In each of last three years, I’ve presented the AV-adjusted age of each roster in the NFL. Measuring team age in the NFL is tricky. You don’t want to calculate the average age of a 53-man roster and call that the “team age” because the age of a team’s starters is much more relevant than the age of a team’s reserves. The average age of a team’s starting lineup isn’t perfect, either. The age of the quarterback and key offensive and defensive players should count for more than the age of a less relevant starter. Ideally, you want to calculate a team’s average age by placing greater weight on the team’s most relevant players.

My solution has been to use the Approximate Value numbers from Pro-Football-Reference.com. The table below shows the average age of each team, along with its average AV-adjusted age of the offense and defense. Here’s how to read the Jaguars line. In 2014, Jacksonville was the youngest team in the league, with an AV-adjusted team age of 25.8 years (all ages are measured as of September 1, 2014). The average AV-adjusted age of the offense was 24.5 years, giving the Jaguars the youngest offense in the NFL (and by over a year!). The average age of the defense was 26.6 years, and that was the 10th youngest of any defense in football in 2014.

Rk Team Ovr Age Off Age Off Rk Def Age Def Rk 1 JAX 25.8 24.5 1 26.6 10 2 STL 25.8 26.6 8 25.2 1 3 SEA 26.2 25.7 2 26.6 11 4 MIN 26.3 26.6 9 26.1 3 5 DAL 26.6 26.8 12 26.4 6 6 GNB 26.7 26.4 6 27.2 21 7 CLE 26.7 26.9 14 26.6 8 8 KAN 26.7 26.8 13 26.6 9 9 CAR 26.7 26.6 10 26.9 14 10 TAM 26.8 27.7 25 26 2 11 BUF 26.8 27.1 18 26.5 7 12 CIN 26.8 25.9 3 27.7 30 13 MIA 26.9 26.1 4 27.9 31 14 PIT 27 26.5 7 27.6 28 15 HOU 27 27.7 24 26.4 5 16 WAS 27 27.1 17 27 17 17 TEN 27.1 27 16 27.1 20 18 PHI 27.1 27.5 23 26.7 12 19 NYJ 27.2 27.5 22 26.9 16 20 ATL 27.2 27.4 20 26.9 15 21 NYG 27.2 26.9 15 27.6 27 22 IND 27.2 26.2 5 28.4 32 23 OAK 27.3 26.8 11 27.7 29 24 DET 27.3 27.1 19 27.5 26 25 ARI 27.5 27.5 21 27.5 24 26 SFO 27.5 27.8 26 27.3 22 27 DEN 27.7 28.7 31 26.4 4 28 SDG 27.7 28.3 30 27.1 19 29 NWE 27.7 28.2 29 27 18 30 BAL 27.7 28 28 27.3 23 31 CHI 27.8 28 27 27.5 25 32 NOR 28.2 29 32 26.8 13

Youngest Offenses

To use a technical term, the Jaguars offense is stupid young. As of September 1, 2015, Blake Bortles was 22.7 years old, while the offensive line consisted of four youngsters (LT Luke Joeckel was 22.8, rookie C Luke Bowanko was 23.2, rookie RG Brandon Linder was 22.6, guard and RT Austin Pasztor was 23.8) and left guard Zane Beadles (27.8). All of those players should again be starters in 2015, although ex-Cowboy Jermey Parnell (29 in July) will likely start at right tackle.

Youth was also prevalent at the skill positions. Three of the team’s four leaders in yards from scrimmage were Denard Robinson (23.9), Allen Hurns (22.8), and Allen Robinson (21.0), while Marqise Lee (22.8) is also an emerging talent. This is an incredibly young offense with the exception of Beadles and the new additions this year, Parnell and ex-Bronco Julius Thomas (27 in June). When your old guys are still under 30, you’re a young offense.

Seattle had the youngest offense in the NFL in 2013, and not much changed. Sure, every one got a year older, but rookies Justin Britt (RT) and Paul Richardson (WR) both saw some playing time and former right tackle Paul McQuistan (30 in 2013) moved to Cleveland; as a result, the average age only jumped up from 25.5 to 25.7. Eight players on the offense recorded at least 5 points of AV: Russell Wilson (25.8), Marshawn Lynch (28.4), J.R. Sweezy (25.4), Britt (23.3), Doug Baldwin (25.9), James Carpenter (25.4), Russell Okung (26.9) and Jermaine Kearse (24.6). Age is certainly not an issue in Seattle, although with Carpenter and Max Unger (28.4) now gone, the same can’t be said for the offensive line.

Finally, in 2012 the Bengals had the youngest offense in the NFL at 25.5 years. Two years later, the average only has only spiked to 25.4. How did that happen, given the limited roster turnover?

Obviously, players like Andy Dalton (26.8), A.J. Green (26.1), Mohamed Sanu (25.0), and Clint Boling (25.3) are all two years older, even if they’re still relatively young. And Andrew Whitworth (32.7) remains the senior member of the squad. But the Bengals also added Jeremy Hill (21.9), Giovani Bernard (22.8), and Russell Bodine (22.2) in the draft; Hill and Bernard were two of three Cincinnati players to gain 1,000 yards from scrimmage, while Bodine started 16 games at center. Dalton (for better or worse) and Green are the keys to the offense, but Cincinnati looks to be in great shape to maintain at least an average offense for the foreseeable future. And in the draft, the Bengals added strong tackle prospects in the first two rounds, giving them a chance to reboot there in 2016. Oh, and Marvin Jones (turned 25 in March) will be back this year.

Oldest Offenses

It’s not surprising to see the Saints come in as the oldest offense int he league. Over half of the team’s starting offense, including Drew Brees (35.6), was over 30 last year, including four offensive linemen (Jahri Evans (31.0), Ben Grubbs (30.6), and Zach Strief (30.9), Jonathan Goodwin (35.7)!) and Marques Colston (31.2). Even Jimmy Graham (27.8) is sneaky old, although that’s not really a problem for 2015.

The Broncos are now totally weighed down by Peyton Manning (38.4) in this analysis. The other issue is other than C.J. Anderson (23.6), there’s not much other young talent. Julius Thomas (26.2) and Demaryius Thomas (26.7) didn’t do much to offset Manning, while the mainstays on the offensive line were Orlando Franklin (26.7), Louis Vasquez (27.4), Manuel Ramirez (31.5, now in Detroit) and Ryan Clady (28.0). The Broncos don’t have an old offense other than Manning as much as they don’t have a young offense; add the Manning boulder, and the average age goes up considerably.

Youngest Defense

In scary news, for the second straight year, the youngest defense belongs to the St. Louis Rams. The Rams were helped, of course, by adding Aaron Donald (23.3) in the 2014 draft, but St. Louis still has young players all over the defense: Robert Quinn (24.3), Alec Ogletree (22.8), Michael Brockers (23.7), Rodney McLeod (24.2), E.J. Gaines (22.6), T.J. McDonald (23.6), and Mark Barron (24.8) were all under 25 when last season started. In fact, 2/3s of the 176 starts by Rams defenders came from players under 25 at the start of the season. And 13 more starts went to Janoris Jenkins (25.8). The majority of the remaining starts went to James Laurinaitis (27.7), Jo-Lonn Dunbar (29.5), and William Hayes (29.3) or Chris Long (29.4). St. Louis had just one defender on the roster in his thirties, linebacker Will Herring (31.0), and he did not start a single game. As a result, you won’t be surprised to learn that St. Louis did not draft a defensive player until the 7th round of the 2015 Draft.

Oldest Defense

For the second year in a row, the Colts took home this honor. For Indianapolis, here were their top defensive players according to AV: D’Qwell Jackson (30.9), Vontae Davis (26.3), Mike Adams (33.4), Cory Redding (33.8), Bjoern Werner (24.0), Erik Walden (29.0), and Josh Chapman (25.0). The Colts also have Greg Toler (29.7) and Jerrell Freeman (28.3) as starters. And all this was without Robert Mathis for the season! Indianapolis also ranked as the oldest defense in Football Outsiders’ Snap Weighted Age.