1. d2d4  1... g8f6  2. g1f3  2... d7d5  3. e2e3  3... c7c5  4. d4c5 [%c_effect c5;square;c5;type;Interesting;persistent;true] This interesting opening was recently tested in a decisive game of the Women's World Championship match. 4... e7e6  5. b2b4 