Teams with most under-25 talent

Robert Quinn and Michael Brockers are two young talents on St. Louis' D-line. Michael Hickey/Getty Images

With training camps opening up around the NFL, the preseason is right around the corner, and teams will have a lot of young talent to evaluate when determining their final roster spots. When an NFL team enjoys a period of sustained success, you can usually point to a small window of time during which that team built its foundation with young talent.

The Super Bowl champion Seattle Seahawks are a prime example, as they ranked first in last year's rankings, which were a little different since they included 25-year-old players, too.

Seattle's ranking this year is a sign of how quickly things change (and age) in this league. It's great to have young players, but having lot of youth is usually the result of a lack of developed veterans. We wanted to create a ranking that balanced opportunity with performance and potential, so we used the following criteria:

• The number of games in 2013 started by players under the age of 25
• The number of snaps played in 2013 by players under the age of 25
• Whether a team's young starters last season were simply injury replacements
• The number of under 25 first-team All-Pros and Pro Bowl players a team has on its roster (All-Pros were given more weight than Pro Bowls)
• Positional value (young quarterbacks and positions impacting the passing game carry more weight; backup running backs and kickers are devalued)
• The amount of value a team added in the 2014 draft, with a focus on the first two rounds (premium picks)
• The expected number of key starters and reserves under the age of 25 in 2014
• A team's recent track record of developing and retaining young talent

Once we had the groundwork for a list, discussion among the Football Outsiders staff further tweaked the list, resulting in the final version presented below. You'll see a number of references to Football Outsiders stats on our list, in particular DVOA (defense-adjusted value over average), which takes every play and compares its success to the NFL average based on situation and opponent. You can read more about that and other FO stats on this page. Here are our organizational rankings for this season. (Note: All ages are as of September 4, 2014.)

1. St. Louis Rams

Thanks in large part to the Robert Griffin III trade, the Rams have stockpiled young talent in recent drafts. Zac Stacy and Tre Mason are a young running back duo worth watching this season. Greg Robinson, the No. 2 overall pick in this year's draft, will likely start his career at left guard. Tavon Austin, Chris Givens and Stedman Bailey have all flashed potential at wide receiver but need to improve. The secondary is filled with young starters (not even counting 25-year-old Janoris Jenkins), but the name to watch out for is safety T.J. McDonald, who could become a star in Gregg Williams' system.

The real reason behind what powered the Rams to the top here: There may not be a better front seven in the league. Alec Ogletree impressed as a rookie linebacker last season. Defensive tackle Aaron Donald (Pittsburgh) was this year's first-round pick, and he should provide even more pass rushing ability to a line that's loaded with Chris Long, Michael Brockers and, of course, Robert Quinn. It was really Quinn's All-Pro season with 19 sacks that edged St. Louis to the top. There are several players with great potential here, but Quinn's the one to actually have started building a track record. If more Rams can follow his lead, then this team will compete in the tough NFC West.

2. Buffalo Bills

In the last three drafts, the Bills have added their starting quarterback (EJ Manuel), their left tackle (Cordy Glenn), their starting wide receivers (Sammy Watkins and Robert Woods) and their top cornerback (Stephon Gilmore). Now they wait for that talent to prove itself on the field, which is a familiar position for Buffalo this century.

Development is most needed on the offensive side of the ball where Marquise Goodwin is another solid, young wide receiver with plenty of room for improvement. Second-round rookie Cyrus Kouandjio could beat out Erik Pears for the starting right tackle job, giving Buffalo bookend tackles for the future.