Author: Robert Hyatt
Date: 11:35:50 01/21/03
Go up one level in this thread
On January 21, 2003 at 09:17:36, Rolf Tueschen wrote: >On January 21, 2003 at 09:09:49, Ricardo Gibert wrote: > >>On January 21, 2003 at 08:52:02, Rolf Tueschen wrote: >> >>>On January 20, 2003 at 23:00:55, Ricardo Gibert wrote: >>> >>>>On January 20, 2003 at 21:57:38, Robert Hyatt wrote: >>>> >>>>>On January 20, 2003 at 21:32:22, Ricardo Gibert wrote: >>>>> >>>>>>On January 20, 2003 at 20:44:21, Robert Hyatt wrote: >>>>>> >>>> >>>>[snip] >>>> >>>>>>>Round 6 Crafty vs Searcher >>>>>>> >>>>>>>A near disaster for the first game of the second day. The same d4 opening >>>>>>>led to a similar position, but things did not go very well here. First score >>>>>>>out of book was -.42, which was typical for every 1. d4 game crafty played as >>>>>>>white. But it was able to pull that up quickly normally. 10 moves out of book, >>>>>>>the score hadn't changed, showing that searcher was playing very well and with >>>>>>>a reasonable amount of understanding of the position. >>>>>>> >>>>>>>Finally by move 24, Crafty was back to a slightly + score, and this held until >>>>>>>it started dropping as it misjudged the queen/rook attacking in the center. At >>>>>>>move 32, the score was -.68 after 16 plies. at move 35, the score was -1.5, at >>>>>>>move 40 -2.0, -2.5 at move 50, -3 at move 60, and at this point Crafty dug >>>>>>>in its heels and pulled the score back to -2.3 where it stayed for a long >>>>>>>while. But it slowly traded pawns, and the score started swinting back. By >>>>>>>move 80, it was -2.0 again, -1.5 by move 85, -1.0 by move 95, and it finally >>>>>>>reported a draw score at move 102. Of all the games it played, this was a >>>>>>>really nice effort as it showed a lot of understanding about king rook and pawn >>>>>>>endings, something I have worked on a lot over the years. >>>>>> >>>>>> >>>>>>I find your last sentence surprising. Crafty was very lucky in this game that >>>>>>Searcherx did not play 62...Re8 62.Kxg3 Rb8 winning easily. >>>>>> >>>>>> >>>>> >>>>>Crafty says if you play Re8 it just plays Rb7 immediately, not Kg3. >>>>> >>>>>Score doesn't change much... >>>>> >>>>>It may be overlooking something, but it isn't going to let black get >>>>>the rook behind the pawn... >>>>> >>>>>Maybe we are at the wrong move? IE you have two move 62's above. >>>>>Do you mean 61. Re8? >>>> >>>> >>>>Yes. 61...Re8 62.Kxg3 Rb8 was my intention. >>>> >>>> >>>>> >>>>>Going back to move 61, and playing Re8 Kg3 Rb8 I get Rd4 and Rb4. White >>>>>loses one of the pawns on the h file, but only one. It isn't clear to me, >>>>>without a lot of study, how black makes progress. The pawn is blockaded, so >>>>>the black rook is stuck on the b file unless it gives check. The black >>>>>king can't abandon the kingside or white will eat the g pawn and the hpawn >>>>>should be enough to force the trade of the rook and a draw... >>>> >>>>[D]8/1p1R2pk/5p2/7P/7P/5Kn1/4r3/8 b - - 0 60 >>>> >>>>61...Re8 62.Kxg3 Rb8 63.Rd4 b5 64.Rb4 Kh6 65.Kg4 Rb7 66.Kh3 Kxh5 67.Kg3 g6 >>>>68.Kh3 f5 69.Kg3 Rb6 70.Kh3 Rc6 71.Rb3 Rc4 is a prosaic and convincing win. >>> >>>A comparable position is available with many different continuations. One is >>>your 61-Re8 others I pointed out in >>>http://www.talkchess.com/forums/1/message.html?278466 >>>The point is that you always winn with the f/g free pawns if they are so good >>>combined. No need to know the rule of the R behind the pawns because you give >>>the b pawn away. >>> >>>Kind regards, >>>Rolf Tueschen >>> >>> >>> >> >> >>Even though it is later given away, it handcuffs the defense giving time to make >>preparations before giving up the b-pawn to win on the K-side, so it is still an >>important tool. > >No doubt about it. But I was looking for the programmers and you said yourself >that this is difficult to program. So I had a look at totally normal chess, >calculable or countable if you like. And this position with the combined pawns >is won and that is the whole thing. I meant the argument of the "difficult" >Re8-b8 is even not necessary. > >Rolf Tueschen > > One of the problems here is that the f and g pawns are _not_ passed. The f pawn is. The g-pawn is not, because white hangs on to the h-pawn. Here are the problems I see that have to be solved: 1. black's rook is behind the b-pawn. If black moves the rook without giving check, the pawn goes away as it is attacked by white's rook. 2. I will assume the h5 pawn is going to "go". After Re8 Kxg3 Rb8 Rd4 b5 Rb4 the rooks are stuck. Black can move to b8/b7/b6. White can't move the rook or the pawn advances. 3. After black takes on h5 and white keeps the king at g3-h3 to hold the h-pawn, black has a couple of plans. But not all work. The king can't go help the rook, because white's king makes that a long path and it is close to the kingside pawns. the king can't win the white h-pawn by itself, and it can't get the rook up to attack it. So either the king goes to the queenside to help the b-pawn advance, or black tries advancing the f-pawn. White definitely has many problems here, but the question is "are they _all_ unsolvable?" It isn't that clear to me. One thing is for sure, it isn't an "easy win". It is going to take a lot of sweat and calculation. >> >>[snip]
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