comment: Black loses a couple of tempi, but it might be worth it as long as the knight manages to comfortably attack the key e5-pawn.
context: 1. b1c3  1... g8f6  2. d2d4  2... d7d5  3. c1f4 Firouzja's bread-and-butter line. 3... c7c5  4. e2e3  4... c5d4  5. e3d4  5... a7a6  6. g1f3  6... b8c6  7. f3e5  7... e7e6  8. g2g3  8... c8d7  9. f1g2  9... c6e5 This line has picked up of late. 10. d4e5 