You may recall a couple of offseasons ago that Pittsburgh Steelers head coach Mike Tomlin talked a lot about the nature of defensive schemes, and over the course of an exchange with the media, he concluded that “the emphasis in today’s NFL is about sub-package football”. Mike Tomlin said this because he is a smart man.
A couple of days ago, Peter King’s Monday Morning Quarterback posted a very interesting and very illuminating “Stat of the Week”, which aimed to track the usage of nickel defenses across the league from 2008 all the way to last season, and what emerges from that data is a very obvious upward trend.
In 2008, with data culled from Pro Football Focus, the NFL defenses employed sub-packages with at least five defensive backs on the field 43.4 percent of the time. After a fairly consistently steady rise of between two to four percentage points per season over the span, by 2015, we have seen defenses employ extra defensive backs 63.4 percent of the time, a full 20 percent increase in the total number of defensive snaps over a span of eight seasons.
The tipping point, according to the data, came between 2010 and 2011, when NFL defenses shifted from a slight majority in their ‘traditional’ base 3-4 or 4-3 defense to a slight majority in nickel or otherwise secondary-heavy sub-packages, which have now essentially for many teams become their base look.
The Steelers have been among the teams to deviate most sharply in that direction since Tomlin made those comments, or rather in the season prior to making those comments, though that was partially fueled by necessity when Larry Foote was lost for the season in the opener. In order to substitute for him, the team employed a quarters defense with an extra cornerback and safety, and used Troy Polamalu as a quasi-linebacker.
Things began to tip a bit more toward normalcy during the 2014 season under the final season with Dick LeBeau manning the sidelines, but still showcased a higher proclivity to use extra defensive backs than had been their norm in prior years.
With the change in command from LeBeau to Keith Butler leading into the 2015 season, however, we saw the Steelers dip into the nickel package more heavily than ever before. I do not recall the exact specific statistics, but Pittsburgh employed extra defensive backs somewhere around 70 percent of the time during the season, which is actually fairly notably in excess of the league average.
It is almost hard to imagine, looking back to just the 2008 season—the last time that the Steelers won the Super Bowl—and to imagine that defenses around the league actually spent over 55 percent of their snaps in their traditional defensive looks. Just a year or two prior and it was likely around 60 percent.
The roles have been near-perfectly reversed since then. Of course, rules changes during that time period have no doubt played a role, but it also stems from the way the game is played at the college level, and the talent that is often available. There are a lot of very good wide receivers coming into the league, so offenses are using three of them at a time. Defenses have had to respond in kind.