This is probably not the best square for the bishop.
1. g1f3  1... g8f6  2. c2c4  2... c7c5  3. b2b3 Carlsen is a player who can literally choose any opening variation. I believe it's the first time he plays this line. It takes great confidence and exceptional memory to do this, qualities he doesn’t lack. Among world champions, none can be compared to him in this versatility. Of elite players, only Ivanchuk manages a similar feat. 3... b8c6  4. c1b2  4... d7d5  5. c4d5  5... f6d5  6. b1c3  6... e7e5  7. d1b1 [%c_effect b1;square;b1;type;Interesting;persistent;true] A theoretical novelty already. This is a thematic move in positions with this pawn structure, and it's curious that it has never been played. This probably happened because nobody saw the need to look for such a move. 7... f8e7  8. e2e3  8... c8e6  9. f1b5  9... f7f6  10. e1g1  10... d5c3  11. d2c3 White decides to change the pawn structure. 11... d8c7  12. f1d1  12... e8g8  13. b5d3  13... f6f5 An ambitious move, in the style of Erigaisi. Against 13...g6 White has perpetual check. I doubt this would be his choice, but there's no advantage anyway. 14. e3e4  14... f5f4  15. d3b5 [%c_effect b5;square;b5;type;GreatFind;persistent;true] The bishop has done its job and now returns to capture the knight. 15... e7f6  16. b5c6  16... c7c6  17. c3c4 White can fight for a small advantage here, as Black's bishops aren't as dangerous with the center closed. Also, the pawn on e5 is a headache. I must admit that during the game I thought the only way to break Black's position would be an exchange sacrifice by putting the rook on d5 at some point. But let's see what happened. 17... c6c7  18. b2c3  18... a8e8  19. b1b2 