Author: Heiner Marxen
Date: 03:44:37 07/18/01
Go up one level in this thread
On July 17, 2001 at 22:09:08, leonid wrote: >On July 17, 2001 at 19:27:49, Heiner Marxen wrote: > >>On July 17, 2001 at 08:33:49, leonid wrote: >> >>>Hello! >>> >>>This position you can try with every program. Its number of moves is only 89. >>> >>>[D]k1qnr3/1qq5/qn2Q3/qN1QqQ1K/qN2QqQ1/RbQQqQ2/1RrbQ3/2BB4 w - - >>> >>>Please indicate your result. >>> >>>Thanks, >>>Leonid. >> >>Hi Leonid! > >Hi, Heiner! > >>This one is not as easy to solve for Chest, as usual. After 2.6 hours on a >>K7/600 with 350 MB hash it just found "no mate in 11". The effective >>branching factor has climbed from below 4 to above 10, so the next depth >>most probably will need more than a day :-( Hence I stop here. > >You are already there. Since you found mate in 11, it is mate in 12. My >selective found mate in 12. Fine! From the increasing EBF I suspected already to be near the mate (increased EBF does often occur in last depth with mate, and sometimes one depth before it). >Was able to reach only 10 moves deep by brute force. It took already 11 hours >and 17 min. I must for sure one day install my hash and see the difference. I >hope in few months from now to have my Linux computer and start writing once >again. For now I do almost nothing useful. See estimated factor reached by hash in Chest below as "speed". >My branching factor, as it happened very often, have the same tendency as your. >It was 5, between 4 and 5 moves and ended by 9.2, between 9 and 10 moves. The exact data to compare: depth time EBF[T] EBF[N] speed # 1 0.00s 0kN 0.87 1- 0 # 2 0.00s 0kN 1.00 1- 0 # 3 0.02s 1kN [ 8.43] 0.94 90- 0 # 4 0.09s [ 4.50] 4kN [ 5.51] 1.06 521- 0 # 5 0.37s [ 4.11] 16kN [ 3.82] 1.36 2000- 0 # 6 1.27s [ 3.43] 55kN [ 3.35] 1.62 6781- 0 # 7 4.84s [ 3.81] 213kN [ 3.90] 2.20 24475- 0 # 8 17.89s [ 3.70] 896kN [ 4.20] 3.05 84227- 0 # 9 111.61s [ 6.24] 6190kN [ 6.91] 3.23 519135- 0 # 10 870.30s [ 7.80] 47882kN [ 7.74] 3.46 4210571- 9399 # 11 9223.60s [ 10.60] 502283kN [ 10.49] 3.40 45603940- 36856039 The effect of the hash table is estimated to speed up by a factor of slightly above 3. That is not dramatic, but quite a difference. Since the estimate sometimes is quite inaccurate, I have run it to depth 8 with hash completely disabled, and found: # 3 0.01s 1kN [ 8.43] 1.00 0- 0 # 4 0.10s [ 10.00] 5kN [ 6.27] 1.00 0- 0 # 5 0.53s [ 5.30] 27kN [ 5.50] 1.00 0- 0 # 6 2.74s [ 5.17] 134kN [ 5.01] 1.00 0- 0 # 7 14.30s [ 5.22] 700kN [ 5.22] 1.00 0- 0 # 8 68.14s [ 4.77] 3405kN [ 4.86] 1.00 0- 0 14.30 / 4.84 = 2.954 > 2.20 68.14 / 17.89 = 3.808 > 3.05 The real speed up appears to be even a bit larger than estimated. Cheers, Heiner
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