Annotated Game #136: What exactly happened?

In this sixth-round tournament game, if one looks at it in the early middlegame then White appears to be sitting pretty, having accomplished all he could hope for out of the opening by move 18.  Indeed, as of move 26 I still had all the cards.  At this point, however, I "lose the thread" of the game and start a strategic downhill slide, becoming distracted from my queenside-based pressure while not properly defending the kingside.  The ineffectiveness of my strategic flailing is highlighted around move 29, as pieces begin to simply shuffle back and forth.  Despite this slide and Black's subsequent takeover of the initiative, my position was objectively at least equal until the board sight blunder on move 40, where my opponent seals the win with material gain.

So was it a simple tactical error that lost the game?  In reality, my mental state was poor after failing to grasp what was needed in the position and handing the initiative and its accompanying pressure over to the opponent.  The pressure of defending successfully (even if not optimally) eventually exhausted me and contributed substantially to the actual game-losing error.  On the other hand, if I had stuck religiously to my thought process, using CCT would have prevented the loss.  In the end, the result came from a combination of factors - tactical, strategic and psychological - as is the case with most chess games.

Even though I understand how the game evolved after analysis, it still makes me shake my head and wonder what exactly happened, especially after having a position that any English Opening player would love to see.  At least the analytic process should help me play stronger in future such situations.

[Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "ChessAdmin"] [Black "Class B"] [Result "0-1"] [ECO "A24"] [Annotator "ChessAdmin/Houdini/Komodo 8"] [PlyCount "114"] [EventDate "2012.07.??"] [EventType "swiss"] [EventRounds "9"] {A24: English Opening vs King's Indian: Lines without ...Nc6} 1. c4 Nf6 2. Nc3 g6 3. g3 Bg7 4. Bg2 O-O 5. Nf3 d6 6. O-O e5 7. d3 c6 8. Rb1 Na6 {Black evidently wants to keep the d7 square free so he can develop his light-square bishop, but a6 is not a good square for the knight.} 9. b4 Bd7 10. b5 Nc5 11. Nd2 Rb8 12. a4 (12. bxc6 $5 Bxc6 13. Ba3 {might put more pressure on Black.}) 12... Qc7 13. Ba3 Ne6 14. e3 {Controls d4+f4} (14. Nde4 Nxe4 15. Nxe4 c5 16. e3 {would be an improved version of the idea.}) 14... Rfd8 15. Qb3 b6 $6 {an unnecessary weakening move.} (15... Nc5 $5 16. Bxc5 dxc5 17. Nde4 $11) 16. bxc6 Bxc6 17. Nb5 Bxb5 18. axb5 $16 {White has achieved his positional goals on the queenside, with a powerful Bg2 helping control the light squares and the Ba3 exerting pressure on d6. Finally, the backward a-pawn can become a target.} Nc5 {Black correctly blocks the bishop, which I decide is best traded for the centrally placed knight.} 19. Bxc5 dxc5 {Opposite coloured bishops appeared, notes Houdini via the Fritz interface. Right now White's is much better.} 20. Ne4 Ne8 (20... Nxe4 $5 21. Bxe4 f5 22. Bd5+ Kh8) 21. Rfd1 f5 {gaining space and kicking the knight.} 22. Nc3 {with an eye on the d5 square.} Nf6 23. Nd5 { if Black exchanges on d5, then White's bishop becomes even more dominant from its central position.} Qf7 24. Nxf6+ Qxf6 {forced, due to the skewer otherwise after Bd5.} 25. Bd5+ Kh8 26. Ra1 {White remains comfortably in control and correctly increases the pressure against the backward a-pawn.} Rd7 27. Ra3 { this is not in fact a bad move, but it marks the beginning of my strategic confusion. I did not understand that my queen should be redeployed along the second rank, as it rather useless on b3. This should be accompanied by increased pressure along the a-file with doubled rooks. In the game I understood the benefits of doubling rooks, but got distracted by Black's pawn advances. As a final point, moving Ra6 would have been just as good as the text move for doubling purposes and would have also blockaded the a-pawn and exerted some indirect pressure along the sixth rank.} f4 {Black wins space, notes Houdini.} 28. Rf1 {White is still fine objectively, but this move starts the strategic slide.} Rf8 {with the obvious threat of ...fxe3, as the Rf1 is now under-protected.} 29. Raa1 $11 {I've now simply wasted several tempi on the queenside and have effectively lost the initiative, although the position remains equal.} (29. Qd1 {would reposition the queen to a much more effective square and accomplish the same thing as the text move to protect the Rf1.}) 29... f3 {this certainly looks threatening, establishing a mate possibility on g2, but White can deal with this resaonbly in several ways.} (29... Qg5 $5) 30. h3 (30. Be4 Qe6 31. Qd1 Rdf7 32. Kh1 Qh3 33. Rg1 {and White has neutralized Black's threats, with good prospect of resuming his queenside pressure.}) 30... g5 31. Kh2 Qh6 {here I only saw the h-file threat and did not note that Black now could open up on the long diagonal with the Bg7.} 32. Rh1 $6 (32. Be4 $14 { is a clever way of blocking the advance of the e-pawn, while maintaining protection of the d3 pawn and controlling f5 and g6.}) 32... e4 $11 33. Rad1 exd3 {this should let White off the hook.} (33... g4 $5) 34. Qxd3 $14 Be5 35. Kg1 {this should still be good enough for a draw, but bolder, more active defense would have been better.} (35. Qe4) 35... Qd6 {although Black is not making objectively strong moves, he retains the initiative and succeeded in pressuring me psychologically as well.} (35... Qg7) 36. Qf1 $6 (36. Qc2 $5 { would have retained some chance for advantage. For example} Qc7 37. g4 Qd8 38. Kf1) 36... Bxg3 $11 37. Bxf3 {I was proud of finding this defensive move, which I assessed would lead to a draw.} Bxf2+ 38. Kxf2 Qf6 39. Kg2 (39. Rxd7 { is a more creative solution.} Qxf3+ 40. Ke1 Qxe3+ 41. Qe2 $11) 39... Rdf7 40. Bd5 $4 {the losing move. I simply miss the long-range check on b2.} (40. Rd5 $11 {was a good chance to save the game, notes Houdini.}) 40... Qb2+ $19 41. Kg1 Rxf1+ 42. Rxf1 Rxf1+ 43. Kxf1 Qd2 {the power of the queen in the endgame is now demonstrated and my opponent plays well in converting the point. I didn't want to give up prematurely, but the struggle is essentially hopeless.} 44. e4 Qd1+ 45. Kg2 Qe2+ 46. Kg1 Kg7 47. Rh2 Qe1+ 48. Kg2 Kg6 49. Rh1 Qe2+ 50. Kg3 (50. Kg1 h5 51. Rh2 Qe1+ 52. Kg2 g4 53. hxg4 hxg4 $19) 50... Qe3+ 51. Kg2 Kh5 52. Rf1 Kh4 53. Rf3 Qe2+ 54. Rf2 Qe1 55. Rf3 h5 56. Ra3 $2 (56. Rf2 $19 { what else? notes Houdini. Instead, the end comes sooner.}) 56... Qd2+ 57. Kf3 g4+ 0-1