1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. g1f3  3... d7d5  4. b1c3  4... f8e7  5. c1f4  5... e8g8  6. e2e3  6... c7c5  7. d4c5  7... e7c5  In some sense a tribute to Kasparov, who mentored both Nakamura and  Carlsen at phases of their chess development. The 13th world champion  successfully implemented the QGD in his first matches against his great  predecessor on the throne, A. Karpov. 8. a2a3  8... b8c6  9. d1c2  9... f8e8  10. f4g5  10... c5e7  11. a1d1  11... d8a5  12. f1d3  12... d5c4 A novelty that allows a  deviation from the main line. 13. d3c4  13... h7h6  14. g5f4 Carlen decided to go off the beaten track as early as he could. He clearly understood that in comparison to another line of  the QGD, his opponent would have two extra tempi but saw no way for him to utilize on those. 14... c8d7  15. e1g1  15... a8c8  16. e3e4 