Classical Variation, Mestel Variation

The Mestel Variation is a branch of the Closed Variation, 4...Qe7, which is itself a minor sideline of the Classical Italian. After 5. d4, Black does not capture on d4. Instead 5...Bb6 retreats the bishop, so the e5-pawn stays in place and the central tension remains. White then plays 6. Bg5, developing with tempo by hitting the queen on e7 along the d8-h4 diagonal. Black has to deal with this threat at once, which shows how the queen can become a target on the e-file.