Puzzle of the week #24

Level: 
3-Bishop
Chess Diagram: 

---n---k
----r---
--------
pr--P-RP
---pNP--
p--P----
------R-
---K----

Link: http://www.suttlesbook.com/
Buy "Chess on the edge" regardless of your level (if any)! It will offer you countless moments of intellectual pleasure and maybe it will influence your play as well...
The next game played by Duncan we are going to stop at is the same Suttles - Hug, Nice Olympiad 1974 (part of the book; used with permission) we looked at with puzzle #22. This time we go all the way to the end of the game where after 39.Rhg2 ... we reached the position (see diagram). White's strategy was successful in the center and King side. Black's only hope rests with the double a-pawns, but he might have bigger fish to fry first!... Questions:
a) What is White threatening with his last move? (3 points)
b) How does Black saves himself from this immediate threat (see first question)? (3 points)
c) Continue the line found in response to "b" until White clearly wins the game (4 points)
Total available points for this puzzle is 10. The answers will be published next week together with puzzle #25.

Puzzle #23 solution:
Looking at the position we can see the following important elements:
a) Same colour Bishop endgames have a high percentage chance to end up as a win for one side or the other; the reason for it is Bishops can battle/ block each other
b) White's hopes rest with the pawn majority on the King side where he can create a passed pawn
c) Black could also create a passed pawn on the Queen side
d) Both Bishops could interfere with the passed pawns and this should be considered when calculating all moves
e) In the end we have to make sure which passed pawn will Queen faster.
The game continued with: 44.g5 fxg5 45.fxg5 Kxd1 46.gxh6! ... (46.g6? Be6) 46... Ba4 47.Kf5 Bc2+ 48.Kf6 Kc1 49.Kg7 Kb2 (the game ended here) 50.h7 Bxh7 51.Kxh7 Kxa3 and after a simple calculation White needs 4 moves to Queen, while Black needs 5; also when White Queens, it controls the a1-square. GM Suba proved once again the exact precision of his analysis! It is interesting to note that even the simpler 44.Bf3 ... causes almost unsolvable problems for Black, as Joanne and I analysed together at the club this past Wednesday.

Correct solutions:
Matthew, Algerd, Joanne - 10 points
Karl, Jeremy, John D - 7 points
Wilson, Nathaniel and Katerina - 5 points

TOP 10 STANDINGS
101.0 John D
94.0 Jeremy
89.0 Jacob
70.0 Matthew
59.0 Katerina
57.0 Joanne
54.5 Karl
52.0 Wilson
48.0 Algerd
30.0 Nathaniel ...
17 more solvers with less points

Comment: 

King in the corner