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Subject: Re: Solution, correction

Author: Martin

Date: 04:26:29 02/19/00

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On February 18, 2000 at 17:51:41, John Merlino wrote:

>>
>>1 Rb5+ Nb6  (Ka7 is mate in 2)  2 Bxb6 Rh2+
>>3 Kg4! (not Kg3) Rxh1  4 Bg1+ Kc7  5 Rb1!
>>The bR is caught. Advancing the h pawn
>>only brings the wK closer to the rook.
>>5... Kd7  6 Re1!
>>Now the bK gets short of white squares.
>>6... Kc6  7 Rd1 Kb5  8 Rc1 Ka4  9 Rb1.
>>
>>>Did your program find all moves?
>>>
>>>Martin
>
>While I agree that most programs will not see the solution in a reasonable
>amount of time, I believe they WILL find it given ENOUGH time. Chessmaster, for
>instance, WILL see the solution (within a few seconds) if you plug in the first
>few moves for both sides.

Does it really "see" the solution? An advantage of 4-5 pawns (it's the material
advantage of just one piece) shows that it doesn't. The plus score should go
beyond +7.

From the above position, however, a typical chess
>program will need to calculate (in my estimation) about 12 or 13 plies before
>discovering the winning combination. This is quite a lot of positions to see,
>given all of the pieces still on the board.

Yes, I agree, if the task is to go deep enough, there are certainly many
positions to calculate. But to see that the rook gets caught requires 9 plies.
So it's also a question of "knowledge"...

>
>jm
>
>p.s. I'm letting CM6000 run on the position at this time. It took 19 minutes to
>get to a depth of 9/11 (and still prefers 1.Bd5, as it did from the outset), so
>it could be QUITE some time before it finds the win. I'll let you know the
>results if I have enough patience.... ;-)

(-: Fritz also prefers Bd5 for a long time; Hiarcs recommends Rb5+ immediately
but without seeing the real advantage (see above).

Martin



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