Carlsen does not intend to play the pure Closed Sicilian. The knight move allows him to switch to the Grand Prix Attack, an annoying way to counter the Najdorf Sicilian.
2...d6 [After the usual 2...Nc6 white can play 3.Nf3 preparing to open the game with d2-d4, throwing the Najdorf players off the track.]
3.f4 Nc6 [In the blindfold game Carlsen-Anand, the Indian grandmaster was prepared and left his knight home for a few moves: 3...g6 4.Nf3 Bg7 5.Bb5+ Bd7 6.Bc4 The last two moves allow white to control the breaks in the center with the d-pawn. 6...Nc6 7.0-0 Na5 8.d3 Nxc4! 9.dxc4 Bxc3! 10.bxc3 Bc6 and black solved all problems. As a matter of fact, Anand thought that white is positionally busted. Here is the rest of the game: 11.e5 Qc7 12.Qd3 f5 13.Ng5 h6 14.Qh3 dxe5 15.Be3 e4 16.Ne6 Qc8 17.Nxc5 Nf6 18.Bd4 Kf7 19.Rae1 a5 20.Re2 b5 21.Nb3 bxc4 22.Nd2 Bd5 23.Rfe1 Qd8 24.Qh4 e6 25.Rb1 Qe7? (25...Nh5! 26.Qf2 Re8 with black's advantage.) 26.Nxc4 Nd7 27.Qxe7+ Kxe7 28.Ne3 Rhb8 29.Rxb8 Rxb8 30.c4 Bc6 31.Rd2 e5 32.Bxe5 Nxe5 33.fxe5 f4 34.Nd5+ Bxd5 35.Rxd5 Rb1+ 36.Kf2 Rb2 (36...e3+! 37.Ke2 Rg1 wins easily for black.) 37.Rd4 Rxc2+ 38.Kf1 f3 39.gxf3 exf3 40.Rd6 g5 41.Rxh6 Rxa2 42.h3 a4 43.Rf6? (After 43.c5!? a3 44.Ra6 Ra1+ 45.Kf2 a2 46.c6 Rh1 47.c7 Kd7 48.Ra7 threatening 49.e6+, black has to take a draw, since 48...a1Q? 49.e6+ Kc8 50.Rxa1 Rxa1 51.e7 wins for white.) 43...Ra1+ 44.Kf2 a3 45.Ra6 a2 , followed by 46...Rh1 47.Rxa2 Rh2+ wins. 0-1 Carlsen,M (2815)-Anand,V (2817)/Monaco MNC 2011]
4.Nf3 g6 5.Bb5 [The more central bishop development 5.Bc4 is twice as popular, but Carlsen's choice should not be underestimated.]
5...Bd7 6.0-0 a6 7.Bxc6 Bxc6 8.d3 Bg7 9.Qe1 Qd7 10.a4!? Threatening to fix the black queenside with 11.a5. It comes from the creative mind of GM Ljubomir Ljubojevic who played it 20 years ago with mixed results against Garry Kasparov and Lajos Portisch.
10...f5? An outright positional blunder, weakening the square e6 and inviting the white cavalry to charge. [10...b6 stops white's intention. It was chosen overwhelmingly by other players, including Kasparov.]
11.Nd5! The knight leaps forward at the right time, disrupting black's development and causing havoc.
11...fxe4 [11...Bxd5 12.exd5 Nf6 13.c4 0-0 14.Ng5 [White is slightly better] ]
12.dxe4 [12.Nb6? Qd8 13.Nxa8 exf3 and black wins.]
12...Rb8 [Black could have saved time with 12...Bxd5 13.exd5 Nf6 (13...Qf5 14.c4 Qd3 15.Qe6 Qxc4 is dangerous, for example 16.Re1 Rd8 17.Ng5 Qd4+ 18.Kh1 Qf6 19.Qe2 Rd7 20.Ne6 Nh6 21.g4 and white has too many threats.) 14.c4 0-0 ]
13.Ng5! Threatening to invade black's position with 14.Ne6, since 14...Qxe6? allows 15.Nc7+ winning the queen. [Deep Fritz 12, a computer engine, prefers 13.Nb6 Qd8 (13...Qg4 14.Ra3 Nf6 15.Ng5 looks dangerous for black.)) 14.a5 for example 14...Nf6 15.Ng5 Bd7 16.e5 and white wins.]
13...Bxd5 14.exd5 Qf5 15.Ne6 [Carlsen jumps in, indirectly protecting the d-pawn (15...Qxd5? 16.Nc7+ wins). He could have covered the light squares with 15.Qd1 Nf6 16.Ne6 Kf7 17.c4 ]
15...Bf6 [Topalov discards the daring 15...Bd4+ for example 16.Be3 (16.Kh1 Qxc2 ) 16...Bxb2 17.Rb1 Bf6 18.Qd2 with white's edge.]
16.Qe2 Threatening to win with 17.g4.
16...h5 [After 16...Nh6 comes 17.h3 ]
17.Ra3! Carlsen turns the forgotten piece into a monster, going after the black queen.
17...Nh6 18.Rg3 Threatening 19.Rg5. [18.Rd3 is not bad either.]
18...Kd7 19.Rg5!? [Carlsen executes his threat, perhaps noticing that 19.c4 gives the black queen a surprising escaping square on b1. Joking aside, white could have cemented his advantage with 19.Rd3. ]
19...Bxg5 20.fxg5 Qxd5 [20...Qg4 21.Qd2 Nf5 22.Rf4 wins.]
21.Nf4 Qd4+ 22.Be3 Qe4 [22...Qxa4 23.gxh6 Rxh6 24.Nd5 wins]
23.gxh6 Rxh6? [23...Rbf8! would make it more difficult for Carlsen, for example: 24.Qf3! the best choice (24.Re1!? Rxf4 (24...Rxh6 25.Ne6+- ) 25.Bxf4 Qxf4 26.Qxe7+ Kc6 27.h7 looks seemingly great for white, but black can still fight either after 27... 27...g5 (or after 27...Qd4+ 28.Kh1 g5 29.Rf1 Qxa4 30.h3 Qxc2 31.Rf7 b6 32.Qd7+ Kd5 33.Rf6 Kc4 34.Qxd6+- ) 28.Rf1 (28.Qg7 Rf8 ) 28...Qxa4 29.Qg7 Qd4+ 30.Qxd4 cxd4 31.Rf7 a5 32.Kf2 b5 ; 24.Qd2?! g5 25.Nd3 Rxf1+ 26.Kxf1 Qf5+ 27.Kg1 c4 28.Ne1 Rxh6 [White is slightly better] ) 24...Qxf3 25.gxf3 Rfg8 26.Nd5 g5 27.h4 gxh4+ 28.Kh2 and white still keeps winning chances because of his strong h- pawn.]
24.Nd5 Rhh8 25.Qd2 Rhf8 26.Re1! Threatening to win with the discovered attack 27.Bxc5.
26...Rf5 Black had no defense. [26...Qf5 27.Bxc5+- ; 26...Kc6 27.c4! Qxc4 28.Nxe7+ Kc7 29.Rd1 Rbd8 30.Bg5 Rd7 31.Nd5+ Kc6 32.Nf6 wins.]
27.Nb6+ Kc6 28.Bxc5 Rbf8 29.Bd4! [Avoiding 29.Rxe4?? Rf1# Carlsen threatens a deadly check 30.Qc3+.] 1-0