1. Main line 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Nf3 Choose a line 1. Main line 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Nf3 2. Main line, 5... dxc4 1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. g3 c6 5. Bg2 dxc4 3. Modern Sharp Variation 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Nf3 Nc6 6. Qa4 Bb4+ Close 1. Main line 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Nf3 2. Main line, 5... dxc4 1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. g3 c6 5. Bg2 dxc4 3. Modern Sharp Variation 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Nf3 Nc6 6. Qa4 Bb4+ Next