Author: Heiner Marxen
Date: 15:19:17 07/18/01
Go up one level in this thread
On July 18, 2001 at 14:07:00, leonid wrote: >On July 18, 2001 at 06:44:37, Heiner Marxen wrote: > >>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. > >This is very useful to know! I looked into Rebel to have some idea about this >position and had impression that advantage grows with the depth. For instance, >on Rebel 10 with and without 20M of hash. > >4 moves - 2 min 46 sec. With hash - 1 min 29 sec. > >5 moves - Went more that 3 hours and half and disconnected. Had no more >patience. With hash only 54 min. > >Hash for 5 moves gave more advantage that for 4 moves. > > >> >>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 > > >Here my program had for sure worst branching factor. > >4 moves - 0.32 sec > 5 - branching factor >5 moves - 1.64 sec > 5.4 >6 moves - 8.9sec > 7.22 >7 moves - 64 sec > 7.19 >8 moves - 7 min 40 sec > 9.58 >9 moves - 1h 13m 27sec > 9.2 >10 moves - 11h 17m 8sec > >Heiner, and do you have your branching factor for previous position without >hash? If you could, send it to me, or indicate here. It is for sake of seeing if >my branching factor is permenantly worst for brute force, or it is something >that depend on given position. It could be that my code could be improved much >more that I initially expected. For now my guess is between 3 and 5 time >counting 5 moves brute force search. > >Previous position was mate in 8 moves. For "maybe", will indicate my time for >brute force. > >4 moves - 0.49sec > 8.77 >5 moves - 4.34 sec > 9.38 >6 moves - 40.7 sec > 9.35 >7 moves - 6 min 20 sec > >8 moves, first mate found in 87 sec. Well, I can just recompute with hash disabled... First, with 30MB hash: # Posted by leonid (Profile) on July 15, 2001 at 13:26:03: # Subject: One easy mate to solve. # http://www.icdchess.com/forums/1/message.shtml?179860 W: Ke1 Qb3 Qc4 Qd5 Qd6 Qf5 Qf6 Qg4 Qh3 Rd2 Rf2 Be2 Nb7 Nh7 (14) B: Ke8 Qb2 Qc8 Qc3 Qd7 Qe7 Qf7 Qg8 Qg3 Qh2 Rb8 Rh8 Be6 Be5 Nd4 Nf4 (16) FEN: [D]1rq1k1qr/1N1qqq1N/3QbQ2/3QbQ2/2Qn1nQ1/1Qq3qQ/1q1RBR1q/4K3 w - - analysing (mate in 8 moves): # 1 -0.00s 0kN 0.87 1- 0 # 2 -0.00s 0kN 1.00 1- 0 # 3 0.02s 1kN [ 10.89] 0.94 92- 0 # 4 0.16s [ 8.00] 10kN [ 9.22] 1.06 738- 0 # 5 1.37s [ 8.56] 78kN [ 7.97] 1.24 5936- 0 # 6 8.91s [ 6.50] 530kN [ 6.82] 1.45 45652- 0 # 7 63.78s [ 7.16] 3612kN [ 6.82] 3.81 340540- 376 # 8 336.93s [ 5.28] 17188kN [ 4.76] 3.04 1946475- 1160071 Without hash: # 3 0.01s 1kN [ 10.89] 1.00 0- 0 # 4 0.14s [ 14.00] 12kN [ 11.15] 1.00 0- 0 # 5 1.79s [ 12.79] 142kN [ 12.06] 1.00 0- 0 # 6 20.44s [ 11.42] 1618kN [ 11.39] 1.00 0- 0 # 7 246.96s [ 12.08] 18481kN [ 11.43] 1.00 0- 0 # 8 1887.10s [ 7.64] 132138kN [ 7.15] 1.00 0- 0 246.96 / 63.78 = 3.872 > 3.81 1887.10 / 336.93 = 5.600 > 3.04 Interestingly, without hash for Chest _your_ EBF[T] is significantly better, here. Uhh, where did I go wrong? :-) Cheers, Heiner
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.