[%c_effect c4;square;c4;type;Inaccuracy;persistent;true] A risky move, especially considering that Black didn't need to unbalance the game.
1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. g1f3  3... b7b6  4. g2g3  4... c8a6  5. b2b3  5... f8b4  6. c1d2  6... b4e7  7. b1c3  7... d7d5  8. f1g2  8... e8g8  9. e1g1 