Loss as black in 4.e3 English / rook ending [FEN ""]
[Date "6/10/2018"]
[Round "4"]
[White "Opponent"]
[Black "Me"]
[Result "1-0"]
[WhiteElo "2383"]
[BlackElo "1874"]

1. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. e3 Be7 5. Qb3 O-O 6. Be2 d6 7. d3 Rb8 8. O-O Bg4 9. a3 Nd7 10. Qc2 f5 11. h3 Bxf3 12. Bxf3 Nf6 13. b4 Qd7 14. Bd2 g5 15. b5 Nd8 16. d4 Nf7 17. Rad1 g4 18. hxg4 Nxg4 19. Bxg4 fxg4 20. Ne4 Qf5 21. Rc1 exd4 22. exd4 Ng5 23. Nxg5 Bxg5 24. Qxf5 Rxf5 25. Bxg5 Rxg5 26. Rfe1 Rf8 27. Re7 Rf7 28. Re8+ Rf8 29. Rce1 Rg7 30. Kh2 h5 31. Kg3 Rgf7 32. Rxf8+ Kxf8 33. Re4 Rf6 34. a4 Kf7 35. a5 b6 36. a6 Rf5 37. Re2 Rf6 38. f3 gxf3 39. gxf3 Rf5 40. f4 Rf6 41. Rh2 Kg6 42. Kf3 Rf5 43. Ke4 Rf6 44. Rg2+ Kf7 45. Rh2 Kg6 46. Rh1 Re6+ 47. Kd5 Rf6 48. Rh4 Rf7 49. Kc6 Rh7 50. d5 Kf5 51. Kb7 c5+ 52. Kb8 Ke4 53. Ka8 Kf5 54. Rxh5+ Rxh5 55. Kxa7 Rh1 56. Kxb6 Ra1 57. Kb7 Kxf4 58. a7 Ke4 59. a8=Q Rxa8 60. Kxa8 1-0


My rating: 1874

Opponent's rating: 2383

I felt that I played strongly in this game but faltered due to a lack of understanding in the endgame. Any critique on the middlegame is also appreciated. Feel free to address any of these points or anything else that is important that I did not mention:


After 7...Rb8, my plan is to develop the bishop to g4 and eventually expand with f7-f5. Is this the right thinking? Perhaps my bishop doesn't belong on g4, or perhaps I could achieve my plan quicker without spending time on ...Rb8 and ...Bg4.
After 10...f5 11.h3 I am losing the bishop pair due to 11...Bh5 12.Nxe5!; was there a better way around this?
14...g5!? was what I felt was the only way forward. Would I be better off preparing this with something like ...Kh8 and ...Rg8?
After playing 17...g4, again perhaps I'm pulling the trigger too quickly.
Instead of 20...Qf5, should I consider 20...d5?
Maybe I could've played 21...Rbe8 and sat for a little longer before starting to liquidate this position.
For some odd reason I felt compelled to play 35...b6 in light of white eventually creating some sort of a pawn breakthrough, but perhaps this isn't a worry with rooks on the board? Keeping my original pawn formation could be important later.
My opponent said 39...Rg6+ was definitely drawing because the kings can't really go away from the f-pawn. Allowing 40.f4 may have been the critical mistake. After that I'm not sure the best defense against white's king march.
And I missed the 54.Rxh5+! trick in advance.


Also please no computer analysis unless something cannot be justified without it. Thanks!
Let me try to cover your bullet points:


After 7...Rb8, ...Bg4 idea:  First I don't see the connection of Bg4 with pushing your f-pawn.  Your pawns are on dark squares so trading your light square bishop is not a great idea either.  How about 8...h6 with the idea of 9...Be6 and 10...d5.
After 10...f5 11.h3 I am losing the bishop pair:  You didn't properly calculate your Bg4 idea.  What did you think was going to happen with Bg4?
14...g5!?: this is fine.  White floundered the last few moves so attacking is good.
A 17...g4:  I would strongly consider 17...e4!  You have 2 knights and no light square bishop so closing the center with a space gain and tempo looks correct.  You can follow with c6, or h5 and g4.
Instead of 20...Qf5, should I consider 20...d5?  I would definitely calculate d5, but why open the whole board for the battle when you have space by his king.  I like throwing pieces to the king-side.
Maybe  21...Rbe8:  21...exd4 is where you start going wrong with the idea of liquidating.  Why do you want to liquidate?  At this point you should be asking yourself "What does White want to do?"  The answer is liquidate! Nc3 is probably his next move. I'd be look at ...Bh4 here. 
compelled to play 35...b6: First, lets go back to move 26 where you should have played 26...Kf7 and have no worries.  You can't let him double rooks on the open file for free.  Of course 35...b6 is horrible.