This next tournament game features an interesting struggle in the English, versus a King's Indian Defense (KID) structure. As often happens, White tries to press on the queenside while Black focuses on the kingside. Here, I think both sides neglected the center too much and missed better opportunities, so that is a useful general lesson to take away.
The key strategic turning point occurred around moves 19-21, where Black makes his initial kingside push. I only considered the idea of pushing g4 too late, when it was forced, and did not consider the full ramifications of Black's strong Nf5. For me, it is a good example of how tactical threats and strategic considerations can intersect and determine the course of a game.
[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "ChessAdmin"]
[Black "Class A"]
[Result "0-1"]
[ECO "A26"]
[Annotator "ChessAdmin/Komodo 11.2"]
[PlyCount "100"]
{[%mdl 8256][%evp 0,100,16,-12,-9,-28,36,28,19,19,11,-1,31,7,50,-10,-2,-17,-4,
-20,-14,-11,-11,-9,44,9,10,1,16,21,20,8,8,-4,-9,-18,-7,-7,2,-13,20,7,43,-68,
-74,-138,-149,-136,-96,-100,-103,-89,-92,-73,-67,-217,-203,-209,-187,-187,-144,
-162,-163,-168,-147,-174,-178,-191,-218,-226,-238,-229,-253,-253,-223,-220,
-230,-244,-111,-273,-274,-274,-274,-300,-338,-289,-229,-235,-242,-242,-241,
-237,-236,-466,-295,-286,-378,-767,-848,-29997,-29998,-29999,-30000] A26:
English Opening vs King's Indian with ...Nc6 and d3} 1. c4 Nf6 2. Nc3 g6 3. g3
Bg7 4. Bg2 O-O 5. Nf3 d6 6. O-O e5 7. d3 {the standard setup for White in the
English, facing the KID structure.} Nc6 8. Rb1 Re8 9. Bg5 {a key idea in this
variation for White. As soon as the Black rook gets off the f-file, the bishop
comes out and can be exchanged for the Nf6. This gets rid of a strong Black
attacking piece on the kingside, while not giving Black as much potential
momentum on the f-file. Naturally it's not the only way to play, but I find
the idea simple to execute.} h6 10. Bxf6 Bxf6 11. b4 Bg4 12. h3 {the first
real decision point for White. This move is not the most incisive, as it's not
clear that the bishop is particularly well placed on g4. The h3 pawn can also
become a target.} (12. b5 $5 {is more straightforward.} Ne7 13. Nd2 $14) 12...
Be6 13. Nd2 (13. b5 Ne7 14. Nd2 Qc8 15. Kh2 Bg7 16. Qb3 f5 17. Nd5 c6 18. bxc6
bxc6 19. Nxe7+ Rxe7 20. Qa3 Qd7 21. Qa4 d5 22. Nb3 Bf7 23. Na5 Rc8 24. Rb7 Qxb7
25. Nxb7 Rxb7 26. Rc1 dxc4 27. Bxc6 Rbc7 {Medjkouh,S (2080)-Chumfwa,K (2180)
Maputo 2011 1-0 (55)}) 13... Rb8 14. b5 Ne7 15. Qc2 {not necessarily a bad
move, but perhaps a little timid. The queen has little prospect on the b1-h
diagonal, nor does it do much to support anything else. On the positive side,
the rooks are connected.} (15. Nd5 $5 {this is a common theme in the English,
the knight leaping into d5 only to be exchanged off with doubled d-pawns.
However, the resulting advanced d5 pawn and dynamic features of White's
position typically compensate for it.} Nxd5 16. cxd5 Bd7 17. Qc2 {and now the
queen has more to do on the half-open c-file.}) 15... Bg7 16. a4 {it would
have been better to immediately play Kh2 here, anticipating Black's next.} Qd7
17. Kh2 f5 18. a5 {we now have a classic queenside vs. kingside expansion
"race" on.} f4 {this is one of those moves that looks aggressive but in
reality is premature. White has several good responses.} (18... c6 19. Rfc1 $11
) 19. Nd5 {an example of a good idea played at a less-optimal time.} (19. g4 $5
{looks a bit loose, but White is set up well enough on the kingside and in the
center to keep Black from breaking through.} Rf8 (19... h5 $2 20. gxh5 gxh5 21.
Rg1 $16 {and it's White who is better positioned for action. For example} Kh8
22. Nde4 Nf5 23. Qa4 Nd4 24. Bf3) 20. a6 $14) (19. Qa4 {is another idea,
lining up on the a4-e8 diagonal.} fxg3+ 20. fxg3 $14) 19... fxg3+ {this
reduces the tension and is a typical Class player inaccuracy.} (19... Nf5 $5)
20. fxg3 $14 Nf5 {we now reach a key strategic decision point, where it is
revealed that I don't know what I'm doing in the position. The overlooked
tactical threat is the knight fork on the e3 square, which is only temporarily
covered by my Nd5. The e2 pawn is also currently undefended.} 21. b6 $6 (21. g4
$5 {kicking the knight is the best solution.} Nd4 22. Qd1 e4 23. e3 $14) 21...
axb6 $15 22. axb6 $6 (22. g4 $5 {is now required, but at a disadvantage to the
previous variation.}) 22... c6 $17 {kicking the Nd5 and gaining the advantage,
although it still wasn't too late to play the g4 idea, which I only find after
it's forced.} 23. g4 Nd4 24. Qd1 cxd5 25. cxd5 Bxg4 $1 {a winning, if tricky,
sacrificial idea.} 26. hxg4 Qxg4 $6 {this could allow White to escape, but I
don't find the correct continuation.} (26... e4 {is the winning continuation,
but it requires a further sacrifice.} 27. e3 exd3 28. exd4 Re2 {the key idea,
as now Black's queen can penetrate to maximum effect.} 29. Rf4 Qe7 30. Kh3 Qg5
31. Bf3 Qxf4 32. Bxe2 dxe2 33. Qxe2 Qxd4 $19) 27. e4 $2 {this optically looks
like a good defensive move, but the d5 pawn is not under threat and the pawn
does much less on e4 than on e3.} (27. e3 {threatens the Nd4 and Black
therefore does not have enough time to generate winning threats.} Qh4+ 28. Bh3
$11) 27... Ne2 $19 (27... Qh4+ {is even more effective.} 28. Bh3 Rf8 29. Nf3
Nxf3+ 30. Rxf3 {and now Black can choose how he wants to win, with White's
pieces overburdened and a hole on the 2nd rank. For example} Rf4 31. Rxf4 exf4
32. Qg4 Qxg4 33. Bxg4 h5 $19) 28. Rf3 Nf4 29. Rg3 Qxd1 {my opponent chooses to
head for an endgame with an advantage.} 30. Rxd1 Ra8 31. Nc4 Bf8 32. Bf3 $6 (
32. Rd2 {defending the 2nd rank is better.}) 32... Ra2+ 33. Rd2 {now things
fall apart quickly.} (33. Kh1 Rea8 $19) 33... Rea8 (33... Rxd2+ 34. Nxd2 Ra8
35. Nc4 $19) 34. Kh1 (34. Rxa2 Rxa2+ 35. Kh1 h5 36. Bxh5 Nxh5 37. Rxg6+ Kh7 $19
) 34... Rxd2 35. Nxd2 h5 {Black's connected passed pawns ensure victory.} 36.
Rg1 Ra6 37. Nc4 Kf7 38. Rf1 Be7 (38... Ke7 39. Kg1 $19) 39. Rd1 $2 (39. Bd1 $5
{taking advantage of the pin on the Nf4.}) 39... g5 40. Rf1 g4 41. Bd1 Kg6 {
by this point the outcome is inevitable, but I stubbornly play on.} 42. d4 {
the only chance for any counterplay, even if it is a false hope.} Kf6 (42... g3
{passed pawns must be pushed!} 43. Rf3 g2+ 44. Kh2 $19) 43. dxe5+ dxe5 44. d6
Bd8 45. d7 {it's great to see my pawn one square away from queening, but
unfortunately there's no way of removing the Bd8 that is blocking it.} g3 46.
Bf3 (46. Rg1 h4 47. Bb3 $19) 46... h4 47. Ne3 (47. Rd1 {a fruitless try to
alter the course of the game} Ra4 48. Ne3 Ra3 49. Ng4+ Ke6 $19) 47... Kg5 48.
Nc4 Ra2 {the engine now shows a mate in 10, but I accelerate the process.} 49.
Nxe5 (49. Rd1 {does not improve anything} Rh2+ 50. Kg1 Rf2 51. Rd2 Rxf3 52. Rc2
h3 53. Rd2 g2 54. Rd1 Ne2+ 55. Kh2 Rf1 56. Rxf1 gxf1=Q 57. Ne3 Qf2+ 58. Kxh3
Ng1#) 49... Rh2+ 50. Kg1 Nh3# {an aesthetic end, at least.} 0-1