3H 16.Kc4H g4H 17.Kb3H
{HT} {80}
211517211 3:45.2 4.32 19. 1...Ka5 2.Kd2 c4 3.bxc4 b3 4.Kc3 Ka4 5.Kb2 Kb4
6.c5 Kxc5 7.Kxb3 Kd4 8.Kc2 Ke4 9.Kc3 Kf3 10.Kc4
Kxg4 11.Kc5 Kf5 12.Kc4 h5 13.Kb3 Kxe5 14.Kc4
Ke4 15.Kb4 Kf3 16.Kc4 g4 17.Kb3 {HT} {80}
225676618 4:03.0 4.72 20++ 1...Ka5 2.Kd2 c4 3.bxc4 b3 4.Kc3 Ka4 5.Kb2 Kb4
6.c5 Kxc5 7.Kxb3 Kd4 8.Kc2 Ke4 9.Kc3 Kf3 10.Kb3
Kxg4 11.Kc4 Kf5 12.Kb3 Kxe5 13.Kc2 Ke4 14.Kb1
e5 15.Kc1H Kf3H 16.Kd2H Kf2H 17.Kc3H Ke3H
18.g4H e4H 19.Kc2H Ke2H 20.Kc1H e3H 21.h4H h5H
22.Kb2H Kf3H 23.Kc3H e2H 24.gxh5H e1=Q+H
25.Kd3H {921}
234413213 4:14.0 5.72 20++ 1...Ka5 2.Kd2 c4 3.bxc4 b3 4.Kc3 Ka4 5.Kb2 Kb4
6.c5 Kxc5 7.Kxb3 Kd4 8.Kc2 Ke4 9.Kc3 Kf3 10.Kb3
Kxg4 11.Kc4 Kf5 12.Kc3 h5 13.Kb3 Kxe5 14.Kb4
Ke4 15.Kc4 Kf3 16.Kd3 Kg2 17.Kc3 e5 18.Kb3 h4
19.g4 Kxh2 20.Kc2 Kg3 21.Kb1 {160}
312960488 5:51.7 8.40 20t 1...Ka5 2.Kd2 c4 3.bxc4 b3 4.Kc3 Ka4 5.Kb2 Kb4
6.c5 Kxc5 7.Kxb3 Kd4 8.Kc2 Ke4 9.Kc3 Kf3 10.Kc4
Kxg4 11.Kc5 Kf5 12.Kd4 h5 13.Kc3H Kxe5H 14.Kc4H
Ke4H 15.Kc5H Kf3H 16.Kc6H {HT} {80}
compared to your
>1...Ka5 2.Kd2 c4 3.bxc4 b3 4.Kc3 Ka4 5.Kb2 Kb4 6.c5 Kxc5 7.Kxb3 Kd4 8.Kc2 Ke3
>9.Kc3 Kf3 10.Kd3 Kxg4 11.Ke4 h5 12.Kd4 Kf5 13.h3 h4 14.Kd3 hxg3 15.Ke2 g4 16.h4
>Kxe5 17.h5
> -+ (-2.64) Depth: 22/55 00:08:45 866518kN
>1...Ka5 2.Kd2 c4 3.bxc4 b3 4.Kc3 Ka4 5.Kb2 Kb4 6.c5 Kxc5 7.Kxb3 Kd4 8.Kc2 Ke3
>9.Kc3 Kf3 10.Kd3 Kxg4 11.Ke4 h5 12.Kd4 Kf5 13.h3 h4 14.Kc4 Kxe5 15.Kd3 hxg3
>16.Ke3 g2 17.Kf2
> -+ (-3.64) Depth: 22/55 00:09:27 933076kN
>1...Ka5 2.Kd2 c4 3.bxc4 b3 4.Kc3 Ka4 5.Kb2 Kb4 6.c5 Kxc5 7.Kxb3 Kd4 8.Kc2 Ke3
>9.Kc3 Kf3 10.Kd3 Kxg4 11.Ke3 Kf5 12.h3 Kxe5 13.Kf3
> -+ (-3.72) Depth: 22/55 00:10:05 995257kN
>1...Kb6 2.Ke3 Kb7 3.Kd3 Kc7 4.Ke3 Kb6 5.Ke4 Kc6 6.h3 Kb7 7.Kf3 c4 8.bxc4 b3 9.c5
>b2 10.Ke4 b1Q+ 11.Ke3
> -+ (-3.73) Depth: 22/55 00:11:11 1097826kN
>1...Kb6 2.Ke3 Kb7 3.Kd3 Kc7 4.Ke3 Kb6 5.Ke4 Kc6 6.h3 Kb7 7.Kd3 Kc7 8.Ke3 Kb6
>9.Kd3 Kb5 10.h4 Kc6 11.Ke3 Kd5 12.Kd3 Kxe5 13.Ke3 Kd5 14.Kd3 c4+ 15.bxc4+ Kc5
>16.Ke4 gxh4 17.gxh4
> -+ (-8.62) Depth: 22/55 00:17:12 1693752kN
Yace thinks, all king moves are winning (all give score > +8 soon). If I disable
all king moves, I get 0.0 score:
23039092 23.821 0.40 15. 1...c4+ 2.bxc4+ Kc5 3.h4 b3 4.Kc3 b2 5.Kxb2
Kxc4 6.Kc2 Kd4 7.Kd2 gxh4 8.gxh4 Kxe5 9.g5 h5
10.Ke2 Kf5 11.Kf3 e5 12.Kf2 e4 13.Kg2 e3 14.g6
e2 15.Kf2 Ke5 16.g7 e1=R 17.g8=Q Ke4
31842929 33.612 0.00 16t 1...c4+ 2.bxc4+ Kc5 3.h4 b3 4.Kc3 b2 5.Kxb2
Kxc4 6.Kc2 Kd4 7.Kd2 gxh4 8.gxh4 Kxe5 9.g5 hxg5
{INTREC} 10.hxg5! Kf5 11.g6 Kf6 12.g7 Kf7
13.g8=Q+ Kxg8! 14.Ke2 e5 15.Kf2 e4 16.Kg2 e3
17.Kg3 e2 18.Kf2! e1=Q+ 19.Kxe1! {No mating
material} {0}
And score does not change for at least 10 minutes.
Regards,
Dieter
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