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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