As many of you know, MSU's defense is pretty ordinary. I know someone here recently compared the UConn and ND defenses as pretty similar (once their numbers are adjusted for Michigan's top level O).
Specifically, MSU has had a pretty bad pass D (sound familiar?). I believe they were rated around the same place as UM's pass defense prior to last weekend's games. Then, Michigan ran into an accurate 5th year QB who threw 64 times....and Sparty ran into an off-day by Tolzien on a run-frist team.
Otherwise, Sparty has a similarly bad pass D, but they look better on paper now because of mistakes by Tolzien and dropped passes. And it wasn't MSU's strong rush either. MSU did not put great pressure on the QB. I think they had one sack and a couple of hurries (worse tham UM).
They basically looked like a Michigan D. They allowed Tolzien to throw and let him try to be mistake-free and he wasn't. We allowed Chappel to throw and he was accurate (and threw a lot more).
Is it a low-risk or high-risk strategy? I don't know. But, it can work I guess....