Modern Attack, Center Variation

After 3...Nxe4, White does not recapture on e5 at once but first develops the bishop with tempo against the centralized knight. Black is temporarily a pawn up, but the e5-pawn remains loose, so White expects to regain it on the next move while keeping the initiative. Engines consider the position roughly balanced, and White scores somewhat better in practice.

The overwhelmingly common answer is 4...d5, which supports the knight, stakes a claim in the center and frees Black's light-squared bishop. White usually follows with 5. Nxe5, entering the main theoretical line covered under the Modern Attack, although 5. dxe5 is an option for those wanting a less symmetrical structure. Black need not defend the knight immediately: 4...Nc6, the Murrey Variation, relies on the fact that if White takes on e4, Black can win back the piece with a pawn fork after ...d5 and an advance of the pawn. The retreat 4...Nf6 concedes time and the initiative, and White scores heavily against it in the database.