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Subject: Re: MAT IN 19 OR LESS Mate in 17 !!!

Author: F. Huber

Date: 07:11:49 03/09/05

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On March 09, 2005 at 07:07:26, James T. Walker wrote:

>On March 08, 2005 at 16:35:44, Olaf Jenkner wrote:
>
>> 1.Le4-d3 Be5-e4  2.Ld3-e4 Be6-e5  3.Le4-d3 Be5-e4  4.Ld3-e4 Se8-d6  5.Le4-d3
>>Sd6-e4  6.Ld3-e4 Sg8-f6
>> 7.Le4-d3 Sf6-e4  8.Ld3-e4 La6-b7  9.Le4-d3 Lb7-e4 10.Tb4-b5 Td8-d5 11.Tb5-d5
>>Dh6-d6 12.Sf7-d6 Kf4-g5
>>13.Sd2-e4 Kg5-h5 14.Se4-f6 Be7-f6 15.Ld3-e4 Ta8-g8 16.Le4-f3 Tg8-g4
>>17.Lf3-g4/Bh3-g4#
>>
>>OJe
>
>Hello Olaf,
>Since you claim it's a mate in 17 instead of 19 something is wrong somewhere!
>Chest says it's mate in 19 and the first deviation from Chest in your line is
>4....Nd6?   Since this leads to a mate in 17 how can it be considered optimal?
>Can you prove that Chest 4....e5 is not optimal?
>Jim

Hello Jim,

well, there´s nothing wrong anywhere! ;-)

_I_ am the ´problem´ (if you want to call it so), but not Chest.
Since this mate problem was posted here as #19, and I also found this position
already in my mate database (also as #19, but still ´unsolved´), I saw no reason
to believe in a shorter solution.
So I told ChestUCI: "look for a mate in 19"!
And since I used the automatic-mode, it´s quite clear that it actually found
only a mate in 19 - especially because the restriction parameter K for this
#19 is lower (K1) than for the #17 (K2), and so the #19 was found earlier!

I really don´t have the time (especially with my slow notebook) to always find
out, if any mate posted here would have a shorter solution than stated, but
of course _if_ I know of such a shorter solution, there´s absolutely no problem
for ChestUCI to find this too - look at the following output:

ChestUCI Ver.3.9:
CPU: Celeron 400MHz
FEN: r2rn1n1/4pN2/b3p2q/1p2pP2/pR1pBk1p/K4p1P/2PN1P2/2B5 w - -
Search for Special-Mate [C0/R-3/K2/P8/X39] in 17 ...  (Hash=64MB)
  17	07:59	   8.942.683	62.479	+M17	1.Bd3
Suche completed ...  (Time=477.79s)
Mate in 17 found !  (1 Solution in 07:57)
 17/17	08:07	  29.345.094	61.418	+M17	1.Bd3 e4 2.Bxe4 e5 3.Bd3 e4
4.Bxe4 Ngf6 5.Bd3 Ne4 6.Bxe4 Nd6 7.Bd3 Ne4 8.Bxe4 Bb7 9.Bd3 Be4 10.Rxb5 Rd5
11.Rxd5 Qd6+ 12.Nxd6 Kg5 13.N2xe4+ Kh5 14.Nf6+ exf6 15.Be4 Rg8 16.Bxf3+ Rg4
17.hxg4+

BTW, if you tell Gustav to look for a #19 (in automatic mode), he also finds
only a #19 (and needs 18 minutes for the complete solution).

Best regards,
Franz.




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