SMU was able to contain our running game with their front 4 and that freed up their LB's to blitz or cover space making passing lanes more difficult. That is one reason why ARod went to screen plays, until Retzlaff threw it right to a DL.
This is why I want Bohanon at QB now... a completely different running style and threat than Retzlaff is. And there is just no way that Bohanon is worse of a passer than Retzlaff.