Puzzle of the week #299

Submitted by eugen on
Basic Rook endgames
Level
4-Rook
Chess Diagram
[Event "Puzzle #299"][Date "2016.06.12"][Result "0-1"][SetUp "1"][FEN "3R4/8/8/7r/8/2K5/3p4/3k4 b - - 0 83"]
After an 83 moves long game I have reached the following position with the black pieces. It is black to move. Your tasks:
a) Verify how many of the 6 principles for the Lucena position apply here
b) Decide if black can win here or not
c) Show the winning line if you think black can win
Total available points for this puzzle is 25. The answers will be published next time together with puzzle #300.

Puzzle #298 solution:
Puzzle by Alexandra Botez, Facebook 2013. The correct answers were:
a) It is called a heavy pieces endgame because there is still a Queen and a Rook left on either side
b) The best winning line is:
[Event "Puzzle #298"][Date "2016.05.30"][Result "0-1"][SetUp "1"][FEN "6k1/5p2/3ppq1p/6p1/1P2P2P/3Q1P1K/2r3P1/6R1 b - - 0 1"]1... Qf4 2. g3 (2. hxg5 hxg5 3. g3 g4+ 4. fxg4 (4. Kh4 Rh2#) 4... Qh6#) 2... g4+ 3. fxg4 Qf2 4. g5 h5

Correct solutions:
Coco, Bradley, Cody, Aaron Y - 20 points
Daniel - 18 points
Benjamin - 12 points
Ethan, Deryk - 10 points
Aaron W - 5 points

Standings:
Bradley - 188 points
Jalen - 179 points
Coco - 145 points
Benjamin - 129 points
Daniel - 128 points
Cody - 125 points
Deryk - 117 points
Aaron W - 79 points
Ethan - 73 points
Yakov - 62 points
Aaron Y - 44 points
Shya - 10 points
Dheera - 5 points