Scotch Game: what to play after Nb4?

In this position arising from the Scotch Game, White's most accurate move according to computer analysis is Be3, evaluating at +1.19. The move develops the queenside bishop while preparing to meet Black's counterplay against the advanced d5 wedge. By developing with Be3, White maintains control over central squares before deciding how to address the misplaced knight on b4.

Strategic Goals of Be3

The primary virtue of Be3 is active piece development combined with central defense. Rather than immediately rushing to kick the knight, White strengthens the center and leaves the option of chasing the b4 on the following turn. An illustrative engine continuation demonstrates this approach: Be3 c6 a3 Na6 c4 Nh6. In this sequence, White drives the knight to the passive rim square a6 while building an enduring spatial advantage with pawns on c4 and d5.

The Popular Move a3

Although the engine evaluates Be3 as slightly superior, human practice heavily favors the direct a3, which occurs in 72.7% of games (56K recorded) with an evaluation of +0.99. This move immediately forces Black's hand, asking the knight to declare its intentions. The engine's illustrative line continues a3 Na6 Be3 Nf6 Bxa6 bxa6, where White liquidates the misplaced knight and leaves Black with doubled pawns on the a-file.

Alternative Setups

White possesses several other sound setups in this position. The natural development Nc3 is chosen in 16.0% of games (12K recorded, eval +0.91), leading into lines like Nc3 Be7 Be3 Nf6 a3 Na6. White can also play the space-gaining c4 (9.9% of games, 7.6K recorded, eval +1.04) or the prophylactic h3 (1.4% of games, 1.0K recorded, eval +1.18), both preserving a comfortable positional plus.