1. e2e4  1... c7c5  2. g1f3  2... d7d6  3. f1b5  3... b8d7  4. a2a4 A relatively rare continuation,  which has been tested by the world champion. Another player who deserves  credit is the Dutch number one, Anish Giri. 4... e7e6  5. b1c3 