Black has no moves to strengthen his position, so White permits himself some prophylaxis – the king moves away from the knight check.

Black resigned.

Black threatens perpetual check, so White must seek a way to advance his pawn with tempo.

Promoting to a queen is no good, so we promote to a knight! The white forces are sufficient to cope with the lone black queen.

Both sides’ passed pawns are very far advanced, and each is a potential queen. Therefore, to gain a tempo, Black sacrifices a rook:

The armada of black pawns marches unstoppably to the promotion squares.

58.a7 d2 59.Rg1 c2 60.Rb8 c1=Q 61.a8=Q Qxg1+ 62.Kxg1 d1=Q+ 63.Kg2 Rc2+–+.

Careful! After 59...c2?, White manages to create threats against the black king: 60.Rf7+ Kh8 61.Rf6=. Black could also win with 59...d1=Q 60.Rxd1 c2–+.

White resigned, since after 61.Rxd1 c2, Black makes a queen with tempo. Incidentally, Black avoided a cunning trap: after 60...c2 61.R6g5, Black cannot avoid move repetition.

It is obvious that in the current pawn battle, White has the better chances. However, after an exchange of one pair of pawns on the queenside and the appearance there of the black knight, the win would be problematical. White’s solution is elegant and convincing: