Pin the c3 knight with ...Bb4, then break with ...d5. Against 7.Bd3, pin too. Also reached by 5.Be3 Qc7 6.Nc3 Nf6, by 2.d4 cxd4 3.Nf3 e6, by 2.Nc3 e6 3.Nf3 a6 4.d4 (or 2.Nf3 e6 3.Nc3), and with 7.Qd2 Bb4 8.f3. Merged lines 1, 3, 9, 10, 21, 28, 40, 41, 42.