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2011 September Report: Defense

With the first quarter of the 2011 season completed, it's time to assess how the Noles have done thus far.  Well, other than a 2-2 record and dropping from top-5 to outside the top-20.  Here we'll attempt to statistically explain what is working and what is not.  The specific topic today is defense.

The pre-season general consensus among the TN staff called for a return to the top-25, by advanced metrics.  I was a bit more optimistic, predicting top-15.  To date, the Noles have faced two high-caliber offenses and one not so potent attack.  It has been a mixed bag, to say the least.  Treating the Sooners to their least productive offensive performance in over a year and a half left us feeling pretty good.  Treating the Tigers to a field day the following week left us scratching our heads.

Despite the poor showing in Clemson, FSU's defense is currently ranked #18, on a per-play basis, and the overall numbers are quite good.  Success rate (SR) is essentially a measure of consistency that quantifies the frequency with which an offense gains enough to stay on track.  It is defined as gaining 50% of necessary yardage on 1st down, 70% on 2nd down and 100% on 3rd or 4th down.  Explosive play rate (Exp Rate) is the big play frequency--its definition derived from 2010 data--counting any play resulting in a statistically significant gain as "explosive".  For passing plays, it's 25+ and running plays it's 15+.  Negative play rate is defined exactly the way it sounds.  Any play stopped behind the line of scrimmage is negative.

Looking at the numbers broken down by quarter, it appears the Noles come out either flat or conservative as the higher ypp and SR indicate offenses come out of the gates with methodical drives.  Also worth noting they are not giving up many long plays and are not getting stops behind the line of scrimmage early in games.


The run defense has been excellent thus far, in every category.  What's even more impressive is that we--similar to NFL stats--properly classify QB sacks as passing plays.  The defense has only yielded two explosive runs so far; a 17 yarder against ULM and a 19 yarder against Clemson.  And they have come up with 18 stuffs (copyright ricobert1).


Despite our most recent memories, the pass defense has been quite good, as well.  Four of the six explosive passing plays occurred in the Clemson game, the other two against Oklahoma.


Now let's take a closer look at the personnel match ups that produced these numbers.  We have seen a few new elements to Stoops' defense, indicative of better player understanding and coaching confidence.  The lack of nickel coverage in the OU game (2 plays) was surprising, given the abundance in the season opener (27 plays).  The lack of nickel against Clemson--likely due to the absence of Greg Reid--might have cost us the game.  As you'll see below, the passing spread formations have been quite lucrative with only four DB's on the field.  In the Clemson game, all four of the big passing plays (50, 33, 62, and 34 yards) came out of four-wide looks, against a 4-3 or 3-4 Noles defense.


As mentioned already, the majority of the nickel defense looks came against ULM.  While it might be unfair to assume more DB's on the field might have prevented some of the big plays given up against Clemson, it certainly wouldn't have hurt to try.


The 3-4 look, with 4-3 personnel, is a new dimension this year.  I'm not sold on its effectiveness just yet, but it hasn't been a disaster either.


And last, but not least, our continuing efforts to track personnel use and depth along the front.


This defense has shown it is capable of greatness and goatness this year.  For the remainder of the season, expect somewhere in the middle.  Don't be surprised, though, if it's closer to greatness.