1. Main line 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Choose a line 1. Main line 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 2. Botvinnik Variation 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. f3 d5 5. a3 Bxc3+ 6. bxc3 c5 7. e3 O-O 8. cxd5 Nxd5 Close 1. Main line 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 2. Botvinnik Variation 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. f3 d5 5. a3 Bxc3+ 6. bxc3 c5 7. e3 O-O 8. cxd5 Nxd5 Next