Originally posted by arterioes
Could anyone post a possible continuation as to why black is losing here?
It looks like black is in zugzwang. He has 11 legal moves, and all of them look bad.
(1) 56. ... Bxf3 and black is sunk after the d-pawn queens with 57. d7 Bxf4 (nothing better) 58. d8=Q+.
(2) 56. ... b6 and 56. ... b5 both lead to the creation of another passed pawn on the b-file, and the bishop controls neither the b8 nor the d8 queening squares.
(3) 56. ... Kf8 and 56. ... Kf7 both give up the h-pawn, creating yet another passed pawn with the h8 queening square again out of reach of black's bishop.
(4) I believe all other bishop moves (Ba4, Bb5, Bd7, Be8, Bd5, Be4) lose to either 57. f4 or 57. d7, depending on whether the bishop ends up on the a4-e8 or a8-h1 diagonal. Possibilities include an exchange of pawns on f5 leading to a passef f-pawn (again the queening square is dark and therefore in white's grasp) or connected passed pawn on the d- and e-files. Either way, black is up a creek without a paddle.