After the UMass game, I got on Greg Robinson's case because he more or less allowed UMass run a quarterback rollout pass at will on the defense. What I couldn't understand was a) why he didn't ever change his scheme to counter the play and b) why Michigan's defenders couldn't figure it out on their own; a basic zone coverage scheme is not susceptible to a rollout on every play, you'd imagine. Bowling Green obviously watched the UMass film and saw the same thing, going to a rollout a number of times in the game. Below is one example of what usually goes wrong, and something that hopefully they can fix. (For the record, the man coverage nickel package that I'm oh-so happy with will mitigate a lot of these issues if it's called at the right time.)
As I said above, I don't really know whose at fault here. It's definitely not Rogers who was playing the deep half of the field. I'm inclined to say it was Gordon's fault for not covering the boundary, but then again, Ezeh's late rotation (not entirely his fault, he got off the snap quickly and just had a lot of ground to cover) seemed to necessitate Leach covering the inside receiver through his zone and Gordon shading over to the middle receiver. UMass torched Michigan on this same play repeatedly and I have no doubt that other teams will as well. And as Michigan faces more talented quarterbacks through the Big Ten schedule, this looks to be the team's Achilles' heel.
The nickel package that Greg Robinson debuted in the Bowling Green game is one way to remedy this problem. Without gaping holes in the zone coverage, Bowling Green doesn't get this easy completion. Having man coverage here probably necessitates three vertical routes with two over-the-top defenders in Floyd and Rogers. I'd prefer this over pitch-and-catch completions, but Robinson is probably worried about the deep ball more. This is bend don't break football.