Slav Indian: what to play after c6?

In the Slav Indian (ECO A50), White's primary and most principled continuation is Nc3, developing a minor piece while establishing firm control over the central d5 and e4 squares. Ranked highest by engine evaluation at +0.23, this natural developing move is chosen in 77.2% of recorded games (2.16M recorded), where White achieves a 53.1% score.

Strategic Objectives of Nc3

By developing the knight to the c3 square, White challenges Black's flexibility and prepares for broader central expansion. Rather than committing the kingside pieces early, Nc3 directly bolsters the d4 pawn and anticipates central pawn breaks. An illustrative engine continuation demonstrates this classical setup: Nc3 d5 Nf3 e6 Bg5 h6, where White steadily develops the kingside minor pieces and challenges Black's coordination.

Alternative Setups for White

White also possesses several sound alternatives that maintain an advantage according to engine analysis. The classical developing move Nf3 is the second most common choice, occurring in 16.3% of games (455K recorded) with an evaluation of +0.19 and a 53.5% score; it frequently leads into Nf3 d5 Nc3 e6 e3 Nbd7. A quieter setup arises after e3, seen in 4.9% of games (136K recorded) with a +0.19 evaluation and a 51.5% score, illustrated by e3 d5 Nf3 Bg4 Qb3 Qb6. White may also opt for a kingside fianchetto via g3 (+0.13, 1.6% of games, 53.1% score) leading to g3 d5 Nf3 Bf5 Nc3 e6, or test Qc2 (+0.07), which continues Qc2 d5 Nf3 g6 Nc3 Bg7.