The Changing NFL Landscape, Part 1: Historical Trends
If you’ve played around with pace stats or looked at league trends lately, you’re probably well aware the number of plays teams run in a season has been steadily rising over the past decade, with pass attempts rising at an even greater rate and rush attempts falling.
While the number of plays an average team ran in a season peaked in 2013 before dropping back a bit in 2014 and 2015, the overall trend is quite clear. I decided to take a longer look at the fantasy football implications of these league-wide trends now that the 2015 regular season is in the books.
Number of Plays
The first thing I wanted to check out was how many more plays the average team runs than teams of old. In other words, while the average team ran 1,030.5 offensive plays in 2015, I was curious how much more that was than, say, the 2000 season, or even 1990. As I looked back, I realized my assumption that plays have been steadily rising over time was baseless. I wound up going all the way back to 1978, the season the NFL moved to a 16-game schedule.
The following is a chart of the number of total plays run in every 16-game season in NFL history. Note that I removed the strike-shortened 1982 season (in which only nine games were played) as well as the strike-shortened 1987 season (in which 15 games were played, but four featured replacement players).
Interestingly, the season with the highest average offensive plays per team was 1981. That said, while I learned average offensive plays used to be higher than present day, a separate hypothesis that passing has also increased steadily (while rushing has declined) was confirmed.
As an aside, I tried to nail down a reason why teams who ran significantly more rushing plays also ran so many plays overall in the late-70s and through most of the ‘80s. The best I could come up with was the NFL used a 30-second play clock until 1988, when they extended it to 45 seconds (they obviously later settled on 40 seconds). The fluctuations don’t perfectly match up with this, but it seems to have been a factor.1
With respect to the charts themselves, first note sacks are not included in the second chart, which explains why the rush and pass totals don’t move perfectly counter to each other. Beyond that, a lot of interesting things can be said about these graphs. For one, 2015 featured fewer rushing plays than any 16-game season in NFL history, as did 2014 before it. It may not look like much in the graph, but we’re talking an average of 30 fewer rush attempts per team over the past decade (i.e. comparing 2015 to that four-year plateau you see between 2003 and 2006).
Likewise, 2015 represented new league heights for pass attempts. But, as you can see, pass attempts had spiked before. It was interesting to see the rise over the last decade actually started with relatively suppressed numbers, as passing from about 1994 to 2002 was more frequent than from 2003 to 2008 or so. In fact, when the league went over 550 pass attempts for the average team in 2012, it wasn’t the first time in NFL history – that had already happened back in 1995.
These historical trends are interesting, but they don’t say much in terms of actionable information. These trends are well known, and the fantasy football world has already started to adjust to them. In fact, at this point it doesn’t seem like there is much we can apply.
That is, until we start considering completion percentage.
League-wide completion percentage has steadily risen over time, and surpassed 62 percent the last two seasons. That number is drastically higher than where it was in, say, the aforementioned pass-heavy 1995 season.2 When we pair the upswing in pass attempts with the increased efficiency of those attempts, the results become extremely noteworthy.
Over the last decade, the average team has added more than 50 completions to their season total. More to the point, from just 2014 to 2015 there was an average of 10.2 more completions per team in the NFL.
It’s hard to know whether this is a trend destined to regress at some point. Interestingly, over the last five seasons those average completion numbers are 327, 338.5, 346.9, 350, and 360.2. That steady, 33.2-completion increase comes out to over 1,000 more receptions that were made in the NFL in 2015 compared to 2011.
That, of course, is actionable in point-per-reception fantasy football leagues. I’m not saying that trend will continue to rise, but according to Pro Football Focus’s average depth of target data, the league-wide aDOT has fallen each season since 2011. Considering these are samples of over 16,000 targeted pass attempts per year, a five-season trend that moves the league average depth of target from 9.02 down to 8.73 is very noticeable.
The simplest narrative to explain all of this is teams shifting some percentage of their carries to the short passing game. That is oft-discussed, but the numbers do seem to bear it out. As I mentioned, the trend can’t continue forever. I can’t imagine in 10 years we’ll be at 650 pass attempts for the average team and a 70 percent league-wide completion percentage. But, considering we can point to an actual philosophical change,3 it would be erroneous to expect any kind of major regression in the immediate future. Even a conservative estimate for the 2016 season would have to be somewhere around 350 receptions per team.
I’ve been seeing a lot of discussions about an overcorrection coming this off-season after Zero RB was such a successful draft strategy in 2015. Many have hypothesized that this plus the influx of great WRs will cause the market to overemphasize the position, and the right move for 2016 drafts will be to go RB heavy. I’ll discuss this more in part two.
Here is the full table of data from the charts above, courtesy of Pro Football Reference.
|Year||Pass Comp||Pass Att||Rush Att||Total (includes sacks)||comp%|