It's always difficult to decide how to break the tension of the pawn structure. Here, for example, which is correct: to exchange on c4, leaving both players with three pawn islands, or to play b4 and move the white knight to the flank, with the potential risk of creating weaknesses on the queenside $2 I think Fedoseev's choice is the best one.
1. e2e4  1... e7e5  2. g1f3  2... g8f6 The Petroff Defense continues to have an unshaken reputation as an indestructible defense, but the problem is that Carlsen is known for winning endgames in which he doesn't need an advantage. This explains his opening choice. 3. f3e5  3... d7d6  4. e5f3  4... f6e4  5. d1e2 When I was a kid this move, preparing the exchange of queens, had the reputation of being a ridiculous and blatant attempt to play for a draw, but post-Carlsen times have put an end to many preconceived ideas. 5... d8e7  6. d2d3  6... e4f6  7. b1c3  7... e7e2  8. f1e2  8... f8e7 The queens are exchanged, and the position is apparently harmless, but it's good to remember that White is two tempi ahead, as he has the knight on c3, and it's his turn to play. 9. c3b5 A move that was played in only a few games. It looks like a move from an under-8 tournament, where brutal threats are so popular, but in the elite it also has a positional idea: to advance the pawn to c4 and bring the knight back. 9... e7d8  10. c2c4 [%c_effect c4;square;c4;type;GreatFind;persistent;true] 10... e8g8  11. c1e3  11... b8c6 The advantage of the move 9...Bd8 is that the knight can be developed on this more active square. 12. h2h3 Useful to prevent Ng4. 12... f8e8  13. e1c1  13... a7a6  14. b5c3  14... b7b5 [%c_effect b5;square;b5;type;GreatFind;persistent;true] An excellent move to create counterplay, taking advantage of the fact that the pawn cannot be captured. 15. h1e1  15... c8b7  16. d3d4 