Main Line

After 3. Nxe5 Qf6, White answers the attack on the knight with 4. d4, the old main line of the Latvian Gambit (also called the Greco Countergambit). Instead of moving the knight, White supports it with a pawn and sets up the pair d4 and e4, which makes developing the remaining pieces straightforward. To dislodge the knight Black has to play ...d6, which blocks the f8-bishop. That is why 4...d6 is chosen in the great majority of games. The traditional continuation is 5. Nc4 fxe4, and play often goes on with 6. Nc3 Qg6. Black's other tries are rare. 4...fxe4 leaves the knight on e5 and does badly in practice, and 4...Nc6 is an occasional alternative.

The engine gives White a clear advantage, yet Lichess results are almost exactly even. Theory now regards the immediate 4. Nc4, the Leonhardt Variation, as the more critical test. It keeps open the option of d2-d3 to challenge a black pawn arriving on e4, and this has pushed 4. d4 into second place.