Similar to puzzle #249

finding forcing moves and also it brings the right piece to right position by sacrificing 2 pieces. excellent idea.

The mechanism is called Damiano's mate, and Pedro Damiano died in the 16th century, so little wonder it also appeared decades ago  

Like this? It's fourteen moves. And very ugly puzzle #7761

A timely reminder that it is the capture of the king that matters - whatever it cost !

In a formal way there are not restrictions to create a "chess puzzle" with an "impossible position" (and the position of puzzle #7761 is impossible, no questions about this fact). In a "chess problem" the position must be legal (but there is no important how the position can be reached), but a chess puzzle is not a chess problem.

In the section <<chess puzzles>> of gameknot site we can see:

The goal of all chess puzzles is to checkmate your virtual opponent no matter what moves they make (i.e. a forced mate), in the requested number of moves. Some chess puzzles are created from actual chess games played online, and some are purely composed chess problems, sometimes even with positions that cannot be reached in a real game of chess...

Moreover, it's obvious from the description of the puzzle #77671 (<<#7756 taken to the extreme, fixed from #7760>>) which was the intention of the puzzle.

Try be cool. "Stupid" is a non fair comment about a "joke" like this... If you did not like the joke, do not laugh, but does not harm the humorist (or the joke).

I can accept impossible positions when there is no other way to show an interesting theme, but that hardly seems necessary here. With a few minutes of fooling around, I've got it up to 17 moves in a position which should be possible, though I'd hate to check it for duplicate solutions:

Thanks. That "four-of-a-kind" restriction is no doubt for the best. Those older puzzles with impossible position filled with promoted pieces can be painful to look at, and the result rarely justifies the excessive force.

This one is almost slapstick.