The Accelerated Dragon with reversed colors is a dangerous weapon for the  English player. The extra tempo that White has makes it easier for him to  prepare and execute the d2-d4 advance.
1. c2c4  1... e7e5  2. g2g3  2... g8f6  3. f1g2  3... d7d5  4. c4d5  4... f6d5  5. g1f3  5... b8c6  6. e1g1  6... d5b6 