I watched some Marius games( AI player rated 1123 ) in ChessMaster GrandMaster Editions and he can beat several A.I. players rated 1300-1500.

As I read in other posts, chessmaster AI players cant "detect" their AI opponentes weak points. But, I have more difficulties to beat Marius than to beat 1300-1500 AI players.

Two examples below. In several other tests, Marius won. Probably there is an explanation for this, Im curious.

Watch some Marius matches against higher rated players, he will won most times easily. Thanks for any advices or explanations.

(Sorry for my english, it is not my language.)

Marius(1123-white) 1x0 Eric(1346-black), 15 minutes for each player: 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 Ne4 6.Be3 Qf6 7.Qd3 Nxf2 8.Bxf2 Qf5 9.e4 Qxf2+ 10.Kxf2 Nc6 11.Qg3 O-O 12.Qxc7 Re8 13.d5 exd5 14.exd5 Ne5 15.Re1 Ng4+ 16.Kg3 Ne3 17.Kf3 d6 18.Rxe3 Bg4+ 19.Kf4 g5+ 20.Kxg4 Rxe3 21.Qxd6 Re4+ 22.Kxg5 Rae8 23.Bd3 f6+ 24.Kxf6 Re3 25.Bxh7+ Kxh7 26.Nf3 Kh8 27.Kg6 Kg8 28.Re1 R3e6+ 29.Rxe6 Rf8 30.Qc7 Rf6+ 31.Rxf6 a6 32.Qd8# 1-0

Liz(1488-white) 0x1 Marius(1123-black), 15 minutes for each player: 1.c4 Nf6 2.Nc3 c5 3.g3 g6 4.Bg2 Ng4 5.e3 d6 6.Nd5 e6 7.Qxg4 exd5 8.Qd1 Nc6 9.Bxd5 Nb4 10.Qb3 Bf5 11.Bxb7 Nc2+ 12.Ke2 Rb8 13.Qa4+ Ke7 14.g4 Bxg4+ 15.Bf3 Nxa1 16.Bxg4 Qc7 17.Nh3 Rb4 18.Qa6 Bh6 19.b3 Nc2 20.Bb2 Rd8 21.f4 f5 22.Bf3 Rdb8 23.Kf2 R8b6 24.Qa5 Kd7 25.Bd5 Rb8 26.Be6+ Kc6 27.Qxc7+ Kxc7 28.Bc3 R4b6 29.Ba5 Re8 30.Bf7 Re7 31.Bg8 Kb8 32.Bd5 Ra6 33.b4 cxb4 34.Bd8 Re8 35.Rb1 Rxd8 36.a4 Rxa4 37.Rb2 Bg7 38.Rb1 Ra1 39.Rb3 Bf6 40.Ng1 h6 41.Nf3 Kc7 42.Bf7 a5 43.Bxg6 a4 44.Rd3 b3 45.Rd5 b2 46.Rb5 Rb8 47.Bxf5 Rxb5 48.Bxc2 Rc5 49.Nd4 Bxd4 50.exd4 Rxc4 51.Bh7 a3 52.Bg6 Rd1 53.Kf3 a2 54.Bd3 b1=Q 55.Bxc4 Qf5 56.Be2 Qh3+ 57.Ke4 Re1 58.Kd5
Qb3+ 59.Ke4 Rxe2+ 60.Kf5 Qe6# 0-1

Engines at default settings.
PC: Intel Core 2 Duo T5800, 3GB DDR-3 Memory

Seconded.

The issue of under and overrated players has been discussed on this forum before, and it seems that personalities that some describe as easy others will describe as hard.

But Marius definitely sticks out as an overrated player.

His endgame is particularly sharp. I have to have a big material or positional advantage in the endgame to take him down. And even then, if I make a slip up, he'll pounce on it.

His mating combinations are impressive, but unrealistic for a 1127 player playing 10-minute games.

I've been playing the computer personalities against each other to get a better feel for which ones are stronger. Marius beat everyone up to Orin, who won (0-19-1). A couple of the lower rated players hung in there (Marius beat Krycek 10-8-2, beat Willow 13-7-0, the rest were larger margins of victory). I play them in G20 matches.

The comment about impressive mating combinations is a good one. You can use the Pandolfini ratings diagnostics on the computer personalities. Even very low rated players can crush the Checkmate part of the exam. I don't remember the details, but I'm sure Marius got all of the mating combinations in the exam. And naturally he can see mate-in-8 in a couple of seconds!

I haven't tried the other portions of the diagnostic exams, but I'll try to get to that some day. Naturally those tests, and particularly the mating tests, play to the computer's strength.

Thanks for the answers, my question is solved.

I played against Marius more 20 times. And my impression is that he is stronger than 1400 rated AI players.

To test my theory, I created a 15min game, Marius(1138) x Liz(1508).

Marius won:

[Event ""]
[Site ""]
[Date "2009.11.21"]
[Round ""]
[White "Marius"]
[Black "Liz"]
[TimeControl "900"]
[Result "1-0"]
[ECO " "]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Bf4 O-O 5.Nd5 Nc6 6.Bxc7 Qe8 7.Nxf6+ exf6 8.Qd2 Qe7 9.c5 Nxd4 10.Qxd4 f5 11.Qd2 Qf6 12.Nf3 Qxb2
13.Rc1 Qxd2+ 14.Nxd2 Re8 15.e3 Bb2 16.Rc2 Bd4 17.Bc4 Bxc5 18.Bxf7+ Kxf7 19.Rxc5 b6 20.Rd5 Ba6 21.Rxd7+ Re7 22.Nf3 Rc8 23.Ne5+
Ke8 24.Rxe7+ Kxe7 25.Kd2 Rxc7 26.Rc1 Rd7+ 27.Nxd7 Kxd7 28.Kc3 Bb7 29.g3 b5 30.Rd1+ Kc7 31.Kb2 a5 32.Rc1+ Kd6 33.e4 Bxe4 34.Rd1+
Bd5 35.a3 h6 36.h4 h5 37.f4 Ke6 38.Re1+ Kd7 39.Re2 Kd6 40.Re8 Be4 41.Rg8 Kc5 42.Rc8+ Kd6 43.Rd8+ Ke7 44.Rb8 Bc6 45.Rh8 Ke6
46.Rg8 Kf7 47.Rc8 Bd7 48.Rc7 Ke6 49.Rc2 Kf7 50.Rd2 Be8 51.Rd8 Bc6 52.Rd6 Bf3 53.Rd7+ Kf6 54.Rd3 Be4 55.Rd6+ Kf7 56.Kc1 Bf3
57.Ra6 Ke8 58.Rxg6 b4 59.axb4 axb4 60.Rb6 Kf7 61.Rxb4 Ke7 62.Rb2 Kf7 63.Ra2 Ke7 64.Kd2 Bd5 65.Ra7+ Kf8 66.Ra5 Be4 67.Kc3 Kg8
68.Rc5 Kf8 69.Kd4 Kg7 70.Rc7+ Kf6 71.Rc8 Ke7 72.Rc5 Kf6 73.Rb5 Kf7 74.Ke3 Kg8 75.Rb6 Kg7 76.Kd4 Bg2 77.Ke5 Be4 78.Rd6 Bc2
79.Rd7+ Kg6 80.Rd2 Bb1 81.Rd6+ Kg7 82.Ra6 Be4 83.Ra7+ Kg6 84.Ra1 Bd3 85.Ra8 Kg7 86.Rc8 Be4 87.Rc7+ Kg6 88.Ra7 Bd3 89.Rb7 Be4
90.Rb8 Kg7 91.Re8 Bc2 92.Re7+ Kg6 93.Rd7 Be4 94.Rd6+ Kg7 95.Rb6 Bd3 96.Rb7+ Kg6 97.Rb3 Be4 98.Rc3 Bg2 99.Ra3 Be4 100.Ra4 Bd3
101.Rd4 Bc2 102.Rb4 Bd3 103.Kd4 Be2 104.Rb6+ Kg7 105.g4 fxg4 106.Rb1 g3 107.Rg1 Ba6 108.Rxg3+ Kf7 109.Rg5 Be2 110.Rf5+ Kg6
111.Ke5 Bb5 112.Rg5+ Kf7 113.Rxh5 Kg6 114.Rg5+ Kh6 115.f5 Bc4 116.Kd6 Bf7 117.Ke7 Bb3 118.f6 Bc2 119.f7 Kh7 120.Kf6 Bg6 121.Rxg6
Kh8 122.Rh6# 1-0

Now I tested Marius(1138) x Kanna(1610), Marius won

1.d4 Nf6 2.c4 e6 3.Nc3 d5 4.c5 Nc6 5.Bg5 Bxc5 6.dxc5 Qe7 7.e4 Bd7 8.Bb5 Qxc5 9.Bxf6 gxf6 10.Bxc6 Bxc6 11.Qh5 Rg8 12.g3 O-O-O
13.Nge2 Rg5 14.Qxf7 Rf8 15.Qxh7 d4 16.Nxd4 Qxd4 17.Qh6 Qc5 18.h4 Rg4 19.O-O-O Rxe4 20.Rd3 Re2 21.Rhd1 Rxf2 22.Qe3 Qxe3+ 23.Rxe3
e5 24.Nb1 Ba4 25.b3 Bd7 26.Red3 Bg4 27.R3d2 Rf3 28.Kb2 Rxg3 29.Rc1 Rd8 30.Rdc2 Rd7 31.Rf2 f5 32.Na3 Rgd3 33.Nc4 e4 34.Rfc2 f4
35.Ne5 f3 36.Nxg4 Rd2 37.Rxd2 Rxd2+ 38.Kb1 Rd5 39.Nf6 e3 40.Nxd5 e2 41.Nc3 Kd7 42.h5 a5 43.h6 a4 44.h7 axb3 45.h8=Q bxa2+
46.Kxa2 f2 47.Qg7+ Ke6 48.Rh1 f1=Q 49.Rh6+ Kf5 50.Qf6+ Kg4 51.Rg6+ Kh5 52.Qg5# 1-0

[Event "EU-Cup final"]
[Site "Lyon"]
[Date "1994.??.??"]
[Round "?"]
[White "Shneider, Aleksandr"]
[Black "Kasparov, Garry"]
[Result "1-0"]
[ECO "A39"]
[WhiteElo "2535"]
[BlackElo "2805"]
[PlyCount "77"]
[EventDate "1994.11.??"]
[EventType "team"]
[EventRounds "3"]
[EventCountry "FRA"]

1. d4 Nf6 2. c4 g6 3. Nf3 Bg7 4. g3 c5 5. Bg2 cxd4 6. Nxd4 O-O 7. O-O Nc6 8.
Nc3 Nxd4 9. Qxd4 d6 10. Qd3 a6 11. Bd2 Rb8 12. Rac1 b5 13. b3 Bf5 14. e4 Bd7
15. h3 bxc4 16. Qxc4 Qa5 17. Qd3 Qa3 18. Rc2 Bb5 19. Nxb5 axb5 20. Rc7 e6 21.
Be3 Rbc8 22. Ra7 Qb4 23. Rd1 Ne8 24. a3 Qc3 25. Qxb5 Qb2 26. Qd3 Rc3 27. Qb1
Qxb3 28. Qxb3 Rxb3 29. a4 h5 30. a5 Ra3 31. a6 Be5 32. Bh6 Bg7 33. Bg5 Bf6 34.
Bxf6 Nxf6 35. Rxd6 Ra1+ 36. Kh2 Ra2 37. e5 Nh7 38. Rad7 Rxf2 39. Rd2 1-0



[Event "EU-Cup 19th"]
[Site "Rethymnon"]
[Date "2003.10.03"]
[Round "6"]
[White "Huzman, Alexander"]
[Black "Kasparov, Garry"]
[Result "1-0"]
[ECO "D45"]
[WhiteElo "2574"]
[BlackElo "2830"]
[PlyCount "43"]
[EventDate "2003.09.28"]
[EventType "team"]
[EventRounds "7"]
[EventCountry "GRE"]

1. Nf3 d5 2. d4 Nf6 3. c4 c6 4. Nc3 e6 5. e3 a6 6. b3 Bb4 7. Bd2 O-O 8. Bd3
Nbd7 9. Qc2 Bd6 10. Ne2 c5 11. O-O b6 12. cxd5 exd5 13. Ng3 Bb7 14. Nf5 Bc7 15.
dxc5 bxc5 16. b4 c4 17. Be2 Ne4 18. Bc3 Nxc3 19. Qxc3 Nf6 20. Rfd1 Bc8 21. Rxd5
Qe8 22. Bxc4 1-0



[Event "Internet blitz 5'"]
[Site "Internet ICC"]
[Date "1998.08.21"]
[Round "?"]
[White "Zarnicki, Pablo"]
[Black "Kasparov, Garry"]
[Result "1-0"]
[ECO "B19"]
[WhiteElo "2515"]
[BlackElo "2825"]
[PlyCount "115"]
[EventDate "1998.05.24"]
[EventType "match (blitz)"]
[EventRounds "1"]

1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 e6 8. Ne5
Bh7 9. Qh5 Qe7 10. Bd3 Bxd3 11. Nxd3 Nf6 12. Qf3 Qd8 13. c3 Nbd7 14. Bf4 Qa5
15. Ne5 Qd5 16. Nxd7 Kxd7 17. Qxd5+ cxd5 18. h5 b5 19. a3 Be7 20. f3 Rhc8 21.
Be5 Ne8 22. Ne2 a5 23. Kd2 Bf8 24. g4 Nd6 25. Bxd6 Bxd6 26. Kd3 f6 27. f4 Rf8
28. Raf1 b4 29. axb4 axb4 30. Ra1 bxc3 31. bxc3 Rfb8 32. Rhb1 Rxb1 33. Rxb1 Kc6
34. Rf1 Ra2 35. Rb1 Bc7 36. Rg1 Ra8 37. Rb1 Rg8 38. Ra1 g5 39. f5 exf5 40. gxf5
Re8 41. Ra6+ Bb6 42. Ra2 Kb7 43. c4 dxc4+ 44. Kxc4 Re3 45. Nc3 Rf3 46. Rb2 Ka6
47. Nd5 Bd8 48. Rb8 Ba5 49. Ra8+ Kb7 50. Rxa5 Rxf5 51. Rb5+ Ka7 52. Ne3 Rf3 53.
Ng4 f5 54. Nxh6 g4 55. Rxf5 Rg3 56. Rg5 Rh3 57. Nxg4 Kb6 58. Rg6+ 1-0



[Event "Internet blitz 5'"]
[Site "Internet ICC"]
[Date "1998.08.21"]
[Round "?"]
[White "Kasparov, Garry"]
[Black "Schmaltz, Roland"]
[Result "0-1"]
[ECO "A49"]
[WhiteElo "2825"]
[BlackElo "2470"]
[PlyCount "88"]
[EventDate "1998.05.24"]
[EventType "match (blitz)"]
[EventRounds "1"]

1. d4 Nf6 2. Nf3 g6 3. g3 Bg7 4. Bg2 O-O 5. O-O d6 6. Nbd2 Nbd7 7. e4 e5 8. c3
b6 9. Re1 Bb7 10. a4 a5 11. b3 Re8 12. d5 Bh6 13. Ba3 Rf8 14. Nc4 Ne8 15. b4
axb4 16. cxb4 f5 17. Nfd2 Ndf6 18. Bb2 fxe4 19. Nxe4 Nxe4 20. Bxe4 Nf6 21. Bg2
Qd7 22. Ra3 Ba6 23. b5 Bb7 24. Rd3 Qf7 25. Bc3 e4 26. Bxf6 exd3 27. Bd4 Rae8
28. Rxe8 Rxe8 29. Ne3 Bxe3 30. Bxe3 Bxd5 31. Qxd3 Bxg2 32. Kxg2 Qe6 33. Kg1 Qe4
34. Qc3 Re7 35. a5 bxa5 36. Qxa5 h5 37. h4 Kh7 38. b6 cxb6 39. Bxb6 d5 40. Qa3
Rf7 41. Qc5 Qc4 42. Qe3 Qe4 43. Qc5 Re7 44. Kh2 Rd7 0-1



[Event "Hoogovens 5'"]
[Site "Wijk aan Zee"]
[Date "1999.01.18"]
[Round "10"]
[White "Kasparov, Garry"]
[Black "Bosboom, Manuel"]
[Result "0-1"]
[ECO "B50"]
[WhiteElo "2812"]
[BlackElo "2490"]
[PlyCount "108"]
[EventDate "1999.01.18"]
[EventType "tourn (blitz)"]
[EventRounds "13"]
[EventCountry "NED"]
[EventCategory "17"]

1. e4 c5 2. Nf3 d6 3. c3 Nf6 4. Bd3 Bg4 5. Bc2 g6 6. h3 Bxf3 7. Qxf3 Bg7 8. O-O
O-O 9. Qd1 Nc6 10. d3 Rb8 11. Nd2 b5 12. a3 Nd7 13. Nf3 Nde5 14. Nxe5 Bxe5 15.
Be3 Qb6 16. Kh1 Bg7 17. f4 a5 18. Qc1 b4 19. Ba4 Rfc8 20. Rb1 Qa6 21. c4 Nd4
22. Qd2 Rb6 23. f5 Qb7 24. Bxd4 Bxd4 25. Bb5 e6 26. f6 Kh8 27. Qg5 Qc7 28. Rbe1
Qd8 29. Re2 Qf8 30. a4 Rd8 31. b3 h6 32. Qh4 Kh7 33. Rf3 d5 34. e5 dxc4 35.
Bxc4 Bc3 36. Re4 Rd4 37. Rff4 Rb8 38. Rxd4 Bxd4 39. Re4 Rd8 40. Qf4 Bc3 41. h4
h5 42. g4 hxg4 43. Qxg4 Qh6 44. Kg2 Rd4 45. h5 Qd2+ 46. Qe2 Qg5+ 47. Kf1 gxh5
48. Rxd4 Bxd4 49. Qe4+ Kh6 50. Qa8 Qg1+ 51. Ke2 Qe3+ 52. Kd1 Qg1+ 53. Ke2 Qh2+
54. Kd1 Bc3 0-1



[Event "Internet blitz 5'"]
[Site "Internet ICC"]
[Date "1998.08.21"]
[Round "?"]
[White "Kasparov, Garry"]
[Black "Zarnicki, Pablo"]
[Result "0-1"]
[ECO "A18"]
[WhiteElo "2825"]
[BlackElo "2515"]
[PlyCount "116"]
[EventDate "1998.05.24"]
[EventType "match (blitz)"]
[EventRounds "1"]

1. c4 Nf6 2. Nc3 e6 3. e4 d5 4. e5 d4 5. exf6 dxc3 6. bxc3 Qxf6 7. d4 e5 8. Nf3
exd4 9. Bg5 Qe6+ 10. Be2 Be7 11. cxd4 Bxg5 12. Nxg5 Qf6 13. Qd2 O-O 14. O-O Nc6
15. Nf3 Bg4 16. Rad1 Rad8 17. d5 Bxf3 18. Bxf3 Ne5 19. Be2 b6 20. Rfe1 Rfe8 21.
Bf1 Nd7 22. Re3 Rxe3 23. Qxe3 Nc5 24. Re1 g6 25. g3 Kg7 26. h4 h5 27. a3 a5 28.
Bg2 Rd7 29. Bf3 Rd8 30. Kg2 Rd7 31. Bd1 Rd8 32. Bc2 c6 33. Rd1 cxd5 34. cxd5
Rd6 35. Rd4 Qd8 36. Qc3 Qf6 37. Qd2 Qe5 38. f4 Qf6 39. Qe3 Kf8 40. Rd2 Kg7 41.
f5 Nd7 42. fxg6 fxg6 43. Qe4 Qe5 44. Qd3 Nc5 45. Qc4 Nd7 46. a4 Nf6 47. Qc7+
Kh6 48. Qb8 Kg7 49. Qc7+ Kh6 50. Qb8 Nh7 51. Kh2 Rxd5 52. Qxe5 Rxe5 53. Kg1 Re6
54. Rd7 Nf6 55. Rb7 Ng4 56. Bb3 Re1+ 57. Kg2 Re2+ 58. Kf1 Rb2 0-1



[Event "Wch blitz"]
[Site "Saint John"]
[Date "1988.??.??"]
[Round "2"]
[White "Kasparov, Garry"]
[Black "Dlugy, Maxim"]
[Result "0-1"]
[ECO "E91"]
[WhiteElo "2750"]
[BlackElo "2550"]
[PlyCount "70"]
[EventDate "1988.??.??"]
[EventType "k.o. (blitz)"]
[EventRounds "5"]
[EventCountry "CAN"]

1. c4 Nf6 2. Nc3 g6 3. e4 d6 4. d4 Bg7 5. Be2 O-O 6. Nf3 Bg4 7. Be3 Nbd7 8. h3
Bxf3 9. Bxf3 c6 10. O-O a6 11. Rc1 e5 12. d5 c5 13. a3 Ne8 14. b4 Qc7 15. Qb3
b6 16. bxc5 dxc5 17. h4 Nd6 18. h5 f5 19. hxg6 hxg6 20. g3 b5 21. cxb5 f4 22.
Bd2 c4 23. Qb4 a5 24. Qb1 Nc5 25. b6 Qf7 26. Nb5 Nxb5 27. Qxb5 Nb3 28. Bg4 Qe7
29. Rcd1 fxg3 30. Be6+ Kh8 31. Kg2 Qh4 32. fxg3 Qxe4+ 33. Kg1 Nd4 34. Qd7 Nf3+
35. Rxf3 Qxf3 0-1

In all tests I made, Marius won, I didnt choose one or two matches, the results you see above are the only tests I made.

It is different from choosing one or two games between hundred options.

This message has been edited. Last edited by: Nosteralien,