The Cowboys offensive line has combined for 13 Pro Bowl appearances, five first-team All-Pro seasons, and six second-team All-Pro seasons. It features three former first-round picks in Tyron Smith, Travis Frederick, and Zack Martin, an undrafted free agent in La’el Collins who was widely held to be a first-round talent, and now 2018 second-round pick Connor Williams.

And when the Cowboys kick off the 2018 season on September 9 against the Carolina Panthers, this will likely be the Cowboys’ starting line-up:

Tyron Smith (27) - Connor Williams (20) - Travis Frederick (27) - Zack Martin (27) - La’El Collins (25)

This lineup will have an average age of 25.8 on opening day of the 2018 NFL season, which makes it the youngest O-line in the NFL. If you’re not a Cowboys fan, that’s got to be a scary thought.

Here’s how all NFL teams compare in total combined O-line age on opening day 2018, based on the Ourlads.com depth charts (which are usually quite accurate) from 4/30/18:

Rank Team Avg. Age Rank Team Avg. Age Rank Team Avg. Age 1 DAL 25.8 12 KC 27.3 23 CAR 28.2 2 HOU 26.2 13 CLE 27.3 24 DET 28.2 3 IND 26.5 14 NO 27.4 25 CHI 28.2 4 CIN 26.6 15 BAL 27.4 26 TB 28.6 5 BUF 26.9 16 NYG 27.6 27 OAK 28.8 6 NE 26.9 17 MIN 27.8 28 ARI 29.6 7 SEA 27.0 18 GB 27.9 29 PIT 30.2 8 JAC 27.1 19 LAC 27.9 30 LAR 30.4 9 WAS 27.1 20 NYJ 28.1 31 ATL 30.4 10 TEN 27.2 21 MIA 28.1 32 PHI 30.9 11 SF 27.3 22 DEN 28.2

As a general rule, you want your O-line (like any other position) to be younger rather than older, because as players become older, the risk of injury increases exponentially and performance often declines suddenly.

Some brainiac will inevitably want to point out that Philly won the Super Bowl with what looks like the oldest O-line in the league, but Philly won with Halapoulivaati Vaitai (24) subbing in for the injured Jason Peters (36) for most of the season, which just underlines the injury risk of older players.

ESPN’s John Clayton explained in his “Theory of 150” that if the combined age of your starting offensive line exceeds 150 years (or a 30.0 average), you should expect a decline in performance.

If a team lets its starting offensive line exceed the total age of 150 years for five starters, the clock is ticking on its remaining success.

The 30-year age limit also chimes nicely with the widely held belief that for NFL players, decline inevitably sets in at age 30.

But nothing lasts forever, and at some point even the Cowboys O-line will grow older - if the Cowboys don’t bring in fresh blood regularly. And that’s why they drafted Connor Williams (20) this year, and brought in young-ish free agents in OT Cameron Fleming (25) and OG Marcus Martin (24). These may not be sexy moves, but they are the type of moves that keep your O-line young and effective.

Tyron Smith is entering his eighth year in the league, Travis Frederick is coming up on his sixth, and Zack Martin is looking at his fifth. Yet combined with La’el Collins and Connor Williams, the Cowboys O-line is still the youngest line in the league.

It's just not fair.