1. c2c4  1... g8f6  2. g2g3  2... e7e6  3. f1g2  3... d7d5  4. g1f3  4... d5d4  5. d2d3  5... b8c6  6. e1g1  6... f8e7 The most popular continuation, although 6...Bc5 is gaining popularity lately. 7. e2e3 