1. Main line 1. d4 Nf6 2. Nf3 g6 3. g3 Bg7 4. Bg2 O-O 5. O-O d5 6. c4 Choose a line 1. Main line 1. d4 Nf6 2. Nf3 g6 3. g3 Bg7 4. Bg2 O-O 5. O-O d5 6. c4 2. Modern Defense 1. d4 Nf6 2. Nf3 g6 3. g3 Bg7 4. Bg2 O-O 5. O-O d5 6. c4 dxc4 3. Polgar Variation 1. d4 Nf6 2. Nf3 g6 3. g3 Bg7 4. Bg2 O-O 5. O-O d5 6. c4 Nc6 Close 1. Main line 1. d4 Nf6 2. Nf3 g6 3. g3 Bg7 4. Bg2 O-O 5. O-O d5 6. c4 2. Modern Defense 1. d4 Nf6 2. Nf3 g6 3. g3 Bg7 4. Bg2 O-O 5. O-O d5 6. c4 dxc4 3. Polgar Variation 1. d4 Nf6 2. Nf3 g6 3. g3 Bg7 4. Bg2 O-O 5. O-O d5 6. c4 Nc6 Next