Since the defensive improvement has been far and away better than anything any of us could have expected, I thought it would be interesting to see the extent of the improvement in historical terms. I collected data on scoring defense and yardage defense from Rivals as far back as 2003 to the present. Here are the results (click on the graphs to embiggen):
And, to compare the two data sets, I've superimposed them by representing each as a percentage of the worst historical performance (i.e., 2010):
The result is striking. Thus far, Hoke, Mattison and the rest of the defensive staff have turned this squad into one of the best 3 defensive teams in the past 9 years.
UPDATE: MGoBlog user Mat suggested that I look at our defense's yards allowed per play. I did some googling and found stats dating back to 2003 foryards per play. The following graph is based on statistics that only take into account performances against other FBS teams:
Which confirms Mat's impression (and ours) that while this defense is excellent we are not yet elite. That's not surprising given that it's year 1 of yet another defensive system and that we are starting two freshmen.