Opposite Coloured Bishops – part 14

I found this example in one of the books by Mark Dvoretsky, in the chapter written by Gregory Kaidanov. The game shows the power of making far reaching long term strategic plans, in positions where your opponent is completely tied up. In endgames with opposite coloured bishops, fortresses are very common; to break through such defensive schemes you have to think in terms of plans, rather than follow “move-by-move, let’s see what happens next” style.

Psakhis Lev (ISR) (2580) - Hebden Mark (ENG) (2435)
Ch World (team) (under 26) Chicago (USA), 1983

White to move – find the winning plan.
Black pieces are completely tied up to the defence of 'f7'. And yet it takes a very original plan from Lev Psakhis to win this game.
43.Kf1 Ba7 44.Ke2 Bb6 45.Kd3 Ba7 46.Kc4 Qc7+ 47.Kb3 Qe7 48.g4 Bb6 49.Kc4 Ba7 50.Kb5 Diagram

What is the king doing? 50...Qe8+ 51.Bc6 Qd8 52.Kc4 Qe7 53.Qd7! This is the point! After the exchange of queens the White king will support the advance of the 'b' pawn. 53...Qe6+ 54.Qxe6 fxe6 55.Rxf8 Kxf8 56.Kb5 Diagram

56...Ke7 57.Ka6 Bxf2 58.c4 Kd8 59.Kb7 Be1 60.b5 Bf2 61.b6 Bd4 62.Ba4 d5 63.cxd5 exd5 64.exd5 e4 65.Kc6 Kc8 66.d6 e3 67.Bb5 Bf6 68.Ba6+ Kb8 69.Kd7 1-0