context: 1. d2d4  1... d7d5  2. c2c4  2... e7e6  3. b1c3  3... g8f6  4. c4d5  4... e6d5  5. c1g5  5... f8e7  6. e2e3  6... c7c6  7. f1d3  7... b8d7  8. g1e2 The knight development on e2 was Kasparov's favorite. White can wait by playing 8.Qc2 before deciding where the knight goes, or he can also play 8.Nf3. 8... d7f8 Many ideas have been developed recently to give a new flavor to Black in the Exchange Variation of the Queen's Gambit. This move is one of those ideas. It's the first time Caruana has played it. 9. d1c2  9... f8e6  10. g5h4  10... g7g6  11. a1d1 Played in just two games, but we will have a transposition in the next move. 11... e8g8  12. e1g1 With the rook on d1, it's clear that White is intending the typical plan with f3-e4. 12... a7a5 An almost new move in this position (it was played in just one game), but a well-known plan from modern games. Historically, Black didn't play this way, advancing the queenside, but computers have shown that this is a viable plan. This active plan has transformed the orthodox from a reliable but somewhat passive defense into as good a weapon for playing for a win as any other. 13. e2c1 This move allows an interesting idea that equalizes the game. 13... e6g7  14. f2f3 The game is back to normal. 14... c8e6  15. c1e2 The knight returns. 15... a8c8  16. g1h1 It's useful to free the g1-square for the bishop, since this may be needed after a possible e4-dxe4-fxe4-Ng4 (considering the bishop is on f2). 16... f6d7  17. h4f2  17... b7b5  18. e2f4  18... d7b6  19. e3e4 The opening is a relative success for White; he has the initiative. 19... e7g5  20. f2e3  20... d5e4  21. f3e4  21... e6g4  22. c3e2 This move is refuted by Caruana's excellent reply. Both 22.Rc1 and 22.Rde1 keep the advantage. 22... f7f5 There is an accumulation of black pieces in the g-file, but interestingly this isn't bad. With this move, Black takes advantage of the strength of the bishops and the support of the knight on g7 to break White's center. 23. e4f5  23... g7f5 The best capture. Excellent calculation by Caruana, since he had to foresee what to do against White's next move. 24. c2b3  24... b6c4  25. d3c4  25... b5c4  26. b3c4  26... f8f7  27. e3c1 This allows a surprising win for Black. 27... d8e7  28. d1e1 The game is again equal. 28... g5h4  29. e2g3  29... e7b4  30. c4b4  30... a5b4  31. g3f5  31... g4f5 Despite being a pawn up, White still has to be careful. The pair of bishops is very strong. 32. g2g3  32... h4f6  33. d4d5 A normal reaction. 33... f5d7  34. f4d3 White has many alternatives. 34... c6d5  35. d3b4  35... d7b5  36. f1f4 The wrong square. 36... f7e7 Caruana is merciless. 37. c1d2  37... e7e1  38. d2e1  38... f6e5  39. e1c3 White has to give up the exchange. 39... e5f4  40. g3f4  40... g8f7  41. b4c2  41... b5c4  42. a2a3  42... c8e8 