White is a piece up, but Black has more pieces attacking. This is what really counts.
1. d2d4  1... g8f6  2. c1f4  2... d7d5  3. e2e3  3... c7c5  4. d4c5 This leads to sharp play. 4... e7e6  5. b2b4  5... a7a5  6. c2c3  6... c8d7 Preparing b7-b6; 7. b1d2  7... a5b4  8. c3b4  8... b7b6  9. c5b6  9... f8b4  10. f4c7  10... d8e7 The right square, sacrificing a piece. 11. b6b7  11... a8a3  12. c7b8  12... d7a4  13. d1c1 I was surprised to find that this position is well-studied by opening theory and that this move is already a losing mistake. 13... e7b7  14. b8e5 