Slav Indian

The Slav Indian arises after 1. d4 Nf6 2. c4 c6, an uncommon second move within the Indian Defense family, classified under ECO A50. The c-pawn advance prepares ...d5 with pawn support. Black usually intends to reach the Slav Defense by a route that delays the central commitment by a move. This differs from the direct 2...d5, the Marshall Defense, where 2...d5 3. cxd5 Nxd5 4. e4 lets White build a broad center with gain of time. Here a later ...d5 can be met by cxd5 and recaptured with the c-pawn, so Black keeps a pawn on d5.

The move order keeps more than one structure open. If Black follows up with ...d5, the game normally enters Slav territory, with its solid d5–c6 chain and play built around developing the queen's bishop outside the pawn chain. If Black instead chooses ...d6, the position can transpose into the Old Indian or, with a kingside fianchetto, even the King's Indian. The pawn on c6 then serves as support for central or queenside expansion rather than for d5. Which structure arises depends largely on Black's third and fourth moves.

White's most popular reply by a wide margin is 3. Nc3, followed by 3. Nf3. Both allow the transposition to the Slav. 3. e3 is an occasional, quieter choice. Players who want to keep Black out of the Slav can try 3. Bf4 instead. In the database sample White scores somewhat better than Black and draws are infrequent. The engine regards the position as roughly balanced, preferring the natural developing moves Nf3 and Nc3.

The opening produces few independent lines, since it so often transposes to established defenses. The main exception is the Kudischewitsch Gambit, 3. Nf3 b5, named after the Israeli International Master David Kudischewitsch. Black challenges the c4-pawn at once instead of preparing ...d5, giving the game a queenside character of its own. The same position can also arise via 1. d4 c6 2. Nf3 Nf6 3. c4 b5. It is an offbeat choice and rarely seen at a serious level.