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Subject: Re: Very slooow position - challange

Author: Heiner Marxen

Date: 11:47:32 05/16/99

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On May 14, 1999 at 23:41:38, William Kerr wrote:

>Here is a position I composed with the purpose of having each color piece
>attacking a piece of the opposite color. Intent was to have as many attacks
>and counter attacks as possible. Also added many pawn qweening possibilities
>just for good measure. Hope you never play into this position:
>
> 8/PPPPPpPk/3rq3/1b1r2b1/2BR1B2/3RQ3/pppppPpK/8 w
>
>Challange: Try to compose a position that has as many attacks and counter-
>attacks for each piece for each side as possible along with pawn promotions.
>You should end up with a very tough position that takes your chess program a
>long time just to grind through a few plys. Post your position for others to
>try.
>
>CM6K on a PII 300 takes a long time with the above nightmare position just to do
>a 4 ply search:
>0:00  1/2  13.33  g7g8Q+
>0:24  1/3  10.69  g7g8Q+
>6:04  1/4  8.49   g7g8Q+

OTOH, for a chess problem solver this is not that hard.  On this position
mine comes up after 144 secs with "no mate in 8 moves" on a not that fast
hardware, what I consider rather fast.

That is comparable to an 8-ply search without extensions and without
q-search.  I guess the missing q-search is the main reason for the
difference in depth.

If you are interested in computationally hard positions, you should have
a look at Valentin Albillos pages: http://www.multimania.com/albillo/cmain.htm

Thanks anyhow, for the "nightmare" position.



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