Scandinavian Variation, Aachen Gambit

The Aachen Gambit arises when Black declines to recapture on d5 and plays 3...Nb4 instead. White stays a pawn up, with doubled d-pawns. The knight hits d5 and eyes c2, aiming to win the pawn back or provoke concessions. The engine rates White's advantage as large. The usual replies are 4. Nc3 and 4. c4, both guarding d5, and 4. c3, which questions the knight at once. White scores well after the first two, while Black has done better against 4. c3.