Time to bring this test position out again....

[JVMerlino]

This is a position from round 3 of Chessmaster vs. GM Larry Christiansen. I've dug this one up a few times since it was played almost 13 years ago. The last time it was posted here was 5 years ago and several engines agreed with the move played, but not how good it was.

[d]8/p1p5/Pp1p2nk/1P1Bq1r1/2P1Pprp/1Q6/5RPP/3R3K b - - 0 53

At this point, Larry played 53...Rg3?! Afterwards, he claimed it was winning. But unfortunately he blundered later on in the game and lost.

Since engines have obviously gotten much stronger in the last five years, I would very much appreciate it if any of you with top-end hardware could run this position and see if any engine can find a win for black by playing Rg3.

Here's the game, for your amusement:

[Event "ICC 2 120 u"]
[Site "Internet Chess Club"]
[Date "2002.09.29"]
[Round "3"]
[White "CM9000 (Botvinnik)"]
[Black "LarryC"]
[TimeControl "120+120"]
[Result "1-0"]
[ECO "A28"]

1.c4 e5 2.Nc3 Nf6 3.Nf3 Nc6 4.d4 exd4 5.Nxd4 Bb4 6.Bg5 h6 7.Bh4 Bxc3+
8.bxc3 Ne5 9.e3 d6 10.Be2 Ng6 11.Bxf6 Qxf6 12.O-O O-O 13.Qc2 Re8 14.Rfd1
Nf8 15.Bd3 Ne6 16.Nb3 Rb8 17.a4 Qe7 18.a5 Bd7 19.a6 b6 20.Nd4 Nc5 21.Nb5
Bxb5 22.cxb5 Qf6 23.Bc4 Re5 24.Bd5 Rbe8 25.Rd4 Ne6 26.Rd2 g6 27.Ra4 Kg7
28.Rd1 Re7 29.Rb4 g5 30.Bc6 Qg6 31.Qb2 f5 32.Qb1 Qf6 33.Bd5 f4 34.e4 Nf8
35.f3 h5 36.Qc2 Ng6 37.Qa2 Kh6 38.Qd2 Rg7 39.Qd4 g4 40.fxg4 Nh4 41.Rb2
Rxg4 42.Kh1 Ng6 43.Rf2 Qe7 44.Qd2 Reg5 45.Ra1 h4 46.c4 Qe5 47.Rc1 Kg7
48.Bc6 Qe7 49.Rcf1 Re5 50.Qc3 Kh6 51.Bd5 Reg5 52.Qb3 Qe5 53.Rd1 Rg3
54.hxg3 hxg3 55.Ra2 Rg4 56.Kg1 Qh5 57.Kf1 f3 58.Ke1 f2+ 59.Kd2 Rh4
60.Qe3+ Kg7 61.Rf1 Qe5 62.Kc2 Rh2 63.Qf3 Qf4 64.e5 Qxf3 65.Bxf3 Nxe5
66.Bd5 Rh5 67.Ra3 Rg5 68.Kd2 Ng6 69.Re3 Ne5 70.Ke2 Kf6 71.Rh1 Ng6 72.Rh7
1-0

Many thanks in advance,
jm

[zullil]

Stockfish sees nothing after Rg3, at least so far:

Code: Select all

info depth 46 seldepth 40 multipv 1 score cp 0 nodes 28340647182 nps 29608018 hashfull 999 tbhits 0 time 957195 pv h2g3 h4g3 f2f3 g5g4 h1g1 e5h5 e4e5 g4h4 g1f1 h5e5 f1g1 e5h5 g1f1 h5e5

[Modern Times]

I tried this with Komodo 9.1 on my modest AMD 8-core, and Komodo sees it as 0.00

48.01 45:13 0.00 1.hxg3 hxg3 2.Rf3 Rg4 3.Kg1 Qh5 4.e5 Qh2+
5.Kf1 Qh1+ 6.Ke2 Qxg2+ 7.Ke1 Rg5
8.Rd2 Qh1+ 9.Rf1 Rxe5+ 10.Re2 Rxe2+
11.Kxe2 Qh2+ 12.Ke1 g2 13.Bxg2 Qxg2
14.Qc3 (30.095.212.915) 11089
TB:5.887.989

[kgburcham]

[d] 8/p1p5/Pp1p2nk/1P1Bq1r1/2P1Pprp/1Q6/5RPP/3R3K b - -

yes hash was empty

8 processor(s) found, POPCNT available
NUMA configuration with 1 node(s), offset 0
8192 MB Hash
Nalimov 6 men EGTB available - 800 MB cache
Engine: Houdini 4 Pro x64 (8192 MB)
by Robert Houdart
other best move - reduce depth to 11
other best move - reduce depth to 12
other best move - reduce depth to 13
17/64 0:01 -0.16 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Qc3 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Qxg2+ 61.Kd3 Nxe5+ 62.Kd4 Nxf3+ 63.Qxf3 Qb2+ 64.Kd3 Qb3+ 65.Ke2 Re5+ 66.Kf1 Qe3 (25.139.709) 18283
18/64 0:01 -0.08-- 53...Rg3 54.hxg3 (29.217.661) 18550
18/64 0:02 -0.06 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Qc3 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Qxg2+ 61.Kd3 Nxe5+ 62.Kd4 Nxf3+ 63.Qxf3 Qb2+ 64.Kd3 Qb3+ 65.Ke2 Re5+ 66.Kf1 Qxf3+ (39.221.836) 19123
19/64 0:02 -0.14++ 53...Rg3 (49.682.949) 19606
19/64 0:02 -0.29++ 53...Rg3 (52.349.524) 19680
19/64 0:02 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Qc3 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Qxg2+ 61.Kd3 Nxe5+ 62.Kd4 Rg4 63.Be4 Kg5 64.Rff1 f3 65.Kd5 Rf4 66.Qc1 Qh3 (56.571.754) 19642
20/64 0:04 -0.07++ 53...Rg3 (92.113.048) 20835
20/64 0:04 -0.22++ 53...Rg3 (94.523.742) 20811
20/64 0:04 -0.42 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Qc3 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Qxg2+ 61.Kd3 Nxe5+ 62.Kd4 Rg4 63.Be4 Kg5 64.Kd5 Qh2 65.Rd2 Qh8 66.Rg2 Qg8+ (101.083.180) 20777
21/64 0:05 -0.34-- 53...Rg3 54.hxg3 (109.803.959) 20709
21/64 0:08 -0.49++ 53...Rg3 (178.303.913) 21691 TB:5
21/64 0:08 -0.45 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Qc3 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Qxg2+ 61.Kd3 Nxe5+ 62.Kd4 Rg4 63.Be4 Kg5 64.Kd5 Qh2 65.Rd2 Qh8 66.Rg2 Qg8+ (182.285.835) 21677 TB:5
22/64 0:10 -0.53++ 53...Rg3 (219.253.243) 21807 TB:5
22/65 0:10 -0.38-- 53...Rg3 54.hxg3 (232.173.256) 21851 TB:5
22/69 0:14 -0.63 53...Rg3 54.hxg3 hxg3 55.Ra2 Rg4 56.Kg1 Rh4 57.Kf1 f3 58.Qe3+ Nf4 59.Ke1 Rh1+ 60.Kd2 Rxd1+ 61.Kxd1 f2 62.Rxf2 Qa1+ 63.Kd2 Qa2+ 64.Ke1 Qb1+ 65.Kd2 Qb2+ 66.Ke1 Qxf2+ (314.049.756) 22191 TB:5
23/69 0:16 -0.73++ 53...Rg3 (372.609.599) 22318 TB:5
23/69 0:17 -0.71 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Qc3 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Qxg2+ 61.Kd3 Nxe5+ 62.Kd4 Rg4 63.Be4 Qh2 64.Qc1 g2 65.Rg1 Kg5 66.Rxf4 Rxf4 (401.757.315) 22334 TB:5
24/69 0:20 -0.61-- 53...Rg3 54.hxg3 (472.102.616) 22519 TB:5
24/69 0:26 -0.47-- 53...Rg3 54.hxg3 (611.585.484) 22825 TB:12
24/73 0:34 -0.13-- 53...Rg3 54.hxg3 (788.093.016) 23055 TB:12
24/85 1:08 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Qc3 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Qxg2+ 61.Kd3 Nxe5+ 62.Kd4 Rg4 63.Be4 Qh2 64.Rff1 Kg5 65.Rh1 Qf2+ 66.Kd5 g2 (1.634.508.386) 23696 TB:879
24/85 2:40 -0.20 53...Qf6 54.c5 Rg3 55.Qb2 Qxb2 56.Rxb2 Re3 57.cxd6 cxd6 58.Rbd2 Ne5 59.Be6 Rxe4 60.Ba2 Rb4 61.Rxd6+ Rg6 62.R6d4 Rxd4 63.Rxd4 f3 64.gxf3 Nxf3 65.Rd1 h3 66.Bd5 Ne5 (3.842.678.029) 23875 TB:1.254
25/85 2:43 -0.20 53...Qf6 54.c5 Rg3 55.Qb2 Qxb2 56.Rxb2 Re3 57.cxd6 cxd6 58.Rbd2 Ne5 59.Be6 Rxe4 60.Ba2 Rb4 61.Rxd6+ Rg6 62.R6d4 Rxd4 63.Rxd4 f3 64.gxf3 Nxf3 65.Rd1 h3 66.Bd5 Ne5 (3.904.544.996) 23844 TB:1.254
26/85 3:21 -0.13-- 53...Qf6 54.c5 (4.801.030.555) 23846 TB:1.409
26/89 28:59 -0.17 53...Qf6 54.c5 Rg3 55.Qb2 Qxb2 56.Rxb2 Re3 57.cxd6 cxd6 58.Rbd2 Ne5 59.Be6 Rxe4 60.h3 Rg3 61.Rxd6 Kg5 62.R6d5 f3 63.gxf3 Rxf3 64.Bg4 Rfe3 65.Kh2 Rb4 66.R1d2 Kf4 (45.682.950.801) 26256 TB:36.069



[Event "ICC 2 120 u"]
[Site "Internet Chess Club"]
[Date "2002.09.29"]
[Round "3"]
[White "CM9000 (Botvinnik)"]
[Black "LarryC"]
[ECO "A28"]
[Result "1-0"]

1. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. d4 exd4 5. Nxd4 Bb4
6. Bg5 h6 7. Bh4 Bxc3+ 8. bxc3 Ne5 9. e3 d6 10. Be2 Ng6
11. Bxf6 Qxf6 12. O-O O-O 13. Qc2 Re8 14. Rfd1 Nf8 15. Bd3
Ne6 16. Nb3 Rb8 17. a4 Qe7 18. a5 Bd7 19. a6 b6 20. Nd4 Nc5
21. Nb5 Bxb5 22. cxb5 Qf6 23. Bc4 Re5 24. Bd5 Rbe8 25. Rd4
Ne6 26. Rd2 g6 27. Ra4 Kg7 28. Rd1 Re7 29. Rb4 g5 30. Bc6
Qg6 31. Qb2 f5 32. Qb1 Qf6 33. Bd5 f4 34. e4 Nf8 35. f3 h5
36. Qc2 Ng6 37. Qa2 Kh6 38. Qd2 Rg7 39. Qd4 g4 40. fxg4 Nh4
41. Rb2 Rxg4 42. Kh1 Ng6 43. Rf2 Qe7 44. Qd2 Reg5 45. Ra1
h4 46. c4 Qe5 47. Rc1 Kg7 48. Bc6 Qe7 49. Rcf1 Re5 50. Qc3
Kh6 51. Bd5 Reg5 52. Qb3 Qe5 53. Rd1 Rg3 54. hxg3 hxg3
55. Ra2 Rg4 56. Kg1 Qh5 57. Kf1 f3 58. Ke1 f2+ 59. Kd2 Rh4
60. Qe3+ Kg7 61. Rf1 Qe5 62. Kc2 Rh2 63. Qf3 Qf4 64. e5
Qxf3 65. Bxf3 Nxe5 66. Bd5 Rh5 67. Ra3 Rg5 68. Kd2 Ng6
69. Re3 Ne5 70. Ke2 Kf6 71. Rh1 Ng6 72. Rh7 1-0

[kgburcham]

[d] 8/p1p5/Pp1p2nk/1P1Bq1r1/2P1Pprp/1Q6/5RPP/3R3K b - -


Engine: Komodo 9 64-bit (8192 MB)
by Don Dailey, Larry Kaufman, Mark Lefler
Threads now set to 8
22.00 0:02 0.00 53...h3 54.Qxh3+ Rh4 55.Qa3 Rg3 56.Rd3 Qh5 57.h3 Ne5 58.Rxg3 Qd1+ 59.Kh2 fxg3+ 60.Kxg3 Qe1 61.Qb2 Qe3+ 62.Rf3 Qg5+ 63.Kf2 Rf4 64.Qc3 Nxf3 65.Qh8+ Kg6 66.Qg8+ Kh6 (41.257.220) 19558
23.00 0:02 0.00 53...h3 54.Qxh3+ Rh4 55.Qb3 Rg3 56.Rd3 Qg5 57.Kg1 Re3 58.Rxe3 fxe3 59.Rf3 e2 60.Qe3 Nf4 61.g3 Qe5 62.Rxf4 Rxf4 63.Qxe2 Rf8 64.Kg2 Qh5 65.Qd3 Kg7 66.Qe3 Kh7 (46.054.329) 19649
24.00 0:03 0.00 53...h3 54.Qxh3+ Rh4 55.Qb3 Rg3 56.Rd3 Qg5 57.Kg1 Re3 58.Rxe3 fxe3 59.Rf3 e2 60.Qe3 Nf4 61.g3 Qe5 62.Rxf4 Rxf4 63.Qxe2 Rf8 64.Kg2 Qh5 65.Qd3 Kg7 66.Qe3 Kh7 (59.327.841) 19673
25.01 0:03 0.00 53...h3 54.Qxh3+ Rh4 55.Qb3 Rg3 56.Rd3 f3 57.gxf3 Nf4 58.Rdd2 Rg5 59.Rf1 Nh5 60.f4 Nxf4 61.Qf3 Nh5 62.Qf8+ Rg7 63.Rg2 Ng3+ 64.Kg1 Qd4+ 65.Qf2 Rf4 66.hxg3 Rxf2 (76.728.174) 19800
26.01 0:06 0.00 53...h3 54.Qxh3+ Rh4 55.Qb3 Rg3 56.Rd3 Qa1+ 57.Qd1 Qxd1+ 58.Rxd1 Rc3 59.Kg1 Ne5 60.Rdf1 Kg5 61.Be6 Re3 62.Bd5 Rd3 63.Be6 Re3 (125.119.452) 19869
26.03 0:07 -0.07++ 53...Rg3 (141.791.314) 19987
26.01 0:07 -0.14++ 53...Rg3 (145.599.560) 19996
26.01 0:09 -0.24++ 53...Rg3 (190.896.222) 20061
26.01 0:09 -0.39++ 53...Rg3 (196.652.136) 20072
26.01 0:10 -0.61++ 53...Rg3 (219.097.540) 20031
26.01 0:13 -0.44-- 53...Rg3 54.hxg3 (267.355.392) 20035
26.01 0:14 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Kg5 65.Kxe3 Nh4 66.Be4 Kg4 (293.831.073) 20069
27.01 0:15 -0.07++ 53...Rg3 (301.686.629) 20049
27.01 0:15 -0.14++ 53...Rg3 (307.888.612) 20065
27.01 0:15 -0.24++ 53...Rg3 (312.954.779) 20068
27.01 0:17 -0.15-- 53...Rg3 54.hxg3 (357.531.780) 20142
27.01 0:19 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Nf4+ 65.Kxe3 Kg5 66.Kf3 Nd3 (397.829.872) 20206
28.01 0:22 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Nf4+ 65.Kxe3 Kg5 66.Kf3 Nd3 (453.652.516) 20246
29.01 0:24 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Nf4+ 65.Kxe3 Kg5 66.Kf3 Nd3 (504.762.073) 20291
30.01 0:34 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Nf4+ 65.Kxe3 Kg5 66.Kf3 Nd3 (696.864.060) 20272
31.01 0:40 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Nf4+ 65.Kxe3 Kg5 66.Kf3 Nd3 (826.355.549) 20317
32.01 0:56 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Nf4+ 65.Kxe3 Kg5 66.Kf3 Nd3 (1.139.514.058) 20348
33.01 1:22 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Nf4+ 65.Kxe3 Kg5 66.Kf3 Nd3 (1.675.771.755) 20243
34.01 2:42 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Ne7 65.Kxe3 Kg5 66.Ke4 Kg4 (3.245.096.346) 19919
35.01 3:12 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Ne7 65.Kxe3 Kg5 66.Kf3 Kh4 (3.865.073.591) 20087
36.01 3:42 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Ne7 65.Kxe3 Kg5 66.Kf3 Ng6 (4.507.715.176) 20249
37.01 4:59 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rg4 56.Kg1 Qh5 57.e5 Rg5 58.Re1 Qh2+ 59.Kf1 Qh1+ 60.Ke2 Rxe5+ 61.Re3 Rxe3+ 62.Qxe3 Qxe1+ 63.Kxe1 fxe3 64.Ke2 Kg5 65.Kxe3 Nh4 66.Kd4 Kg4 (6.145.869.244) 20536
37.12 9:31 -0.07++ 53...Qf6 (11.639.202.674) 20367
37.01 14:27 -0.14++ 53...Qf6 (17.618.183.624) 20305
37.01 21:57 -0.15 53...Qf6 54.Rdf1 Rg3 55.Qd1 Kg7 56.Bb7 Re3 57.Bc6 Kh6 58.Qd2 Qc3 59.Qxc3 Rxc3 60.Be8 Rxc4 61.Bxg6 Kxg6 62.Rxf4 Rxb5 63.h3 Re5 64.Rg4+ Rg5 65.Rxh4 Rc2 66.Rh8 Rcxg2 (26.664.441.757) 20242
38.01 26:06 -0.08-- 53...Qf6 54.Rdf1 (31.713.680.100) 20239
38.01 34:46 -0.15++ 53...Qf6 (42.489.996.876) 20366
38.01 38:03 -0.08-- 53...Qf6 54.Rdf1 (46.462.116.048) 20344
38.01 39:54 -0.10 53...Qf6 54.Rdf1 Rg3 55.Qd1 Kg7 56.Bc6 Re3 57.Qd2 Qc3 58.Qxc3+ Rxc3 59.Be8 Rxc4 60.Bxg6 Kxg6 61.Rxf4 Rxb5 62.h3 Re5 63.Rg4+ Rg5 64.Rxh4 Rc2 65.Rh8 Rcxg2 66.Ra8 b5 (48.700.833.058) 20341
39.01 49:46 -0.17++ 53...Qf6 (60.803.413.893) 20360
39.01 62:56 -0.24++ 53...Qf6 (77.002.060.451) 20387
39.01 63:57 -0.17-- 53...Qf6 54.Qb2 (78.300.696.853) 20401
39.01 82:29 -0.21 53...Qf6 54.Qb2 Qxb2 55.Rxb2 Re5 56.Rf2 Re7 57.Rdf1 Kg7 58.Bb7 Rg5 59.Rf3 Rh5 60.Bd5 Kf6 61.Kg1 Rg7 62.R1f2 Rg5 63.Kh1 Rg4 64.Rf1 Ke7 65.R1f2 Rh7 66.Rf1 Rg5 (100.804.355.410) 20366
40.01 88:28 -0.22 53...Qf6 54.Qb2 Qxb2 55.Rxb2 Re5 56.Rf2 Kg7 57.Rdf1 Re7 58.Rd1 Kf6 59.Rdf1 Rh7 60.Rf3 Rh8 61.R3f2 Rg5 62.Rf3 Ke7 63.Bc6 Rh7 64.Bd5 Rg7 65.R3f2 Kf6 66.Rf3 Rh5 (108.100.804.581) 20363
41.01 97:42 -0.22 53...Qf6 54.Qb2 Qxb2 55.Rxb2 Re5 56.Rf2 Kg7 57.Rdf1 Re7 58.Rd1 Kf6 59.Rdf1 Rh7 60.Rf3 Rh8 61.Kg1 Ke7 62.Kh1 Rg5 63.Bc6 Rhh5 64.Bd5 Rh7 65.R3f2 Rh8 66.Bc6 Re5 (119.437.032.653) 20372
best move: Qe5-f6 time: 103:05.578 min n/s: 20.394.106 nodes: 126.149.026.669

[JVMerlino]

This is a position from round 3 of Chessmaster vs. GM Larry Christiansen. I've dug this one up a few times since it was played almost 13 years ago. The last time it was posted here was 5 years ago and several engines agreed with the move played, but not how good it was.

[d]8/p1p5/Pp1p2nk/1P1Bq1r1/2P1Pprp/1Q6/5RPP/3R3K b - - 0 53

At this point, Larry played 53...Rg3?! Afterwards, he claimed it was winning. But unfortunately he blundered later on in the game and lost.

Since engines have obviously gotten much stronger in the last five years, I would very much appreciate it if any of you with top-end hardware could run this position and see if any engine can find a win for black by playing Rg3.

Here's the game, for your amusement:

[Event "ICC 2 120 u"]
[Site "Internet Chess Club"]
[Date "2002.09.29"]
[Round "3"]
[White "CM9000 (Botvinnik)"]
[Black "LarryC"]
[TimeControl "120+120"]
[Result "1-0"]
[ECO "A28"]

1.c4 e5 2.Nc3 Nf6 3.Nf3 Nc6 4.d4 exd4 5.Nxd4 Bb4 6.Bg5 h6 7.Bh4 Bxc3+
8.bxc3 Ne5 9.e3 d6 10.Be2 Ng6 11.Bxf6 Qxf6 12.O-O O-O 13.Qc2 Re8 14.Rfd1
Nf8 15.Bd3 Ne6 16.Nb3 Rb8 17.a4 Qe7 18.a5 Bd7 19.a6 b6 20.Nd4 Nc5 21.Nb5
Bxb5 22.cxb5 Qf6 23.Bc4 Re5 24.Bd5 Rbe8 25.Rd4 Ne6 26.Rd2 g6 27.Ra4 Kg7
28.Rd1 Re7 29.Rb4 g5 30.Bc6 Qg6 31.Qb2 f5 32.Qb1 Qf6 33.Bd5 f4 34.e4 Nf8
35.f3 h5 36.Qc2 Ng6 37.Qa2 Kh6 38.Qd2 Rg7 39.Qd4 g4 40.fxg4 Nh4 41.Rb2
Rxg4 42.Kh1 Ng6 43.Rf2 Qe7 44.Qd2 Reg5 45.Ra1 h4 46.c4 Qe5 47.Rc1 Kg7
48.Bc6 Qe7 49.Rcf1 Re5 50.Qc3 Kh6 51.Bd5 Reg5 52.Qb3 Qe5 53.Rd1 Rg3
54.hxg3 hxg3 55.Ra2 Rg4 56.Kg1 Qh5 57.Kf1 f3 58.Ke1 f2+ 59.Kd2 Rh4
60.Qe3+ Kg7 61.Rf1 Qe5 62.Kc2 Rh2 63.Qf3 Qf4 64.e5 Qxf3 65.Bxf3 Nxe5
66.Bd5 Rh5 67.Ra3 Rg5 68.Kd2 Ng6 69.Re3 Ne5 70.Ke2 Kf6 71.Rh1 Ng6 72.Rh7
1-0

Many thanks in advance,
jm

So it appears that engines still disagree on whether or not Rg3 was the best move. But all engines agree that Rg3 leads to no better than a draw (although there is always a horizon effect, even if that horizon is dozens of plies away).

Thanks to everybody who spent some cycles on this.

jm

[Eelco de Groot]

So it appears that engines still disagree on whether or not Rg3 was the best move. But all engines agree that Rg3 leads to no better than a draw (although there is always a horizon effect, even if that horizon is dozens of plies away).

Thanks to everybody who spent some cycles on this.

jm

Yes, I also got that, Qf6 is just another way to draw I think.

41/71 24:58 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rh5+
56.Kg1 Rh2 57.Rdd3 Qh5 58.Rxg3 Rh1+
59.Kf2 Qh4 60.Qc3 fxg3+ 61.Rxg3 Qf4+
62.Rf3 Qh4+ 63.Ke2 Qg4 64.Kf2 Qh4+ (5.177.893.936) 3454

42/71 34:30 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rh5+
56.Kg1 Rh2 57.Rdd3 Qh5 58.Rxg3 Rh1+
59.Kf2 Qh4 60.Qc3 fxg3+ 61.Rxg3 Qf4+
62.Rf3 Qh4+ 63.Ke2 Qg4 64.Kf2 Qh4+ (7.135.145.703) 3445

43/71 47:18 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rh5+
56.Kg1 Rh2 57.Rdd3 Qh5 58.Rxg3 Rh1+
59.Kf2 Qh4 60.Qc3 fxg3+ 61.Rxg3 Qf4+
62.Rf3 Qh4+ 63.Ke2 Qg4 64.Kf2 Qh4+ (9.748.865.413) 3434

44/71 90:03 +0.06++ 53...Qf6 (17.860.185.871) 3305

44/71 97:03 0.00-- 53...Qf6 54.c5 (19.195.535.232) 3296

44/71 106:01 0.00 53...Qf6 54.c5 Rg3 55.Qb2 Qxb2
56.Rxb2 Re3 57.cxd6 cxd6 58.Rf2 h3
59.gxh3 f3 60.Bc4 Rxe4 61.Bf1 Ne5
62.Rxd6+ Kh5 63.Rd8 Rg7 64.Rb8 Rd4
65.Rb7 Rdd7 66.Rxd7 Rxd7 (20.965.243.904) 3295

But maybe a nice testposition is where Chessmaster Botwinnik already went astray, 55. Ra2 {?}, okay it's 2002 but this is wrong. It is not so easy to get a win score, even though hash was filled with the first position, but after a long think:


[d]8/p1p5/Pp1p2nk/1P1Bq1r1/2P1Pp2/1Q4p1/R5P1/3R3K b - -

Engine: Rainbow Serpent Sf20150607_015 MOD MP (512 MB)
by Tord Romstad, Marco Costalba and Joona Kiiski

21/50 0:02 +0.72 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Ne5
58.Be6 f3 59.Bh3 Qf4 60.Rad2 Kg7
61.Qc3 fxg2+ 62.Kxg2 Qh4 63.Kf1 Qxh3+
64.Rg2 Qh1+ 65.Rg1 Qxe4 66.Qxg3+ Ng6
67.Qxg6+ Qxg6 68.Rxg6+ Kxg6 (7.243.651) 2550
.
.
.
34/96 3:43 +1.20 55...Rh5+ 56.Kg1 Rh4 57.Kf1 f3
58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+
61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4
64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+
67.Rff2 Qe1+ 68.Kf3 Qc3+ (808.510.790) 3615

35/97 5:23 +1.20 55...Rh5+ 56.Kg1 Rh4 57.Kf1 f3
58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+
61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4
64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+
67.Rff2 Qe1+ 68.Kf3 Qc3+ (1.165.661.419) 3603

36/97 7:50 +1.20 55...Rh5+ 56.Kg1 Rh4 57.Kf1 f3
58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+
61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4
64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+
67.Rff2 Qe1+ 68.Kf3 Qc3+ (1.704.413.856) 3620

37/102 9:45 +1.20 55...Rh5+ 56.Kg1 Rh4 57.Kf1 f3
58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+
61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4
64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+
67.Rff2 Qe1+ 68.Kf3 Qc3+ (2.108.077.049) 3600

38/102 12:17 +1.20 55...Rh5+ 56.Kg1 Rh4 57.Kf1 f3
58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+
61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4
64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+
67.Rff2 Qe1+ 68.Kf3 Qc3+ (2.666.361.212) 3617

39/110 21:10 +1.26++ 55...Rh5+ {Same move but green for finally a Fail High} (4.761.701.999) 3748

39/110 21:54 +1.32++ 55...Rh5+ (4.916.234.305) 3741

39/110 24:07 +1.26-- 55...Rh5+ 56.Kg1 (5.288.291.475) 3654

39/110 24:34 +1.34++ 55...Rh5+ (5.384.913.404) 3651

39/110 26:11 +1.55++ 55...Rh5+ (5.686.721.587) 3617

39/110 27:31 +1.86++ 55...Rh5+ (5.947.369.500) 3601

39/110 28:45 +2.33++ 55...Rh5+ (6.197.572.842) 3592

39/110 35:47 +3.03++ 55...Rh5+ (7.564.133.817) 3522

39/110 49:58 +3.77 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Be6 Nh4 59.Ke2 Nxg2 60.Kd3 Qh5
61.Kc3 Ne3 62.Rxh2 Qxh2 63.Rc1 g2
64.Qb2 g1Q 65.Rxg1 Qxg1 66.Qd2 Qa1+
67.Kd3 Kg6 68.Qf2 Qb1+ (10.590.643.335) 3531

40/110 57:03 +3.83++ 55...Rh5+ (12.066.036.520) 3524

40/110 58:28 +3.81 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Be6 Nh4 59.Ke2 Nxg2 60.Kd3 Qh5
61.Kc3 Ne3 62.Rxh2 Qxh2 63.Rc1 g2
64.Qb2 g1Q 65.Rxg1 Qxg1 66.Qd2 Qa1+
67.Kd3 Kg5 68.Bf7 Qh1 (12.345.152.770) 3518

{I edited Fail Lows and Fail Highs from here on}

41/110 76:35 +4.00 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Bb7 Ne5 59.Bc8 f3 60.Kg1 Qf4
61.Rf1 Qxe4 62.Rd2 Nd3 63.Qxd3 Rxg2+
64.Rxg2 f2+ 65.Rfxf2 gxf2+ 66.Kxf2 Qxd3
67.Bg4 Qxc4 68.Be2 Qf4+ (16.154.980.774) 3515

42/110 145:15 +4.24 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Bb7 Ne5 59.Bc8 f3 60.Kg1 Qf4
61.Rf1 Qxe4 62.Rd2 Nd3 63.Qxd3 Rxg2+
64.Rxg2 f2+ 65.Rfxf2 gxf2+ 66.Kxf2 Qxd3
67.Rh2+ Kg5 68.Rg2+ Kf6 (31.023.468.107) 3559

43/110 249:25 +4.48 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Bb7 Ne5 59.Bc8 f3 60.Kg1 Qf4
61.Rf1 Qxe4 62.Rd2 Nd3 63.Qxd3 Rxg2+
64.Rxg2 f2+ 65.Rfxf2 gxf2+ 66.Rxf2 Qxd3
67.Rh2+ Kg5 68.Rg2+ Kf6 (53.528.028.394) 3576

44/110 340:58 +4.54 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Bb7 Ne5 59.Bc8 f3 60.Kg1 Qf4
61.Rf1 Qxe4 62.Rd2 Nd3 63.Qxd3 Rxg2+
64.Rxg2 f2+ 65.Rfxf2 gxf2+ 66.Kxf2 Qxd3
67.Rg4 Qd2+ 68.Kg1 Qe1+ (74.234.535.114) 3628

45/110 449:16 +4.70 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Bb7 Ne5 59.Bc8 f3 60.Kg1 Qf4
61.Rf1 Qxe4 62.Rd2 Nd3 63.Qxd3 Rxg2+
64.Rxg2 f2+ 65.Rfxf2 gxf2+ 66.Kxf2 Qxd3
67.Bg4 Qxc4 68.Rh2+ Kg7 (97.505.984.457) 3617

[Uri Blass]

This is a position from round 3 of Chessmaster vs. GM Larry Christiansen. I've dug this one up a few times since it was played almost 13 years ago. The last time it was posted here was 5 years ago and several engines agreed with the move played, but not how good it was.

[d]8/p1p5/Pp1p2nk/1P1Bq1r1/2P1Pprp/1Q6/5RPP/3R3K b - - 0 53

At this point, Larry played 53...Rg3?! Afterwards, he claimed it was winning. But unfortunately he blundered later on in the game and lost.

Since engines have obviously gotten much stronger in the last five years, I would very much appreciate it if any of you with top-end hardware could run this position and see if any engine can find a win for black by playing Rg3.

Here's the game, for your amusement:

[Event "ICC 2 120 u"]
[Site "Internet Chess Club"]
[Date "2002.09.29"]
[Round "3"]
[White "CM9000 (Botvinnik)"]
[Black "LarryC"]
[TimeControl "120+120"]
[Result "1-0"]
[ECO "A28"]

1.c4 e5 2.Nc3 Nf6 3.Nf3 Nc6 4.d4 exd4 5.Nxd4 Bb4 6.Bg5 h6 7.Bh4 Bxc3+
8.bxc3 Ne5 9.e3 d6 10.Be2 Ng6 11.Bxf6 Qxf6 12.O-O O-O 13.Qc2 Re8 14.Rfd1
Nf8 15.Bd3 Ne6 16.Nb3 Rb8 17.a4 Qe7 18.a5 Bd7 19.a6 b6 20.Nd4 Nc5 21.Nb5
Bxb5 22.cxb5 Qf6 23.Bc4 Re5 24.Bd5 Rbe8 25.Rd4 Ne6 26.Rd2 g6 27.Ra4 Kg7
28.Rd1 Re7 29.Rb4 g5 30.Bc6 Qg6 31.Qb2 f5 32.Qb1 Qf6 33.Bd5 f4 34.e4 Nf8
35.f3 h5 36.Qc2 Ng6 37.Qa2 Kh6 38.Qd2 Rg7 39.Qd4 g4 40.fxg4 Nh4 41.Rb2
Rxg4 42.Kh1 Ng6 43.Rf2 Qe7 44.Qd2 Reg5 45.Ra1 h4 46.c4 Qe5 47.Rc1 Kg7
48.Bc6 Qe7 49.Rcf1 Re5 50.Qc3 Kh6 51.Bd5 Reg5 52.Qb3 Qe5 53.Rd1 Rg3
54.hxg3 hxg3 55.Ra2 Rg4 56.Kg1 Qh5 57.Kf1 f3 58.Ke1 f2+ 59.Kd2 Rh4
60.Qe3+ Kg7 61.Rf1 Qe5 62.Kc2 Rh2 63.Qf3 Qf4 64.e5 Qxf3 65.Bxf3 Nxe5
66.Bd5 Rh5 67.Ra3 Rg5 68.Kd2 Ng6 69.Re3 Ne5 70.Ke2 Kf6 71.Rh1 Ng6 72.Rh7
1-0

Many thanks in advance,
jm

So it appears that engines still disagree on whether or not Rg3 was the best move. But all engines agree that Rg3 leads to no better than a draw (although there is always a horizon effect, even if that horizon is dozens of plies away).

Thanks to everybody who spent some cycles on this.

jm

It seems that during the game CM did a mistake at move 55 and after 55.Ra2 CM could lose against correct moves.

[d]8/p1p5/Pp1p2nk/1P1Bq1r1/2P1Pp2/1Q4p1/R5P1/3R3K b - - 1 55

Stockfish_15070415_x64_modern:
1/1 00:00 32 16k -2.98 55. ... Rg4
2/2 00:00 129 32k -3.80 55. ... Nh4 56.Kg1
3/3 00:00 193 39k -3.86 55. ... Nh4 56.Kg1 Rg4
4/5 00:00 495 71k -3.32 55. ... Rh5+ 56.Kg1 Rh2 57.Rad2 Nh4
5/6 00:00 1k 142k -1.28 55. ... Rg4 56.Kg1 Qh5 57.Rad2 Qh2+ 58.Kf1
6/8 00:00 3k 298k -0.44 55. ... Rg4 56.Kg1 Qh5 57.Rd4 Qh2+ 58.Kf1 Qh1+ 59.Ke2
7/12 00:00 5k 458k -0.31 55. ... Rg4 56.c5 Qh5+ 57.Kg1 Qh2+ 58.Kf1 Qh1+ 59.Ke2 Qxg2+ 60.Kd3 Ne5+ 61.Kc3 Qf3+ 62.Kb4 bxc5+ 63.Ka4
8/14 00:00 6k 614k +0.12 55. ... Rg4 56.Rdd2 Qh5+ 57.Kg1 Qh2+ 58.Kf1 Qh1+ 59.Ke2 Ne5 60.Be6 Qxg2+ 61.Kd1
9/19 00:00 15k 1,104k +0.21 55. ... Rg4 56.Kg1 Qh5 57.Qb2 Qh2+ 58.Kf1 Qh1+ 59.Ke2 Qxg2+ 60.Ke1 Qf3 61.Bb7
10/19 00:00 39k 1,679k -1.54 55. ... Rg4 56.Kg1 Qh5 57.Be6 Qh2+ 58.Kf1 Rh4 59.Re1 Ne5 60.Ke2 Qxg2+ 61.Kd1 Qf3+ 62.Qxf3 Nxf3 63.Ree2 Rh1+ 64.Kc2
11/21 00:00 46k 1,855k -1.48 55. ... Rg4 56.Kg1 Qh5 57.Be6 Qh2+ 58.Kf1 Rh4 59.Re1 Ne5 60.Ke2 Qxg2+ 61.Kd1 Qf3+ 62.Qxf3 Nxf3
12/21 00:00 64k 2,051k -1.15 55. ... Rg4 56.Kg1 Qh5 57.Be6 Qh2+ 58.Kf1 Rh4 59.Bh3 Rxh3 60.gxh3 Qh1+ 61.Ke2 Qh2+ 62.Kd3 g2 63.Re2 Ne5+ 64.Kc2
13/28 00:00 107k 2,318k -1.29 55. ... Rg4 56.Kg1 Qh5 57.Be6 Qh2+ 58.Kf1 Rh4 59.Bh3 Rxh3 60.gxh3 Qh1+ 61.Ke2 Qxe4+ 62.Kd2 Ne5 63.h4 Nxc4+ 64.Kc1 Ne3
14/28 00:00 125k 2,400k -1.23 55. ... Rg4 56.Kg1 Qh5 57.Be6 Qh2+ 58.Kf1 Rh4 59.Bh3 Rxh3 60.gxh3 Qh1+ 61.Ke2 Qxe4+ 62.Kd2 Ne5 63.Kc3 f3 64.Kb4 Qf4
15/28 00:00 156k 2,336k -1.06 55. ... Rg4 56.Kg1 Qh5 57.Be6 Qh2+ 58.Kf1 Rh4 59.Bh3 Rxh3 60.gxh3 Qh1+ 61.Ke2 Qxe4+ 62.Kd2 Ne5 63.c5 bxc5 64.Qg8 Ng6 65.Kc1
16/32 00:00 889k 2,469k +0.48 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qf3+ 60.Kc2 Qxb3+ 61.Kxb3 f3 62.Kc3 f2 63.e5 Nxe5 64.Re2 g2 65.Rxf2 Rg3+ 66.Kc2 g1Q 67.Rf6+ Kh5 68.Rxg1
17/33 00:00 1,322k 2,709k +0.22 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qf3+ 60.Kc2 Qxb3+ 61.Kxb3 f3 62.Kc3 f2 63.Rf1 Rf4 64.e5 dxe5 65.Kd3 Rd4+ 66.Ke3 Nf4
18/33 00:00 1,406k 2,740k +0.22 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qf3+ 60.Kc2 Qxb3+ 61.Kxb3 f3 62.Kc3 f2 63.Rf1 Rf4 64.e5 dxe5 65.Kd3 Rd4+ 66.Ke3 Nf4 67.Rfa1 Kg5 68.Kf3 Rd3+ 69.Ke4
19/33 00:00 2,244k 3,070k +0.25 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qf3+ 60.Kc2 Qxb3+ 61.Kxb3 f3 62.Kc3 f2 63.Rf1 Rf4 64.e5 dxe5 65.Kd3 Rd4+ 66.Ke3 Nf4 67.Raa1 Kg5 68.Kf3 Rd3+ 69.Ke4 Kg4 70.Be6+ Kg5 71.Bf7
20/37 00:00 3,254k 3,327k +0.28 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qf3+ 60.Kc2 Qxb3+ 61.Kxb3 f3 62.Kc3 Kg5 63.Kd4 Kf4 64.Be6 Rh4 65.Rf1 Ne5 66.Bd5 f2 67.Rfxf2+ gxf2 68.Rxf2+ Nf3+ 69.Kd3 Kg3 70.Ke3 Ne5 71.Rf5
21/37 00:01 4,236k 3,444k +0.29 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qf3+ 60.Kc2 Qxb3+ 61.Kxb3 f3 62.Kc3 Kg5 63.Kd4 Kf4 64.Be6 Rh4 65.Rf1 Ne5 66.Bd5 Rh6 67.Bb7 f2 68.Raxf2+ gxf2 69.Rxf2+ Kg3 70.Rf8 Rh2 71.Rg8+ Kf4 72.Rf8+ Kg5
22/39 00:01 5,730k 3,579k +0.36 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qf3+ 60.Kc2 Qxb3+ 61.Kxb3 f3 62.Kc3 Kg5 63.Kd4 Kf4 64.Be6 Rh4 65.Rf1 Ne5 66.Bd5 Rh6 67.Rd2 Rh2 68.Rxh2 gxh2 69.Bb7 Kg3 70.Ke3 Nxc4+ 71.Kd4
23/39 00:01 7,229k 3,644k +0.48 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qf3+ 60.Kc2 Qxb3+ 61.Kxb3 f3 62.Kc3 Kg5 63.Kd4 Kf4 64.Be6 Rh4 65.Rf1 Ne5 66.Bd5 Rh6 67.Kc3 Rg6 68.Kd4 g2 69.Rg1 Rg4 70.Bb7
24/39- 00:03 11,981k 3,693k +0.27 55. ... Rg4 56.Kg1
24/39 00:03 13,718k 3,658k +0.27 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qf3+ 60.Kc2 Qxb3+ 61.Kxb3 f3 62.e5 Nxe5 63.Rf1 g2 64.Rg1 Rg3 65.Rf2 Rh3 66.Bxf3 Nxf3 67.Rgxg2 Ne1+ 68.Ka4 Nxg2 69.Rxg2 Kh7 70.Kb4 Rh1 71.Kb3 Re1 72.Kc3 Kh6 73.Rg8 Rf1 74.Ra8
25/46+ 00:06 23,086k 3,705k +0.33 55. ... Rh5+
25/46- 00:06 24,157k 3,701k +0.27 55. ... Rh5+ 56.Kg1
25/46 00:07 28,721k 3,712k +0.20 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qf3+ 60.Kc2 Qxb3+ 61.Kxb3 f3 62.e5 Nxe5 63.Rf1 g2 64.Rg1 Rg3 65.Rf2 Rh3 66.Bxf3 Nxf3 67.Rgxg2 Ne1+ 68.Ka4 Nxg2 69.Rxg2 Rh4 70.Kb3 Rd4 71.Kc3 Rh4
26/46 00:11 42,311k 3,722k +0.22 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qf3+ 60.Kc2 Qxb3+ 61.Kxb3 f3 62.e5 Nxe5 63.Rf1 g2 64.Rg1 Rg3 65.Rf2 Rh3 66.Bxf3 Nxf3 67.Rgxg2 Ne1+ 68.Ka4 Nxg2 69.Rxg2 Rh4 70.Kb3 Kh7 71.Kc3 Re4 72.Rg1 Re8 73.Kd4 Kh6
27/46+ 00:15 58,187k 3,785k +0.28 55. ... Rg4
27/46+ 00:15 59,206k 3,786k +0.34 55. ... Rg4
27/46+ 00:15 60,139k 3,789k +0.44 55. ... Rg4
27/46- 00:17 66,008k 3,789k +0.36 55. ... Rg4 56.Kg1
27/46+ 00:17 67,476k 3,792k +0.47 55. ... Rg4
27/46 00:18 70,013k 3,794k +0.55 55. ... Rg4 56.Kg1 Qh5 57.Kf1 Qh1+ 58.Ke2 Qxg2+ 59.Kd3 Qh3 60.Rg1 g2+ 61.Kc2 Rg3 62.Qb4 Ne5 63.Qd2 Qg4 64.Raa1 Kg6 65.Rab1 Nf3 66.Qf2 Nxg1 67.Rxg1 f3 68.Kd2 Rh3 69.Bc6 Rh1 70.Ke3 Kg5 71.Kd3 Rxg1 72.Qxg1
28/47+ 00:25 98,499k 3,849k +0.61 55. ... Rg4
28/47+ 00:26 101,163k 3,855k +0.67 55. ... Rg4
28/47+ 00:28 110,388k 3,842k +0.77 55. ... Rg4
28/47+ 00:29 114,725k 3,852k +0.91 55. ... Rg4
28/47+ 00:30 118,083k 3,852k +1.12 55. ... Rg4
28/52- 00:33 128,113k 3,866k +0.96 55. ... Rg4 56.Kg1
28/64+ 00:39 152,462k 3,908k +1.19 55. ... Rg4
28/64 00:41 162,079k 3,927k +1.24 55. ... Rg4 56.Kg1 Rh4 57.Kf1 f3 58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+ 61.Ke1 Ng6 62.Rc2 Qh4 63.e5 dxe5 64.Re3 Nf4 65.Kd2 Nxd5 66.cxd5 Qd4+ 67.Rd3 Qf2+ 68.Kc3 Qe1+ 69.Kb2 Qb4+ 70.Rb3 Qd4+ 71.Rcc3 Kh5 72.Ka3 Qxd5 73.Rxg3 e4 74.Rbe3 Qc5+ 75.Ka4
29/64+ 00:44 175,459k 3,949k +1.31 55. ... Rg4
29/64- 00:46 184,234k 3,929k +1.24 55. ... Rg4 56.Kg1
29/64+ 00:47 186,713k 3,925k +1.31 55. ... Rg4
29/64 00:47 187,046k 3,925k +1.24 55. ... Rg4 56.Kg1 Rh4 57.Kf1 f3 58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+ 61.Ke1 Ng6 62.Rc2 Qh4 63.e5 dxe5 64.Re3 Nf4 65.Be4 Qh1+ 66.Kd2 Qg1 67.Re1 Qf2+ 68.Kd1 Qc5 69.Kd2 Kg5 70.Kc1 Qa3+ 71.Kd2 Qd6+ 72.Kc1 Qc5 73.Kd2 Qf2+ 74.Kd1 Qd4+ 75.Kc1 Qa1+ 76.Kd2 Qa5+ 77.Rc3
30/64+ 00:52 205,506k 3,936k +1.31 55. ... Rg4
30/64+ 00:54 215,361k 3,948k +1.37 55. ... Rg4
30/64+ 00:57 228,639k 3,967k +1.46 55. ... Rg4
30/64- 01:01 243,852k 3,970k +1.38 55. ... Rg4 56.Kg1
30/64- 01:08 272,020k 3,966k +1.17 55. ... Rg4 56.Kg1
30/64+ 01:09 275,553k 3,965k +1.33 55. ... Rg4
30/64 01:10 279,233k 3,965k +1.44 55. ... Rg4 56.Kg1 Rh4 57.Kf1 f3 58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+ 61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4 64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+ 67.Rff2 Qe1+ 68.Kf3 Qc3+ 69.Ke2 gxf2 70.Kxf2 Kf4 71.Re2 Qd4+ 72.Kf1 Qa1+ 73.Re1 Qc3 74.Kf2 Qg3+ 75.Kf1 Ke5 76.Rd1 Qf4+ 77.Kg1 Qe3+ 78.Kf1 Qg3 79.Bc6
31/64- 01:24 334,214k 3,932k +1.37 55. ... Rg4 56.Kg1
31/64- 01:26 341,274k 3,937k +1.31 55. ... Rg4 56.Kg1
31/64 01:29 351,457k 3,937k +1.24 55. ... Rg4 56.Kg1 Rh4 57.Kf1 f3 58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+ 61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4 64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+ 67.Rff2 Qe1+ 68.Kf3 Qc3+ 69.Ke2 gxf2 70.Kxf2 Kf4 71.Re2 Qd4+ 72.Kf1 Kg4 73.Ra2 Qd3+ 74.Kf2 Kf4 75.Re2 Qg3+ 76.Kf1 Ke5 77.Rd2 Qf4+ 78.Rf2 Qc1+ 79.Ke2 Qc2+ 80.Ke3
32/64 01:57 463,114k 3,943k +1.24 55. ... Rg4 56.Kg1 Rh4 57.Kf1 f3 58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+ 61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4 64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+ 67.Rff2 Qe1+ 68.Kf3 Qc3+ 69.Ke2 gxf2 70.Kxf2 Kf4 71.Re2 Qd4+ 72.Kf1 Kg4 73.Ra2 Qd3+ 74.Kf2 Kf4 75.Re2 Qg3+ 76.Kf1 Ke5 77.Rd2 Qf4+ 78.Rf2 Qc1+ 79.Ke2 Qc2+ 80.Kf3 Qd1+ 81.Kg3 Qe1 82.Kf3
33/64 02:35 624,212k 4,016k +1.24 55. ... Rg4 56.Kg1 Rh4 57.Kf1 f3 58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+ 61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4 64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+ 67.Rff2 Qe1+ 68.Kf3 Qc3+ 69.Ke2 gxf2 70.Kxf2 Kf4 71.Re2 Qd4+ 72.Kf1 Kg4 73.Ra2 Qd3+ 74.Kf2 Kf4 75.Re2 Qg3+ 76.Kf1 Ke5 77.Rd2 Qe3 78.Rf2 Qd3+ 79.Re2 Qd1+ 80.Re1 Qd2 81.Re2 Qc1+ 82.Re1 Qc3 83.Re2
34/69+ 04:20 1,063,521k 4,085k +1.31 55. ... Rh5+
34/69+ 04:25 1,082,175k 4,083k +1.37 55. ... Rh5+
34/69+ 04:31 1,105,838k 4,076k +1.46 55. ... Rh5+
34/69+ 04:39 1,138,636k 4,074k +1.60 55. ... Rh5+
34/69+ 04:50 1,181,935k 4,069k +1.81 55. ... Rh5+
34/69+ 05:38 1,373,622k 4,054k +2.12 55. ... Rh5+
34/69+ 06:43 1,621,342k 4,017k +2.59 55. ... Rh5+
34/69 09:16 2,252,512k 4,047k +2.59 55. ... Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2 58.Ke2 Ne5 59.Rg1 f3+ 60.Kd1 f2 61.Rf1 Rxg2 62.Raxf2 gxf2 63.Qh3+ Kg7 64.Qe6 Rg1 65.Qg8+ Kh6 66.Qxg5+ Kxg5 67.Ke2 Nd3 68.e5 Nf4+ 69.Kxf2 Rxf1+ 70.Kxf1 Nxd5 71.exd6 cxd6 72.cxd5 Kf4 73.Kg1 Ke5 74.Kf2 Kxd5 75.Ke3 Kc5 76.Ke4 Kc4 77.Kf5 Kxb5 78.Ke6
35/69- 09:59 2,423,782k 4,040k +2.53 55. ... Rh5+ 56.Kg1
35/69+ 10:12 2,470,436k 4,033k +2.59 55. ... Rh5+
35/69- 10:15 2,478,476k 4,030k +2.53 55. ... Rh5+ 56.Kg1
35/69+ 10:38 2,564,192k 4,016k +2.61 55. ... Rh5+
35/69 10:47 2,598,926k 4,011k +2.61 55. ... Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2 58.Ke2 Ne5 59.Rg1 f3+ 60.Qxf3 Nxf3 61.Kxf3 Qe5 62.Rd2 Qf6+ 63.Ke3 Qc3+ 64.Ke2 Qa3 65.Rdd1 Qb4 66.Kd3 Qb3+ 67.Ke2 Qa3 68.e5 dxe5 69.Rgf1 Qb2+ 70.Ke3 Rh4 71.Rf6+ Kg5 72.Rf3 Rf4 73.Rxg3+ Kf5 74.Rh3 Kg4 75.Rf3 Qxg2 76.Rdf1 Rd4 77.Rf4+ exf4+ 78.Rxf4+ Rxf4 79.Bxg2 Rxc4

[JVMerlino]

So it appears that engines still disagree on whether or not Rg3 was the best move. But all engines agree that Rg3 leads to no better than a draw (although there is always a horizon effect, even if that horizon is dozens of plies away).

Thanks to everybody who spent some cycles on this.

jm

Yes, I also got that, Qf6 is just another way to draw I think.

41/71 24:58 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rh5+
56.Kg1 Rh2 57.Rdd3 Qh5 58.Rxg3 Rh1+
59.Kf2 Qh4 60.Qc3 fxg3+ 61.Rxg3 Qf4+
62.Rf3 Qh4+ 63.Ke2 Qg4 64.Kf2 Qh4+ (5.177.893.936) 3454

42/71 34:30 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rh5+
56.Kg1 Rh2 57.Rdd3 Qh5 58.Rxg3 Rh1+
59.Kf2 Qh4 60.Qc3 fxg3+ 61.Rxg3 Qf4+
62.Rf3 Qh4+ 63.Ke2 Qg4 64.Kf2 Qh4+ (7.135.145.703) 3445

43/71 47:18 0.00 53...Rg3 54.hxg3 hxg3 55.Rf3 Rh5+
56.Kg1 Rh2 57.Rdd3 Qh5 58.Rxg3 Rh1+
59.Kf2 Qh4 60.Qc3 fxg3+ 61.Rxg3 Qf4+
62.Rf3 Qh4+ 63.Ke2 Qg4 64.Kf2 Qh4+ (9.748.865.413) 3434

44/71 90:03 +0.06++ 53...Qf6 (17.860.185.871) 3305

44/71 97:03 0.00-- 53...Qf6 54.c5 (19.195.535.232) 3296

44/71 106:01 0.00 53...Qf6 54.c5 Rg3 55.Qb2 Qxb2
56.Rxb2 Re3 57.cxd6 cxd6 58.Rf2 h3
59.gxh3 f3 60.Bc4 Rxe4 61.Bf1 Ne5
62.Rxd6+ Kh5 63.Rd8 Rg7 64.Rb8 Rd4
65.Rb7 Rdd7 66.Rxd7 Rxd7 (20.965.243.904) 3295

But maybe a nice testposition is where Chessmaster Botwinnik already went astray, 55. Ra2 {?}, okay it's 2002 but this is wrong. It is not so easy to get a win score, even though hash was filled with the first position, but after a long think:


[d]8/p1p5/Pp1p2nk/1P1Bq1r1/2P1Pp2/1Q4p1/R5P1/3R3K b - -

Engine: Rainbow Serpent Sf20150607_015 MOD MP (512 MB)
by Tord Romstad, Marco Costalba and Joona Kiiski

21/50 0:02 +0.72 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Ne5
58.Be6 f3 59.Bh3 Qf4 60.Rad2 Kg7
61.Qc3 fxg2+ 62.Kxg2 Qh4 63.Kf1 Qxh3+
64.Rg2 Qh1+ 65.Rg1 Qxe4 66.Qxg3+ Ng6
67.Qxg6+ Qxg6 68.Rxg6+ Kxg6 (7.243.651) 2550
.
.
.
34/96 3:43 +1.20 55...Rh5+ 56.Kg1 Rh4 57.Kf1 f3
58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+
61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4
64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+
67.Rff2 Qe1+ 68.Kf3 Qc3+ (808.510.790) 3615

35/97 5:23 +1.20 55...Rh5+ 56.Kg1 Rh4 57.Kf1 f3
58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+
61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4
64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+
67.Rff2 Qe1+ 68.Kf3 Qc3+ (1.165.661.419) 3603

36/97 7:50 +1.20 55...Rh5+ 56.Kg1 Rh4 57.Kf1 f3
58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+
61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4
64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+
67.Rff2 Qe1+ 68.Kf3 Qc3+ (1.704.413.856) 3620

37/102 9:45 +1.20 55...Rh5+ 56.Kg1 Rh4 57.Kf1 f3
58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+
61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4
64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+
67.Rff2 Qe1+ 68.Kf3 Qc3+ (2.108.077.049) 3600

38/102 12:17 +1.20 55...Rh5+ 56.Kg1 Rh4 57.Kf1 f3
58.Qxf3 Rf4 59.Rd3 Nh4 60.Qxf4+ Qxf4+
61.Ke1 Ng6 62.Rc3 Qh4 63.Rf3 Nf4
64.Kd2 Qh2 65.Ke3 Kg5 66.Rxf4 Qg1+
67.Rff2 Qe1+ 68.Kf3 Qc3+ (2.666.361.212) 3617

39/110 21:10 +1.26++ 55...Rh5+ {Same move but green for finally a Fail High} (4.761.701.999) 3748

39/110 21:54 +1.32++ 55...Rh5+ (4.916.234.305) 3741

39/110 24:07 +1.26-- 55...Rh5+ 56.Kg1 (5.288.291.475) 3654

39/110 24:34 +1.34++ 55...Rh5+ (5.384.913.404) 3651

39/110 26:11 +1.55++ 55...Rh5+ (5.686.721.587) 3617

39/110 27:31 +1.86++ 55...Rh5+ (5.947.369.500) 3601

39/110 28:45 +2.33++ 55...Rh5+ (6.197.572.842) 3592

39/110 35:47 +3.03++ 55...Rh5+ (7.564.133.817) 3522

39/110 49:58 +3.77 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Be6 Nh4 59.Ke2 Nxg2 60.Kd3 Qh5
61.Kc3 Ne3 62.Rxh2 Qxh2 63.Rc1 g2
64.Qb2 g1Q 65.Rxg1 Qxg1 66.Qd2 Qa1+
67.Kd3 Kg6 68.Qf2 Qb1+ (10.590.643.335) 3531

40/110 57:03 +3.83++ 55...Rh5+ (12.066.036.520) 3524

40/110 58:28 +3.81 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Be6 Nh4 59.Ke2 Nxg2 60.Kd3 Qh5
61.Kc3 Ne3 62.Rxh2 Qxh2 63.Rc1 g2
64.Qb2 g1Q 65.Rxg1 Qxg1 66.Qd2 Qa1+
67.Kd3 Kg5 68.Bf7 Qh1 (12.345.152.770) 3518

{I edited Fail Lows and Fail Highs from here on}

41/110 76:35 +4.00 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Bb7 Ne5 59.Bc8 f3 60.Kg1 Qf4
61.Rf1 Qxe4 62.Rd2 Nd3 63.Qxd3 Rxg2+
64.Rxg2 f2+ 65.Rfxf2 gxf2+ 66.Kxf2 Qxd3
67.Bg4 Qxc4 68.Be2 Qf4+ (16.154.980.774) 3515

42/110 145:15 +4.24 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Bb7 Ne5 59.Bc8 f3 60.Kg1 Qf4
61.Rf1 Qxe4 62.Rd2 Nd3 63.Qxd3 Rxg2+
64.Rxg2 f2+ 65.Rfxf2 gxf2+ 66.Kxf2 Qxd3
67.Rh2+ Kg5 68.Rg2+ Kf6 (31.023.468.107) 3559

43/110 249:25 +4.48 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Bb7 Ne5 59.Bc8 f3 60.Kg1 Qf4
61.Rf1 Qxe4 62.Rd2 Nd3 63.Qxd3 Rxg2+
64.Rxg2 f2+ 65.Rfxf2 gxf2+ 66.Rxf2 Qxd3
67.Rh2+ Kg5 68.Rg2+ Kf6 (53.528.028.394) 3576

44/110 340:58 +4.54 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Bb7 Ne5 59.Bc8 f3 60.Kg1 Qf4
61.Rf1 Qxe4 62.Rd2 Nd3 63.Qxd3 Rxg2+
64.Rxg2 f2+ 65.Rfxf2 gxf2+ 66.Kxf2 Qxd3
67.Rg4 Qd2+ 68.Kg1 Qe1+ (74.234.535.114) 3628

45/110 449:16 +4.70 55...Rh5+ 56.Kg1 Qg5 57.Kf1 Rh2
58.Bb7 Ne5 59.Bc8 f3 60.Kg1 Qf4
61.Rf1 Qxe4 62.Rd2 Nd3 63.Qxd3 Rxg2+
64.Rxg2 f2+ 65.Rfxf2 gxf2+ 66.Kxf2 Qxd3
67.Bg4 Qxc4 68.Rh2+ Kg7 (97.505.984.457) 3617

Not sure if later versions of The King changed this, but the version in CM9000 cleared its hash tables after every move.

The reason for this seems kind of silly to those of us who understand how engines work. But you have to consider the typical Chessmaster user. Essentially, if the hash tables weren't cleared, then if you went backwards in a game you would see different thinking output (and perhaps different moves) from the engine and from analysis, which would definitely confuse our typical user.

But I have no idea if Johan disabled this crippling "feature" for tournaments that he entered.

jm

[Vinvin]

This is a position from round 3 of Chessmaster vs. GM Larry Christiansen. I've dug this one up a few times since it was played almost 13 years ago. The last time it was posted here was 5 years ago and several engines agreed with the move played, but not how good it was.

8/p1p5/Pp1p2nk/1P1Bq1r1/2P1Pprp/1Q6/5RPP/3R3K b - - 0 53
...

A video with analyze from Christiansen in 2002 :
There are serious blunders in some lines.