Traditional thought has always said that the lynchpin of a successful 3-4 defense like the Packers run is a giant nose tackle who can contain the pocket against a double team and a versatile outside linebacker who can rush the passer. Ted Thompson definitely followed that philosophy to a T the very first year that the Packers implemented the 3-4 defense by drafting a nose tackle #9 overall with BJ Raji and then following that by trading up to select Clay Matthews III. However since then Thompson has been rather apathetic when it comes to nose tackles; since Raji the Packers haven’t really drafted a player who fits the mold of a 3-4 NT (Boyd and Thornton might be the closest but both have played more DE than NT so far). At this point, with the prevalence of the passing game and the subsequent shift to more nickel and dime looks that feature only 2 down linemen, nose tackle has become a rotational player more than a foundation of a defense.
With the Packers on the clock at 30 in draft, plenty of people were clamoring for an inside linebacker (myself included) but a sizable minority of fans also wanted the Packers to take a nose tackle like Jordan Phillips or Malcolm Brown but the Packers passed on both positions in favor of cornerback Damarious Randall. Much like inside linebacker, Thompson doesn’t appear to value nose tackle that much. Was Thompson right to ignore the nose tackle in favor of a cornerback, where the team definitely has more depth? Or to put it another way, how much effect does a nose tackle have on the outcome of a game? Is he really the key to the defense as has been said in the pass?
To test this question, pun/pass/total grades were pulled of nose tackles playing 3-4 defenses for every regular season game from the 2014-2015 season from pro Football focus and tabulated with game data from Pro Football reference. New England (who plays a 3-4 on paper) was excluded from the analysis since they run so much 4-3 defense and really are a hybrid defense at this point.
The easiest and most straight forward way to see just how important nose tackles are is to compare how well they play versus whether or not the team won the game. Unfortunately, there is no statistical difference between PFF grades and whether or not their team won the game. In other words, a nose tackle was just as likely to play well and win the game as he was to play well and lose the game. Obviously wins and losses are way more complicated than just how the nose tackle plays; a nose tackle could play spectacularly only to have the offense sink the game or perhaps the defensive secondary couldn’t stop any receivers.
While it doesn’t appear as if nose tackles directly control the outcome of a game, it is possible that good nose tackle play could limit the number of points that an opposing offense can score, which would factor out how well his defense plays. This graph looks at the correlation between the PFF scores that each nose tackle received and the number of points the defense gave up in that game. There does appear to be a statistically significant negative correlation between nose tackle play and score, meaning the better a nose tackle played, the less points his team gave up. However, only 14% of the variation in score can be accounted by nose tackle play, so while it is a significant result, the expected outcome is rather small.
Nose tackle is supposed to be the anchor in run defense, but ironically there isn’t any significance between how well a nose tackle defends the run versus how many points his team give up. It is possible that the prevalence of throwing the ball skews this correlation, but I decided not to split points into pass and run since I didn’t want to overemphasize drives where the quarterback throws the ball down the field and the running back punches it in from 2 yards out.
Interestingly, good play from nose tackle defending the pass does seem to affect the ability of opposing teams to score points. Again while it’s significant, only 15% of the variation in points can be linked to nose tackle passing defense, which again would seem to be quite minor but what’s also interesting is that you don’t see much variation in PFF pass defense scores, especially compared to run defense scores. While this might be an artifact of PFF’s grading system, it would also point to the fact that nose tackles don’t contribute much to pass defense (which makes sense intuitively) one way or another, which of course would agree with the fact that importance of nose tackles on pass defense is quite small. You can interpret the data as you see fit, but personally I would say that even if nose tackle pass defense actually influenced how many points were scored, the effect would be very minor.
In conclusion, nose tackle play seems to have at best a very minor role and at very worst is not correlated with winning or losing games. I will say that context is important and having r values for quarterbacks and punters would be useful in really framing how important 15% correlation is (if anyone else wants to take a stab at this you have my gratitude). Furthermore, nose tackle play is notoriously difficult to grade, BJ Raji has been quoted that it’s pretty rare for a nose tackle to run a “jet” (i.e. rush the passer, which would be easier to grade) play and a nose tackle could appear to be blocked by an offensive linemen when in reality he’s actually walling off the offensive linemen and allowing other players to fill in the gaps. Overall, I would say that this probably corroborates with my previous analysis that shows that nose tackles aren’t all that important. I’d say on the importance scale of quarterback to long snapper, nose tackle is probably right next to inside linebacker as one of the less important positions on the team.——————
Thomas Hobbes is a staff writer for Jersey Al’s AllGreenBayPackers.com.