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Mohamed10
12-03-2011, 02:20 PM
Longest checkmates : The Complete set
Interesting List!!
http://www.chess2u.com/t179-longest-checkmates-the-complete-set#8278

Capablanca-Fan
16-02-2013, 02:07 PM
The longest mate 7 pieces 524 moves: KQN v KRBN (http://www.youtube.com/watch?v=wxIaMcO2amE)

Here is one place where computer chess analysis is way beyond human capacity. Most of the moves make no sense to me, but apparently they inexorably lead towards a forced win (ignoring the 50 move rule by a factor of 10). I would also like to know what that vocal music is.

wxIaMcO2amE

Adamski
16-02-2013, 02:44 PM
I feel like saying that Black's 276th was wrong and led to the loss. I do like the music but have no idea what it is!

Desmond
16-02-2013, 03:05 PM
Chuck Norris had White

James Watson
28-03-2013, 02:54 PM
The nuisances of the game will never cease to amaze me.

oh and I doubt this is the longest mate, just the longest mate to be discovered to date. When/if stronger table bases are created longer mates may be discovered.

Rincewind
28-03-2013, 03:05 PM
oh and I doubt this is the longest mate, just the longest mate to be discovered to date. When/if stronger table bases are created longer mates may be discovered.

My understanding is that this (524 moves) is the longest possible forced checkmate with 7 pieces or less. There may be longer checkmate sequences found in the future but they will require 8 pieces or more.

James Watson
28-03-2013, 03:20 PM
My understanding is that this (524 moves) is the longest possible forced checkmate with 7 pieces or less. There may be longer checkmate sequences found in the future but they will require 8 pieces or more.

Right, I didn't notice the part about using seven pieces

Rincewind
28-03-2013, 03:30 PM
Right, I didn't notice the part about using seven pieces

I might be wrong as I assumed there were complete 7-man databases with a distance to mate metric for every position. Not sure if this is true.

James Watson
28-03-2013, 03:34 PM
I might be wrong as I assumed there were complete 7-man databases with a distance to mate metric for every position. Not sure if this is true.


No I'm pretty sure you're right, at the moment I think all 7 piece endings have been 'solved'

What I meant before was that as stronger table bases come out I.e all 8 piece endings solved, then longer mates will probably be found.

Rincewind
28-03-2013, 03:48 PM
No I'm pretty sure you're right, at the moment I think all 7 piece endings have been 'solved'

What I meant before was that as stronger table bases come out I.e all 8 piece endings solved, then longer mates will probably be found.

Then we agree. I would be surprised if longer mates did not arise from an exhaustive search of 8-man positions.

Jesper Norgaard
28-03-2013, 05:46 PM
Then we agree. I would be surprised if longer mates did not arise from an exhaustive search of 8-man positions.

I would be surprised. 524 moves is actually quite a lot. Getting so bad coordination problems but still winning, might not be easier to obtain with 8-man positions. I am willing to bet you "David Levy" style that they won't find one the next 10 years.

Rincewind
28-03-2013, 10:02 PM
I would be surprised. 524 moves is actually quite a lot. Getting so bad coordination problems but still winning, might not be easier to obtain with 8-man positions. I am willing to bet you "David Levy" style that they won't find one the next 10 years.

No because I don't know if they will have a distance to mate metric exhaustively completed for all 8-man endings in the next ten years. But I do think an exhaustive 8-man search (whenever that might be completed) will lead to a longer forced mate.

Eight-man is just such a big increase in terms of the number of unique positions that I would be surprised that any 7-man ending gives a longer DTM than all 8-man endings.

James Watson
08-04-2013, 05:41 PM
The thing is, couldnt you take any position thats winning say a piece and pawn up and claim that its mate in x number of moves? or would this not count because there would be many many variations that lead to the same result.

Rincewind
08-04-2013, 07:38 PM
The thing is, couldnt you take any position thats winning say a piece and pawn up and claim that its mate in x number of moves? or would this not count because there would be many many variations that lead to the same result.

You would have to know precisely the maximum number of moves that black is able to defend (forestall mate) given best play by both black and white. In most complicated positions this is simply not known as the number of variations is too great, or else the number is much less than 500.

Aaron Guthrie
08-04-2013, 08:15 PM
I would be surprised if longer mates did not arise from an exhaustive search of 8-man positions.Or 9 or 10. It is fairly trivial to get positions that are forced conversions to the 524 position. And here we go, an extra full move on the 524 position.
3q4/1r6/8/6n1/5k2/1b6/3Q3N/2K4Q b - - 0 1
But it might not be easy to get many moves extra, via this method. (New puzzle challenge!?)

And for the record; I claim longest known mate position in the world.

Rincewind
08-04-2013, 08:56 PM
Or 9 or 10. It is fairly trivial to get positions that are forced conversions to the 524 position.

Is that a forced conversion? It seems Black can also avoid check by moving the king to one of a number of squares, following which White could take the queen, the knight or make some other move.

Aaron Guthrie
08-04-2013, 08:59 PM
Is that a forced conversion? It seems Black can also avoid check by moving the king to one of a number of squares, following which White could take the queen, the knight or make some other move.I was presuming that Black has to make the best moves, and that allowing Qxd8 will allow mate in less than 524. If I've got this wrong somehow, the position after Qxd2+ is still one half move longer, and forced in the only-legal-move sense.

Rincewind
08-04-2013, 09:05 PM
I was presuming that Black has to make the best moves, and that allowing Qxd8 will allow mate in less than 524. If I've got this wrong somehow, the position after Qxd2+ is still one half move longer, and forced in the only-legal-move sense.

It might be involved to prove the suboptimality of K-somewhere through exhaustive search. After Qxd2 the only alternative is Kb1 which can probably be shown to be suboptimal fairly easily.

But I believe that by your reasoning you have practically proved my conjecture that more men will lead to longer sequences of forced mate - even if they are relatively trivial extensions of the seven-man result. For that I thank you. :)

Aaron Guthrie
08-04-2013, 09:13 PM
It might be involved to prove the suboptimality of K-somewhere through exhaustive search.With a computer it probably isn't, since one should be able to find a conversion to a won 7-piece endgame. (Or even to a 6-piece.)

After Qxd2 the only alternative is Kb1 which can probably be shown to be suboptimal fairly easily.Whoops, not quite legal-move-sense; at least there are multiple mate in 2's for black there.

moremover
11-05-2013, 11:04 PM
... the longest mate ever composed you can find here ( mate in 551 moves ) :

http://www.youtube.com/watch?v=JnLiwJ3qe_M

... and the history of the worldrecord from 1889 - 2013 you can find here :

http://www.youtube.com/watch?v=mwYQRteeHbE

kindly regards
from Germany:owned: