In case you haven’t noticed, 2014 is on pace to become the greatest passing season in NFL history. Which may not be surprising, since just a few months ago, the three best passing seasons in NFL history were the 2012, 2011, and 2013 seasons. Falling into fifth place will be the… 2010 NFL season. So passing numbers are on the rise, but you already knew that.
Through week 13 of the 2014 season, the NFL average Adjusted Net Yards per Attempt — defined as gross passing yards, plus 20 yards for every touchdown pass, minus 45 yards for every interception, and minus sack yards, all divided by the total number of pass attempts plus sacks — was at 6.26. Most passing statistically typically take a trip south in December (and prior to SNF, the week 14 average was 5.85), but 6.26 would be a significant outlier even in our high-flying times. The graph below shows the NFL average ANY/A for each season since 1950. Of course, we are doing a bit of apples-to-oranges comparisons by using full season numbers for all years and through-13-weeks numbers for 2014, but so be it:
Obviously ANY/A spiked after the 1978 rules changes, and has been steadily increasing over the last 35 years. But 2014 — depending on what happens in December — has the chance to mark another large increase in passing efficiency.
Since ANY/A is a combination of many statistics, it’s natural to wonder what exactly is driving the increase in ANY/A. Let’s first look at generic yards per attempt: i.e., gross passing yards divided by pass attempts (excluding sacks). While the peak Y/A was in the early ’60s (this if NFL-only data, so the AFL numbers are not included), the 2014 season stands out relative to recent years:
Why has yards per attempt increased? Well, yards per attempt is the product of two other statistics: completion percentage and yards per completion. Here’s a look at completion percentage over time:
The 2014 season is set to smash the completion percentage record of 61.2%, set last year. Through thirteen weeks, teams are completing an incredible 63.0% of passes. But while a higher completion percentage often leads to a lower yards per completion average, that hasn’t really been the case this year. Take a look:
So teams are completing passes at an insanely high rate, but yards per catch averages aren’t dropping by a commensurate rate; as a result, yards per attempt is high. But what about the other parts of ANY/A?
Relative to 2013, the sack rate has declined from 6.7% to 6.1%; that’s a sizable difference, and one reason why ANY/A has increased this year. But in general, the 2014 sack rate is not a big outlier relative to other recent seasons:
On the other hand, quarterback interception rate looks to set yet another new low. This is the metric that has seen the steadiest pro-offense change over the last few decades, and 2014 continues that trend:
But what might be the most interesting is the change in touchdown rate. Take a look:
This is pretty surprising, and not something you have heard much about. Consider: in every year in the sixties, the NFL average was at least 4.6 touchdown passes per 100 attempts. That level was never reached from 1970 to 2013, but through 13 weeks in 2014, the rate was 4.7 touchdowns per 100 throws. That’s kind of incredible, isn’t it?
A quick thought as to a possible explanation would be that teams are throwing more often near the goal line, and plays that used to be a rushing touchdown are now passing touchdowns. I haven’t crunched the numbers on the average length of touchdown passes this year, but I will note that rushing touchdowns per game are slightly down, so that jives with that hypotheses.
Completion percentage is through the roof in 2014, as the short-passing game has dominated the NFL. But yards per completion hasn’t dropped much at all, which has led to an increase in yards per attempt. Throw in small improvements in both sack rate and interception rate, plus a large increase in touchdown rate, and it all adds up to a big improvement in ANY/A. We’ll have to check back in the off-season to see where the final 2014 season numbers.