Horwitz Gambit

After 2...Nf6 3. Nc3, a position also reachable from the Vienna Game via 2. Nc3 Nf6 3. Bc4, Black strikes at the c4-bishop with 3...b5, giving up a pawn to divert it from its watch over d5 and f7. White usually accepts with 4. Bxb5, while 4. Nxb5 and the retreat 4. Bb3 are also seen. The gambit is rarely played, White scores well, and the engine gives White a clear advantage.