1. Main line 1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. Nf3 Bg7 5. Bf4 O-O 6. e3 Choose a line 1. Main line 1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. Nf3 Bg7 5. Bf4 O-O 6. e3 Close 1. Main line 1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. Nf3 Bg7 5. Bf4 O-O 6. e3 Next