Author: Roy Eassa
Date: 12:04:28 06/11/02
Go up one level in this thread
On June 11, 2002 at 14:49:21, Dieter Buerssner wrote:
>On June 11, 2002 at 11:52:47, Robert Hyatt wrote:
>
>>On June 10, 2002 at 18:45:03, Dieter Buerssner wrote:
>>
>>>I'd like to add, that not for all engines, it is some sort of luck, when they
>>>remember past analysis, and when not. I am convinced, that for my engine, it is
>>>better in general, to analyze from back to front. I am also convinced, that it
>>>will not forget previous analysis.
>>
>>It _must_ unless you have a hash table of infinite size...
>
>In theory, yes. In practice, no. There are many more entries to remember crucial
>info, than the number anybody could try out in practice. Uri showed several
>time, that he could use the backwards analysis of Yace efficiently.
>
>I could prove a mate in (at least) 182 by this feature by analyzing the
>following PGN from back to front (including the variations in the PGN). A task,
>that would be totally impossible by analyzing from front to back by a normal
>playing program. Anybody should be able to reproduce this. It took me about 45
>minutes (I didn't have the variants, and had to input many moves with the mouse.
>With the PGN and all its variants, I should be able to reproduce this much
>faster). At the end of the analysis I got (with German piece letters):
>
>[D] n1K5/b1p3pp/1pP3p1/1P6/6p1/1p4Pn/1P2N1br/3NRn1k w - -
>
>
>Position stored with depth 6
> 8.01 0:00 +M182 1.Kd8 g5 2.Ke7 Lb8 3.Kf8 g6 4.Kg7 La7 5.Kf6 Lb8 6.Ke5 La7
>7.Kd4 Lb8 8.Kc3 La7 9.Kb4 Lb8 10.Ka4 La7 11.Ka3 Lb8 12.Kb4 La7 13.Kc3 Lb8 14.Kd4
>(67.216) 114.5
> 8.12 0:02 +M182 1.Kd8 g5 2.Ke7 Lb8 3.Kf8 g6 4.Kg7 La7 5.Kf6 Lb8 6.Ke5 La7
>7.Kd4 Lb8 8.Kc3 La7 9.Kb4 Lb8 10.Ka4 La7 11.Ka3 Lb8 12.Kb4 La7 13.Kc3 Lb8 14.Kd4
>(349.585) 145.0
>
>The GUI I used cannot show the whole line, while it was in principle available,
>
>The search tree I analyzed from back to front:
>
>[Event "Fabel-haft"]
>[Site "?"]
>[Date "2002.04.26"]
>[Round "?"]
>[White "Yace"]
>[Black "Yace"]
>[Result "*"]
>[SetUp "1"]
>[FEN "n1K5/b1p3pp/1pP3p1/1P6/6p1/1p4Pn/1P2N1br/3NRn1k w - -"]
>
>1. Kd8 {23s} Bb8 {17s} (1... h6 {37s} 2. Kc8 {4s} h5 {9s}
>(2... g5 {Matt in 158}) 3. Kd8 {4s} Bb8 {3s} (3... g5
>{13s}) (3... h4 {19s} 4. Ke7 {5s} g5 {Matt in 134}) 4. Ke7
>{2s} g5 {7s} (4... Ba7 {14s} 5. Kf8 {2s} Bb8 {4s} 6. Kxg7
>{1s} Ba7 {4s} 7. Kf6 {Matt in 126}) 5. Kf8 {10s} g6 {Matt
>in 149}) 2. Ke7 {24s} g5 {14s} (2... Ba7 {1:02m} 3. Kf8
>{7s} h6 {4s} (3... Bb8 {26s} 4. Kxg7 {5s} Ba7 {5s} 5. Kf6
>{15s} Bb8 {0s} 6. Ke5 {1s} Ba7 {1s} 7. Kd4 {1s} Bb8 {0s}
>8. Kc3 {2s} Ba7 {0s} 9. Kb4 {3s} Bb8 {0s} 10. Ka3 {1s} Ba7
>{0s} 11. Ka4 {2s} Bb8 {0s} 12. Kb4 {1s} Ba7 {0s} 13. Kc3
>{3s} Bb8 {1s} 14. Kd4 {2s} Ba7 {1s} 15. Ke5 {1s} Bb8 {1s}
>16. Kf6 {9s} Ba7 {1s} 17. Ke7 {1s} Bb8 {1s} 18. Kd8 {1s}
>Ba7 {4s} 19. Kc8 {2s} g5 {Matt in 149}) 4. Kxg7 {3s} h5
>{5s} (4... Bb8 {23s} 5. Kf6 {39s} Ba7 {5s} 6. Ke7 {2s} Bb8
>{1s} 7. Kd8 {2s} Ba7 {0s} 8. Kc8 {4s} Bb8 {19s} (8... g5
>{Matt in 128}) 9. Kxb8 {2s} h5 {6s} 10. Kc8 {Matt in 15})
>5. Kf6 {28s} Bb8 {6s} 6. Ke5 {2s} Ba7 {0s} 7. Kd4 {2s} Bb8
>{0s} 8. Kc3 {2s} Ba7 {0s} 9. Kb4 {2s} Bb8 {0s} 10. Ka3 {2s}
>Ba7 {0s} 11. Ka4 {2s} Bb8 {0s} 12. Kb4 {1s} Ba7 {1s}
>13. Kc3 {1s} Bb8 {0s} 14. Kd4 {2s} Ba7 {0s} 15. Ke5 {1s}
>Bb8 {1s} 16. Kf6 {2s} Ba7 {0s} 17. Ke7 {1s} Bb8 {0s}
>18. Kd8 {1s} Ba7 {0s} 19. Kc8 {2s} h4 {3s} 20. Kd8 {9s} Bb8
>{1s} 21. Ke7 {8s} Ba7 {2s} 22. Kf6 {2s} Bb8 {0s} 23. Ke5
>{1s} Ba7 {0s} 24. Kd4 {1s} Bb8 {1s} 25. Kc3 {4s} Ba7 {0s}
>26. Kb4 {3s} Bb8 {0s} 27. Ka3 {1s} Ba7 {0s} 28. Ka4 {2s}
>Bb8 {0s} 29. Kb4 {1s} Ba7 {0s} 30. Kc3 {1s} Bb8 {0s}
>31. Kd4 {1s} Ba7 {0s} 32. Ke5 {1s} Bb8 {0s} 33. Kf6 {1s}
>Ba7 {0s} 34. Ke7 {2s} Bb8 {0s} 35. Kd8 {1s} Ba7 {0s}
>36. Kc8 {1s} hxg3 {Matt in 94}) 3. Kf8 {23s} g6 {4s}
>(3... h6 {18s} 4. Kxg7 {4s} h5 {3s} (4... Ba7 {15s} 5. Kf6
>{1:01m} Bb8 {0s} 6. Ke5 {3s} Ba7 {1s} 7. Kd4 {1s} Bb8 {0s}
>8. Kc3 {3s} Ba7 {0s} 9. Kb4 {7s} Bb8 {0s} 10. Ka3 {1s} Ba7
>{11s} 11. Ka4 {1s} Bb8 {0s} 12. Kb4 {2s} Ba7 {0s} 13. Kc3
>{1s} Bb8 {0s} 14. Kd4 {2s} Ba7 {0s} 15. Ke5 {1s} Bb8 {0s}
>16. Kf6 {3s} Ba7 {1s} 17. Ke7 {1s} Bb8 {0s} 18. Kd8 {1s}
>Ba7 {0s} 19. Kc8 {3s} h5 {5s} 20. Kd8 {6s} Bb8 {1s} 21. Ke7
>{1s} Ba7 {0s} 22. Kf6 {2s} Bb8 {0s} 23. Ke5 {1s} Ba7 {1s}
>24. Kd4 {1s} Bb8 {0s} 25. Kc3 {2s} Ba7 {0s} 26. Kb4 {1s}
>Bb8 {1s} 27. Ka3 {1s} Ba7 {0s} 28. Ka4 {1s} Bb8 {0s}
>29. Kb4 {1s} Ba7 {0s} 30. Kc3 {1s} Bb8 {1s} 31. Kd4 {1s}
>Ba7 {2s} 32. Ke5 {2s} Bb8 {0s} 33. Kf6 {1s} Ba7 {0s}
>34. Ke7 {1s} Bb8 {0s} 35. Kd8 {1s} Ba7 {0s} 36. Kc8 {Matt
>in 95}) 5. Kf8 {28s} (5. Kh7 {14s}) 5... Ba7 {8s} 6. Ke7
>{13s} h4 {6s} (6... Bb8 {16s} 7. Kd8 {7s} Ba7 {1s} 8. Kc8
>{6s} h4 {13s} 9. Kd8 {Matt in 94}) 7. Kf6 {14s} Bb8 {3s}
>8. Ke5 {2s} Ba7 {1s} 9. Kd4 {3s} Bb8 {0s} 10. Kc3 {1s} Ba7
>{0s} 11. Kb4 {2s} Bb8 {0s} 12. Ka3 {2s} Ba7 {0s} 13. Ka4
>{1s} Bb8 {0s} 14. Kb4 {1s} Ba7 {0s} 15. Kc3 {3s} Bb8 {0s}
>16. Kd4 {1s} Ba7 {0s} 17. Ke5 {1s} Bb8 {1s} 18. Kf6 {1s}
>Ba7 {4s} 19. Ke7 {1s} Bb8 {0s} 20. Kd8 {2s} Ba7 {0s}
>21. Kc8 {2s} Bb8 {5s} (21... hxg3 {27s} 22. Nxg3+ {etc.,
>Matt in 77}) 22. Kxb8 {2s} hxg3 {3s} 23. Nxg3+ {3s} Kg1
>{0s}) (3... Ba7 {28s} 4. Kxg7 {3s} Bb8 {2s} 5. Kf6 {25s}
>Ba7 {0s} 6. Ke7 {1s} Bb8 {0s} 7. Kd8 {1s} Ba7 {0s} 8. Kc8
>{4s} h6 {6s} (8... Bb8 {16s} 9. Kxb8 {2s}) 9. Kd8 {7s} Bb8
>{2s} 10. Ke7 {Matt in 127}) 4. Kg7 {19s} Ba7 {8s} 5. Kf6
>{48s} Bb8 {6s} 6. Ke5 {25s} Ba7 {4s} 7. Kd4 {7s} Bb8 {1s}
>8. Kc3 {4s} Ba7 {23s} 9. Kb4 {3s} Bb8 {6s} 10. Ka4 {3s} Ba7
>{27s} 11. Ka3 {1s} Bb8 {6s} 12. Kb4 {3s} Ba7 {19s} 13. Kc3
>{1s} Bb8 {6s} 14. Kd4 {3s} Ba7 {3s} 15. Ke5 {4s} Bb8 {29s}
>16. Kf6 {1s} Ba7 {3s} 17. Ke7 {5s} Bb8 {0s} 18. Kd8 {4s}
>Ba7 {4s} 19. Kc8 {20s} h6 {6s} 20. Kd8 {35s} Bb8 {0s}
>21. Ke7 {3s} Ba7 {3s} 22. Kf8 {3s} Bb8 {0s} 23. Kg7 {6s}
>Ba7 {32s} 24. Kh7 {3s} Bb8 {2s} 25. Kh8 {1s} Ba7 {45s}
>26. Kg7 {3s} Bb8 {2s} 27. Kf8 {3s} Ba7 {1s} 28. Ke7 {13s}
>Bb8 {0s} 29. Kd8 {3s} Ba7 {0s} 30. Kc8 {5s} h5 {28s}
>(30... Bb8 {12s} 31. Kxb8 {2s} h5 {6s} 32. Kc8 {2s} h4 {2s}
>33. Kd8 {7s} hxg3 {4s} 34. Nxg3+ {3s}) 31. Kd8 {41s} Bb8
>{2s} 32. Ke7 {2s} Ba7 {0s} 33. Kf8 {2s} Bb8 {0s} 34. Kg7
>{1s} Ba7 {0s} 35. Kh8 {6s} Bb8 {0s} 36. Kh7 {2s} Ba7 {1s}
>37. Kg7 {2s} Bb8 {0s} 38. Kf8 {1s} Ba7 {0s} 39. Ke7 {1s}
>Bb8 {1s} 40. Kd8 {1s} Ba7 {0s} 41. Kc8 {2s} h4 {21s}
>(41... Bb8 {30s} 42. Kxb8 {5s} h4 {9s}) 42. Kd8 {31s} Bb8
>{0s} 43. Ke7 {3s} Ba7 {1s} 44. Kf8 {9s} Bb8 {0s} 45. Kg7
>{1s} Ba7 {0s} 46. Kh8 {1s} Bb8 {0s} 47. Kh7 {1s} Ba7 {2s}
>48. Kg7 {3s} Bb8 {0s} 49. Kf8 {1s} Ba7 {0s} 50. Ke7 {1s}
>Bb8 {0s} 51. Kd8 {1s} Ba7 {0s} 52. Kc8 {2s} hxg3 {31s}
>53. Nxg3+ {17s} Kg1 {3s} 54. Ne2+ {36s} Kh1 {1s} 55. Kd8
>{40s} Bb8 {0s} 56. Ke7 {8s} Ba7 {1s} 57. Kf6 {1s} Bb8 {3s}
>58. Ke5 {2s} Ba7 {0s} 59. Kd4 {2s} Bb8 {0s} 60. Kc3 {1s}
>Ba7 {1s} 61. Kb4 {2s} Bb8 {1s} 62. Ka3 {6s} Ba7 {3s}
>63. Ka4 {6s} Bb8 {0s} 64. Kb4 {1s} Ba7 {0s} 65. Kc3 {3s}
>Bb8 {0s} 66. Kd4 {1s} Ba7 {1s} 67. Ke5 {1s} Bb8 {0s}
>68. Kf6 {4s} Ba7 {4s} 69. Ke7 {1s} Bb8 {0s} 70. Kd8 {1s}
>Ba7 {1s} 71. Kc8 {3s} g3 {34s} 72. Nxg3+ {1s} Kg1 {1s}
>73. Ne2+ {2s} Kh1 {2s} 74. Kd8 {34s} Bb8 {1s} 75. Ke7 {2s}
>Ba7 {0s} 76. Kf6 {2s} Bb8 {0s} 77. Ke5 {1s} Ba7 {0s}
>78. Kd4 {2s} Bb8 {1s} 79. Kc3 {1s} Ba7 {0s} 80. Kb4 {3s}
>Bb8 {2s} 81. Ka3 {3s} Ba7 {1s} 82. Ka4 {1s} Bb8 {0s}
>83. Kb4 {1s} Ba7 {0s} 84. Kc3 {2s} Bb8 {0s} 85. Kd4 {2s}
>Ba7 {2s} 86. Ke5 {2s} Bb8 {0s} 87. Kf6 {1s} Ba7 {0s}
>88. Ke7 {1s} Bb8 {0s} 89. Kd8 {1s} Ba7 {0s} 90. Kc8 {3s} g4
>{3s} 91. Kd8 {40s} Bb8 {0s} 92. Ke7 {1s} Ba7 {0s} 93. Kf6
>{2s} Bb8 {1s} 94. Ke5 {1s} Ba7 {1s} 95. Kd4 {3s} Bb8 {2s}
>96. Kc3 {1s} Ba7 {1s} 97. Kb4 {1s} Bb8 {0s} 98. Ka3 {1s}
>Ba7 {1s} 99. Ka4 {1s} Bb8 {0s} 100. Kb4 {1s} Ba7 {0s}
>101. Kc3 {1s} Bb8 {1s} 102. Kd4 {1s} Ba7 {0s} 103. Ke5 {1s}
>Bb8 {1s} 104. Kf6 {1s} Ba7 {2s} 105. Ke7 {1s} Bb8 {0s}
>106. Kd8 {1s} Ba7 {0s} (106... g3 {1:48m}) 107. Kc8 {2s} g5
>{36s} (107... g3 {216:34m} 108. Nxg3+ {1:26m} Kg1 {3s}
>109. Ne2+ {1s} Kh1 {4s} 110. Kd8 {9s} Bb8 {2s} 111. Ke7
>{1s} Ba7 {0s} 112. Kf6 {2s} Bb8 {0s} 113. Ke5 {1s} Ba7 {0s}
>114. Kd4 {1s} Bb8 {1s} 115. Kc3 {3s} Ba7 {0s} 116. Kb4 {1s}
>Bb8 {1s} 117. Ka3 {1s} Ba7 {0s} 118. Ka4 {1s} Bb8 {0s}
>119. Kb4 {2s} Ba7 {1s} 120. Kc3 {4s} Bb8 {4s} 121. Kd4 {1s}
>Ba7 {0s} 122. Ke5 {1s} Bb8 {0s} 123. Kf6 {1s} Ba7 {0s}
>124. Ke7 {1s} Bb8 {0s} 125. Kd8 {1s} Ba7 {0s} 126. Kc8 {1s}
>g5 {4s}) (107... Bb8 {16s} 108. Kxb8 {6s} g5 {3s} 109. Kc8
>{21s} g3 {4s} 110. Nxg3+ {2s} Kg1 {4s} 111. Ne2+ {1s} Kh1
>{2s} 112. Kd8 {10s} g4 {3s}) 108. Kd8 {4s} Bb8 {0s}
>109. Ke7 {1s} Ba7 {0s} 110. Kf6 {2s} Bb8 {0s} 111. Ke5 {1s}
>Ba7 {0s} 112. Kd4 {2s} Bb8 {0s} 113. Kc3 {1s} Ba7 {0s}
>114. Kb4 {2s} Bb8 {0s} 115. Ka3 {1s} Ba7 {0s} 116. Ka4 {1s}
>Bb8 {0s} 117. Kb4 {1s} Ba7 {0s} 118. Kc3 {2s} Bb8 {1s}
>119. Kd4 {3s} Ba7 {1s} 120. Ke5 {1s} Bb8 {1s} 121. Kf6 {1s}
>Ba7 {1s} 122. Ke7 {1s} Bb8 {0s} 123. Kd8 {1s} Ba7 {1s}
>124. Kc8 {2s} g3 {3s} (124... Bb8 {46s} 125. Kxb8 {4s} g3
>{12s}) 125. Nxg3+ {17s} Kg1 {8s} 126. Ne2+ {3s} Kh1 {0s}
>127. Kd8 {22s} Bb8 {3s} 128. Ke7 {1s} Ba7 {0s} 129. Kf6
>{2s} Bb8 {0s} 130. Ke5 {1s} Ba7 {0s} 131. Kd4 {1s} Bb8 {1s}
>132. Kc3 {4s} Ba7 {8s} 133. Kb4 {1s} Bb8 {0s} 134. Ka3 {1s}
>Ba7 {1s} 135. Ka4 {1s} Bb8 {0s} 136. Kb4 {1s} Ba7 {0s}
>137. Kc3 {1s} Bb8 {0s} 138. Kd4 {1s} Ba7 {0s} 139. Ke5 {1s}
>Bb8 {0s} 140. Kf6 {2s} Ba7 {0s} 141. Ke7 {1s} Bb8 {0s}
>142. Kd8 {1s} Ba7 {0s} 143. Kc8 {3s} g4 {3s} 144. Kd8 {26s}
>Bb8 {0s} 145. Ke7 {1s} Ba7 {0s} 146. Kf6 {1s} Bb8 {0s}
>147. Ke5 {1s} Ba7 {0s} 148. Kd4 {1s} Bb8 {0s} 149. Kc3 {1s}
>Ba7 {0s} 150. Kb4 {1s} Bb8 {0s} 151. Ka3 {2s} Ba7 {0s}
>152. Ka4 {1s} Bb8 {0s} 153. Kb4 {1s} Ba7 {0s} 154. Kc3 {7s}
>Bb8 {0s} 155. Kd4 {1s} Ba7 {0s} 156. Ke5 {1s} Bb8 {0s}
>157. Kf6 {2s} Ba7 {0s} 158. Ke7 {3s} Bb8 {0s} 159. Kd8 {2s}
>Ba7 {0s} 160. Kc8 {1s} g3 {17s} 161. Nxg3+ {2s} Kg1 {2s}
>162. Ne2+ {2s} Kh1 {0s} 163. Kd8 {31s} Bb8 {0s} 164. Ke7
>{1s} Ba7 {0s} 165. Kf6 {1s} Bb8 {0s} 166. Ke5 {1s} Ba7 {1s}
>167. Kd4 {2s} Bb8 {1s} 168. Kc3 {1s} Ba7 {0s} 169. Kb4 {2s}
>Bb8 {1s} 170. Ka3 {1s} Ba7 {0s} 171. Ka4 {1s} Bb8 {0s}
>172. Kb4 {1s} Ba7 {0s} 173. Kc3 {1s} Bb8 {1s} 174. Kd4 {2s}
>Ba7 {0s} 175. Ke5 {1s} Bb8 {1s} 176. Kf6 {2s} Ba7 {0s}
>177. Ke7 {1s} Bb8 {0s} 178. Kd8 {1s} Ba7 {0s} 179. Kc8 {5s}
>Bb8 {2s} 180. Kxb8 {2s} Bf3 {5s} 181. Rxf1+ {6s} Ng1 {6s}
>182. Rxg1# {3s} *
>
>I did not find the solution myself (neither could my engine). The solution
>(shown as the main line in the above PGN) was given by a poster to the German
>CSS forum. Because the search engine of the forum doesn't seem to work right
>now, I can unfortunately not cite his name.
>
>Regards,
>Dieter
I would expect Fritz 7 to find the mate in 8 here quickly, but it doesn't:
[d] n7/b1p5/1pP5/1P6/3K4/1p5n/1P2N1br/3NRn1k w - - 0 175
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