context: 1. d2d4  1... g8f6  2. g1f3  2... d7d5  3. c1f4  3... e7e6  4. e2e3  4... c7c5  5. f1e2 5.c3 was played in the sixth game of the match. 5.Nbd2 is very popular. 5... f8d6  6. d4c5  6... d6c5  7. c2c4  7... e8g8 