Author: Heiner Marxen
Date: 08:17:37 05/06/01
Go up one level in this thread
On May 06, 2001 at 06:39:02, leonid wrote: >On May 05, 2001 at 20:12:25, Heiner Marxen wrote: > >>On May 05, 2001 at 18:41:22, Paul wrote: >> >>>On May 05, 2001 at 17:47:38, Heiner Marxen wrote: >>> >>>>>>[D]3k4/b2r4/4q3/2q3n1/1nnNbqnN/1Q1qpNBQ/r1BPQPp1/qNQRKR1N b - - >>>>> >>>>>And this one took a while longer as usual with your creations :), mate in 8: >>>>> >>>>>01:22 BM8 07 exf2+ Nxf2 Qaxd4 Bxd3 Qxf2+ Bxf2 Qxf2+ Rxf2 Bxf2+ Qxf2 Bxd3+ Qe3 >>>>>g1=Q+ Nxg1 Qf2# >>>>> >>>>>Greetings, >>>>>Paul >>Hey, wait a second... while I write this answer, Chest comes up with a mate >>in 7! Sorry Paul, that is unexpected for me, too. Here we go: >>There are two key moves: exf2+ and Qaxd4 (the first two moves of your PV). >>My PVs (with some more variants) look like: > > >Thanks, Heiner! Very appreciated. I will try to solve this position later in 7. >Was not even sure if mine will have enough time to do this. Had very bad >branching factor for this one. Just to give you an idea: > >3 moves - 0.1 sec > branching factor - 66 >4 moves - 6.59 sec > - 38.6 >5 moves - 4 min 14 sec > >And this is where and why I stopped searching by brute froce the last time. > >Cheers, >Leonid. I don't know, why your effective branching factor is so much worse than mine, but here is my data for comparison: depth seconds speed # 3 0.05 0.98 110- 0 # 4 1.03 1.05 2162- 0 # 5 21.94 1.21 52287- 0 # 6 470.91 1.51 1467975- 11 # 7 8123.31 1.68 27139229- 18391335 As you can see from the "speed" (estimated hash table speed up) the hash table is not the main difference this time. More data for you to compare: the executed moves per depth to go: black white mvx 7: 108 133 [108.000 1.231] mvskip lvskip mvx 6: 2191 2615 [ 16.474 1.194] mvx 5: 61015 60627 [ 23.333 0.994] 1101 mvx 4: 1629538 1488284 [ 26.878 0.913] 37238 10 mvx 3: 30390508 27233557 [ 20.420 0.896] mvx 2: 409525400 71961657 [ 15.038 0.176] mvx 1: 84923563 0 [ 1.180 ] The defender (white) manages to nearly always check the defender. Whenever I start to generate legal moves I look, how often the side to move is in check: mg 352166449 W; inchk: 240798413 none 109366513 one 2001523 double mg 27752191 B; inchk: 4158972 none 23475046 one 118173 double Of 27.7 million times generated black moves, black is only 4.1 million times not in check. I know, that you try check moves first. When there are multiple check moves, do you sort them? There are good checks and bad checks: the goal is to have more check moves the next time, also. Just an idea... Cheers, Heiner
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