Author: martin fierz
Date: 17:33:43 12/22/01
Go up one level in this thread
On December 22, 2001 at 03:36:46, K. Burcham wrote: >in this game there was a big swing from a positive score of about five to a >losing score of a mate in 11 in the final position. i have had several questions >about this game since i found this out at that time. this game has been >discussed here before. this was not a blitz game. shredders score >gradually increased to the +5, and back to a mate in 11 with 80 moves. all this >made me curious. here are my questions about this game. > >questions: > 1. was there one or more blunders? > 2. will some of the other top programs have this large eval swing? > 4. how miscalculated was this plan by shredder to push its own two pawns? > 5. can we find a key move in this game that will end in a draw? > 6. will shredder duplicate the same eval, in an analysis? > 7. one of the top programmers that post here, made this statement: > "well we know we cant trust shredders eval, so we should not > use this program to analyze games". i assumed he was basing > that comment on this game. so is his statement true? > 8. did deep junior eval also swing, the same as shredder? > 9. when did deep junior see the problem shredder was in? > 10. does this game indicate that deep junior can see far ahead > of most programs? > >now i am able to get some accurate answers. with dual 1533 and 1 gig ram, >i can run deep junior7. in the list below you will see i also used other >programs to compare. i tried to keep most depths from about 12 to 15. >deep junior was getting depths of 4 to 5 more than other programs. >sometimes the post would hang during analysis. but i think this info >is accurate. i started with move 21. shreddder was in book until about move 11. >deep junior also did not have 11...Rc8 in its book. it seems stefan >was using a different book than the commercial shredder5. maybe this was the >shredder5.32 book, not sure. at move 21 shredder eval was up about one pawn. > >all scores are for white, deep junior7. > >deep junior7, shredder5, chess tiger 14.0, deep shredder, crafty 18.08 > >21.Qh3 -.30 -1.25 -1.28 -.92 -.69 >31.Na4 -1.25 -3.05 -2.04 -2.88 -.2.05 >47.hxg4 -1.95 -4.08 -2.88 -4.25 -3.19 >55.Kh3 -1.76 -4.92 -4.52 -4.95 -3.00 >57.g5 -2.63 -5.37 -4.98 -5.40 -4.20 >61.Kh4 -1.75 -5.58 -3.92 -5.40 -3.25 >...a4 -1.08 -5.51 -3.62 -5.09 -3.00 >62.f6 -.92 -3.60 -3.60 -3.95 -2.95 >...Rb8 -.37 -2.00 -2.90 -2.80 -2.46 >63.Bf3 .00 -.27 -1.38 .00 -2.44 >... >64.g6 +.20 +.45 .00 +.37 +.19 >...Rd8 +3.50 +2.33 +3.88 +5.50(Qc2) +4.36 >66.Qc2 +4.00 +4.75 +4.08 +5.15 +2.47 >69.Nxd5 +3.16 +7.06 +3.48 +5.40 +2.33 >...Kf7 +5.75 +7.35 +6.85 +7.50 +6.62 >71.Qf3 +6.10 +9.00 +10.85 +10.11 +8.44 > >80...Kb6 mate in 11 stefan resigns > >with the above info all of my questions have been answered. >i am not saying that any of these programs would have played the same lines as >shredder to lead into this same game. but it is obvious that junior did not see >the win any sooner than the other programs. although dj eval was lower than >shredder considerably. shredder5 eval and large eval swing was a little more >than the others. but most programs evals were similiar. also at move 71 >deep junior eval is still 3 points lower than others. so DJ7 eval is >conservative on both ends. it seems to me that deep junior had no idea >that it could promote and mate, before the other programs could see this. >but in this game deep junior played for the win, and was the victor. > >i also studied some of the key moves in this game. after using ct14 and deep >shredder i found that on move 48...Bxf5, 49.exf5, the two pawns could now >advance forward for the queen. in the Maastricht game shredder did not see >this combination. instead if shredder had played 48...Nc2, >shredder wins. of course i know this was just one game. but dj was running >on 2x1533 and getting deep search. with this only one move change, shredder >wins. also slate and i tried another line with changing just one move in >this game and shredder had a draw with slate. slate if you read this, >i found another line that shredder could win. >here is the one move change, 48...Nc2 that shredder wins this game. > >[Event "Maastrict 2001 with move 48...Nc2"] >[Site "?"] >[Date "2001.12.22"] >[Round "6"] >[White "Deep Junior"] >[Black "Shredder5"] >[Result "0-1"] >[SetUp "1"] >[FEN "1r5k/2qb3p/3p3b/p3pN2/N3P1P1/2P1n1P1/6B1/R3Q2K b - -"] > >1... Nc2 2. Qd1 Nxa1 3. Nxh6 Bxa4 4. Qxa4 Nb3 5. g5 Nc5 6. Qa2 >Rf8 7. Qd5 a4 8. Nf5 a3 9. g4 Qd7 10. Qa2 >Qa4 11. Kh2 Nxe4 12. c4 Rb8 13. c5 Qb3 14. Qe2 >a2 15. Qa6 Qb2 16. Qa7 Rg8 17. g6 hxg6 18. Nh6 >a1=Q 19. Qxa1 Qxa1 20. Nxg8 Nc3 21. Kh3 Ne2 22. Ne7 0-1 > > >this is 48.Nf5 > [D] 1r5k/2qb3p/3p3b/p3pN2/N3P1P1/2P1n1P1/6B1/R3Q2K b - - > >here is the complete game. >[Event "WMCCC"] >[Site "Maastricht"] >[Date "2001.08.22"] >[Round "6"] >[White "Junior"] >[Black "Shredder"] >[Result "1-0"] > >1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 >e6 7. Be2 Qc7 8. f4 b5 9. a3 Bb7 10. Bf3 Nbd7 11. Nde2 Rc8 >12. O-O Be7 13. Kh1 O-O 14. b4 Nb6 15. Qd3 Rfd8 16. f5 Nc4 >17. fxe6 fxe6 18. Bd4 Rd7 19. Bxf6 Bxf6 20. Bg4 Re7 21. Qh3 >Rce8 22. a4 bxa4 23. Bh5 Rf8 24. Bg4 Bc8 25. Rxa4 Ree8 >26. Raa1 g6 27. Qg3 Qb6 28. Bh3 Qxb4 29. Qd3 Bg7 30. Rfb1 >Qc5 31. Na4 Qc7 32. c3 Rf6 33. Nd4 Ref8 34. Nf3 Rf4 35. Nd4 >Re8 36. Rf1 Rxf1+ 37. Rxf1 Bd7 38. Ra1 Kh8 39. Qf1 g5 >40. Qd1 Ne5 41. g3 g4 42. Bg2 a5 43. Qc2 Rb8 44. Qc1 Nc4 >45. Qe1 Bh6 46. h3 Ne3 47. hxg4 e5 48. Nf5 Bxf5 49. exf5 >Nc2 50. Qd1 Nxa1 51. Qxa1 e4 52. Qd1 e3 53. Bf3 Bg7 54. Kg2 >Re8 55. Kh3 Qc4 56. Be2 Qc6 57. g5 Be5 58. Nb2 d5 59. Nd3 >Bxc3 60. Nf4 d4 61. Kh4 a4 62. f6 Rb8 63. Bf3 Qb5 64. g6 >Rd8 65. g7+ Kg8 66. Qc2 Rd6 67. Qa2+ Qb3 68. Bd5+ Rxd5 >69. Nxd5 Kf7 70. Qg2 d3 71. Qf3 Qb8 72. Qh5+ Ke6 73. Nxc3 >e2 74. Qg4+ Kf7 75. Kg5 h6+ 76. Kxh6 e1=Q 77. Qg6+ Ke6 >78. f7+ Kd7 79. Qxd3+ Kc7 80. Qc4+ Kb6 1-0 > >final position. stefan resigns with two queens on board. 80...Qb6 >and mate in 11. > > [D] 1q6/5PP1/1k5K/8/p1Q5/2N3P1/8/4q3 w - - > >kburcham dear kburcham, interesting analysis, but i think you have not got the right answer... hmm, so you are basically saying that Bxf5 is supposed to be *the* mistake? i looked at the game, and if one of my chess pupils had been black, he would have gotten a serious talking-to! let me explain: the position after 51. Qxa1 is clearly winning for black. if you ask any strong chess player, he will tell you what the plan is: exchange queens - at any price, for a pawn or two even. the *only* thing that can go wrong for black in this position is that he will have a problem with his king, and this only happens when there are queens on the board. besides, an exchange is not worth much in the middle game, but decisive once you enter the endgame, and there is no other pair of rooks on the board. this is what all strong humans know, and what obviously even top programs have not got programmed into their evaluation. so, returning to the position after 51.Qxa1, how should black proceed? since his position is already completely winning, he doesnt have to win a second time by queening the e-pawn. i'll suggest a line, you can try to improve for white. my line is 'human' in the sense that i will just attempt to exchange queens. i do this by activating my queen first, and look for a possible exchange. The white moves are made by fritz 5.32 running in chessbase. mostly the move indicated got by far the best evaluation. 51. ..Qc4 52. Qd1 Rg8 53. Bf3 e4 54. Be2 Qa2 (menacing Qd2, game over) 55. Nb6? Qd2 56. Qxd2 Bxd2 and i'm not going to look at this position any more, it is so winning for black. i find it very interesting that fritz 5.32 doesnt mind the queen exchange, and would also not play 55. ...Qd2! itself. this clearly shows that this version of fritz has no clue about what is going on here. since you have all top programs, could you give this a try and see which program would exchange the queen here? alternatively, white could play 55. Qxd6 Qxe2 56. Qxh6 Qxg4 57. Qf6+ Qg7 and black has again achieved his goal of exchanging the queens. believe me, there is no other viable plan for black in this position than the exchange of queens. i have made this experience too many times as the guy who should have done anything to get the queens off the board, the last time our team lost a match 4.5-3.5 in the highest swiss league where i allowed a perpetual check in a winning position. i have seen my pupils lose games a piece up because they were checkmated. of course these are kids, but it's the same here. there is a nice website called www.chesscafe.com, there there used to be a column of some guy teaching weaker players. his motto was GTS, "go to sleep": if you are a piece up, trade the queens then you can GTS - else you always have to keep your eyes open for surprises, just like in this game. do the test and see which program will play ...Qd2. of course, other moves win too there, but that's not the point - the point is, do the programs know = have it coded in their evaluation, that being an exchange up is worth more once the queens are gone? thanks & best regards martin
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