Author: KarinsDad
Date: 15:50:08 07/27/99
Go up one level in this thread
On July 27, 1999 at 18:25:20, Dave Gomboc wrote: >On July 27, 1999 at 17:28:48, KarinsDad wrote: > >>On July 27, 1999 at 14:07:22, Dave Gomboc wrote: >> >>>Last night I reached the following position as White in the blitz portion of a >>>game/30: >>> >>>White: Kg2, Qd5, pawns on b3, f2, g3, h4. >>>Black: Kf6, Qe5, pawns on b4, g7, h7. >>>White to move. >>> >>>I played 43. Qc6+, and my opponent blundered with 43...Qe6?? I went on to win >>>the pawn ending after 44. Qxe6+ Kxe6 45. Kf3. >> >>Why was this a blunder? There are no good moves. What better move did black >>have? >> >>43 ... Ke7 44. Qb7+ any 45. Qxb4 winning a pawn >>43 ... Kf7 44. Qb7+ Qe7 (to protect the b pawn) 45. Qxe7 and black's king is >>even further back than with what was played >>43 ... Kf4 44. Qf3+ Kg3 45. Qg4+ any 46. Qxb4 >>43 ... Kf4 44. Qf3+ Kg4 45. h4+ Kg3 46. Qg4+ any 47. Qxb4 >>43 ... Kf4 44. Qf3+ Kg4 45. h4+ Kh3 46. g4 and black cannot take the b pawn or >>47. Qf4+ Kg3 48. h5++ or Kh4 48. Qg5++ >>43 ... Kg4 44. h4+ and a variety of other moves which lead to the same capturing >>of the b pawn or mate with the same themes as above >> >>And eventually, no matter how black plays, once white wins the b pawn, all white >>has to do is place the queen on b7 and push the b pawn. If black tries to check >>white first, white plays Kh3, interposes his queen on any other check, puts his >>king back on g2, eventually plays Qf3, and can push b3 to protect the b pawn. It >>will be REAL hard for black to prevent white from trading queens and having a >>passed pawn. >> >>This seems lost no matter what, so how exactly did black blunder here? Not >>trading queens does not delay the inevitable much, if at all. >> >>KarinsDad :) > >Some of your variations don't make sense. You must have reset your board to the >wrong position. Specifically, White has a pawn on h4, and some lines you have >Black playing ...Kg4 and White playing h4+. My apologies. I had the pawn on h2. It doesn't change much except to prevent the Kg5 line. I also screwed up and keep placing the king on f4, g4 and g3 instead of f5, g5, and g6 (I have a type of dyslexia when I type variations from my head). 43 ... Ke7 44. Qb7+ any 45. Qxb4 winning a pawn 43 ... Kf7 44. Qb7+ Qe7 (to protect the b pawn) 45. Qxe7 and black's king is even further back than with what was played 43 ... Kf5 44. Qf3+ Kg6 45. Qg4+ any 46. Qxb4 43 ... Kf5 44. Qf3+ Ke6 45. Qb3+ any 46. Qxb4 > >Your general argument is that White can pick up the b-pawn, and this is true. >(That had been my plan until I was presented with an easier win.) After White >grabs the b-pawn, he needs to cover b3 and f2 without allowing perpetual check, >and slowly work his b-pawn forward. You're right in saying that this also wins. > It's not really so much that it takes longer in the terms of "number of moves", >it's just that it takes thought. In the game as played, White was able to play >on auto-pilot. The win is clear, and Black has zero counterplay. This was >important: we only had about a minute or so each at that point. > >"Blunder" is how I felt about allowing the queen exchange as the game was being >played. I'll agree that that is too strong a word when there's plenty of time >to look at the position, though. Part of my impression was because Black _had_ >his king in the corner earlier, but instead of playing h6, or g6 and h5, he went >and played it into the middle. In the game he had time to go back and hide, but >by the time we reached the position that I posted, it was already too late for >that. The point was that Black is lost. Crafty realized it was lost and saw Qe6 as the best of a series of lousy moves, most of which lose an additional pawn. Saving that pawn and preventing perpetual checks is very easy for a computer, so I did not understand the term blunder when it seems the best move, unless you want to try to swindle a human into a draw or you are playing against a human with low time. I don't see Crafty not picking a swindle move in a lost game as being inferior. That's all. > >The main point of my post was that Crafty was misevaluating the position after >the exchange of queens. The static eval is about 1.3, and it probably needs to >be something like 4 (higher than an extra minor piece, anyway.) The tricky part >to doing that is to make sure you are not assigning scores like that to pawn >endings that aren't clearly winning at the same time. > >Dave KarinsDad :)
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