O'Neill Gambit: what should White play?

In the O'Neill Gambit, White faces the immediate flank challenge of an undefended b-pawn. The strongest and most direct continuation is Bxb5, capturing the offered material to claim a clear positional and material advantage. By accepting the gambit, White secures a +1.70 engine evaluation and achieves a 63.1% scoring rate across 437K recorded games.

Accepting the Gambit with Bxb5

Capturing the pawn via Bxb5 is chosen in 31.4% of the 1.39M recorded positions, proving to be White's most effective option. Black concedes a pawn on the second move without an immediate tactical recovery, allowing White to develop a piece while gaining material. An illustrative continuation shows play unfolding with Bxb5 Bb7 d3 e6 Nf3 c5, where White solidifies the center and completes kingside minor-piece development with an extra pawn in hand.

Positional Alternatives: Nf3 and d4

Despite the objective strength of taking the pawn, Nf3 is the most popular choice, occurring in 39.2% of games (545K recorded) and yielding a 57.7% score. Following Nf3 Bb7 d4 Bxe4 Bxb5 c6, play simplifies while White maintains a modest +0.73 advantage. Another common path is d4, selected in 27.1% of games (377K recorded) with an evaluation of +1.03 and a 58.2% score, leading into lines such as d4 a6 Nd2 e6 a4 b4.

Secondary Options

White can also explore Qf3, which appears in 2.4% of games (33K recorded) with an evaluation of +0.65 and a 63.3% score, often continuing Qf3 a6 a4 b4 d4 e6. Alternatively, Ne2 offers a +0.61 evaluation, with an engine continuation running Ne2 Bb7 Ng3 a6 d4 Nf6. While several setups leave White in a solid position, accepting the pawn immediately via Bxb5 remains the most decisive response.