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Subject: Re: CCT5 - Crafty perspective

Author: James T. Walker

Date: 02:56:47 01/21/03

Go up one level in this thread


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).
**************************************************************************

>
>>
>>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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