Grob Opening: what to play after d5?

In the Grob Opening, White typically continues with Bg2 to develop the kingside bishop and exert pressure along the long diagonal. This move is the most frequent choice in the position, appearing in 75.7% of the 6.42M recorded games, and aims to stabilize the position despite an engine evaluation of -1.55. By playing Bg2, White prepares to contest the center and potentially regain the pawn on g4 if Black chooses to capture it.

Strategic Objectives of Bg2

The move Bg2 is the cornerstone of the Grob system, placing the bishop on the long diagonal to influence the center and the queenside. Although the engine evaluates this position at -1.55, White maintains a 53.6% scoring rate from this point. The main line following this development is Bg2 Bxg4 c4 c6 Qb3 e6, where White sacrifices the g4 pawn to gain rapid piece activity and pressure against the b7 and d5 squares.

Black's Defensive Options

Black has several ways to exploit White's aggressive kingside expansion. The most direct response involves the capture of the gambit pawn, leading to the line Bg2 Bxg4. Alternatively, Black may focus on central control with e5, which is a common response when White plays g5 or e3. In the variation g5 e5 d4 exd4 c3 dxc3, the game takes on a highly tactical character where Black accepts a lead in development in exchange for White's space on the kingside.

Alternative Continuations

While Bg2 is the standard, other moves are occasionally employed to vary the pressure. The move g5 is played in 10.9% of games, pushing the pawn further to restrict Black's kingside development, though it carries an engine evaluation of -1.42. White also utilizes h3 in 4.9% of games to solidify the g4 pawn, often leading to the sequence h3 h5 gxh5 e5 d3 Nc6. Finally, c4 is a sharp alternative played in 57K games, leading to complex lines such as c4 Bxg4 Qb3 dxc4 Qxb7 Nd7.