Zukertort Opening: Tennison Gambit: what to play after Ng5?

In the Zukertort Opening: Tennison Gambit, Black faces an immediate assault against the advanced pawn on e4. The top engine recommendation is Bf5, which defends the pawn while developing a minor piece to secure a clear advantage evaluated at -1.14. By prioritizing piece activity and pawn defense, Black neutralizes White's early aggression and keeps the gambit pawn safely in hand.

Strategic merits of Bf5

Played in 20.0% of recorded games (3.49M recorded), Bf5 is Black's most effective continuation against the Tennison Gambit. It develops the light-squared bishop outside the pawn chain before White can mobilize an attack against f7 or reclaim the gambit material. The engine main line demonstrates this resourcefulness through Bf5 Nc3 Nf6 d3 exd3 Qf3, where Black comfortably transitions into active piece play while managing White's threats against the bishop and the queenside.

Alternative defenses

Black can also return the pawn or seek open development with e5, chosen in 7.9% of games (1.38M recorded) and evaluated at -1.10. Following the continuation e5 d3 exd3 Bxd3 Nc6 O-O, Black stakes a claim in the center and achieves easy piece development. Solid alternatives include Nc6 (eval -0.76, 4.0% of games, 700K recorded), following Nc6 Bc4 e6 Nxe4 f5 Ng3, and e6 (eval -0.71, 3.1% of games, 535K recorded), continuing e6 Nxe4 f5 Nec3 Nc6 Bc4.

The popular Nf6

By far the most common human choice is Nf6, appearing in 65.0% of encounters (11M recorded) out of 17,439,386 total games. Despite its overwhelming popularity, the engine evaluates it at -0.51, offering Black a smaller edge than the top lines. An illustrative continuation runs Nf6 Bc4 e6 Nc3 b6 Ncxe4, where White regains the pawn but Black retains a sound, functional setup.