fredthebear: <waustad> Your endgame approach seems logical (...the Black king has headed to stop pawn promotion on the h8 square leaving the White knight to stop the four Black pawns, an easy task by waiting on Nc2). As you suggest, the White knight does not capture all the Black pawns, or stalemate would occur (Kg6 & h7 vs Kh8). One Black c-pawn must be allowed to move and promote while the White knight dashes for f7. It will be important to place the White king on g6. If Kh6, Black could promote with check c2-c1=Q+.
The White knight must carefully plan his path to Nf7# to get there in a minimum of moves. It seems the best scenario is Nxa3, Nxc4, Nd6, Nf7# (if Kh8 has already been forced upon Black by h7).
HOWEVER, by my calculations, the White knight cannot get to f7 in time before the new Black queen will be able to check and fork her way to victory!
White: Kg6, Nd6, h7 (3).
Black*: Kh8, Qc1 (2).
White's last move was Nd6. The Black queen will now play Qc2+ and Qxh7. Therefore, this is the WRONG plan for White -- he'll lose!
As I see it, in order for White to win the ending (and avoid stalemate), the White king will have to capture the Black pawns while the White knight protects the passed h-pawn from behind. The White king is far too far away to stop Black pawn promotions. A few moves by the a-pawn forces Nc2 to cover the a-file. Therefore, it seems this ending is a draw with best play by White. White cannot win the ending against proper defense, and could very well lose if it's mistimed.
This ending comes down to a matter of one tempo. It's possible my calculations are one tempo off. With so many units still on the board, one tempo can easily be misplayed, so it should be played out to completion. Black definitely should NOT have resigned after move 43. If White plays for the win by allowing a c-pawn promotion, Black will win (although White can halt his "winning" plan and use zugzwang to capture ALL the Black pawns and easily draw).
I have considered other locations for the White knight in an attempt to vary play, but they don't seem useful. Black should not have resigned; make White prove it!