Winawer Variation, Advance Variation, Moscow Variation

The Moscow Variation replaces the usual 5. a3 with 5. Qg4, striking at g7 while the bishop on b4 is still developed away from the kingside. White skips the exchange on c3 and goes straight for the dark squares around Black's king. The most common answer is 5...Ne7, which guards g7 at the cost of leaving g7 to its own protection. Black also plays 5...g6 and 5...Kf8, and White has done better against 5...g6. It is rarely seen, the engine considers the position balanced, and White has scored somewhat better in practice.