Author: Ricardo Gibert
Date: 03:42:40 01/21/03
Go up one level in this thread
On January 21, 2003 at 05:56:47, James T. Walker 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. >> >>The idea of getting the rook behind a passed pawn for a won rook ending also >>occurred in the CCT where both programs (one was Diep) missed it. If I remember >>correctly, Diep won anyways by a more circuitous and eventful route. >> >>In this same tournament, the other idea of abandoning the outside passer to get >>2 connected passers also occurred (as in the above augmented analysis). I can't >>remember the program names, but that game was particularly funny. The defending >>side tried to invite the other side to win in this way (!) and the other program >>resisted! I stopped watching the game at this point, so I don't know how it >>turned out. >> >>My point is that Rook endings are a major achilles heal for programs. Part of >>the problem is that the programmers really *do* have understand how to play Rook >>endings to be able to get their programs to play them well. The trouble is, >>learning to play them and then program it is very very difficult. I know of no >>program that has done this competently. For example, Ruffian too is blind to the >>move 61...Re8. >> >>The proper methods of treating the diagrammed position are stock methods that >>are part of every decent endgame players arsenal and so far programs remain >>clueless. > >************************************************************************** >Not all programs are clueless in this position. Fritz 8 locks on to Re8 >instantly (after searching about 50K nodes). >************************************************************************** I don't have F8. What continuation does it give? > >> >>> >>>However, my comments were based on the game itself, as it was played, without >>>any long analysis about whether either side made a fatal mistake or not... >>> >>> >>> >>>>> >>>>>The game ended at move 115 with a repetition. >>>>> >>>>>Round 7 quark vs Crafty >>>>> >>>>>18 book moves, score 0 on leaving book, not a bad start as black. A tactical >>>>>oversight saw the score drop to +.70 (good for white) at move 21, but this >>>>>pawn "sac" was quickly recovered positionally and by move 24 the score was -.10 >>>>>and I was breathing easier. By move 30 the score was -.7. By move 65 the >>>>>score was nearly equal, and it looked to be headed to another draw. However, >>>>>at move 65 quark sacrificed a bishop for crafty's last pawn, leaving it in a >>>>>KRB (crafty) vs KNPPP (quark). The bishop/rook quickly ganged up on the >>>>>pawns and won them one by one, leading to a krb vs kn endgame table loss for >>>>>quark. A good game by quark, and the bishop for pawn looked like a draw, but >>>>>with a lot of maneuvering, the two pieces were simply overwhelming. >>>>> >>>>>Round 8 Pepito vs Crafty (two blacks in a row to offset two whites earlier) >>>>> >>>>>I didn't know much about pepito, so I simply watched the game. Out of book at >>>>>move 7 had a score of -.37 so this seemed promising. Around move 25 the score >>>>>started dropping and pepito won a pawn. As in round 6, crafty dug in and by move >>>>>63 this was a drawscore game as well. Nothing good or bad to say here, it was >>>>>just "a game". >>>>> >>>>>Round 9 Crafty vs Tao >>>>> >>>>>A Ruy Lopez that endedthat ended after 11 moves, and after Crafty played >>>>>Bh6, Bxh6, Qxh6 and then Qg7 the game instantly turned into a K, two rooks >>>>>and two minors for each side ending, with 3 pawns on each wing.. My score >>>>>was dead zero here and it really looked like a draw. >>>>> >>>>>However, around move 24, black moved his rook off the e-file and that >>>>>gave crafty a window of opportunity to penetrate, and it did so with a >>>>>score of +.5 at move 24. By move 33, the score was solidly at +.5 and >>>>>by move 50 it was clear that white was going to infiltrate and eat the >>>>>queenside, which it did... >>>>> >>>>> >>>>>All in all an interesting experience. >>>>> >>>>>Again, as always, the book is critical, and I did _zero_ book preparation >>>>>which hurt in several games. Using an automatically produced book can >>>>>work, I am convinced, but it needs to include recent games, so that old >>>>>lines with refutations are not played. >>>>> >>>>>The next tournament will find me with a better book. :)
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