Perfect play! Shankland wants the long diagonal  for his bishop, and he needs it now.
1. d2d4  1... g8f6  2. g1f3  2... d7d5  3. e2e3  3... c7c6  4. c2c4  4... e7e6  5. b1c3  5... b8d7  6. d1c2  6... f8d6  7. f1d3  7... d5c4  8. d3c4  8... e8g8  9. e1g1  9... b7b5 Shankland was very successful with this concrete,  double-edged line against Ding Liren last year. But his choice is peculiar as one other top player who enjoys playing this as Black is... Korobov! 10. c4e2  10... c8b7  11. e3e4  11... e6e5  12. d4e5  12... d7e5  13. f3h4 White needs the opponent's knight in the center to gain tempos for his central pawns to advance. 13... g7g6  14. f2f4  14... e5g4 But Black also enjoys owing the knight. The position is  extremely sharp. If Black does not demonstrate enough activity with his  pieces, he will get blown away by the white central pawn pair. 15. g2g3  Cementing the position. 15... d6c5  16. g1h1  16... b5b4  17. c3d1  17... c5d4  18. e2f3  18... c6c5 The most logical move turns out to be a novelty. 19. e4e5  19... f6d5  20. c2g2 Korobov wants to push back the black pieces in the  most comfortable way, but this turns out to be too slow. 20... d8d7  21. h2h3 