Old Indian Defense: what to play after d6?

In the Old Indian Defense (ECO A53), reached over 14 million times in master-level practice, White's most direct and principled choice is Nc3. The move stakes out central control by reinforcing the d4 pawn, preparing the advance to e4, and providing White with a slight structural edge evaluated at +0.50.

The strategic role of Nc3

Developing the knight with Nc3 is the traditional approach to confronting Black's setup. White takes immediate command over the key central squares d5 and e4 without committing the kingside pieces prematurely. In an illustrative engine continuation, play develops along central lines with Nc3 e5 Nf3 exd4 Nxd4 Be7, where White utilizes the active placement of the central knight to maintain space and easy piece coordination.

Main alternatives for White

White also possesses flexible development schemes that avoid immediate queenside commitment. The natural Nf3 matches the primary choice in evaluation at +0.50, often transposing into main systems after Nf3 g6 Nc3 Bg7 e4 Bg4. Other solid, if somewhat less ambitious, continuations include e3 (eval +0.34), h3 (eval +0.26), and the fianchetto preparation g3 (eval +0.16), the latter of which can lead into g3 e5 d5 Be7 Nc3 O-O. While these secondary moves keep the position sound, Nc3 remains the most assertive route toward seizing central space.