After 5.e5, either 5...Ne4 or 5...Ng4 is a playable reply, but most common and natural is 5...d5 6.Bb5 Ne4 7.Nxd4 Bc5, with sharp play.
0-0 с примерным вариантом 4…Kf6:e4 5. d2-d4* 4. d2-d3 — Ведёт к спокойной игре.