Take a look at the following position, reached in the #40974 Tactics Problem on chess.com
[fen "4N1K1/5P2/6k1/8/6n1/8/N7/8 w - - 0 1"]
The engine gives +6.22 for white in this position. I already understand that any move other than f8=N+ draws. (For example, promoting to a queen allows perpetual Nh6+ and Nf7+ unless white gives up the queen which would also draw)
My question is: Is white really winning after promoting the pawn to a knight with check?
How does one proceed to checkmate in this position, with three knights against a knight? And worse, in less than 50 moves? (otherwise it's a draw, of course)
I know that three knights versus lone king is possible (although quite hard!), but it seems to me that three knights versus knight is extremely unlikely to be winning upon perfect play...