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Subject: Re: Mate in 9 positions (correction)

Author: Paul

Date: 12:02:31 05/08/01

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On May 08, 2001 at 07:31:58, leonid wrote:

>On May 07, 2001 at 19:42:35, Ignacio Santos Crespo wrote:
>
>>How much time does your program need to find a forced mate in these positions ?

Hi Ignacio,

A lot of time ;), these are great positions!

>>[D]6k1/1p3p2/p1p2P1p/8/P1P3P1/8/1PP3PK/4q3 b - -
>
>I tried to solve your first position but 6 moves took already 2 min and 45 sec.
>Disgracefully, I needed my computer to go farther. Programs that use hash will
>do much better, like Heiner mate solver.
>
>Time of search by brute force (perfect search). Celeron 600Mhz. LLchess mate
>solver.
>
>4 moves - 0.44 sec
>5 moves - 9.39 sec
>6 moves - 2 min 45 sec
>
>Will try later, if it will be possible, to put my computer for search for night
>already for 9 moves. Maybe mate will come sooner that it is suggested after my
>branching factor. My selective search (one that find mate rapidly) here is
>useless.
>
>Thanks for your positions!
>Leonid.

I also tried them yesterday, but didn't have enough patience to wait for them to
finish, as I think nullmove doesn't compute in these cases. Today, for a change,
I tried the most "brute force" I can get with Pretz, and surprise, surprise,
just got a mate in 9 for the first one after several hours:

BM9 18 Kh7 g5 hxg5 g4 Qf2+ Kh1 Kg6 c5 Kxf6 b4 Ke5 a5 Ke4 c4 Kf3 b5 Qg2#

Don't know whether I'll try the second one, as brute force is not my forté ...
but at least you've got a response now, Ignacio!

Groetjes,
Paul

>>[D]1nk5/1pp2pp1/8/1P2PNq1/Q7/6Pr/P3PP2/3R2K1 w - -



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