Puzzle of the week #230

Submitted by Eugen on Tue, 06/04/2013 - 23:43

Endgame - King on the edge

Chess Diagram
[Event "Puzzle #230"][Date "2013.06.04"][Result "1/2-1/2"][SetUp "1"][FEN "8/8/5K2/7k/8/p7/1p6/1R6 w - - 0 1"]
This one looks like a joke you share with friends and starts like this: "2 pawns walk into a bar...". They don't really walk into a bar, but for sure are coming down the board with vengeance. The White Rook looks hopeless like a deer in the headlights. What should we do now, eh?... Your tasks:
a) White to move and draw
b) Can you find the correct idea to help White save half a point?

Total available points for this puzzle is 20. The answers will be published next week together with puzzle #231.

Puzzle #229 solution:
Lisitzin, #620. The best two answers follow below.
Leo's answer:
a) To prevent the pawn promotion, the first thing for Black to do is to keep the White King on the h8-pawn. So, the Black King must control the g7- and g8-squares. To do this, the next move for Black King is to move to one of the two: f7- or f8-squares. See solution
James answer:
b) White's goal is to control the f7-/ f8-square so Black can't go there and not check him because Black will just move away and White can only move the Knight. Also, the Knight can only jump on to an opposite coloured square so the King must copy and follow the colour the Knight jumps on: if the Knight moves on a dark square, it can only control light squares and since Black just followed the Knight into a dark square, it cannot be controlled because White must move the Knight away, so then Black will have the light square again. Therefore, it's a draw.
[Event "Puzzle #229"][Date "2013.05.28"][Result "1/2-1/2"][SetUp "1"][FEN "7K/4k2P/8/8/8/8/8/3N4 b - - 0 1"]1...Kf7 {Key is to move on a square of the same color as the one where the Knight sits} (1...Kf8? 2.Ne3 Kf7 3.Ng4 Kf8 4.Ne5 Ke7 5.Kg8 {White wins}) 2.Ne3 Kf8 3.Ng4 Kf7 4.Ne5+ Kf8 5.Ng6+ Kf7 6.Ne5+ Kf8

Correct solutions:
Leo, James - 20 points
Daniel - 10 points

James - 311 points
Daniel - 289 points
Leo - 236 points
Justin - 116 points
Jerry - 92 points
Derrick, Richard - 89 points
Aditya - 53 points
Alex - 7 points