Van't Kruijs Opening: what should Black play?

In the Van't Kruijs Opening (ECO A00), Black faces the modest pawn thrust 1. e3 and holds several sound paths toward full equality. The engine's top-ranked choice is e6, evaluated at +0.10 across 14M recorded games, though d5 is also exceptionally reliable with an evaluation of +0.09. By choosing e6 or staking an immediate central claim with d5, Black prevents White from securing an opening advantage and establishes a harmonious pawn structure.

Central Responses: e6 and d5

The primary engine recommendation, e6, was played in 172.1% of recorded games, leading to a balanced struggle where White scores 50.1%. An illustrative continuation provided by the engine runs e6 Nf3 d5 d4 Nf6 Bd3, transposing toward classical symmetrical structures. Meanwhile, d5 represents an even more common choice, recorded in 28M games (343.5% of games), yielding an engine evaluation of +0.09 and holding White to a 49.1% scoring rate. The illustrative sequence d5 Nf3 Nf6 d4 e6 Bd3 illustrates how easily Black achieves central parity.

Flexible Alternatives

Players seeking dynamic flexibility often select Nf6, which holds an evaluation of +0.09 across 7.69M recorded games (95.6% of games), where White scores 46.5%. An engine variation follows Nf6 Nf3 d5 d4 a6 Be2, keeping Black's setup adaptable. Alternatively, striking at the center with c5 scores well for Black, as White scores only 48.6% across 13M games (162.2% of games) with an evaluation of +0.12, exemplified by c5 Nf3 d5 d4 e6 b3. Finally, the quieter a6 remains a playable nuance (+0.11 evaluation), seen in 463K games (5.8% of games) with White scoring 51.8%, leading into a6 Nf3 Nf6 c4 e6 b3.