Developing the rook and freeing the f1-square for an escape by the king, or a protective withdrawal of the knight.
1. d2d4  1... g8f6  2. c1g5 Even Carlsen recognizes the brilliant discovery of Octávio Trompowsky, the 1939 Brazilian chess champion who supposedly invented or popularized this opening. 2... d7d5 Black ignores the knight capture on f6, which was assumed to be a \"threat\" when this variation was invented. White, for his part, completely ignores the knight, even when the bishop is provoked by the h-pawn. Such are modern times. 3. e2e3  3... c7c5  4. b1d2  4... b8c6  5. c2c3  5... c5d4  6. e3d4  6... h7h6  7. g5h4  7... c8f5 In terms of theory, Black solves his problems when this bishop can be developed so easily. 8. g1f3  8... e7e6  9. f1e2  9... f8d6  10. e1g1  10... d8c7 Firouzja is a very aggressive player and he delays castling because he is eyeing an attack on the kingside. 11. h4g3  11... d6g3  12. h2g3  12... h6h5 [%c_effect h5;square;h5;type;Interesting;persistent;true] A new move, with a very direct idea: to advance the h-pawn and deliver checkmate, sacrificing whatever is necessary along the way.