Why couldn't I win this Maroczy Bind (vs 2000)? [FEN ""]
[Date "6/10/2018"]
[Round "5"]
[White "Me"]
[Black "Opponent"]
[Result "1/2-1/2"]
[WhiteElo "1874"]
[BlackElo "2000"]

1. e4 c5 2. Nf3 g6 3. d4 cxd4 4. Nxd4 Bg7 5. c4 Nf6 6. Nc3 Nc6 7. Be3 O-O 8. Be2 d6 9. O-O Bd7 10. Rc1 a5 11. f4 a4 12. Bf3 a3 13. b3 Qa5 14. h3 Nxd4 15. Bxd4 e5 16. Be3 Bc6 17. Qxd6 exf4 18. b4 Qd8 19. Bxf4 Qb6+ 20. Qc5 Qxc5+ 21. bxc5 Rfd8 22. Nd5 Nd7 23. Bc7 Re8 24. Bd6 Bd4+ 25. Kh1 Ra5 26. Bg4 Nxc5 27. Bc7 Ra4 28. Bb6 Rxe4 29. Bxc5 Rxg4 30. Ne7+ Kg7 31. Nxc6 bxc6 32. hxg4 Bxc5 33. Rb1 Rxc4 34. Rb7 Rxg4 35. Rfxf7+ Kh6 36. Rxh7+ Kg5 37. Rbc7 Rc4 38. Rcd7 Rc1+ 39. Kh2 Bg1+ 40. Kh1 Be3+ 41. Kh2 Bg1+ 42. Kh1 Be3+ 1/2-1/2


My rating: 1874

Opponent's rating: 2000

I felt that I had a big initiative throughout this game and failed to convert it and ended up in a worse position in the end. Feel free to address the following points or any other analysis that is important.


I played 11.f4 with the intention of maintaining control over e5 and keeping open the option of eventually breaking with e4-e5 or f4-f5. Perhaps 11.b3 is a better first move to slow down a5-a4? Perhaps black can also consider ideas with ...Ng4.
12.Bf3 kind of feels like a wasted move at the moment but I felt it would eventually play a role in supporting a knight on d5, perhaps 12.h3 is more straightforward in this position.
I felt happy with 14.h3, considering Nd5 next.
I instantly felt that my opponent made quite an error with 15...e5.
17.Qxd6 looked safe, but perhaps I was better off with 18.Qxf4 or 19.Qxf4 rather than 19.Bxf4?!, allowing 19...Qb6+.
I didn't like 20.Kh1 Rad8 21.Qe7 Rfe8 when I have too much trouble hanging on to the b4 pawn and have to resort to Qc5, so I just played 20.Qc5 right away.
After 22.Nd5 I felt I still had a nice initiative and I really don't understand where I could've improved between now and 29...Rxg4. Maybe I could slow down and not allow 24...Bd4+? And after 26.Bg4 Nxc5 I really felt that I was losing grip.
I was a bit low on time and didn't see much better than 29.Bxc5.
In hindsight, perhaps I should've been a little more patient than 33.Rb1 and try slowly improving my position, perhaps it's still roughly equal though.
My opponent generously offered a draw after 42...Be3+ but I felt he was the one who could play on.


Also, please no computer analysis unless it's absolutely vital to explaining something. Thanks!
You couldn't win mostly due to the mistake on move 19, but you still had chances.


  
  I played 11.f4 with the intention of maintaining control over e5 and keeping open the option of eventually breaking with e4-e5 or
  f4-f5:
  


That statement is not enough of a plan, and your following moves don't support either idea.  That pawn cannot move backwards and you might wish it were on f3.


  
  12.Bf3, perhaps 12.h3
  


Again you are not playing with any plan, but Bf3 supports e4 and is probably a better square for the Bishop


  
  I felt happy with 14.h3
  


Why? How does 14.h3 help your position?  I can't help thinking there is something wrong with your position.  Your rooks aren't connected and the long dark-square diagonal is loose, but I don't know that Black can take advantage of that.


  
  error with 15...e5.
  


Yes that is dubious, and I think Black could have improved his rooks before trading knights in the center.


  
  17.Qxd6 looked safe, but perhaps I was better off with 18.Qxf4 or 19.Qxf4 rather than 19.Bxf4?!, allowing 19...Qb6+.
  


or 19.Qd8, which looks to give you a big advantage!  19...Rfxd8 20.Bxf4 Rd4?! 21.Ne2 +/-


  
  After 22.Nd5 I really don't understand where I could've improved
  


Well, what did 26.Bg4 achieve but to weaken your e-pawn?  How about, 26.Rcd1 Bxc5 27.Bc7 Ra4 28.Bg4


  
  33.Rb1
  


Why help Blacks rook get in the game?  Also, every pawn trade makes it harder to win the game.