Puzzle of the week #180

Submitted by eugen on Sat, 01/14/2012 - 19:15

L-shape setup

Level
4-Rook
Chess Diagram
[Event "Puzzle #180"][Date "2012.01.14"][Result "1-0"][SetUp "1"][FEN "8/8/p7/8/K4k2/5P1P/8/8 w - - 0 1"]
In normal conditions an endgame with 2 pawns advantage is an easy win; still this does not mean we can play careless. A very much true chess saying goes like this:
The hardest to win is a won game
It means when you are getting closer to win, your efforts and concentration should increase; no relaxation is allowed since that can cause a mistake and a loss of all winning chances. This position gives you a very good opportunity to use the L-shape setup we talked about at the club. It is the only one giving you a chance to win. Your task:
a) Show how White wins (moves first) against the best defence by using the L-shape setup. It is not as simple as it seems!

Total available points for this puzzle is 10. The answers will be published next week together with puzzle #181.

Puzzle #179 solution:
Game Carl Schlechter vs Philip Meitner, 1898. It proved to be a much more difficult puzzle for you than I thought. I know it requires a Queen sacrifice to start, but the positional advantage for White (all pieces except the Queen could attack the Black King directly or within a move) should have given you a big clue at least how to start it. In the end just Philip, Jeffrey, Alex and James did reasonably well; some of you did forget about solving it. Solution:
[Event "Puzzle #179"][Date "2012.01.08"][Result "1-0"][SetUp "1"][FEN "1r2q2r/pp1nn2k/2p1p1pp/b2p3N/P2P4/Q2BBP2/5P1P/R5RK w - - 0 1"]1.Qxe7+!! {The main Black defender in the way of the attack is the g6-pawn. It is under attack and also defended a few times, so eliminating some of the defenders is necessary} 1...Qxe7 2.Rxg6 {Now White threatens to deliver the final blow 3.Rg7++ and mate. Black's only defence is to give his Majesty the h8-square} 2...Rhf8 {This is the only move allowing later on "Rf8-f5" or "Rf8-f6" and a delay of mate} (2...Rhg8?? 3.Rxh6#) 3.Rag1! {A move as important as the first one. It threatens 4.Rxh6# and in the same time it makes sure the Black King stays in his corner} 3...Qg5 {The only move stopping the mate in 1} 4.R6xg5+ Kh8 5.Rg6 {Another mate in 1 threat 6.Rh6#. At this point in the game it only matters how fast can White mate} 5...Rf6 6.Nxf6 Nxf6 7.Rxh6+ Nh7 8.Rxh7# {This is faster than 10 moves as originally claimed}

Correct solutions:
Philip - 20 points
Jeffrey - 18 points
Alex - 14 points
James - 12 points
Leroy, Derrick - 2 points

Coco - 10 points from puzzle #178

Standings:
Philip - 40 points
Jeffrey - 36 points
James - 32 points
Alex - 31 points
Ziyao, Harmony - 20 points
Daniel - 19 points
Leo - 16 points
Coco - 10 points
Derrick - 8 points
Leroy - 2 points