Quarterbacks and the Progression of Air Yards

by Scott Kacsmar

So far this season, new starting quarterbacks have been a huge storyline. Eight teams have already given a quarterback his first start with the team through three weeks. Some of the situations are connected, like how Brock Osweiler's move to Houston prompted the rise of Trevor Siemian in Denver. Teddy Bridgewater's injury in Minnesota led to the trade for Sam Bradford, which opened the door for rookie Carson Wentz in Philadelphia. We also have rookie Dak Prescott replacing an injured Tony Romo in Dallas, and Brian Hoyer has had to step in for an ailing Jay Cutler in Chicago. Jimmy Garoppolo and rookie Jacoby Brissett made their starting debuts in New England due to Tom Brady's suspension, and naturally Cleveland is involved with rookie Cody Kessler as the current starter.

So many new faces, and yet the No. 1 pick in the draft has yet to take a snap for the Los Angeles Rams. While Jared Goff's time will come, we are trying to learn what we can about these young quarterbacks given the limited data that is available so far. Siemian and Wentz were just named the Offensive Player of the Week in their respective conferences. The two also share something else in common: a high volume of short throws.

Air yards are the average distance each pass travels beyond the line of scrimmage. As of Week 3, Siemian (6.85) and Wentz (6.86) rank in the bottom three for average air yards, sandwiched between Philip Rivers (6.55) and Alex Smith (7.08). The league average is roughly 8.5. Last season, the correlation between air yards in the first three weeks of the year and air yards for the entire season was 0.80.

Generally, air yards are a stat where you don't want to rank at the bottom, because that is where many ineffective passers dwell, including Blaine Gabbert. That preference for short throws often extends to crucial downs, which is why these quarterbacks tend to do poorly in ALEX and attacking the sticks. However, it is not preferable to rank at the very top in air yards either, because that is how "screw it, I'm going deep" players such as Michael Vick, Tim Tebow, Vince Young and Rex Grossman have earned their reputation as inefficient passers. The ideal quarterback would rank a little above the average, capable of effectively mixing in a variety of passes from screens to bombs, and everything in between.

Today, our interest is not in projecting the future for these young quarterbacks after three games, but to go over the collection of data on the veterans with whom we are very familiar. Earlier this week, I was asked on Twitter if a quarterback's air yards increase over time. Before looking at the numbers, I had an inkling that there would be more decreases over time, as quarterbacks figure out which throws they can get away with in the NFL. Unfortunately, it is not as if we have consistent data to study the full careers of many recent quarterbacks. Air yards are notorious for having different calculation methods depending on the source of the data. At Football Outsiders, we can go back to the 2006 season with our refined charting data, using the same dataset we use for passing plus-minus, which removes passes that were intentionally thrown away, batted down or when the quarterback was hit in motion.

I gathered that yearly data on 21 quarterbacks with at least four years of starting experience, all of whom are still active starters this year except for the retired Peyton Manning. The following table shows their average air yards by year for the period of 2006 to 2015. The final "AVG" column is an average of the averages, which means each season is weighed equally. In addition to seasons nullified by injury, I also removed any season with fewer than 100 pass attempts. This only applied to Tom Brady (2008), Aaron Rodgers (2006-07), and Matthew Stafford (2010). The season highlighted in green is the highest average season for that quarterback, and the one in red is the lowest average.

If there was a most predictable outcome here, it would be Alex Smith and Sam Bradford throwing the shortest passes on average. Let's go over the findings in different sections.

The Range

The average range of air yards for this group was 2.22 yards when looking at the difference between the highest and lowest season. No one has been more consistent than Andy Dalton, with a range of 1.03 and standard deviation of 0.38. Tom Brady is right there with him with a range of 1.17 and standard deviation of 0.40. Despite Brady's long-time reputation for running a dink-and-dunk offense, his air yards have always been above 8.0 outside of 2010, when he just dipped down to 7.78.

If you know my work well, you know I like to group Brady, Peyton Manning, Drew Brees, Aaron Rodgers, and Ben Roethlisberger as the five best quarterbacks in this era. All five of them have a standard deviation of 0.60 or lower, and only Dalton and Cam Newton join them. Meanwhile, Alex Smith (1.07), Tony Romo (1.08), Carson Palmer, (1.09) and Sam Bradford (1.11) are the only quarterbacks with a standard deviation greater than 1.0.

What could be the cause of that? I want to say more than just being a consistent player. The low deviation group has largely had the benefit of staying with the same head coach on the same team since 2006. Only Manning from that group changed teams and coaches, but until his final season, he usually ran his brand of offense regardless. This covers a span of two head coaches and three offensive coordinators for Roethlisberger, but he too has always kind of done his own thing. Meanwhile, Smith, Palmer, and Bradford have gone through multiple teams, coaches, coordinators and injuries as starters. While those changes may have been less frequent had they played better more consistently, the system obviously has an impact on air yards.

The Lowest Season

Sam Bradford, as a 2010 rookie, was the only quarterback to have his lowest air yards season in his first year on the table. In fact, the only other quarterbacks with their lowest season in the second year listed are Andrew Luck (2013) and Brees (2007), the latter of whom was in his seventh NFL season at the time. Our sample is obviously biased towards successful careers, but given that success is the goal, it is probably a good sign if the young quarterback is getting the ball down the field.

I found it interesting that Joe Flacco (2015), Palmer (2008), and Romo (2015) had their lowest seasons in years they were seriously injured. Then again, that can probably be explained by the shortened season not allowing the quarterback to build up reliable data with his usual sample size of passes. Romo's second-lowest season (2010) was also one in which he broke his collarbone and missed 10 games.

One could also argue the worst statistical season for seven of these quarterbacks -- Dalton (2014), Brees (2007), Wilson (2014), Rodgers (2015), Flacco (2015), Palmer (2008), and Romo (2015) -- happened during their lowest air yards season. On the other hand, Ryan Tannehill (2014) had his best season with his shortest passes, while Peyton Manning broke many records in Denver in 2013 with what was an abnormal YAC-based offense for him. Brady's best season was 2007, but he also won an MVP award for his 2010 season. That year's drop in air yards can be explained by the in-season trade of Randy Moss, and the move towards an underneath passing offense led by Wes Welker and rookie tight ends Rob Gronkowski and Aaron Hernandez.

Overall, the lowest air yards season was usually not showcasing these quarterbacks at their best. Two offensive coordinators tried to help undo the lack of protection issues provided by Bruce Arians' style of offense. In Pittsburgh, Roethlisberger's two lowest seasons (2012 and 2013) were the first two years with Todd Haley taking over as offensive coordinator, as Haley wanted to get the ball out quicker. In Indianapolis, Pep Hamilton reunited with Andrew Luck from their Stanford days, but the 2013 results were not as impressive, and Luck has already moved on to his third coordinator (Rob Chudzinski).

Some other coordinator changes have been more instantly effective. Eli Manning's two lowest seasons are 2014 and 15 after switching to Ben McAdoo's system, and that will likely continue with McAdoo as the head coach now. Matthew Stafford has also adopted more of the dink-and-dunk from offensive coordinator Jim Bob Cooter, though as we looked at in the offseason, Stafford was already playing like this before the coaching switch last year. For better or worse, all three of Alex Smith's lowest seasons have been since he went to Kansas City in Andy Reid's offense.

The talent around these quarterbacks can also explain some of the lowest seasons. Is it any surprise that Rivers' air yards have gone down since he has lost Vincent Jackson, and Antonio Gates and Malcom Floyd got old? Matt Ryan's 2013 can likely be explained by Julio Jones 11-game absence, as well as the sudden decline of Roddy White, and Tony Gonzalez playing on his last legs. Seattle's trade for Percy Harvin threatened to ruin the offense in 2014 with Russell Wilson not taking as many deep shots as he should.

Then there are two seemingly random cases: Jay Cutler (2014) and Ryan Fitzpatrick (2011) took the air out of the ball in familiar systems. In Cutler's case, he still had Brandon Marshall and Alshon Jeffery, but checked down to Marc Trestman's delight for a record number of receptions (102) to running back Matt Forte that season.

The Highest Season

When looking at the highest air yards seasons, we find six quarterbacks who came out firing in their first season as a starter: Cutler (2006), Romo (2006), Rodgers (2008), Ryan (2008), Luck (2012), and Wilson (2012). Peyton Manning was in his ninth year in 2006, which I still consider his greatest season; that season also gave him the highest average air yards of his last decade in the NFL.

Three of our study's quarterbacks enjoyed their best statistical season in 2015, and it was the deepest they had ever thrown the ball, too. We are of course talking about Newton, Palmer, and Dalton. Bruce Arians has been great for Palmer in Arizona, while Newton won MVP last year with No. 1 wide receiver Kelvin Benjamin missing the entire season due to a torn ACL. Dalton displayed an increased level of efficiency, though as mentioned above, he still kept his passes close to his usual depth level. Roethlisberger was a fourth quarterback to have his highest air yards in 2015, and while it was not his best overall season, one could argue it was his most impressive from a purely physical throwing standpoint. There is also an argument that Rivers had the best season of his career in 2009 when he had the highest DVOA (41.7%) and air yards of his career.

Likely just a coincidence, but a third of the list had their highest season in 2012, including Brees' lone year with head coach Sean Payton suspended, and Flacco's Super Bowl season. Peyton Manning (2006) was the only other player to win a Super Bowl in his highest (listed) air yards season, though he likely had a larger number sometime during the period of 1998 to 2005.

Finally, there are the cases of Smith and Bradford, each of whom had his highest air yards season in the second listed year (the third NFL season for Smith). Yes, believe it or not, but Smith was not always ALEX in San Francisco. His air yards were quite high at 9.78 in 2007, albeit in seven games that season. It would have been interesting to see him in Mike Martz's system in 2008, but he missed that entire season with a shoulder injury. My theory on Smith has been that upon his return in 2009, he took on a much more conservative playing approach for fear of losing his job again should he throw too many interceptions. With the team building up a better defense, this began to work, and it really took off when the 49ers hired Jim Harbaugh as head coach in 2011. Smith's numbers dropped in interception rate and ALEX, while he took more sacks and was content with settling for field goals. He has continued this style with Reid in Kansas City, though a conservative offense can only go so far in January.

Bradford would just like to see a postseason start, though he has his best chance now on a 3-0 Vikings team. In St. Louis and Philadelphia, his offenses were inept, but that 9.24 air yards really stands out from 2011. The most interesting part is that Josh McDaniels was the offensive coordinator. Instead of bringing some of the shotgun-spread from his New England days, that offense tried to throw downfield to Brandon Lloyd and Danario Alexander. The result was the No. 32 offense in DVOA, and a career-worst sack rate (9.2 percent) for Bradford, as well as a high ankle sprain that limited him to 10 games. Now running Norv Turner's offense in Minnesota, Bradford's air yards are low again at 7.51, and his sack rate is 9.2 percent through two starts. Much like Smith, Bradford will rely on the defense to make this formula work.

Conclusion

While some very good quarterbacks have entered the league since 2006, we still have a small sample size of consistent starters with several seasons' worth of data to study. It could easily take another decade before we can more definitively conclude anything about how air yards progress over a quarterback's career. Just with this look at 21 quarterbacks, we ran into issues with players such as Manning and Brady having several years of experience by the time their first data point appeared.

One reasonable conclusion is that air yards do not tend to increase over time. From the 14 quarterbacks with at least eight years of data, we observed a gradual decline from 9.11 yards in the first year to 8.33 yards in the eighth year. But again, this includes a mixture of players at various career points rather than seasons 1-to-8 of their careers. As a quarterback ages, expectations would be for him to not get as much air on the deep ball, and perhaps to get rid of the ball faster to avoid taking more hits that become harder to overcome with age.

It is essential to continue studying this data, because air yards provide context for a quarterback's performance, including his relationships with different receivers and schemes. Only time will tell what kind of passers these young quarterbacks are going to become.