context: 1. g1f3  1... g8f6  2. g2g3  2... g7g6  3. b2b3 Carlsen decides not to enter into a theoretical battle in the opening and chooses the calm double fianchetto variation. 3... f8g7  4. c1b2  4... d7d6  5. f1g2  5... e7e5 