Puzzle of the week #76

Chess Diagram: 

[Event "Puzzle #76"][Date "2009.07.03"][Result "1-0"][SetUp "1"][FEN "3k4/7R/3K4/3P4/8/8/8/2r5 b - - 0 1"]

Wikipedia presents him like this:
"Emanuel Lasker (December 24, 1868 - January 11, 1941) was a German chess player, mathematician, and philosopher who was World Chess Champion for 27 years. In his prime Lasker was one of the most dominant champions, and he is still generally regarded as one of the strongest players ever."
No other chess player has ever been able to hold the title for so long, so his chess teachings while difficult to understand must be studied in order to become a better player. The above position should ring a bell to those who attended last night's lesson so without any further ado here are your tasks:
a) Black to move; White still wins
b) Explain your solution

If anyone needs a copy of last night's lesson, please feel free to ask for it. Total available points for this puzzle is 20. The answers will be published next week together with puzzle #77.

Puzzle #75 solution:
An easier puzzle this time with the focus on being prepared for any response the opponent might throw at you. More than half did it, so signs are positive. You must make sure you get into the habit of looking at all possible moves the opponent can make, as well as plan for them.
Andy Q:
a) See solution:
b) Our newest club champion Andy Y wrote:
White's strategy is based on gaining tempi. Inserting a few checks while furthering his plan, White ensures a draw. Such is the advantage of possessing a piece in the endgame.
I would add only this: when stopping the pawn is not possible, White ensures the upcoming Black Queen is left alone, as Black's King and pawn are blocked in the corner. No progress can be made.

[Event "Puzzle #75"][Date "2009.06.26"][Result "1/2-1/2"][SetUp "1"][FEN "2N3k1/6p1/8/6P1/8/K3p3/8/8 w - - 0 1"]1.Ne7+ Kh7 (1...Kh8 2.Ng6+ Kh7 3.Nf4 {Draw}) (1...Kf7 2.Nc6 Kg6 (2...e2 3.Ne5+ Ke6 4.Nd3 {Draw}) 3.Nd4 {Draw}) (1...Kf8 2.Ng6+ Kf7 3.Nf4 {Draw}) 2.g6+ Kh8 (2...Kh6 3.Nf5+ Kxg6 4.Nxe3 {Draw}) 3.Kb4 e2 4.Kc5 e1=Q 5.Kd6 {Black cannot win}

Correct solutions:
Joshua, Katerina, Andy Y - 20 points
James, Andy Q - 18 points
Marcus, Alex, Karl - 12 points
Wilson - 6 points

We have finished another batch of puzzles during this semester and have our top 3 winners. I will continue to post puzzles in the following weeks for the whole summer. Let's see how many (hopefully a lot) will continue to solve them.

John - 499 points
Joshua - 471 points
Andy Qian - 444 points

Each won $20 cash for their efforts. Congratulations!


Basic endgame