Puzzle of the week #100

Chess Diagram: 

[Event "Puzzle #100"][Date "2010.01.15"][Result "1-0"][SetUp "1"][FEN "5k2/5p2/1K3P2/1P4Q1/8/8/5r2/5r2 w - - 0 1"]

Back from holidays, beginning of the year and a puzzle with a round number 100 require a warm up challenge. This means the challenge is not too easy, not too hard, comes up from an existing game and the solution is hidden behind a few obvious but not very helpful moves. A heavy pieces endgame is not easy to play, especially a Queen versus Rooks; at anytime one side gets the initiative and has a chance to mate or decisively win material. Today your task is simple:
1. White to move and mate in 5

Total available points for this puzzle is 20. The answers will be published next week together with puzzle #101.

Puzzle #99 solution:
It is from a game between Hartlaub - Testa, Boema 1912. Answer provided by Rick:
a) Analysis:
Material: Black is up by four pawns, so White probably can't recover it.
King safety: White's King might look less protected, but it's the Black King that has four attacking pieces pointed at it.
Position: Looking at where White's Bishops are, I think the opening was the Danish Gambit (1.e4 e5 2.d4 exd4 3.c3!? dxc3 4.Bc4!? cxb2 5.Bxb2). This is a highly dangerous opening because White gets a huge lead in development, although down by two pawns. Black is indeed way behind in development, so White has to take advantage of it. White's plan: being way behind in material, White really has only one choice, to deliver an all-out attack! White should also fearlessly sacrifice pieces if there is a good oppurtunity.
Black's plan: being way behind in development, Black also has only one choice, to defend at all costs! Even "Nbc6" would have delayed Bhite's attack. Black knows that a tough game lies ahead.
b) See solution
c) Reasoning:
White's plan worked because he had all the necessary conditions for an attack:
1. Huge lead in development
2. King is not in danger of a counterattack
3. four out of five pieces are greedily eyeing the black king
4. Capablanca's famous saying " For an attack to be successful, you need more pieces attacking than your opponent has defending." White has a 4-3 piece advantage here!
If it was Black to move, a simple "Qc6+" or "Nbc6" could have changed the game significantly. Black must be very ashamed of grabbing so much material, yet ignoring King safety!

Additional note: A good counter against the Danish Gambit: 1.e4 e5 2.d4 exd4 3.c3!? d5!? 4.exd5 Qxd5 5.cxd4 leaves White with an isolated pawn on d4.

[Event "Puzzle #99"][Date "2009.12.30"][Result "1-0"][SetUp "1"][FEN "rn3rk1/pppq1ppp/3p4/4n3/2BQ4/8/PB3P1P/R5RK w - - 0 1"]1.Rxg7+ Kxg7 2.Rg1+ {There are four reasons why White sacrificed his Rook: 1. To expose the Black King* out into the open 2. Black's g-pawn was his best pawn defender; White's attack is now much more likely to be succesful 3. To weaken the dark squares around Black's King, so White's battery will have more power 4. "Ra1" was not doing anything in the corner, and now it suddenly plays an effective part in the attack. Black has three legal moves (assuming that he doesn't play ...Qg4), but they all lead to an ugly death} 2...Kh8 (2...Kf6 3.Qh4+ Kf5 4.Qg5+ Ke4 5.Re1+ Kf3 6.Qg3#) (2...Kh6 3.Qh4#) 3.Qxe5+!! dxe5 (3...f6 {Not taking the Queen leads to the same mate} 4.Qxf6+ Rxf6 5.Rg8#) 4.Bxe5+ f6 {The diagonal is open for Bc4} 5.Bxf6+ Rxf6 6.Rg8#

Correct solutions:
Rick, Karl, Owen, Humphrey - 30 points
Jeffrey - 29 points
Andy Q - 25 points
Alex - 10 points
Peter - 5 points

Karl - 284 points
Owen - 274 points
Rick - 244 points
Andy Q - 241 points
Jeffrey - 189 points
Humphrey - 141 points
Alex - 97 points
Nathaniel - 52 points
James - 40 points
Peter - 30 points
Katerina - 22 points
Wilson - 7 points


Queen vs. Rooks endgame