FREE - In Google Play
FREE - in Win Phone Store
eddysallin - But what happens after Nd6 Na7? It seems like white can't continue to pursue the black knight. It seems like a long and arduous effort for white at best.
It's not so easy at it seemed first. Black can also move the b-Pawn. If white runs stupidly with the d-Pawn, black wins (promotion to queen with check and mate in three). If black plays b5 in the first or second move (after Kf4), there are also lines with Nb6. But white can force the win in all lines.