1. e2e4  1... e7e5  2. g1f3  2... g8f6  3. f3e5  3... d7d6  4. e5f3  4... f6e4  5. c2c4 This move is not known to be wildly dangerous, and while Firouzja was playing very quickly to a point, I have to believe there was a better choice available against the Petroff. 5... b8c6  6. d2d3  6... e4f6 