Salvio Gambit

The Salvio Gambit arises when White, faced with 4...g4 hitting the f3-knight, moves it to e5 rather than giving it up as in the Muzio Gambit (5. O-O). From e5 the knight joins the c4-bishop in eyeing f7, but h4 is no longer covered, and Black answers 5...Qh4+ in roughly four games out of five. Since the f4-pawn rules out g3, White must play 6. Kf1, giving up castling with a loosened king. This is the main reason the line is considered better for Black. Engines rate Black's advantage as clear, and Black wins most online games after the check.

After 6. Kf1 Black chooses between consolidation and counterattack. The Silberschmidt Defense, 6...Nh6, is the safe option, guarding f7. After 7. d4 d6 it becomes the Anderssen Counterattack, which challenges the e5-knight. The Cochrane Gambit, 6...f3, gives back a pawn to open lines toward White's king. Meanwhile 6...Nc6 (Viennese Variation) and 6...Nf6 (Santa Maria Defense) develop with gain of time against the knight or the e4-pawn. The rarer 5...Nh6 and 5...d5 score better for White.