I think the real issue for ISU is that they are not good at running out of the shotgun, so passing becomes more defendable. Basically they know ISU is not going to gash them with the running game, so they build the defense around stopping the short passing game. ln addition, for some weird reason, the ISU offense almost never throws over the middle on short routes, which means that Sam is throwing 30 yard passes to the sideline instead of 10 yard passes down field. Not throwing short over the middle also makes defending the run easy for other teams. Their LBers never have to drop back in pass coverage.
Trying to gain 1 yard for a first down out of the shotgun is the most frustrating thing for me. Now that Lanning is getting some playing time the QB sneak may get back in the playbook.