Polish Opening: what to play after e5?

In the Polish Opening after 1. b4 e5, White's most reliable and statistically dominant choice is Bb2. The move develops the queenside bishop along the long diagonal while counterattacking the undefended pawn on e5, which offsets the immediate loss of the b4 pawn. Evaluated by engines at -0.27, Bb2 is played in 85.5% of recorded games (7.94M recorded) and yields a White score of 55.9%.

Strategic concepts behind Bb2

The move Bb2 exemplifies the primary strategy of the Polish Opening (ECO A00). Instead of expending a tempo defending the advanced b4 pawn, White focuses on rapid piece activity against Black's central presence. The bishop exerts long-term pressure down the a1-h8 diagonal, turning Black's capture on b4 into an exchange of central control for flank material.

Illustrative engine continuations

The primary engine line continues with Bb2 Bxb4 Bxe5 Nf6 c3 Ba5. In this sequence, White immediately regains material by capturing on e5, gains time by hitting Black's dark-squared bishop with c3, and maintains an active post on the central diagonal. Another thematic alternative is the flank advance b5, seen in 7.5% of games (697K recorded) with an evaluation of -0.69, leading to lines like b5 a6 e3 d5 Bb2 axb5.

Minor alternatives

White occasionally opts for quiet pawn structures, though they yield less favorable evaluations. The prophylactic a3 is selected in 5.8% of games (537K recorded) and holds an evaluation of -0.44, typically leading toward a3 d5 e3 Bd6 Bb2 Nf6. A more passive option is c3, which carries a -0.82 evaluation and scores 44.0% for White across 113K recorded games, followed in engine analysis by c3 d5 Bb2 Nf6 e3 a5.