Firouzja has played 6...Nc6, 6...g6 and 6...e5 before. Now he tries a fourth move. Black stops g2-g4 in the most primitive way.
1. e2e4  1... c7c5  2. g1f3  2... d7d6  3. d2d4  3... c5d4  4. f3d4  4... g8f6  5. b1c3  5... a7a6  6. h1g1 This is a relatively modern move that is unmistakably intended to put a pawn on g4, a strategy that White normally begins with f3 or h3. But why not support this advance with the rook $2 Several of the best chess players in the world have attempted this ambitious idea, including Carlsen a few times previously.