Puzzle of the week #193

Level: 
4-Rook
Chess Diagram: 

[Event "Puzzle #193"][Date "2012.04.16"][Result "1-0"][SetUp "1"][FEN "6k1/p2r1p1p/1pp2Qp1/4P3/3P1R2/2P4P/q5PK/8 w - - 0 1"]

Simple positions with very few pieces left are very hard to play; whatever is easier for you to see, it is easier for the opponent to see as well. A better understanding of the position, a moment of not paying attention by one side or a simple positional advantage can be deadly.
Normally in simple positions a mistake decides the game. So seems to be the case here; your tasks:
a) Analyse the position and decide what advantages each side has
b) White to move - find the best lines for both sides based on your findings

Total available points for this puzzle is 20. The answers will be published next week together with puzzle #194.

Puzzle #192 solution:
Smyslow - end of a study, 1936. Pretty good answers this time around; still Philip remains the one with the most complete one. Here it is:
a) White's h-pawn is one step away from promoting. But Black's Bishop is defending the h8-square. Also, White has a potential mate threat with Nc7# but Black's Queen is defending that square.
White's plan: Try to promote the h-pawn to take a decisive lead and get a win.
Black's plan: Since Black is leading by 4 points, Black needs to stop White's h7-pawn and eliminate the potential Nc7# mate threat.
b) Solution:

[Event "Puzzle #192"][Date "2012.04.08"][Result "1-0"][SetUp "1"][FEN "k3N3/p2p3P/8/2p5/K1pbP3/6q1/P2P4/1R6 w - - 0 1"]1.e5!! Bxe5 (1...Qxe5 2.h8=Q Bb2 (2...Qxh8 3.Nc7#) 3.Rxb2 Qxb2 4.Qxb2 {White wins}) (1...Qb3+ 2.Rxb3 cxb3 3.h8=Q Bxe5 4.Qxe5 {White wins}) 2.Nc7+ Bxc7 3.h8=Q+ Bb8 4.Qh1+ Qf3 5.Qxf3+ d5 6.Qxd5#

Correct solutions:
Philip - 20 points
Ziyao, Justin, Leo - 19 points
Derrick, Daniel, Coco - 18 points
Jeffrey, James, Leroy - 16 points
Kevin, Alex - 15 points

Jeffrey - 5 points puzzle #191

Standings:
Philip - 297 points
Ziyao - 235 points
James - 217 points
Jeffrey - 206 points
Harmony - 187 points
Daniel - 186 points
Leo - 181 points
Derrick - 177 points
Coco - 158 points
Leroy - 151 points
Alex - 141 points
Justin - 51 points
Kevin - 42 points

Comment: 

Interference (3)