Puzzle of the week #125

Level:
5-Queen
Chess Diagram:

Today, July 9, in Windsor, Ontario takes place the last round of CYCC and new Canadian Champions will be crowded in each age group. Our BC players are doing quite well, especially 5 former club members who are going to win at least 2 national titles. You can follow my comments on Facebook for the up to date results.
Yesterday afternoon two of them: Jacob Jensen - John Doknjas, faced each other in round 6 of their under 12 group; a very nice and hard fought endgame emerged. Jacob's last move was 34.Kxh5 ... and the game continued as follows:
"34... Kc4 35.Be3 b4 (after a long thought; John has only a few minutes left on the clock) 36.axb4 axb4 37.Kxh4 Kc3 38.g4 Nd4 39.Bc1 Kc2 40.g5 Kxc1 41.g6 Ne6 42.f4 b3 43.f5 b2 44.fxe6 b1Q 45.Kg5 Qb8 and Black won after a few more moves 0-1"
a) Analyse the position;
b) Could you find a few alternate winning ways for Black? This means at different moments in the endgame Black could have played differently and still win (sometimes faster).

Each line you can find is valued 10 points, or as much as the answer to "a". Total available points for this puzzle is about 40 if I am not mistaken; however here I am open to receive valuable lines and award more points for them. The answers will be published next week together with puzzle #126.

Puzzle #124 solution:
Kasparov - Ivanchuk played this game back in 1988. Karl has sent a beautiful solution which I have preferred over a couple of other nice ones.
"a) Analysis
Material: Black is up a pawn.
King safety: the White King is obviously safer because of the fact that all of White’s pieces (excluding pawns) are attacking the Black King. The White King, however, has no attackers.
Position: Black is in a defensive position, while White is attacking. The Black Rook is trapped on the back rank, and has reduced mobility. If Bc6 wasn’t there, Re8 would be checkmate instantly. White can catch Black in all sorts of squares such as h7. White has a Rook on the 7th rank, and a good attack. Now a tactic or two and some action will get a win for White.
Conclusion: White is better by far in the positional view, and just needs to increase his attack for a win.
Key ideas to attack:
- The Black King is trapped in the corner
- Back rank is weak
- Nf7+ and there’s a discovered check
- These 3 pieces aren’t enough to make the attack successful, and a fourth is needed…
b) White to move and win
1.f6!! Nf7
Note: 1... Ne6 seems to work for Black as well, but after 2.Bxe6 ... Black isn’t in a better position.
This is the main line, because all the other lines lead to a quick mate. Bringing the pawn into the attack is the best choice here due to the fact that the 3 pieces aren’t enough. These are some of the ways Black could lose quickly:
1... gxf7? 2.Rh7#
1... Bxd5? 2.Re8+ Bg8 3.f7! Nxf7 4.Nxf7#
1... Rc8?? 2.fxg7#
1... h6?? 2.fxg7#
2.Nxf7+ Kg8 3.Nh6+! Kf8
If 3... Kh8?? 4.fxg7#
4.Rf7+ Ke8 5.fxg7! Kd8
Kd8 is forced because White is threatening g8=Q#, and Kd8 is the only move that escapes this by letting the Bishop be able to block the checkmate.
6.Bxc6! bxc6
Eliminating the defender, White has forced mate in one. Black might as well resign.
7.g8=Q#
The key to this puzzle is Black’s major positional disadvantage. Ra8 doesn’t even do anything! The King is trapped on the back rank, and a Knight on the side of the board is a bad one. White is the opposite, with a Rook on the seventh rank and the Knight and Bishop placed on powerful squares."

If I am not mistaken Ivanchuk resigned after 1.f6!! ... He knew what was coming!

Correct solutions:
Rick, Karl, Owen, Andy Y - 20 points
Alex, Jeffrey - 18 points
Frank - 10 points

FINAL STANDINGS

Owen - 502 points
Andy Y - 482 points
Karl - 430 points

Edwin - 375 points
Jeffrey - 323 points
Alex - 265 points
James - 231 points
Andy Q - 214 points
Humphrey - 180 points
Rick - 162 points
Nathaniel - 150 points
Amir - 103 points
Frank - 95 points
Marko - 10 points

Comment:

CYCC 2010 endgame challenge