Our coaching staff bought the instructional videos on Michigan State's 4-3 Over Quarters defense. The videos are very well done, and I would advise every coach to buy those videos, regardless of the scheme you employ. In short, MSU believes in quarters coverage and Narduzzi says that he is a very conservative play caller. That fits my personality as a DC, so I have used a lot of what he says on the videos as I game-plan / prepare our defense. I will put up a post detailing the basics of their quarters coverage in a later post.
Grantland did a great article on MSU's defense and here is the link: A Defense to Match. I would advise every DC to read this article, buy the DVD's, and you will become a better defensive coach.