Puzzle of the week #156

Chess Diagram: 


In soccer the same as in hockey a breakaway is one of the most exciting moments. Everyone, including the player involved, is highly excited by the opportunity provided and the very likely outcome - a goal - brings them on their feet. Will it be a goal? Will it be a great save? The game balances on the edge of a knife. The closest in chess to a breakaway is a discovered check. The effects are simply devastating and have a direct influence on the final result like a goal. Here we are in this position, with Black ready to make the decisive pass for a breakaway, ehhh discovered check that it. Your tasks:
a) Analyse the position for both sides;
b) Black to move and win.

Total available points for this puzzle is 20. The answers will be published next week together with puzzle #157.

Puzzle #155 solution:
Game Makogonov - Chekhover. It is surprising how many were fooled by my deceiving line for option "a". The answer was right there looking you in the eye and only 2 students (Philip and Harmony) saw it. Philip missed on his first try a faster mate for option "b". The most complete answer was sent (again) by Harmony; see below:
"Option A is the best, which will bring Black a definite and quick win.
Option B ends with a quick loss for Black.
Option C will end with a loss game for Black in a long run, but if White messes it up in the middle, Black still could get a draw.
Option A
1... Rf8

White cannot move Rd8, as this is a really quick loss for white.
Main line: 2.Rd8 Qh4+ (White loses its Queen!) 3.Kg2 Qxf6 4.Rxf8 ... (White has to exchange the Rook, or it will be checkmated really quick) 4... Qxf8 and Black wins with ease
White has to sacrifice its Queen for a Rook to survive longer.
Alternate line 2.Qxf8+ Kxf8
Now here is a Queen vs Rook endgame. Black will still win with ease. Depending on White Rook’s movement, Black has several options. If the White Rook protects its Queen side pawns, Black just pushes up its King side pawns. If the White Rook tries to stop the King side pawn storm, the Black Queen can easily take away White's Queen side pawns.
Option B
1... g5 2.Qg6+ ...

All ends up with checkmates in maybe four to five moves, for examples:
2... Kf8 3.Qxh6+ Kf7 4.Qh7+ Kf8 5.Rf6#
or 2... Kh8 3.Qxh6+ Kg8 4.Rg6+ Kf7 5.Qg7#
Option C
1... h5 2.Qxg6+ Qxg6 3.Rxg6+ Kf7 4.Rg5 ...
Black will lose both its pawns.
4...h4 5.Rxc5 Rh8 6.Kg2 ...
or 4...Rb8 5.Rxh5 Rxb2 6.Rxc5 ...
White has at least three more pawns, and should win the game after careful play."

Observation for option "c": this is the reason why Black must move 3... Kh7 and stay close to the passed h5-pawn. The chosen 3... Kf7 is not very good.

Correct solutions:
Harmony - 19 points
Philip - 18 points
Ziyao, James - 12 points
Leroy - 10 points
Daniel - 5 points
Frank, Derrick, Leo, Jeffrey, Alex - 3 points


Ziyao - 159 points
Harmony - 152 points
James - 125 points
Alex - 121 points
Philip - 109 points
Leo - 100 points
Leroy - 78 points
Jeffrey - 75 points
Derrick - 73 points
Frank - 36 points
Kevin - 34 point
Daniel - 22 points
Danny - 19 points
Karl - 13 points