Author: blass uri
Date: 02:39:21 06/09/00
Go up one level in this thread
On June 09, 2000 at 01:11:03, Paulo Soares wrote:
>On June 09, 2000 at 00:08:07, Oliver Roese wrote:
>
>>On June 09, 2000 at 00:03:02, Paulo Soares wrote:
>>
>>>On June 08, 2000 at 22:49:28, Oliver Roese wrote:
>>>
>>>> [Event "NRW 4er-Pokal"]
>>>> [Site "Germany"]
>>>> [Date "2000.06.04"]
>>>> [Round "?"]
>>>> [White "Grimm, S."]
>>>> [Black "N.N"]
>>>> [Result "1/2-1/2"]
>>>> [FEN "8/4k1pp/5p2/P1p1p3/2Qq4/1P4P1/5PKP/8 b - - 0 1"]
>>>>
>>>> 1...Qxc4 ({This position occured last sunday in a team event. It was the
>>>>last game. I and a team colleague of mine were "kibitzes". Our man had white.
>>>>Obviously black is in trouble here. But black has the chance here to swap the
>>>>queens and go into a pawn ending. He pondered a while and finally he played
>>>>1...Qd6. The game went on with 2.Qe4 and finally he lost. My teammate took me
>>>>aside: "What do you think about 1.Qxc4?" he asked. "Well, white opens the
>>>>kingside with g4 and wins.", i said. "Wrong!" he told me. We made a blindgame,
>>>>me playing white and he took me along up to the 18th move in this analysis. "I
>>>>see.", i said, "But maybe white has some other possibilities." I went to the
>>>>board, puzzled a while, and came back. "What about f4?" i asked. He hesitated
>>>>shortly and showed me the winning line for black. In a few seconds he refuted a
>>>>line that costed me several minutes! I went to the board again, trying hard to
>>>>refute Qxc4. Eventually i came back. "What about g4, Kg3 and then f4?" He
>>>>ponderd a while and then quick as a flash he showed me the refutation again. "So
>>>>this guy is tough!", i concluded for myself. After the end of the game, we
>>>>showed them what he had found. They were both surprised. Finally we were
>>>>interested to see if there are any winningchances in the resulting QQ-endgame.
>>>>Should i tell you who told us 19..Kc2 ? This is one of the few examples, there
>>>>a skilled human can outperform current hard/software. If they can solve it all!
>>>>I tried a few minutes with crafty, but gave up at the end. Can your computer
>>>>come up with 1...Qxc4! ? Oliver Roese } 1...Qd6 ) 2.bxc4 Kd6 3.g4 ( 3.f4??
>>>>exf4 4.gxf4 f5 -+ 5.Kg3 g6 6.Kh4 ( 6.h4 h5 ) 6...h6 ) 3...g6 4.Kf3 ( 4.Kg3?? Kc6
>>>>5.f4 Kb7 6.fxe5 fxe5 7.Kf3 Ka6 8.Ke4 Kxa5 9.Kxe5 Kb4 10.Kd5 g5 -+ ) 4...f5
>>>>5.gxf5 gxf5 6.Kg3 Kc6 7.Kh4 h6 8.Kh5 e4 9.Kh4 Kb7 10.Kg3 Ka6 11.Kf4 Kxa5 12.Kxf5
>>>>Kb4 13.Kxe4 Kxc4 14.f4 Kb3! 15.f5 c4 16.f6 c3 17.f7 c2 18.f8=Q c1=Q = 19.Qb8+
>>>>Kc2! 20.Qc7+ Kd1 21.Qxc1+ Kxc1 22.Kf5 Kd2 23.Kg6 Ke3 24.Kxh6 Kf4 1/2-1/2
>>>
>>>I think 3.Kf3! is a winner move. Black have no chances.
>>>
>>>1... Qxc4 2. bxc4 Kd6 3. Kf3!
>>>
>>>Paulo Soares, from Brazil
>>
>>But _why_ do you think that?
>
>I was wanting to place the answer quickly in the forum and I analyzed the
>position believing in the evaluation of the program, without giving the
>necessary time for a good evaluation. My mistake, sorry.
>
>1... Qxc4 2. bxc4 Kd6 3. Kf3 f5 {!}
>4. g4 g6 5. gxf5 gxf5 6. Kg3 Kc7 7. Kh4 h6 8. Kh5 e4 9. Kh4 Kb7 (9... f4 10.
>Kg4 e3 11. fxe3 fxe3 12. Kf3 {+-}) 10. Kg3 Ka6 11. Kf4 Kxa5 12. Kxf5 Kb4 13.
>Kxe4 Kxc4 14. f4 Kb3 15. f5 c4 16. f6 c3 17. f7 c2 18. f8=Q c1=Q {=}
>
>Paulo
The problem is that programs do not know to evaluate unstoppable pawns
try the following position that can happen after
3.Kf3 f5 4.g4 g6 5.gxf5 gxf5 6.kg3 Kc6 7.Kh4 h6 8.Kh5 e4 9.a6 Kb6 10.Kxh6 f4
[D]8/8/Pk5K/2p5/2P1pp2/8/5P1P/8 w - - 0 1
Programs cannot see at evaluation time that black is winning because of
unstoppable pawn.
If I give them to analyze at 1 ply depth they give a big advantage for white.
part of the programs know that h2 is unstoppable but they do not know that e4 is
unstoppable and that e4 can be a queen faster than h2
Uri
This page took 0.01 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.