by Scott Kacsmar

Whether it's the record number of underclassmen declaring for the NFL draft or the "No Carries for Old Men" movement, the average roster age may be trending towards youth. Fortunately, with the availability of snap data, we have a way to track this accurately so that the 38-year-old long-snapper won't age your team much since he's only playing a small percentage of the time. Every player's age is weighted by how many snaps they played.

Danny Tuccitto introduced Snap-Weighted Age (SWA) last year and we have crunched the numbers again for the 2013 regular season. With data back to the 2006 season, the average age has been getting younger, but it's more noticeable on offense than on defense perhaps due to the rising expectations of rookie quarterbacks. Thirteen of the league's 32 projected starters were Week 1 rookie starters and that number could easily grow this September.

In 2006 the average SWA was 27.6 on offense and 27.1 on defense. In 2013 the average SWA was 27.0 on offense and 26.7 on defense. That's a new benchmark for youthful defenses while the offense rebounded slightly after dipping to 26.9 in 2012.

Snap-Weighted Ages for 2013

The following table shows SWA for the overall team (TOT) along with the unit breakdown for offense, defense and special teams. Teams are ranked from oldest to youngest.

Team TOT Rk OFF Rk DEF Rk ST Rk ARI 27.8 1 27.9 3 28.1 2 27.1 2 ATL 27.0 12 27.7 6 26.7 15 26.0 20 BAL 26.9 13 26.7 18 27.5 6 25.9 21 BUF 26.2 25 26.4 24 26.0 26 26.1 13 CAR 27.3 5 28.3 2 26.6 16 26.6 7 CHI 27.4 3 27.5 11 27.3 10 27.6 1 CIN 26.6 20 26.0 29 27.4 9 26.4 8 CLE 25.8 31 26.6 21 25.5 30 24.9 31 DAL 26.2 26 26.6 22 26.1 24 25.4 28 DEN 27.1 9 27.9 4 26.3 19 26.8 6 DET 27.0 10 27.0 15 27.1 13 26.9 5 GB 26.0 29 26.0 30 26.4 18 25.4 29 HOU 26.7 15 27.5 10 26.3 20 25.8 24 IND 26.6 21 25.8 31 27.7 4 26.0 19 JAC 26.1 27 26.6 20 26.1 23 24.7 32 KC 26.2 24 26.1 28 26.5 17 25.8 25 Team TOT Rk OFF Rk DEF Rk ST Rk MIA 26.7 19 26.5 23 27.1 12 25.9 22 MIN 26.8 14 26.7 19 27.2 11 25.9 23 NE 26.5 22 27.6 7 25.8 29 25.6 27 NO 27.1 8 28.4 1 26.1 25 26.2 10 NYG 27.2 6 27.5 12 27.4 7 26.0 18 NYJ 26.5 23 26.2 26 26.9 14 26.2 11 OAK 27.0 11 26.7 17 27.6 5 26.1 16 PHI 26.7 16 27.5 9 26.2 22 26.1 17 PIT 27.1 7 26.4 25 28.4 1 25.8 26 SD 26.7 18 27.6 8 25.9 27 26.1 14 SEA 25.9 30 25.8 32 25.9 28 26.1 15 SF 27.5 2 27.9 5 27.4 8 26.9 4 STL 25.5 32 26.1 27 25.0 31 25.0 30 TB 26.1 28 27.1 14 25.0 32 26.2 12 TEN 26.7 17 27.3 13 26.2 21 26.4 9 WAS 27.4 4 27.0 16 27.9 3 27.1 3 AVG 26.7 - 27.0 - 26.7 - 26.1 -

NFC West Dynamics

The 2013 NFC West was a very impressive division, but the teams are split when it comes to the fountain of youth. The Cardinals and 49ers fielded the oldest teams in the league while the Seahawks (30th) and Rams (32nd) almost had the two youngest with Cleveland (31st) nudging in between. Guess the Browns needed more Brandon Weeden (and less weed) for us to have perfect NFC West symmetry.

Arizona and San Francisco were the only teams to rank in the top 10 for every unit. The Rams were the only team to rank in the bottom 10 for every unit. The one area Seattle differed was on special teams where it ranked a mediocre 15th.

St. Louis is receiving plenty of pub for its 2014 draft, so if that's anywhere near as successful as some think, then they may continue to field a young team trying to find its way in the league's best division.

San Francisco's defense has been one of the league's 12 oldest in seven of the last eight seasons, ranking No. 8 last season. Bringing in what will be a 30-year-old Antoine Bethea ages them more, but safety Jimmie Ward was drafted in the first round and this could be the year for Tank Carradine to start making an impact. Part of what ages the 49ers offensively is that they are one of just five teams to feature a running back in his thirties (Frank Gore). Gore's 276 carries were the most by any running back at age 30-plus last season. He'll still get most of the carries as long as he's running well, but the 49ers could give sophomore Marcus Lattimore's knees a shot. The 49ers did not re-sign center Jonathan Goodwin (35), one of the league's oldest starting linemen.

Arizona's situation is a bit more worrisome. The Cardinals' team SWA increased by 0.6 from 2012, the second highest increase behind Carolina (1.0). But while the Panthers said goodbye this offseason to Jordan Gross, Steve Smith and every other recognizable body at wide receiver, the Cardinals return much of the same core. The 2004 draft was incredible for this team, but Larry Fitzgerald (31) and Darnell Dockett (33) will both be at least 31 this season. Carson Palmer will be a 35-year-old quarterback and rookie Logan Thomas is a project at best. John Abraham really stepped up last season, but how much does he have left at 36? The good news is that players like Jonathan Cooper (last year's first-round guard) and Sam Acho should return from injury and 36-year-old safety Yeremiah Bell is a free agent. Arizona drafted safety Deone Bucannon in the first round.

Seattle: Jealous, Bro?

Like Danny before me, I prefer not to make any sweeping conclusions on whether it's better to get older or younger as a team. Of the 10 teams with the biggest youth movement in 2013, only San Diego (the biggest drop at -1.2) had a winning record. Half of the top 10 "aged teams" made the playoffs. What I do know is that getting as many good players as possible playing at a high level should breed success, whether they are old or young. The Seattle Seahawks have a lot of good players and they just so happen to be young.

Seattle's impressive collection of talented youth is why this team is such a favorite to go on a dynastic run. Sure, the salary cap will catch up eventually. They now have three players (Percy Harvin, Earl Thomas and Richard Sherman) with contracts that pay at least $10 million annually. Russell Wilson will soon top them all (you know, quarterback money) when the time comes for his second contract. But for now, the window is open for Seattle to make a run at multiple titles.

The Seahawks were able to win the Super Bowl with the youngest offense (25.8) in the league. That's a stark contrast from what the youngest offense has accomplished and the type of offense that has won the Super Bowl since 2006.

Season Youngest Offense Super Bowl Winner Team SWA Result Team SWA Rk 2006 SF 25.8 7-9, no playoffs IND 27.9 13 2007 BUF 26.3 7-9, no playoffs NYG 27.6 15 2008 MIA 26.2 11-5; lost AFC-WC PIT 26.4 30 2009 PHI 26.0 11-5; lost NFC-WC NO 27.5 12 2010 PHI 25.6 10-6; lost NFC-WC GB 27.2 19 2011 DEN 25.6 8-8; lost AFC-DIV NYG 27.4 13 2012 CIN 25.1 10-6; lost AFC-WC BAL 27.3 10 2013 SEA 25.8 Won Super Bowl SEA 25.8 32

Before Seattle, the seven youngest offenses combined for one playoff win. That was the Tim Tebow-led Broncos beating another old Pittsburgh defense from the 2011 season.

For Super Bowl winners, we see five of the eight teams clustered in that 10-15 range, bringing a solid mix of youth and experience. Seattle winning with a 25-year-old quarterback is nothing new in this era. Fourteen of the last 15 Super Bowl winners had a quarterback in his age 30 or younger season. A unique feature was Seattle's young, unheralded receiving corps. Tight end Zach Miller was the oldest contributor of significance at age 28. Doug Baldwin (25) and Jermaine Kearse (23) were undrafted, homegrown prospects. Even leading receiver Golden Tate (25) was only in his fourth season. The offensive line had some issues, but Paul McQuistan (30), now in Cleveland, was the oldest player to play any snaps in 2013. With 22-year-old wide receiver Paul Richardson drafted in the second round and Harvin (26) expected to play a lot more than 19 offensive snaps this season, the Seahawks should again field a very young offense with the potential to be even better than last season's championship unit.

Seattle's defense was clearly the best in the league last year, but it was still the fifth-youngest unit as well (second youngest in 2012). Sherman and Kam Chancellor will be 26 and Thomas will be 25 this season. The "Legion of Boom" is signed up for the next couple of years and these guys are in their prime. The rotational pass rush is also filled with guys in their 20s.

Literally any player of significance who would be at least 30 years old in 2014 is no longer on the team (Brandon Browner, Paul McQuistan, Red Bryant and Chris Clemons). So it's a juggernaut rolling with only 20s, coached by Pete Carroll, just like everyone predicted a few years ago when the NFC West was the joke of the league, right?

Colts: Where's the "D" in Indy?

The Colts are a great example of why the SWA metric is necessary. Adam Vinatieri, 42 in December, is the oldest active player in the NFL, but at least he's just a kicker. The Colts also have the oldest quarterback in football, Matt Hasselbeck (39 in September), but ideally he will never take a snap this season.

In 2013, no team had a larger differential between its SWA on offense and defense than the Colts, who ranked as the second-youngest offense, but fourth-oldest defense. No defense got older than the Colts from 2012 to 2013 with a 1.1 gain in SWA thanks in part to signings like LaRon Landry, Erik Walden and Greg Toler.

We knew the offense would be young with so many key pieces coming in the 2012 draft alone: Andrew Luck, T.Y. Hilton, Vick Ballard, Coby Fleener and Dwayne Allen. Throw in a serious injury to Reggie Wayne, now the oldest receiver in football after the retirements of Tony Gonzalez and Brandon Stokley, and the youthful offensive ranking makes a lot of sense.

What GM Ryan Grigson has yet to do is bolster the defense with a great draft. That likely did not happen in 2014 either, given that his only defensive picks were Jonathan Newsome (fifth round) and Andrew Jackson (sixth round). Last year's first-round pick Bjoern Werner played on 28.9 percent of the defense's snaps. A 32-year-old Robert Mathis carried the defense with arguably the best season of his career. Cory Redding and Aubrayo Franklin were defensive line starters at age 33, making them two of the oldest positional starters in the league. Landry will be 30 while the other starting safety remains a mystery/eyesore after the team let Antoine Bethea go to San Francisco.

The Colts overcame many disastrous injuries on offense last season, but the defense had a pretty solid bill of health. Things just did not always click in Chuck Pagano's second season and in the playoffs, the Colts allowed 87 points in two games. The Colts are banking on free-agent acquisitions Arthur Jones and D'Qwell Jackson (he'll be 31) to help the front seven, but the defense continues to lack young building blocks.

Steelers Really Are Old on Defense

It's become passé to call the Pittsburgh Steelers old on defense, but someone like Warren Sapp will rarely turn down the opportunity. Still, the facts are indisputable: for the seventh season in a row, the Steelers fielded the oldest defense in the NFL.

Even after saying goodbye to Casey Hampton (35) and James Harrison (34) and losing Larry Foote (33) to injury after one game, Pittsburgh still couldn't finish anything but No. 1. It's not like the team hasn't tried to add fresh blood, but the development process of those players has been sketchy at best in recent years.

The good news is the Steelers have a real shot of not finishing first again in 2014. Jason Worilds (26) and Jarvis Jones (25) should start at outside linebacker with Lawrence Timmons (28) and first-round rookie Ryan Shazier (22) playing inside. The Steelers loved using six defensive backs last season (a league-high 45 percent of defensive snaps) but the Shazier pick could allow for more 2-4-5 fronts. Unless Kevin Colbert has another one of his "get the band back together" moments with a soon-to-be 36-year-old Brett Keisel, the Steelers will be younger at defensive end. Cameron Heyward (25) finally looked the part last year and second-round rookie Stephon Tuitt (21) could see action early.

The problem remains in the secondary. It's unlikely a 33-year-old Troy Polamalu plays every defensive snap like he did in 2013, but he's still a featured player for Dick LeBeau. Sophomore Shamarko Thomas (23) could see the field more as well. The other starting safety will be eight years younger with Mike Mitchell (27) replacing Ryan Clark (35). Though without truly addressing the cornerback position, that leaves the same trio of Ike Taylor (34), William Gay (29) and Cortez Allen (26) to hog up the snaps. Allen was supposed to challenge for a starting role, but it has yet to work out.

So if the Steelers can get some instant impact out of their draft class, they may only be the second-oldest defense in the league in 2014. Either way, this is a unit that's just trying to be good again. Age was never a big concern during those 12-4 campaigns.

Detroit Doubles Down

The Detroit offense had the biggest youth movement in 2013 (-1.3 SWA). This was due to the retirement of left tackle Jeff Backus and the ascension of young linemen Riley Reiff and Larry Warford to full-time starters. Detroit could be set for another drop if first-round rookie tight end Eric Ebron and free-agent signing Golden Tate become the top two targets behind Calvin Johnson. Last season 32-year-old receiver Nate Burleson played 497 snaps for Detroit, but he's in Cleveland now. What could really bring the Lions' SWA down is the eventual replacement of starting center Dominic Raiola (36 this year). With the retirement of Jacksonville center Brad Meester and Jonathan Goodwin's free-agent status, Raiola can be considered the oldest starting offensive lineman in the NFL. The Lions drafted Travis Swanson in the third round, but he'll likely begin the season as a backup.

San Diego Recharged

The biggest age change in the league belonged to San Diego's defense, dropping 1.9 in SWA from where they were in 2012. That's going from the sixth-oldest defense to the sixth youngest. Much was said (mostly negative) about San Diego's 2013 defense. By some traditional statistics, it looked mediocre. But given the Chargers had the fewest defensive drives (162) of any team, it's not as surprising that on a per-play basis they ranked dead last in defensive DVOA.

How much of that was due to a new head coach (Mike McCoy) implementing younger players? That's hard to say, but it likely had an impact. Five of the 10 players who played at least 50 percent of the defensive snaps in 2012 were no longer on the team in 2013. The defense was playing better late in the season, arguably peaking in the Wild Card win in Cincinnati.

Just based on 2013 (small sample warning), the correlation between a defense's SWA and defensive DVOA was essentially zero.

The Washington Tradition

Danny noted last year that SWA correlated best (0.303) with DVOA on offense. Results were very similar for 2013 with a correlation of 0.334. Once again the top offenses led by older quarterbacks in Peyton Manning, Drew Brees, Tom Brady and Philip Rivers deserve a lot of credit for this.

However, the strongest correlation for 2013 was actually on special teams. It was also negative (-0.348), perhaps implying a younger, cheaper special teams unit may be the better way to go. Juicing the numbers were the Washington Redskins, owners of the worst special teams and the third oldest. Of course, being old on special teams is nothing new for Washington. 2013 was the eighth season in a row that the Redskins ranked among the four oldest special teams in the league. That's what happens when draft picks, a common resource used to acquire cheap depth and fill out the special teams, are constantly traded away.