Wanted, the most difficult puzzles possible...

I am particularly looking for a puzzle that was supposedly only ever solved at a tournament by Mikhail Tal, none of his competitors were able. I remember it had the themes of underpromotion to knights and sacrifice to keep the initiative. However, I will gladly take submissions of the absolute hardest puzzles that you can find.

Thanks in advance....

http://www.chess.com/forum/view/more-puzzles/worlds-hardest-puzzle-ever

Find the mate in 253 moves...

Thanks for the puzzles guys. I really appreciate it.

it isn't possible.50 move draw

Not necessarily.  The move counter resets with each pawn move and with each capture.  Of course, it's possible (and probably likely) that during this 253 move sequence there WILL be 50 conscutive moves without a pawn move or capture.  But unless you know the sequence you can't say it isn't possible with 100% certainty.

That aside, Black's best move is Qh8.  White can then win in 253 beginning with Kg2.  Interestingly, Kg1 or Kg3 is a draw.

http://www.shredderchess.com/online-chess/online-databases/endgame-database.html

lol, nice link... it shows the mate in 253, which did surprise me tbh.

I'll bet there were a few who thought i was kidding...

what about mate in 262...

http://www.chess.com/forum/view/more-puzzles/i-will-gift-a-diamond-membership-to-first-person-to-win-this?page=1

do you know the 50 move rule?

that one has been posted several times, I'll see if i can find a link

In the meantime, Seleysky'd Nagic flute, Whiyr to play and win

http://www.chess.com/forum/view/more-puzzles/worlds-hardest-puzzle-ever

the tal puzzle

I am looking for the hardest one move puzzles. I am specifically looking for puzzles that don't require the opposing color to have to move first, as in the tactics trainer's pgn. Thanks.