Author: Martin Baumung
Date: 03:44:26 04/17/05
Go up one level in this thread
On April 16, 2005 at 18:38:59, John Merlino wrote:
>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
Hi John,
it looks like it's a mate in 19 - maybe even less.
After 1.dxc4 a5 ChestUCI finds a mate in 18 within a reasonable amount of time
using the parameters P=3 and X=8 (IIRC). It would take too long from the very
beginning though...
Martin
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