Chess Opening Theory/1. d4/1...d5/2. c4/2...c6/3. cxd5/3...cxd5/4. Nc3

Slav defence D10 Exchange variation 4. Nc3 White doesn't reveal their intentions yet and simply develops the knight to its most natural square, putting pressure on d5. Black's main response is /4...Nf6/, overprotecting the d5 pawn and developing the kingside. Black can also play /4...Nc6/, often transposing to the same lines as 4...Nf6. However, this move does give White additional options. One of those options being 5. e4, which would have been prevented by 4...Nf6, transposing into a position resembling the French defence. Theory table 4...Nf6 5. Bf4 Nc6 6. e3 a6 4... ... 5. Nf3 Nc6 6. Bf4 Bf5 Boor attack 4... ... 5. f3 Nc6 6. e4 dxe4 References