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Subject: Re: interesting game, and a couple difficult positions

Author: Uri Blass

Date: 15:36:40 11/13/05

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On November 13, 2005 at 18:25:19, Uri Blass wrote:

>On November 13, 2005 at 15:01:29, Jon Dart wrote:
>
>>This game had an interesting ending:
>>
>>[Event "?"]
>>[Site "chessclub.com"]
>>[Date "2005.11.12"]
>>[Round "?"]
>>[White "Arasan 9.0"]
>>[Black "thebaron"]
>>[Result "0-1"]
>>[ECO "B42"]
>>[WhiteElo "2599"]
>>[BlackElo "2506"]
>>[TimeControl "1200+10"]
>>
>>1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 a6 5. Bd3 Nf6 6. O-O Nc6
>>7. Nxc6 dxc6 8. Bf4 Bd6 9. e5 Nd5 10. Qg4 Nxf4 11. Qxg7 Rf8 12. exd6
>>Nxd3 13. cxd3 Qxd6 14. Nc3 f5 15. Qxh7 Bd7 16. Qh5+ Kd8 17. Rfe1 Kc7
>>18. Qe2 c5 19. Rad1 Rh8 20. Qe5 Rh4 21. Qxd6+ Kxd6 22. g3 Rg8 23. Kg2
>>b5 24. f3 Bc6 25. a3 e5 26. Rd2 Rf4 27. Re3 b4 28. axb4 cxb4 29. Nd1
>>a5 30. Rde2 Rd4 31. Nf2 Re8 32. Nh3 a4 33. Ng5 Bd5 34. Kf2 Ra8
>>35. Re1 a3 36. Rxe5 a2 37. R5e2 Rxd3 38. Ra1 b3 39. h3 Rc8 40. Kf1
>>Rc2 41. Ke1 Rdc3 42. Rd1 0-1 {ArasanX resigns}
>>
>>In this position, White is already in trouble, but 36. Rxe5 looks
>>like a mistake. Chess Tiger avoids it immediately, and gives a
>>+2 or so plus score for Black after forcing Rxe5. But several other
>>programs, including mine, want to play it.
>>
>>[D] r7/8/3k4/3bppN1/1p1r4/p2PRPP1/1P3K1P/4R3 w - -
>>
>>At move 38, we have this position for Black:
>>
>>[D] r7/8/3k4/3b1pN1/1p6/3r1PP1/pP2RK1P/R7 b - -
>>
>>Here b3 is indeed the best move, but Arasan doesn't find it
>>readily. This is my lastest build in multi-variation mode,
>>1 hour per move:
>>
>>result: Kd7     3600 seconds.   score: +1.38    2038387785 nodes.       ** error
>>
>>Kd7 Kg1 Bb3 Kf2 Rd8 Ree1 Rd2+ Ke3 Rxh2 Kf4 Rf8 Re5 Rd2 Rb5 Rd4+ Ke5 Rc4 Ne6
>>result(2):      Rc8     3600 seconds.   score: +2.22    2000296738 nodes.
>>** error
>>Rc8 b3 Bxb3 g4 Rg8 h4 fxg4 fxg4 Rf8+ Ke1 Rd4 Ne4+ Kc6 Nf2 Bc4 Raxa2 Bxa2 Rxa2 Rh
>>8 Rd2 Rxd2
>>result(3):      b3      3600 seconds.   score: +3.00    2030428316 nodes.
>>++ correct
>>b3 h4 Rc8 Ke1 Bxf3 Nxf3 Rxf3 Rd2+ Kc5 Rc1+ Kb6 Rd6+ Ka7 Rd7+ Kb8 Rcd1 Rxg3 Kf1 R
>>h3 Kg1 Rxh4
>>
>>So it actually had to be forced to eliminate Kd7 and Rc8 before
>>selecting b3. I am still looking into the reason. Chess Tiger and
>>Pharaon play b3 very quickly here, but Crafty 19.17 prefers Rg8 with
>>an even score, at least for several minutes.
>>
>>--Jon
>
>I wonder why you use 19.17 that is known to be one of the weakest versions of
>Crafty in the last years(see ssdf results)
>
>
>http://web.telia.com/~u85924109/ssdf/rlwww052.txt
>
>Crafty18.12/CB 2617
>Crafty19.17    2522
>
>The difference is not because of better book of chessbase but mainly because of
>weaknesses of the engine and I know that 19.17 got weaker results than 19.15 in
>every tournament that both versions played.
>
>About the position I doubt if Rxe5 is so bad and I think that white is losing
>the game both with Rxe5 and without it and the losing mistake was earlier(note
>that fruit also likes Rxe5 with a clear advantage for black of near 1.5 pawns
>for black in few minutes).
>
>b3 is not an easy move to find for fruit but even without it black is probably
>winning.
>
>Uri
>
Here is analysis by my fruit favourite personality(history=50)
It has no problem to find 38...b3 in the main line so maybe not having clear
hash caused fruit to have problems with 38...b3


Arasan 9.0 - thebaron, chessclub.com 2005
[D]r7/8/3k4/3bppN1/1p1r4/p2PRPP1/1P3K1P/4R3 w - - 0 1

Analysis by Fruit 2.2.1:

36.bxa3 bxa3 37.Rxe5 Rxd3 38.Rxf5
  ±  (0.89)   Depth: 1/5   00:00:00
36.bxa3 bxa3 37.Rxe5 Rxd3 38.Rxf5
  ±  (0.89)   Depth: 2/9   00:00:00
36.bxa3 bxa3 37.f4 exf4
  =  (-0.16)   Depth: 3/14   00:00:00
36.bxa3 bxa3 37.Ra1 Rb4 38.h4
  µ  (-0.71)   Depth: 4/14   00:00:00
36.bxa3 bxa3 37.Ra1 a2 38.h4 f4 39.gxf4 Rxf4
  µ  (-0.88)   Depth: 5/15   00:00:00
36.bxa3 bxa3 37.Ra1 a2 38.h4 f4 39.gxf4 exf4 40.Ne4+ Bxe4 41.Rxe4 Rxd3 42.Rxf4
  µ  (-0.85)   Depth: 6/17   00:00:00  30kN
36.bxa3 bxa3 37.Ra1 a2 38.h4 f4 39.gxf4 exf4 40.Ne4+ Ke5 41.Re2 Rxd3
  µ  (-1.13)   Depth: 7/20   00:00:00  76kN
36.bxa3 bxa3 37.Ra1 a2 38.h4 Rb8 39.Re2 Rxd3 40.Raxa2 Bxa2 41.Rxa2 Rd4
  µ  (-0.99)   Depth: 8/22   00:00:00  205kN
36.Rxe5 a2 37.R5e2 Rxd3 38.Ra1 Rh8 39.h4 f4 40.Rc1 fxg3+ 41.Kxg3
  µ  (-0.82)   Depth: 8/22   00:00:00  347kN
36.Rxe5 a2 37.R5e2 Rxd3 38.Ra1 Rh8 39.h3 Rc8 40.h4 f4 41.gxf4
  ³  (-0.61)   Depth: 9/24   00:00:01  563kN
36.Rxe5 a2 37.R5e2 Rxd3 38.Ra1 Rh8 39.h3 b3 40.Rae1 Rc8 41.h4
  ³  (-0.65)   Depth: 10/24   00:00:01  957kN
36.Rxe5 a2 37.R5e2 Rxd3 38.Ra1 Rh8 39.h3 b3 40.Rae1 Ra8 41.Ra1 Rc8
  ³  (-0.65)   Depth: 11/27   00:00:02  1753kN
36.Rxe5 a2 37.R5e2 Rxd3 38.Ra1 Rg8 39.h4 Rxg5 40.hxg5 Rxf3+ 41.Kg2 Rf4+ 42.Kg1
Rg4 43.Kf2 Rxg5
  µ  (-0.94)   Depth: 12/34   00:00:05  4097kN
36.Rxe5 a2 37.R5e2 Rxd3 38.Ra1 Rg8 39.h4 Rxg5 40.hxg5 Rxf3+ 41.Kg2 Rf4+ 42.Kg1
Rg4 43.Kf2 Rxg5 44.Rc1
  µ  (-0.88)   Depth: 13/35   00:00:08  7319kN
36.Rxe5 a2 37.R5e2 Rxd3 38.Ra1 b3 39.Kg1 Bxf3 40.Nxf3 Rxf3 41.Rd1+ Kc5 42.Ree1
Kc4 43.Kg2 Rd3 44.Rc1+ Kb5
  µ  (-1.24)   Depth: 14/38   00:00:19  17243kN
36.Rxe5 a2 37.R5e2 Rxd3 38.Ra1 b3 39.h4 Rc8 40.Rae1 Rc2 41.h5 f4 42.gxf4 Rdd2
43.Rxd2 Rxd2+ 44.Ke3 Rxb2
  µ  (-1.18)   Depth: 15/41   00:00:43  39423kN
36.Rxe5 a2 37.R5e2 Rxd3 38.Ra1 b3 39.Kg1 Bxf3 40.Nxf3 Rxf3 41.Rd2+ Ke6 42.Re1+
Kf6 43.Rd6+ Kg5 44.Rdd1 f4 45.Kg2 Re3 46.h4+ Kf5
  -+  (-1.46)   Depth: 16/43   00:01:18  71436kN
36.Rxe5 a2 37.R5e2 Rxd3 38.Ra1 b3 39.h4 Rc8 40.Rae1 Rc2 41.h5 Rdd2 42.Rxd2 Rxd2+
43.Ke3 Rxb2 44.Rd1 Rb1 45.Nf7+ Kc5
  -+  (-1.95)   Depth: 17/51   00:04:04  220784kN
36.Rxe5 a2 37.R5e2 Rxd3 38.Ra1 b3 39.h3 Rg8 40.f4 Rc8 41.Rae1 Rc2 42.g4 Rdd2
43.Rxd2 Rxd2+ 44.Ke3 Rxb2 45.gxf5 Rb1
  -+  (-2.23)   Depth: 18/51   00:09:38  520317kN
36.bxa3 bxa3 37.Rxe5 a2 38.Rxf5 Rb4 39.Ra1 Rb1 40.Rxa2 Rxa2+ 41.Ke3 Rxh2 42.Ne4+
Bxe4 43.dxe4 Rb3+ 44.Kf4 Rf2 45.Kg4 Ke6 46.Rf8 Ke7 47.Rf5 Ra2 48.Rd5
  -+  (-1.97)   Depth: 18/54   00:13:44  741768kN

(,  14.11.2005)



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