With 9...Nb8 Black frees the c-pawn and intends to route the knight to d7 where it supports e5. If White fortifies the centre with 10.d3 the opening is classified "ECO" code C94. The more common continuation, 10.d4, is "ECO" C95. The main line continues 10.d4 Nbd7 11.Nbd2 Bb7 12.Bc2 Re8 13.Nf1 Bf8. Black is threatening to win the e4-pawn via ...exd4 uncovering an attack on the pawn, so White plays 14.Ng3. Black generally plays 14...g6 to stop White's knight from going to f5. White then usually tries to attack the Black queenside via 15.a4. Black seeks in the centre via 15...c5. White can attack either the kingside or the queenside. This forces resolution of the centre via 16.d5. Black can exploit the weak squares on the queenside via 16...c4. White will try to attack on the kingside via 17.Bg5, moving forces to the kingside. Black will kick the bishop with 17...h6. The logical retreat is 18.Be3, which is met by 18...Nc5. White plays 19.Qd2, forcing 19...h5. The point of this manoeuver was to weaken Black's kingside.