Author: Uri Blass
Date: 06:48:08 08/14/02
Go up one level in this thread
On August 14, 2002 at 08:40:45, Vincent Diepeveen wrote: <snipped> >In the leo blitz games of course diep would go qxd1 too there at the blitz >level with the new version. leo's time control is 40 minutes/40 moves and he is using dual PIII1266. > >>By your definition of sacrifice Qxd1+ is a sacrifice. > >That is very obvious. you give away material for good mobility. > >>By my definition it is only a trade of material and >>nobody sacrificed material. > >That is a wrong definition, because white wins material after qxd1. > >>I can imagine that I am going to have more mistakes >>if I increase the evaluation of queen to more than 2 rooks. > >You could implement mobility and put it high. Qxd1 is not a winning >move here. it is a speculative move. Just like in some mainlines in >sicilian some GMs give up a queen for sometimes only rook + bishop. > >Good example is some dragon lines i play myself with white. Even Anand >manages to get it a draw, but i would love to see DIEP - Anand in that >position. Anand would get toasted of course. Computers are way better >with more material. > >Another consideration is that you should print the number of times that >movei is having queen+pawn versus 2 rooks, or even queen versus 2 rooks. > >You will see that the queen directly after that picks up material in >95% of the cases. A queen grabs material simply easier than rooks. I have not a lot of games when I get 2 rooks against queen but here is one example when it did not happen and rooks of old movei grabbed material and got a draw. [Event "Computer chess game"] [Site "URI-PC"] [Date "2002.02.18"] [Round "-"] [White "movei0056"] [Black "resp_0_1_4"] [Result "1/2-1/2"] [TimeControl "40/300"] 1. e4 d5 2. exd5 Qxd5 3. Nc3 Qd6 4. d4 Nf6 5. Nf3 Bg4 6. Be2 Nbd7 7. Nb5 Qb6 8. Bf4 Nd5 9. Be5 Bxf3 10. gxf3 e6 11. c4 Nxe5 12. dxe5 Nf4 13. Qd2 Nxe2 14. Qxe2 Bb4+ 15. Kf1 a6 16. Nc3 Bxc3 17. bxc3 O-O 18. Kg1 f6 19. f4 fxe5 20. fxe5 Rf4 21. Rd1 Raf8 22. Rd2 Qb1+ 23. Kg2 Rxf2+ 24. Qxf2 Qe4+ 25. Kg1 Rxf2 26. Rxf2 Qxc4 27. Kg2 Qd5+ 28. Rf3 Qxa2+ 29. Kf1 a5 30. h4 Qd5 31. Kf2 Qxe5 32. h5 a4 33. Rh4 a3 34. Ra4 g6 35. hxg6 hxg6 36. c4 Qb2+ 37. Kg3 a2 38. Rfa3 Qe5+ 39. Kf3 Qh5+ 40. Kg3 Qg5+ 41. Kf3 e5 42. Rxa2 Qf4+ 43. Ke2 g5 44. c5 e4 45. R2a3 Qg4+ 46. Ke3 Qf5 47. Kd4 c6 48. Ra7 Qd5+ 49. Ke3 Qxc5+ 50. Kxe4 Qd5+ 51. Ke3 b5 52. R3a6 b4 53. Ra5 c5 54. Re7 b3 55. Raa7 Qd4+ 56. Ke2 Kf8 57. Reb7 Qe4+ 58. Kf2 Qf4+ 59. Ke2 Qh2+ 60. Ke3 Qh3+ 61. Ke4 Qe6+ 62. Kd3 Qg6+ 63. Kc4 Qc2+ 64. Kb5 Qe2+ 65. Kxc5 Qf2+ 66. Kc4 Qf1+ 67. Kb4 Qe1+ 68. Ka3 Qa1+ 69. Kxb3 Qb1+ 70. Kc3 Qc1+ 71. Kd3 Qf1+ 72. Kd4 Qf4+ 73. Kd5 Qf5+ 74. Kd6 Qf6+ 75. Kc5 Qe5+ 76. Kc4 Qe4+ 77. Kc3 Qf3+ 78. Kd2 Qf2+ 79. Kc1 Qe1+ 80. Kc2 Qe2+ 81. Kb1 Qd1+ 82. Kb2 Qd2+ 83. Kb3 Qd3+ 84. Kb4 Qd4+ 85. Kb5 Qd5+ 86. Kb6 Qd6+ 87. Kb5 Qd8 88. Kc5 Qe8 89. Kd4 Qd8+ 90. Ke4 Qe8+ 91. Kf5 Qc8+ 92. Kxg5 Qc5+ 93. Kf4 Qd6+ 94. Ke4 Qe6+ 95. Kd4 Qd6+ 96. Kc4 Qc6+ 97. Kb4 Qd6+ 98. Kc3 Qc5+ 99. Kd3 Qd5+ 100. Ke3 Qe5+ 101. Kf3 Qf5+ 102. Ke2 Qe4+ 103. Kd2 Qd4+ 104. Kc2 Qc4+ 105. Kd1 Qd4+ 106. Kc1 Qf4+ 107. Kb1 Qe4+ 108. Ka1 Qd4+ 109. Ka2 Qd2+ 110. Kb1 Qd1+ 111. Kb2 Qd2+ 112. Kb3 Qd3+ 113. Ka4 Qc4+ 114. Ka5 Qc5+ 115. Ka6 Qd6+ 116. Rb6 Qd3+ 117. Kb7 Ke8 118. Rc6 Qb5+ 119. Kc7 Qe5+ 120. Kb6 Qb2+ 121. Ka6 Qe2+ 122. Ka5 Qa2+ 123. Kb6 Qb2+ 124. Ka6 Qe2+ 125. Kb6 Qb2+ 1/2-1/2 <snipped> >That means that getting 2 rooks is directly like +13.0 with just >mobility and that getting a good queen is +10.5 with good mobility >if we assume 5+5 versus 9. > >You miss 2.5 pawns then for the queen! I have not that big score for mobility but I consider mobility of rooks as a natural situation so I may consider punishing rooks without mobility in my evaluation when I change my evaluation to be more complex. > >>Reducing the evaluation of queen can also cause mistake so >>I am not going to change it in the near future. > >You forgot to mention at which values the stuff is set at now. Also >you do not have mobility i already know this for sure now. It is interesting >to know what the values from quark are. I bet they are closer to DIEP >than they are to Movei!! I use the number of legal moves in my evaluation so I have mobility in my evaluation but black's mobility based on this evaluation is not bigger than white's mobility. It is not the optimal way to evaluate mobility but it is clearly better than nothing and I have games when movei won thanks to it's mobility evaluation. Here is an example from a game against yace when movei found the winning Qa4 thanks to it's mobility evaluation (it is possible to find it for tactical reasons but at the time control of the game movei needed positional reasons) [D]2kr1b1r/ppp1pppp/2n5/2N1P2q/2bP4/4BN1P/PP3PP1/R2Q1RK1 w - - 0 14 My values for pieces are about 10 for queen and 5.2 for rook and 3.5 pawns for bishop or knight so queen against rook bishop and pawn is considered as a small advantage. Uri
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.