Antonio Torrecillas wrote:
I examined 37 ... b6?! I can't see Black drawing unless White makes a
mistake. It would be close... one wrong move, and Black has a draw.

After 37...b6 38.c6 is also good and do not require special precision,
simply following Ke4, f4 and a later g5 white wins.

That makes it simple. Black's King is tied to blocking the connected
passed pawn while White's King gobbles up everything on the
kingside--minimal drawing chances.