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Subject: Re: try this one....

Author: John Merlino

Date: 15:38:59 04/16/05

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On April 16, 2005 at 18:16:22, F. Huber wrote:

>On April 16, 2005 at 17:28:27, John Merlino wrote:
>
>>On April 16, 2005 at 17:15:21, F. Huber wrote:
>>
>>>On April 16, 2005 at 16:24:31, John Merlino wrote:
>>>
>>>>Just for fun, I made a few tiny adjustments to the position, and came up with
>>>>this:
>>>>
>>>>[D]8/8/pp1p4/6p1/2ppK1Pk/3P3P/5PP1/8 w - - 0 1
>>>>
>>>>After playing around with several lines, I'm guessing that this is a Mate for
>>>>White in no less than 20 moves. The King can't find it easily unless I push all
>>>>the way past White's 8th move, and then it says Mate in 14.
>>>>
>>>>White has to spend a lot more time in this position ensuring that he wins the
>>>>pawn race AND avoids stalemate.
>>>>
>>>>What does your awesome machine say? How about ChestUCI, Franz?
>>>
>>>"awesome"? My old Celeron/400? LOL!
>>>
>>>Well, I´ve tried it now (#22) with almost the same parameters as for the
>>>original #13, but had no luck yet. :-(
>>>
>>>This seems to be a lot harder, and maybe the restriction K=1 (i.e. black king
>>>can´t move at all) won´t hold any longer for _this_ position.
>>
>>You're correct, it will no longer hold. To avoid stalemate, White will have to
>>play g3+, allowing Kxh3 and Kxg4. Eventually, there will only be 5-6 men on the
>>board, so tablebases might help.
>
>Stalemate??? Do you want to say that in your solution mate has to capture
>almost all black pawns, even the ones an a/b-line?
>Then your way of solution must really be completely different than the one
>for the original #13, and I´ve absolutely no idea how it might look like.
>OTOH if the black king captures h3/g4-pawns, how should he be mated then -
>at least in ´only´ 22 moves?
>
>Would be interesting to see your solution ...
>
>Franz.

Indeed, by my playing around, it appears that all Black pawns except for the
g-pawn will definitely be captured. White's d-pawn will queen, and White's h3
and g4 pawns will be captured.

Here's what I believe to be best play:

[Event ""]
[Site ""]
[Date "2005.4.16"]
[Round ""]
[White "Merlin"]
[Black "Merlin"]
[TimeControl "-"]
[Result "*"]
[Setup "1"]
[FEN "8/8/pp1p4/6p1/2ppK1Pk/3P3P/5PP1/8 w - - 0 1"]

1.dxc4 a5 2.Kxd4 a4 3.Kc3 d5 4.cxd5 b5 5.d6 b4+ 6.Kxb4 a3 7.g3+ Kxh3
8.Kxa3 Kxg4 {and now White has a Mate in at most 12 moves with 9.d7, resulting
in a total mate sequence of at most 20 moves -- slightly better than my initial
estimate}

The other main option for White is:

6.Kb2 a3+ 7.Kb3 a2 8.Kxa2 b3+ 9.Kb1 b2 {and now 10.f3, 10.f4 or 10.g3+ are
required, and all lead to slower mates than the line above -- The King reports
that 10.f3 is a Mate in 14, for a total length of at most 23 moves}

jm



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