1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. g1f3  3... d7d5  4. g2g3 The choice of the Catalan Opening shows how seriously Carlsen was taking this match. That was his main opening in the world championship duel against Nepomniachtchi. 4... f8e7  5. f1g2  5... e8g8  6. e1g1  6... d5c4  7. d1c2  7... a7a6  8. a2a4  8... c8d7  9. c2c4  9... d7c6  10. c1g5 This is one of the most important positions in the Catalan. 10... a6a5 A rare move in Nakamura's games. The two most popular alternatives, 10...Bd5 and 10...Nbd7, had already been tried by him. 11. b1c3  11... b8d7  12. f1d1  12... h7h6  13. g5f6  13... d7f6  14. f3e5  14... c6g2  15. g1g2  15... c7c6  16. e2e4  16... e7b4  17. c4e2  17... d8b6 The first new move.