1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. g1f3  3... d7d5  4. g2g3  4... d5c4  5. f1g2  5... c7c6 The game begins as a Catalan opening, but now we have a transposition to a line that often occurs in the Semi-Slav move order where White sacrifices the pawn on c4. This leads to extremely complicated and risky positions. 6. e1g1 