In order to bring the knight out, but Black lacks  the time for this.
1. g1f3  1... d7d5  2. e2e3  2... g8f6  3. c2c4  3... e7e6  4. b1c3  4... d5c4  5. f1c4  5... a7a6  6. e1g1  6... b7b5  7. c4e2  7... c8b7  8. a2a4 Technically speaking, a  novelty. However, White plays this move sooner or later, therefore, it  should come as a surprise for Black. Still, there is an important  difference in comparison to the usual lines. 8... b5b4  9. c3b1  9... c7c5  10. d2d3  10... b8c6  11. b1d2  11... f8e7  12. e3e4  12... a6a5 "A big mistake"  according to Artemiev. "It is not a good square (for the pawn) in the  endgame." 13. d2b3 This is the difference. The b3 spot is available  for the knight and Artemiev can put a lot of pressure against the a5 and  c5 pawns. 13... c5c4 Vitiugov decided to solve the problem of the backward pawn  at once, but this creates other issues. "Risky" said Artemiev. 14. d3c4  14... f6e4  15. d1d8  15... a8d8  16. c1e3  16... e8g8  17. e3b6 This bishop is the  problem. It paralyzes the black pieces because of the weak a5 pawn, and  provides control over the d-file for the white rooks. Artemiev also has a  valuable queenside majority. 17... d8a8  18. f1d1  18... f8c8  19. g1f1  19... e4f6  20. a1c1  20... e7d8 Finally Vitiugov decides to solve the problem of the  annoying bishop. 21. b6d8  21... c6d8  22. f3e5  22... g8f8  23. d1d6 That is one of the problems with the bishop swap.  White gets a square for his rook to infiltrate into the enemy camp. 23... a8a7  24. c1d1  24... d8c6  25. f2f4 Artemiev did not do anything exceptional and  nevertheless improved his position greatly. 25... b7a8  26. e2f3 With his next move Vitiugov makes things even worse for him. 26... c6e5  27. f4e5  27... a8f3  28. g2f3  28... f6e8  29. d6d4  29... f8e7  30. f1e2 