Puzzle of the week #89

Level: 
4-Rook
Chess Diagram: 

--r---k-
-----qpp
--pBp---
---nP---
P-------
-----r--
-P--QP-P
R--R--K-

Year after year we see pretty good juniors improving their play and becoming better players. Here for sure I include all of you from the club this year. The best juniors in the province battle in November for the BC Junior Championship and the level of games has increased lately. Today we are going to look at the end of the game Alexandra Botez - Chang He Li from the BC Junior Championship a couple of years ago. Your tasks:
a) Start by analyzing the position and determine what each side should do (10 points)
b) Black to move and win; use the above analysis and come up with the best winning line for Black (10 points)

Total available points for this puzzle is 20. The answers will be published next week together with puzzle #90.

Puzzle #88 solution:
Very good responses this time around; congratulations! Most of you guys are in mid season form as they say in hockey... Here are the best contributions:
Rick:
"A) What is the opening? The opening is the Petroff Defense, named after Russian player Alexander Petroff.
B) & C) White to move and win plus explanation: First of all, the reason I think Black blundered was because Nf5 wasn't a common place for a knight. He probably didn't expect the next move....
1.Nxg7!! ... The g-pawn was one of Black's most vital defenders too! White's Queen and 2 Bishops draw closer...
1... Kxg7 2.Qh5! ... Threatening 3.Qxh7#
2... Rh8 2... f5? loses to 3.exf6 Rxf6 4.Qxh7+ Kf8 5.Bg6! where Black must sacrifice his Rook.
3.Bh6+ Kg8 4.e6! fxe6 If 4... Bxe6? 5.Qe5! Bf6 6.Qg3+ ... wins. But 4... fxe6 is blocking Bc8, which opens up the g4 square. Notice how all of Black's moves were forced?
5.Qg4+ Kf7 6.Qg7+!! ... Black loses, because now White picks up a free Rook with check."

Owen:
"c) If I can comment Black should have played 11...c4 to attack the Bishop; then 12.Nf5 Kh8 13.Nxe7 Qxe7 14.Be2 Qxe5 and black gets his pawn back and has a better center.

Correct solutions:
Rick, Andy, Owen, Karl - 25 points
Alex, Jeffrey - 10 points
James - 5 points
Humphrey - 2 points
Jeffrey - 2 points for puzzle #87

STANDINGS

Rick, Karl - 60 points
Andy Q - 59 points
Owen - 55 points
Jeffrey - 27 points
James - 17 points
Katerina, Alex - 10 points
Humphrey - 7 points
Wilson - 2 points

Comment: 

Storming the castle