mate in 4

Several things wrong with this puzzle.

1. Nf3, why bring the pieces back? I see that the reasoning behind this is to gain back the tempo with the bishop, but black has better defenses.

2. I would not say Na6 is a good move for black, white's centered knight is pretty strong and is probably wise to exchange it for one of black's weaker pieces.

3. Qc8? This sets up a fork for white, this isn't a good move for black. Maybe black should've played f6 after Nf3?

4. After Ne7+, what if black played Kg7?

1. You have the answer yourself but black was unable to move the defences with whites threats

2.Na6 was to free the queen because the queen was useless in the backfield

3. if the queen was to go all the way awy from the rook closer to the queen than it would not be able to help the king, and if it moved right next to the rook closer to the king than it would also set up a fork

4. thst move for the king would let the queen attack the pawn supported by the knight that would lead to mate so it ends up being forced

I hope that answered all your questions, but do you like the puzzle

1... Nxd5 and black can hang on. Black is already down a bishop and a pawn, but there is no mate.

I agree that 1. Nf4 seems odd. Rybka recommends 1. f4, but there are probably other good moves for white here.

there are many ways to avoid mate but anyway nice puzzle.

Also what if black moved f6 after 2.Bg5? after that white may get a rook and a pawn exchanged for a knight and a bishop?

Na6 is not a good move better was to take the knight from the center.