Contest: Find Position with the most moves

[CRoberson]

Find and post a position which has the most legal moves. The fastest way to do this may be to load a game into your favorite GUI and run your favorite engine, then march through the game one move at a time with the GUI displaying the engines legal/pseudo legal move choices. You don't have to count for yourself. I know most UCI GUI's support this feature with UCI engines, but I am not aware of an Xboard GUI that supports it with Xboard engines.

I prefer positions from games played by humans or computers as opposed to compositions.

I'll get the contest started:

A couple of engines report this position as having 45 moves with the given side to move.

[D] r4rk1/p1pn1p2/1p1p3p/6p1/2PPq3/2P1P1B1/P3Q1PP/R4RK1 b - - 3 18

[Paloma]

Try this:

[D] 4r1k1/p4pp1/2n2n1B/2b5/N6Q/P2q1N2/1r4PP/R4R1K b - - 0 23

79 black move choices

[CRoberson]

I forgot to mention: please, post where the position comes from. If possible post the pgn.

[zullil]

Try this:

[D] 4r1k1/p4pp1/2n2n1B/2b5/N6Q/P2q1N2/1r4PP/R4R1K b - - 0 23

79 black move choices

Perhaps taken from http://timkr.home.xs4all.nl/records/ , where its source is given as: Davis - Panchanathan, Minneapolis 2005

Possibly this:

Code: Select all

[Event "HB Global Chess Challenge"]
[Site "Minneapolis USA"]
[Date "2005.05.19"]
[EventDate "2005.05.18"]
[Round "2"]
[Result "1/2-1/2"]
[White "Loal Davis"]
[Black "M Panchanathan"]
[ECO "C59"]
[WhiteElo "?"]
[BlackElo "2473"]
[PlyCount "120"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 d5 5. exd5 Na5 6. Bb5+
c6 7. dxc6 bxc6 8. Be2 h6 9. Nf3 e4 10. Ne5 Bd6 11. f4 exf3
12. Nxf3 O-O 13. d4 Rb8 14. a3 Re8 15. O-O c5 16. Nc3 cxd4
17. Qxd4 Nc6 18. Qh4 Bf5 19. Bd3 Bc5+ 20. Kh1 Bxd3 21. cxd3
Qxd3 22. Bxh6 Rxb2 23. Na4 Rc2 24. Nxc5 Rxc5 25. Bg5 Ne4
26. Bf4 Rc2 27. Ng5 Nxg5 28. Qxg5 Nd4 29. Rfe1 Rce2 30. Rxe2
Qxe2 31. h3 Nc2 32. Rc1 Qe4 33. Bg3 Ne3 34. Bf2 f6 35. Qxe3
Qxe3 36. Bxe3 Rxe3 37. Ra1 a5 38. Ra2 a4 39. Kg1 Kf7 40. Kf2
Rc3 41. Rb2 Rxa3 42. Rb7+ Kg6 43. Ra7 Ra1 44. Kg3 a3 45. Kf2
Kh6 46. Ra5 g6 47. Kg3 Ra2 48. Kf3 f5 49. Ra7 Ra1 50. Kf2 f4
51. Ra8 a2 52. Ra5 f3 53. Kg3 Kg7 54. Ra6 Kf7 55. Kf2 Ke7
56. Kg3 Kd7 57. Kf2 Kc7 58. Ra3 Kb6 59. Ra8 Kc5 60. Rc8+ Kb6
1/2-1/2

[Edmund]

You said that you rather prefer not to see any compositions, I think this position has to be quoted anyhow.

[d]R6R/3Q4/1Q4Q1/4Q3/2Q4Q/Q4Q2/pp1Q4/kBNN1KB1 w - - 0 1
with 218 moves

[Paloma]

Hi Louis,
you are right

[bob]

Find and post a position which has the most legal moves. The fastest way to do this may be to load a game into your favorite GUI and run your favorite engine, then march through the game one move at a time with the GUI displaying the engines legal/pseudo legal move choices. You don't have to count for yourself. I know most UCI GUI's support this feature with UCI engines, but I am not aware of an Xboard GUI that supports it with Xboard engines.

I prefer positions from games played by humans or computers as opposed to compositions.

I'll get the contest started:

A couple of engines report this position as having 45 moves with the given side to move.

[D] r4rk1/p1pn1p2/1p1p3p/6p1/2PPq3/2P1P1B1/P3Q1PP/R4RK1 b - - 3 18

There was one posted on r.g.c.c several years ago with 218 legal moves. I am not aware of anyone breaking that record, although it was looked at for quite a period of time back then (someone wanted to quantify the max move list size required to be 100% safe).

[bob]

You said that you rather prefer not to see any compositions, I think this position has to be quoted anyhow.

[d]R6R/3Q4/1Q4Q1/4Q3/2Q4Q/Q4Q2/pp1Q4/kBNN1KB1 w - - 0 1
with 218 moves

That's the record-holder from r.g.c.c several years back...

[marcelk]

Find and post a position which has the most legal moves. The fastest way to do this may be to load a game into your favorite GUI and run your favorite engine, then march through the game one move at a time with the GUI displaying the engines legal/pseudo legal move choices. You don't have to count for yourself. I know most UCI GUI's support this feature with UCI engines, but I am not aware of an Xboard GUI that supports it with Xboard engines.

I prefer positions from games played by humans or computers as opposed to compositions.

I found this ICC game, computer vs. (bored) IM.

[D] K7/7q/8/8/6q1/1q6/4q3/2qqk3 b - - 0 1
Black has 110 moves after White's 91th move.

Code: Select all

[Event "ICC 2 0"]
[Site "Internet Chess Club"]
[Date "2010.09.15"]
[Time "07:27:08"]
[Round "-"]
[White "Rookie"]
[Black "scacho"]
[Result "0-1"]
[WhiteElo "2408"]
[BlackElo "2180"]
[TimeControl "120"]
[ECO "A01 Nimzovich-Larsen attack, classical variation"]

1. b3 d5 2. e3 c6 3. Bb2 Bf5 4. g4 Bg6 5. Bg2 e6 6. Nh3 Nf6 7. Nf4 Bd6 8. g5
Bxf4 9. gxf6 Bh6 10. f4 gxf6 11. Bh3 Rg8 12. Rg1 f5 13. Qf3 Bg7 14. Bxg7 Rxg7
15. Nc3 Qh4+ 16. Qg3 Qxg3+ 17. Rxg3 Nd7 18. a4 Ke7 19. a5 Rag8 20. a6 b6 21.
Ne2 Bh5 22. Rxg7 Rxg7 23. Ng3 Bg4 24. Bf1 h5 25. Ne2 Bxe2 26. Kxe2 Kd6 27. b4
b5 28. Ra5 Kc7 29. Kd3 Kb6 30. Kd4 f6 31. Kc3 Nb8 32. d4 Nxa6 33. Ra1 Rg1 34.
Rb1 Nc7 35. Ra1 Ne8 36. Kb2 Nd6 37. Bd3 Rxa1 38. Kxa1 Nc4 39. Bxc4 dxc4 40. Kb2
a5 41. bxa5+ Kxa5 42. Kc3 Ka4 43. Kb2 b4 44. c3 b3 45. h4 Kb5 46. Kc1 Kb6 47.
Kb1 Kc7 48. Kc1 Kd6 49. Kb1 Kd5 50. Kc1 Ke4 51. Kd2 Kf3 52. Kd1 Kxe3 53. Kc1
Kd3 54. Kb2 Kd2 55. d5 cxd5 56. Ka3 Kxc3 57. Ka4 b2 58. Kb5 b1=Q+ 59. Kc6 Qe4
60. Kd7 d4 61. Ke7 d3 62. Kf7 Qxf4 63. Kxe6 Qxh4 64. Kf7 Qg4 65. Ke8 f4 66. Kd8
f3 67. Kc7 f2 68. Kd6 f1=Q 69. Kc7 f5 70. Kd7 f4+ 71. Kd6 f3 72. Kc7 f2 73. Kd6
Qfe2 74. Kc5 f1=Q 75. Kc6 d2 76. Kc5 d1=Q 77. Kc6 h4 78. Kc5 h3 79. Kc6 h2 80.
Kc5 h1=Q 81. Kb5 Kd2 82. Ka5 Ke1 83. Kb4 Kd2 84. Ka5 c3 85. Kb6 c2 86. Kc7
c1=Q+ 87. Kb8 Ke1 88. Ka7 Qff3 89. Kb6 Qfb3+ 90. Ka7 Qh7+ 91. Ka8 Qd8#
{White checkmated} 0-1

[marcelk]

Here another one. 121 possible moves after Black's 116th move

[D] 1k4K1/3QQQQQ/8/8/B1Q5/8/8/4Q3 w - - 23 117

Code: Select all

[Event "ICC 6 7"]
[Site "Internet Chess Club"]
[Date "2010.11.27"]
[Time "21:31:38"]
[Round "-"]
[White "Pinduca"]
[Black "Rookie"]
[Result "1-0"]
[WhiteElo "2256"]
[BlackElo "2618"]
[TimeControl "360+7"]
[ECO "A46 Queen's pawn game"]

1. d4 Nf6 2. Nf3 e6 3. c3 d5 4. Bf4 Bd6 5. Bg3 h5 6. Nbd2 a5 7. e3 Bxg3 8. hxg3
a4 9. a3 Ng4 10. e4 Qf6 11. Bd3 Nc6 12. Qe2 Kf8 13. O-O-O Ra5 14. e5 Qh6 15.
Nh2 Nxh2 16. Rxh2 g6 17. g4 h4 18. g3 h3 19. Rdh1 Qg7 20. Rxh3 Rxh3 21. Rxh3
Ke8 22. f4 Kd7 23. Qh2 Ne7 24. Rh7 Qf8 25. Qh4 c5 26. Rh8 Qg7 27. Qf6 Qxf6 28.
exf6 Nc6 29. Nf3 Nd8 30. Ne5+ Kc7 31. Nxf7 Nxf7 32. Rh7 Bd7 33. Rxf7 c4 34.
Bxg6 Ra8 35. g5 Kd6 36. Rg7 Be8 37. Rg8 Kd7 38. f7 Bxf7 39. Bxf7 Rxg8 40. Bxg8
Ke7 41. Kd2 Kd6 42. Ke3 Ke7 43. g4 b6 44. f5 Kf8 45. Bxe6 Kg7 46. Bxd5 b5 47.
Bc6 Kf8 48. Bxb5 Kg7 49. d5 Kg8 50. d6 Kf7 51. Kd4 Kf8 52. Kxc4 Kf7 53. Bxa4
Kf8 54. Bd7 Kg7 55. a4 Kg8 56. a5 Kg7 57. a6 Kh8 58. a7 Kg7 59. b4 Kh7 60. b5
Kg7 61. b6 Kh7 62. Kd5 Kg7 63. c4 Kh7 64. c5 Kg7 65. c6 Kh7 66. b7 Kg7 67. c7
Kh7 68. Bc6 Kg7 69. Ke6 Kh7 70. d7 Kg7 71. d8=Q Kh7 72. c8=Q Kg7 73. b8=Q Kh7
74. a8=Q Kg7 75. Bf3 Kh7 76. Qa2 Kg7 77. Qbb3 Kh7 78. Qcc4 Kg7 79. Qdd5 Kg8 80.
Ke5+ Kh8 81. Qcc2 Kg7 82. Qbb1 Kh7 83. Qg2 Kg7 84. Qaf2 Kh8 85. Qdd1 Kg7 86.
Qh2 Kg8 87. f6 Kf7 88. Qdf1 Kf8 89. Qhh7 Ke8 90. Qbe1 Kd8 91. Qf7 Kc8 92. Qe7
Kb8 93. Ke6 Kc8 94. Kf7 Kb8 95. Ke8 Kc8 96. g6 Kb8 97. g7 Kc8 98. f7 Kb8 99. g5
Kc8 100. g6 Kb8 101. g8=Q Kc8 102. f8=Q Kb8 103. g7 Kc8 104. Qh8 Kb8 105. g8=Q
Kc8 106. Bd1 Kb8 107. Qfd2 Kc8 108. Qdd7+ Kb8 109. Qf8f7 Ka8 110. Kf8 Kb8 111.
Qhg7 Ka8 112. Q8h8 Kb8 113. Kg8 Ka8 114. Q1c4 Kb8 115. Ba4 Ka8 116. Qhh7 Kb8
117. Bb5 Ka8 118. Ba6 Kb8 119. Kh8 Ka8 120. Qea1 Kb8 121. Qcc7+ Ka8 122. Bb7#
{Black checkmated} 1-0