Panteldakis Countergambit

The Panteldakis Countergambit meets the King's Gambit by copying it. With 2...f5, Black strikes at e4 and offers a pawn of their own rather than taking or ignoring the one on f4. It is one of the oldest ways to decline the gambit, and Gioachino Greco won a game with it as Black in 1625. The symmetry costs Black, though, because Black's king is more exposed than White's. The usual refutation is 3. exf5, which opens the h5–e8 diagonal and prepares Qh5+. The engine gives White a clear advantage. 3. exf5 is the most common reply, 3. Nf3 is played nearly as often, and 3. fxe5 is less frequent.

After 3. exf5, the natural 3...exf4 is risky because of 4. Qh5+. Black can then try the Shirazi Line, 4...Ke7, or the Pawn Sacrifice Line, 4...g6 5. fxg6 Qe7+ 6. Kd1. If White instead answers 3...exf4 with 4. Nf3, play can enter the Symmetrical Variation, 4...d5 5. d4 Bd6 6. Bd3. Black can also avoid capturing on f4 altogether. The Greco Variation, 3...Qh4+, uses the open e1–h4 diagonal at once, and Schiller's Defense, 3...Bc5, aims the bishop at g1.