Author: Dieter Buerssner
Date: 11:41:13 08/15/03
Go up one level in this thread
On August 14, 2003 at 20:35:02, Omid David Tabibi wrote: >On August 14, 2003 at 20:11:22, Dieter Buerssner wrote: > >>See for example: http://fortuna.iasi.rdsnet.ro/ccc/ccc.php?art_id=232537 >> >>Another interesting question would be: What is a sure maximum of the number of >>possible pseudo legal move. An upper bound for that question can also be found >>rather easily (for legal positions in "normal" chess). You cannot have more than >>9 queens, each queen has at most 27 moves, ... >> > >Those kind of positions with 200+ moves (or pseudo-legal moves) never arise in >actual games, so setting the size of move list to something less than 200 would >practically suffice, wouldn't it? Do you want to make your engine crash, when a user setups some weird position? From the PGNs I downloaded from Dann Corbit (3.4 million games in Dann's diroctories a/b/c/d/e-opening), the maximum number of legal moves was 99 in this position: [D] 3QQ3/PR6/8/3K4/3B1Q2/7k/3Q4/8 w - - 5 83 [Event "Computer chess game"] [Site "LAPTOP"] [Date "2002.02.24"] [Round "3"] [White "Jester082"] [Black "Pentagon 1.2"] [Result "1-0"] [ECO "B00e"] [Variation "Owen Defence: French"] [TimeControl "300"] 1. e4 e6 2. d4 b6 3. Nc3 Bb4 4. Qg4 Bxc3+ 5. bxc3 g6 6. Nf3 Nf6 7. Qh4 d5 8. Bg5 Nbd7 9. Ne5 Nxe5 10. Bxf6 g5 11. Qxg5 Qd7 12. Bxh8 Ng6 13. exd5 Qxd5 14. Qxd5 exd5 15. Bf6 Kf8 16. c4 Bb7 17. cxd5 Bxd5 18. Kd2 Kg8 19. c4 Be6 20. d5 Bf5 21. Rc1 c6 22. d6 Re8 23. Bd3 Be6 24. Rhe1 Nf4 25. Be4 Bd7 26. Bf3 c5 27. Rxe8+ Bxe8 28. Ke3 Ne6 29. Rb1 h6 30. Rb3 Ng5 31. Bg4 Nh7 32. Bc3 Nf8 33. Bf5 Bc6 34. Be4 Bxe4 35. Kxe4 Kh7 36. Ra3 a5 37. Rb3 Nd7 38. Kf5 h5 39. f4 h4 40. a4 h3 41. gxh3 Kh6 42. Ke4 Kg6 43. h4 f5+ 44. Kd5 Kf7 45. h5 Kf8 46. h6 Kg8 47. Ke6 Nf8+ 48. Kxf5 Nd7 49. h4 Kh7 50. Bg7 Kg8 51. Ke6 Kh7 52. Kxd7 Kg6 53. Rxb6 Kf5 54. h7 Kxf4 55. h8=Q Ke3 56. Kc6 Kd2 57. Bc3+ Kd3 58. Kxc5 Ke3 59. d7 Ke4 60. Qa8+ Kf4 61. d8=Q Kg4 62. Rb7 Kf4 63. Kd5 Ke3 64. c5 Kd3 65. Qaxa5 Ke3 66. Bd4+ Kf4 67. c6 Kf3 68. c7 Kf4 69. c8=Q Kf3 70. h5 Kg2 71. h6 Kg3 72. h7 Kg2 73. h8=Q Kf3 74. Qhe8 Kg2 75. Qb8 Kh3 76. Qba8 Kg2 77. Qd2+ Kg3 78. a5 Kh3 79. a6 Kg3 80. a7 Kh3 81. Qab8 Kg4 82. Qbf4+ Kh3 83. Qdd7# 1-0 There are human games with positions with over 80 legal moves. The number of pseudo legal moves will in general of course be higher. Most probably, in the search tree, positions with more moves will be found. Regards, Dieter
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.