Sensibly clearing the long diagonal, as the Catalan bishop is always a pain. Up to here, Mamedyarov was practically blitzing.
1. d2d4  1... g8f6  2. g1f3  2... d7d5  3. c2c4  3... e7e6  4. g2g3 Carlsen keeps milking his amazing Catalan WCC preparation. 4... d5c4  5. f1g2  5... f8b4 Mamedyarov chooses a line that was tested by Topalov in both his WCC matches against Kramnik and Anand—and which was also often a choice of Carlsen himself. 6. c1d2  6... a7a5  7. e1g1  7... e8g8  8. e2e3 A very fresh line.