1. e4 c5 2. Nf3 g6 3. d4 cxd4 4. Nxd4 Nc6 5. Be3 Nf6 6. Nc3 Bg7 Pretty standard Sicilian
7. f3 O-O 8. Qd2 d5 9. Nxc6 bxc6 A common Sicilian position
10. O-O-O e5 would normally be played here.
e6 The plan for black here is to try and maintain the centre, while pressuring whites castled position via the half-open b-file
11. Bg5 Pins the knight to the queen threatening to win it with e5
Qc7 Unpins the knight. On c7 the queen watches the e5 square and provides support for c6-5. Bf4 is now met by e5. If black had played Qb6 then Na4 Qb2 Nc5 and black wont control the b-file and the c pawn is blockaded by a well outposted knight
12. Bd3 d4 Bd3 has blocked whites major pieces on the d-file, so black can claim some space
13. Ne2 c5 Not e5. The c-pawn can be used to provoke white to play b3 and then black can exert pressure by pushing the a-pawn. blacks immediate threat is c4 trapping the bishop
14. Bc4 avoids b3 for now blockading the pawn with the threatened bishop
a5 Two ideas here. The first is that it prepares the a-pawn for when the b-pawn gets provoked. The second idea is that it allows black to play Ba6 getting whites light bishop out of the picture
15. h4 White tries to counter with an attack on blacks king. White has three pieces in this attack ( and the pawn ) . Black has two key defenders, the dark bishop and the knight. White would need to give up his dark bishop to get rid of either of these so whites attack shouldn't work
Ba6 Getting whites light bishop out of the way
16. Bxa6 Rxa6 Note black has one major piece on each rank ( 1,2,3 ) so can quickly sieze the b-file
17. h5 White plays to control the h-file
Nxh5
18. g4 Rxh5 peters out after something like gxh5 Bh6 ( threatening Qg5 ) f6. g4 gains full control of the h-file
Ng3 This apparently risky move ensures whites knight will not play a part in a kingside attack. Nf6 loses to Bxf6 Bxf6 Qh6->Qh7#. Black is fine if white plays Bf4 forking knigt and queen since white can play Nxe2+ getting out of the fork and winning a piece
19. Nxg3 Qxg3 The queen may look uncomfortable here, but attempts to trap her fail
20. Bh6 Black can't play Bxh6 due to Qxh6->h7#. White threatens Bxg7 Kxg7 Qh6+ Kg8 Qxh7#
Qe5 Protects the bishop
21. Bxg7 white can't add pressure by playing f4 since it blocks the diagonal that white needs
Qxg7 22. Rh6 f6 23. Rdh1 Note how both black and white have one major piece on each rank. White is closer to controlling his half open file, but will be unable to claim it thanks to blacks king supporting h7
Rf7 h7 is now attacked twice and defended thrice, so bringing Qh2 will not help white
24. f4 Tring to open up the kingside. Not sure that it would help white anyway.
Qf8 Allow the rook to capture on h7 first, rather than the queen. Also keeps one piece on each rank. Black wants to get a rook to b7 where it can both attack and defend.
25. f5 Threatens fxg6 hxg6 Rh8+ winning queen for rook
exf5 The alternative is g5 fxe5 Rxe5 Qxa5 losing a pawn
26. gxf5 exf5 probably better. The text move left the e pawn backward and exposed to attack
g5 27. Qe2 Threatening the rook
Raa7 Rb6 possibly better
28. Qc4 A move with a nice threat. Pins the rook and threatens Rxh7. Also blockades the c-pawn
Kh8 Releases the pin
29. R6h3 Qe7 Threatening e4 while still supporting c5
30. Qe2 Qe5 Keeps pressure on e4 and allows a rook to come to e7
31. Rb3 Trying to rob the b-file
Rab7 But black owns it
32. Rhh3 Rxb3 Trading down will allow blacks king to move again
33. Rxb3 Qf4+ Ironically, white is allowed the b-file only by giving black the h-file, where black hsa two protected passed pawns
34. Kd1 Bringing the king closer to the centre for the endgame
Re7 e4 is lost
35. Rf3 Qxe4 36. Qxe4 Rxe4 Blacks position is 'obviously winning' but I struggle with end games. white still has the threat of the three connected pawns here
37. Ra3 h5 The Re4 is blocking the white king from the h-file, so whites rook will have to stop the h-pawn. Taking the a-pawn will be risky
38. Rxa5 Re5 h4 probably better, since the white rook will be forced back to protect h1
39. Ra3 Rxf5 Taking the pawn allowed the white king back into the game
40. Ke2 g4 41. Rg3 Rf4 42. a4 h4 43. Rg1 Re4+ 44. Kd3 f5 45. Rf1 Re5 46. a5 c4+ A sacrifice to clean up the a-pawn
47. Kxc4 Rxa5 48. Kxd4 g3 49. Rg1 f4 50. Ke4 Ra4+ 51. Kf3 h3 52. Rh1 h2 53. Kg2 Kg7 54. Rd1 Re4 55. Kf3 Re6 Black leaves the f-pawn hanging because Kxf4 g2 and there will be queens
56. c4 Rg6 57. Kg2 f3+ sacrificing the f-pawn to get the pawn dua on the 2nd rank
58. Kxf3 g2 0-1