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Subject: Re: Another monster endgame - kqnnkqn (282 moves)

Author: Tony Werten

Date: 23:23:02 01/15/06

Go up one level in this thread


On January 15, 2006 at 07:14:13, Uri Blass wrote:

>On January 15, 2006 at 05:30:18, Tony Werten wrote:
>
>>On January 14, 2006 at 14:25:38, Marc Bourzutschky wrote:
>>
>>>On January 14, 2006 at 13:15:20, Mark Rawlings wrote:
>>>
>>>>On January 14, 2006 at 08:59:29, Marc Bourzutschky wrote:
>>>>
>>>>>kqnnkqn, while generally a draw, contains positions that require up to 282 moves
>>>>>to capture or mate.  This brings it very close to the current record holder
>>>>>krrnkrr which requires up to 290 moves.  kqnnkqb looks to be in third place now
>>>>>with 272 moves, but that database has not yet been verified.  kqnnkqn took about
>>>>>8.5 days to generate on a 3.8 GHZ Pentium machine, using Yakov Konoval's
>>>>>program.
>>>>>
>>>>>Note that play after the capture on move 282 will not be the same as would be
>>>>>obtained from a Nalimov database, because the latter maximizes distance to mate
>>>>>rather than distance to mate or capture.
>>>>
>>>>So, in other words, if the Nalimov database was computed for this, it may be a
>>>>mate in greater than 288, however there would be a capture in < 282, if I
>>>>understand correctly?
>>>
>>>All we know is that for a Nalimov database the mate would be in >= 282 moves.
>>>If the mate is in > 282 moves, than there must be a capture in <= 282 moves.
>>
>>I think you are wrong here.
>>
>>There are basicly 2 possibilities. The Nalimov egtb says <=282 or it says <282
>>:)
>>
>>Suppose the Nalimov line is correct (wrt 50 move counter). DTC might try to
>>capture all oponent pieces missing a shorter mate and needing more moves. It
>>will never need less moves. result: Nalimov <=282
>
>You miss the fact that based on DTC the line is 288 moves.
>The first capture is after 282 moves and this is the reason for the title.

I see. I overlooked the 288 and 282 difference.

Thanks,

Tony

>
>We do not know if the distance to mate is smaller or bigger than 288 moves
>because it is possible that without capture white can mate earlier(less than 288
>moves) and it is possible that by allowing a capture at move 260 black can lose
>later and be mated only in 290 moves.
>
>Uri



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