Welcome to Chessdom live commentary. Today's game is the most important in group C: the two players are leading with 5/7, and a win for either player means very good chances to win the tournament.
Braun almost always plays 1.d4. Against the Slav (1.d4 d5 2.c4 c6), current Caruana's main defence, Arik has a very good score, so he probably won't avoid it with 1.Nf3, his secondary choice. After 3.Nf3 Nf6, in recent times 4.Qc2 is the star move, but it's not in Braun's repertoire. We'll probably see a main line Slav, with 4.Nc3 dxc4 5.a4.
1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bf5 6.e3 e6 7.Bxc4 Bb4 8.O-O O-O Main line Slav :)
9.Nh4 Qe7 Until now they're following round 6 game Krush-Caruana.
10.f3 Irina Krush played the standard move 10.Nxf5. The text move was played in Piceu-Rosmuller, Vlissingen 2005.
10... Rd8 Black doesn't bother about Nxf5, since the pawn at f5 would challenge the e4 square.
11.Qb3 Here Rosmuller played ...c5. ...Bg6 and ...Na6 or ...Nbd7 are also possible.
11... Bg6 A novelty.
12.Nxg6 hxg6 13.Na2 Ba5 14.Rb1 White has the two bishops, but ...c5 will soon follow and his center will be broken. Black has almost reached the equality.
14... a6 Black puts a first obstacle to the minority attack (Qc2, b2-b4-b5) that White is going to play after the preparatory Rb1. He's also ready to play ...b5.
15.Qc2 Nbd7 16.b4 Bc7 White can now complete his minority attack with 17.b5, but after ...axb5 18.axb5 c5! 19.Rd1 cxd4 20.Rxd4 Rdc8 followed by ...Bb6 he doesn't obtain any advantage on the Queenside, while Black's pieces will assume very active posts.
17.a5 White chooses instead to block the Queenside, and ...c5 is stopped, but the b4 pawn is weak. Black can now attack the center with ...e5.
17... e5 White now has a difficult decision: to get an isolated d4 pawn, or to allow the exchange of dark sqaured bishops, after say 18.Bb2 exd4 19.Bxd4 Be5, or to allow Black to assume control on the 'd' file.
18.dxe5 After this exchange, Black's pieces will become very active: ...Nxe5, idea ...Nd3! and ...Qd6 is threatened, and a nice Bishop endgame is at the horizon.
18... Nxe5 And now Black takes command of the center, thanks to White's quite passive Queenside pieces.
19.Be2 g5 ! Threatening ...g4, for example: 20.Bb2? g4 and now 21.f4 fails to ...Nd3 and White should lose at least a pawn.
20.Rb3 Preventing ...Nd3.
20... Nd5 Increasing the pressure on b4 and e3.
21.g3 To defend g4 threatening e3-e4.
21... Bd6 Allows a retreat for the Knight after e3-e4, while brings another attack to b4.
22.Qb1 Defending b4. (22.e4 simply failed to 22... Nxb4 23.Nxb4 Bxb4 24.Qb2 Bc5+ followed by ...Rd7.) ( A strong alternative was 22.Bb2 and b4 is defended, beacuse of Bxe5.)
22... Bb8 With the idea ...Ba7; now 23.e4 is risky because the King will be unsecure.
23.e4 Ba7+ 24.Kh1 Nc7 25.f4 A risky decision, but what else? White pieces are somewhat uncoordinated and Black threatened to take command of the whole board, with moves like ...Ne6-d4, ...Rd7 and ...Rad8.
25... Ng6 26.e5 White overextends his center and surrenders the d5 square.
26... Nd5 27.Qe4 Re8 ( More accurate was 27... Rd7 followed by ...Rad8. Now White can reduce the pressure with 27.Nc3.)
28.Bd3 Qd7 29.Qf3 With the annoying threat Bxg6.
29... Qh3 Strange choice: Caruana allows the destruction of his Kingside pawns for a vague attack; White has also another chance of simplifying with Nc3.
30.Nc3 Nxc3 31.Rxc3 White has solved some problems in the center, but he's still faced with a difficult endgame after Bxg6.
31... Rad8 32.Bc4 White keeps his bishops and threatens further simplifications with Rd3.
32... gxf4 33.Bxf4 Braun accepts an isolated pawn but he gains good chances along the 'f' file. Now ...Nxf4 fails to 34.Qxf4 winning.
33... Rf8 Having a displaced Queen, Caruana is forced to defence.
34.Rd3 Rxd3 35.Qxd3 Bb8 36.Rf2 Setting up the trap ...Nxe5?? 37.Bxe5 Bxe5 38.Bxf7+, while at the same time threatening Qxg6.
36... Qh5 37.Qe4 More enterprising 37.Qd7.
37... Nxe5 Caruana wins a pawn, but the opposite Bishops and the blocked position on the Queenside may easily lead to a draw.
38.Be2 Not understandably White avoids that ending and keeps his bishop pair, but that's very dangerous, being a pawn down!
38... Qg6 39.Qd4 Ng4 40.Rf1 Bxf4 Exchanging White's bad Bishop, but depriving him of the Bishop pair. The endgame is still slightly favourable to Black.
41.Rxf4 Nf6 42.Bd3 Qg5 43.Rf5 Qh5 ( Another try would be 43... Qg4 trying to enter a favourable Rook and minor piece ending.)
44.Re5 Qh3 45.Kg1 Qc8 Caruana needs to reorganize his forces to start playing for a win.
46.Bc4 Prevents ...Nd5 but allows ...Rd8.
46... Rd8 47.Qf2 ? (47.Qc5 was the only try, keeping the pressure: 47... Qg4 ? 48.Bxf7+)
47... Qd7 ( Missing 47... Qg4 winning.)
48.Re1 Qd4 Fabiano tries to exchange the Queens in a very favourable position now.
49.Qxd4 Rxd4 50.Rc1 Black has now a won position. First of all he needs to centralize his King.
50... Kf8 51.Kf2 ? Better was 51.h3, preventing the following move.
The b4 pawn is going to fall, and Black two pawns up is winning.
Caruana gained some advantage in the opening, but then dissipated it; in the mutual zeitnot, White obtained good drawing chances, but refused to enter the opposite bishops ending, at the same time losing a pawn. Then Caruana played perfectly and scored his point. He's now the clear leader of the tournament, and has good chances to win it. Go Fabiano! 0-1