ESPN just ranked teams by their under-25 age talent. There is some sort of calculus that scores the teams, that includes snaps by U-25 players, accolades for U-25 players, and positional value for the U-25 players. The New England Patriots came in 29th. That's out of 32 teams. New England ranked 12th in 2014.
The Patriots still beat the Indianapolis Colts (30th) and the Seattle Seahawks (32nd). Washington ranked 31st. Just based on these rankings, a team's U-25 value has nothing to do with current success.
It's important to note that these rankings do not include players who are 25. So this removes pretty important players like linebackers Jamie Collins and Dont'a Hightower, edge defender Chandler Jones, defensive tackle Sealver Siliga (and Chris Jones), cornerback Malcolm Butler, and, heck, even punter Ryan Allen.
So the Patriots are still young, but everyone just happened to have a poorly timed birthday for these rankings.
New England does have a few key players under the age of 25. Defensive tackles Malcom Brown (21) and Dominique Easley (23) will have key roles. So will rookie offensive linemen Tre Jackson (22) and Shaq Mason (21), and second-year center Bryan Stork (24). Experienced rotational players include cornerback Logan Ryan (24), safety Duron Harmon (24), and wide receiver Aaron Dobson (23).
Back-up quarterback Jimmy Garoppolo is also 23.
The Patriots are well stocked with youth- experienced youth- and are well on their way to another stretch of success. It's even better that with all of the 25-year-olds on the roster, New England still ranks ahead of the Colts.