Snap-Weighted Age: 2020 NFL Rosters
Subject: Please stop wrecking our stats.
2020 was a strange year.
Football Outsiders has been tracking snap-weighted age (SWA) since 2006, calculating a team's age not by just averaging the ages of the players on the roster, but by weighting the age of each player by the number of snaps he played in the regular season. Most years, these articles end up covering much the same ground, as consistent trends keep rising to the top. Even 2020 wasn't quite strange enough to break every pattern.
In all but two years, the league's average age has dropped, as the benefit of players on cheap rookie contracts continues to drive roster construction. That was true again in 2020, as we now have a new all-time low league average SWA of 26.4. The oldest team in the league last year wouldn't have cracked the top half of the league in 2006. The current CBA means that it's much more cost-effective to fill out your roster with players on rookie deals rather than savvy veterans, especially on the margins. While there has to be a floor somewhere, we're not there quite yet. Sixty-five rookies started at least half of their team's games last season, and there's no reason to expect that number to drop in the future.
At the same time, almost every year there is a decently strong correlation between the age of a roster and its DVOA, and yes, that was true again in 2020—in fact, 2020 saw the highest correlation between age and DVOA we have seen in over a decade. It makes sense that contending teams would have more veterans on their roster than rebuilding ones; it's fairly normal to be either good and old (see: New Orleans) or young and terrible (see: Jacksonville). Six of last year's 14 playoff teams were among the 10 oldest in the league; only two were among the 10 youngest, and none were below average on both offense and defense. If you're a veteran player who has survived to your second or third contract, you're probably pretty good, and teams with high numbers of good players tend to be good themselves, shockingly enough.
And every year, there's a significant year-to-year correlation in this stat, which also makes sense—old teams tend to stay old. You don't generally overhaul an entire roster overnight; you replace pieces one at a time. The average year-to-year correlation is 0.59, and until this year it had only dropped below 0.50 once
But here, 2020 finally breaks with tradition. With just a 0.40 correlation to SWA from 2019 to 2020—the lowest we have ever recorded—there were some massive swings and dramatic changes to cover across the league. The unusual is to be expected in 2020, a year unlike any other in the league's history. But at the end of the day, a familiar face was responsible for much of 2020's strangeness.
2020 Snap-Weighted Age: By Unit
The following table shows SWA for the overall team (TOT) along with the unit breakdown for offense, defense, and special teams. Units are ranked from oldest to youngest.
|2020 Snap-Weighted Age|
There aren't any real surprises at the top of the table. The Saints have been one of the 10 oldest teams in football in seven of the past eight years, as their team-building strategy the last couple of seasons has been to try to keep the old band together as long as possible, pushing out contract hits into the future and using salary cap chicanery to keep everyone around while there was still life in Drew Brees. They had seven players aged 30 or over play at least 500 snaps (third in the league behind the Steelers and Colts), and only 10,238 snaps from players 25 or under (second-fewest in the league behind the Bears). To a certain extent, this has worked—the 2017-2020 Saints are only the fourth team to have a DVOA above 25.0% in at least four consecutive years, in part because of the high level of continuity, plus a willingness to bring in aging free agents to plug holes as they tried to turn that regular season success into a Lombardi Trophy.
Ultimately, this era of Saints teams will be remembered more for postseason failures than anything else, and now the piper has come due—not only is Brees gone, but the Saints also need to replace thirtysomethings such as Jared Cook, Janoris Jenkins, Emmanuel Sanders … the list goes on. At least they have young, sprightly, soon-to-be 31-year-old quarterback prospect Taysom Hill in the wings! The 2021 Saints should look significantly different on this table, is what we're saying.
And speaking of significantly different…
When we first ran the numbers and saw the historically low correlation to last year's results, I chalked it up to COVID problems. Between opt-outs, a lack of a real preseason, various COVID scares throughout the league, the increased roster flexibility brought by the temporary injured reserve and practice squad rules and so on, it would make sense for rosters to be more in flux than in a regular year. And that almost assuredly did play a part, in ways both small and large throughout the league. If you were to arbitrarily eliminate the five biggest year-to-year differences in any given season, to avoid outliers who had particularly active roster movement, 2020's correlation would clock in at 0.62, compared to an average of 0.85 in previous years. Your average rank-and-file team had more uncertainty and change on their rosters in 2020 thanks in large part to the ongoing global pandemic.
But with only 32 datapoints in a given season, a few outliers can swing those correlation numbers one way or another. And boy howdy, do we have some notable outliers. Here's a table of the five teams with the biggest changes between their 2019 and 2020 SWA.
|Biggest Changes in SWA, 2019-2020|
|Team||2019 SWA||2020 SWA||Diff||2019 OFF||2020 OFF||Diff||2019 DEF||2020 DEF||Diff|
Why am I not surprised that Tom Brady remains a bigger force of nature than the novel coronavirus?
The top five changes from last year are all offensive-driven moves and, if we're honest, quarterback-driven ones. Brady bringing his 43-year-old body down to Tampa Bay in part of his never-ending war on the concept of time itself is enough to significantly impact the two teams that saw the age of their rosters change the most significantly from 2019. An 11.2-year SWA drop is huge, and that was with a veteran like Cam Newton under center -- imagine the impact if they had gone after a rookie in last year's draft! The Buccaneers saw their quarterback SWA shoot up by 17.5 years going from Jameis Winston to Brady, and bringing in veterans in Brady's orbit (hiya, Rob Gronkowski!) had an impact as well.
You can trace Philip Rivers' movement with the Chargers and Colts in third and fourth place, too. The Cowboys are here because of the departure of Jason Witten and significant changes along the offensive line (Terence Steele, Brandon Knight, and Connor McGovern all had 500-plus snaps at 23 years old), but the other four teams are all in this table due to a couple of quarterback moves. The travels of Brady and Rivers, more than anything else, upended this stat last season.
There are outliers every year, for sure—teams that suddenly see all their veterans leave due to salary cap constraints or what have you. But they normally clock in around where the Chargers finished, losing maybe a year of SWA as everything goes belly up. That happens, on average to 1.3 teams a year; that's the usual high. However, a change of 1.7 years—either a gain or a loss—is almost unheard of. The Patriots join the 2008 Chiefs as the only two teams to lose 1.5 years of SWA in a single season, and a -2.9 loss in offensive SWA is the biggest drop we have ever recorded.
|Largest Drops in Offensive SWA, 2006-2020|
|1||2020||NE||29.3||26.4||-2.9||Tom Brady (42)|
|2||2018||ARI||28.6||26.1||-2.5||Carson Palmer (38)|
|3||2008||KC||29.3||26.9||-2.4||Damon Huard (34)|
|4||2011||CIN||28.9||26.5||-2.4||Terrell Owens (37)|
|5||2009||PHI||28,3||26.0||-2.2||Jon Runyan (35)|
|6||2012||MIN||27.7||25.5||-2.2||Steve Hutchinson (34)|
|7||2011||DAL||28.7||26.6||-2.1||Jon Kitna (38)|
|8||2012||IND||27.9||25.9||-2.0||Jeff Saturday (36)|
|9||2014||JAX||26.6||24.7||-1.9||Brad Meester (36)|
|10||2011||SEA||27.8||25.8||-1.9||Matt Hasselbeck (35)|
Quarterbacks are the driving force behind most of these drops—a change at quarterback is a decent enough proxy for the beginning of a rebuild, which is itself a decent proxy for an incoming youth movement. Carson Palmer's departures hit both the 2011 Bengals and 2018 Cardinals. The 2011 Seahawks said goodbye to Matt Hasselbeck. The 2012 Colts and 2014 Jaguars had highly-touted rookie passers—Andrew Luck and, er, Blake Bortles, respectively. But no single player has ever had as significant effect on the league's SWA as Tom Brady did in 2020. Maybe they can squeeze that one on to his Hall of Fame plaque.
Moving from the very old to the very young, we head down to Florida. The Jacksonville Jaguars were the youngest team in the league for the second year in a row, a feat only previously matched by the 2015-2016 Rams. The Jaguars the fourth-youngest team in our database, one year removed from being the eighth-youngest team—and, frankly, I wouldn't expect them to get any older anytime soon, as they continue to try to build some semblance of a functioning roster. They were very bad, but at least they were also very young, which puts them in a better situation than teams such as the Lions, Eagles or Jets, who were close to as bad with significantly older rosters. Jacksonville got the tanking portion of their rebuild done correctly, with plenty of young players getting experience that will hopefully come in handy when the team is actually competitive once again. The Jaguars had a league-high 11 players aged 25 or less rack up 500-plus snaps last season, and a couple of them actually looked like they might belong on a professional football team. Urban Meyer has his work cut out for him, but at least he doesn't have a lot of aging veterans to worry about.
While the Jaguars were the standout in overall SWA, three teams were among the 10 youngest we have ever recorded in offensive SWA: in descending order, the Broncos, Cowboys and Ravens. The Ravens, in particular, are worth noting—they were the only team in the top quarter of DVOA to have a snap-weighted age below 26.4; they're the one team in the NFL in the top quartiles of both being young and good. Mark Ingram led all Ravens 30-somethings in offensive snaps; he had just 160. Your grizzled veterans in the Baltimore offense were 29-year-old D.J. Fluker, 28-year-old Willie Snead, and 27-year-old Matt Skura, none of whom are under contract for 2021. Their oldest returning key offensive player was born in 1994. Before the season, the Ravens ranked first in our under-25 talent rankings, and even though their offensive DVOA dropped from 28.2% to 4.3% last year, there's still a very bright outlook for this offense in years to come, especially if they ever find a wide receiver.
2020 Snap-Weighted Age: By Position
Not all teams are old in the same ways. Because offensive SWA is so affected by the offensive line, and defensive SWA tends to give teams with young secondaries an advantage, it can be useful to see where teams are young or old in particular.
The following table lists every team's SWA in each positional group and is fully sortable. The colors trend from red (older) to blue (younger).
|2020 Snap-Weighted Age by Position|
No team quite managed the feat of being older or younger in every position group last season, though a couple came close. The Saints actually had a younger-than-average offensive line, thanks in large part to using their first draft picks in both 2019 and 2020 on Erik McCoy and Cesar Ruiz. Every Saints offensive lineman was under 30 last season, so that's at least one position group that won't be filing for social security next year.
Jacksonville just misses out on being younger everywhere thanks to their tight end; Tyler Eifert was the only Jaguars player in his 30s to play even 300 snaps last season. That clearly cannot stand, and the Jaguars declined his option for 2021. They're joined by the Chargers, where the duo of Casey Hayward and Chris Harris kept the Los Angeles secondary above average, and even that only barely scraped into the top 10.
And yes, Tom Brady can be seen clearly here, too. The Buccaneers were 13.4 years older at quarterback than the average NFL team; that's a record as well. One day, Brady will turn into a pumpkin and we can write these articles without referencing him. I mean, theoretically at least. There's a chance.
Subject: Re: Re: Fountain of Youth location Florida?