Snap-Weighted Age: 2017 NFL Rosters

by Scott Kacsmar

The NFL is increasingly turning into a young man's game. The average snap-weighted age (SWA) in 2017 was 26.46 years, which just breaks the record low set a year ago at 26.55 years. The age could go down even more in 2018 if Adam Vinatieri (46 this season), Tom Brady (41), and Terence Newman (40) ever hang it up for good.

The differing roles of those players serve as good examples for why we calculate a team's age based on how many snaps each player played in the regular season. Brady was a starting quarterback, so he played almost every play and logged 1,118 snaps in 2017. Newman was a part-time cornerback for the Vikings, so he had 570 snaps. Vinatieri only needed to be the kicker for a low-scoring Indianapolis offense, so he had 61 snaps (all on special teams). Vinatieri doesn't dramatically affect the Colts' numbers because he didn't have to play often, but Brady's age and importance did have a big impact on the Patriots' stats. We'll later look at exactly where each team was old or young by position.

Of course, the "age-old question" is where should a team rank in SWA? In 2016, the seven oldest teams all failed to make the playoffs. In 2017, five of the top seven oldest teams made the playoffs, including both Super Bowl teams. It was the third year in a row where both Super Bowl teams were in the top 10 in SWA. In the previous nine seasons, only one matchup (2011 Giants-Patriots rematch) featured two teams in the top 10 for SWA. For reference, we've included a table of where both Super Bowl teams ranked in SWA since 2006.

Perhaps the most interesting result here is that only four of these 24 teams ranked in the bottom 10 in SWA: the Colts in 2006 and 2009, and the Seahawks in 2013 and 2014. Peyton Manning led the Colts to a Super Bowl win in 2006, but a similarly young team lost the big game in 2009. The Seahawks looked to be the next dynasty after dismantling Manning's Broncos in 2013, but lost to the Patriots the following year. Seattle hasn't reached the big game since and has aged to the middle of the pack. For what it's worth, Bill Belichick's Patriots have ranked in the top 10 in SWA in eight of the last 12 seasons.

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2017 was a good year for young teams finally breaking through. The Jaguars ranked 27th or lower (read: younger) in SWA for every year since 2013, but finally put things together on defense to make a deep playoff run. The Rams have finished 31st or 32nd in SWA for five years in a row, but rookie head coach Sean McVay finally got great production out of the high draft picks that Jeff Fisher was wasting. The Rams made their first postseason appearance since the 2004 season.

2017 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. We ranked the units from oldest to youngest, but that is really done for reader convenience rather than making any definitive statement of quality.

There is consistently non-zero correlation between SWA and DVOA, but last year it was just 0.20 -- down from 0.38 in 2016 and 0.27 in 2015. Last season was a bit unique for big-name injuries that drastically changed a team's performance. Things like the Packers getting younger at quarterback because Aaron Rodgers broke his collarbone, or the Cardinals getting older at running back because David Johnson was lost in Week 1, did not help those teams play better. In fact, the correlation between offensive DVOA and offensive SWA was down to 0.17, while defense was at -0.27. Those numbers are in line with the past two seasons, though still a departure from the period before that when the offensive number was usually around 0.30.

Arizona almost pulled off the rare feat of having the oldest offense and the oldest defense, but finished as the second-oldest team in the latter category. Last year was literally a last hurrah for head coach Bruce Arians' run with the team as he retired after the season. Quarterback Carson Palmer also retired, but the Cardinals may not be getting much younger at the position. After all, Palmer missed nine games last year, and then the Cardinals brought in Sam Bradford. Then again, given Bradford's injury history, he may be out of the lineup before his 31st birthday in November. We could definitely see 21-year-old rookie quarterback Josh Rosen in action this year, and with David Johnson hopefully in the backfield again.

Carolina had the oldest defense, but ranked 25th on offense. The only team with a larger gap in SWA between offense and defense was rival New Orleans, which ranked as the sixth-oldest offense, but the second-youngest defense. That could be good news for the defense moving forward if the young players continue to develop as the Saints' 2016 rookies improved in 2017. Cornerback Marshon Lattimore also deservedly won the Defensive Rookie of the Year award last season.

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Buffalo had the second-oldest roster last season and finally ended its long playoff drought. However, it is hard to make much sense of that roster after another offseason where the Bills have cleaned house. The Buffalo roster turnover that has gone on the last few years deserves some attention. From 2015 to 2017, 19 players accumulated at least 10 points of approximate value for the Bills according to Pro Football Reference. A whopping 12 of those players are no longer with the team: Tyrod Taylor (traded), Richie Incognito (quasi-retired), Preston Brown, Eric Wood (retired), Cordy Glenn (traded), Stephon Gilmore, Sammy Watkins (traded), Marcell Dareus (traded), Corey Graham, Zach Brown, Robert Woods, and Ronald Darby (traded). The team is basically held together by LeSean McCoy, Kyle Williams, and the unholy quarterback trio of A.J. McCarron, Josh Allen, and Nathan Peterman. We don't know if the Bills will stay old or trend way younger this year, but it seems like a safe bet that they won't be any good either way.

Speaking of Tyrod Taylor and bad teams, the 0-16 Browns had a clean sweep for the youngest team last season. In fact, Cleveland's 24.6 SWA makes it the youngest team in the NFL since 2006. The previous youngest teams were the 2013 Rams and 2014 Jaguars (both at 25.4 SWA). Obviously the plan for Cleveland is, like those two teams, to get back into the playoff mix in a couple of years after continuing to acquire talent. Taylor may start some games this year at quarterback after the Bills traded him there, but the future is up to 23-year-old Baker Mayfield, the No. 1 pick in the draft. He'll have a chance to help turn the Browns around after they added Myles Garrett and other talented players in recent drafts. However, it doesn't seem too likely that the coach with the 1-31 record (Hue Jackson) is going to be the one who develops this talent into wins. Everyone wants a Sean McVay-level transformation now, but we know there's not much of a pipeline for great, young coaches coming into this league.

On a similar note, Dallas had the third-youngest roster and just let Dez Bryant and Jason Witten go. Instead of talking about the young Rams and Jaguars underperforming, we could be talking about Dallas and Cleveland as those teams the next few years. Dallas was just 9-7 last year after winning a No. 1 seed in 2016 behind its two great rookies (Dak Prescott and Ezekiel Elliott). We know there were suspensions and a few big injuries last year, but Dallas is a team that always carries high expectations. Jason Garrett is getting an eighth full season -- or at least an eighth Week 1 -- as head coach and has yet to get to a conference title game, which puts him in exclusive company. Based on that past history, it doesn't look promising that it will ever happen.

2017 Snap-Weighted Age: By Position

Finally, we have adjusted SWA by position. This excludes fullbacks since some teams never use one. "ST" includes the specialists on special teams -- kickers, punters, and long snappers. The method used was to create a z-score for each team's SWA by position. We then took the average z-score for all positions for a team to rank them in the table below. Instead of overloading you with z-scores for every position, we just posted where the team's z-score at each position ranked, sorted from oldest (first) to youngest (32nd). The 12 playoff teams are highlighted, and each team's rank is broken down into quarters: red (eight oldest), orange (ninth to 16th), blue (17th to 24th), and green (eight youngest). This should help highlight where each team is older, younger, or about average in regards to the rest of the league in SWA.

With this table, we can see how the Cardinals were pretty old everywhere except tight end, where they just haven't been good period in a long time. For as old as the Cardinals were, the Browns were just as young, except for the offensive line. Joe Thomas retired, so that's a big loss for that unit. Meanwhile, we can see how the Rams are very young, but have the second-oldest offensive line, which was a big help to last year's success. We'll have to see if left tackle Andrew Whitworth and center John Sullivan continue to hold up this season, or that could be the spot where the Rams look to improve next offseason.

We'll conclude by pointing out that the Saints had the youngest secondary (23.7 years) of any NFL team in the last eight seasons. This is something we will look at in more depth for the New Orleans and Green Bay chapters in Football Outsiders Almanac 2018 (available this summer), but it has been recently difficult to win a Super Bowl with such a young secondary. You never know when a guy might just duck under a receiver and give up a 61-yard touchdown in the final seconds of a divisional round playoff game. However, Seattle's Legion of Boom was once the youngest secondary in 2011 and 2012, and we know how that turned out for that team.

Talent trumps everything, but there is an undeniable advantage to young talent in this salary-cap era. Not only should today's players be viewed as "bigger, stronger, faster," but let's add "cheaper" to that list as well (at least for the first contract).