1. e2e4  1... c7c6  2. d2d4  2... d7d5  3. e4e5  3... c8f5  4. g2g4 An ultra-aggressive option against the Caro-Kann Defense. 4... f5e4 [%c_effect e4;square;e4;type;GreatFind;persistent;true] The most accurate move, provoking the white pawn to f3.