As rosters shake out this summer, you'll hear a fair amount about the "youngest" and "oldest" teams in the NFL. Sometimes those figures and rankings can be skewed by aged kickers or an exceptionally youthful set of reserves, so I like what colleague Mike Sando compiled this week over on the NFC West blog.

Sando has a comprehensive chart ranking teams by the average age of their projected starters, ostensibly the most important 22 players on the roster. (Specialists weren't included, mostly because age isn't as relevant for them.) Naturally, there are some best guesses involved when you're looking at a starting lineup in May, but most teams have provided enough clues either through minicamps or organized team activities (OTAs) to make a reasonable projection.

As it turns out, the Chicago Bears have the NFL's oldest set of starters when viewed in this way. As it stands now, their starting defense includes four players who are at least 30 and two more who are 29. That figure could change if either (or both) of their two rookie linebackers, Jon Bostic (22) and Khaseem Greene (22) win a starting job. But for now, the Bears' starting linebackers are Lance Briggs (32), D.J. Williams (30) and James Anderson (29). They are set to play alongside defensive end Julius Peppers (33), cornerback Charles Tillman (32) and cornerback Tim Jennings (29).

The Detroit Lions rank No. 16 overall largely because their offensive starters are the NFL's sixth-oldest, headed by center Dominic Raiola (34), receiver Nate Burleson (31) and tight end Tony Scheffler (30). For the purposes of this projection, Corey Hilliard (28) is considered the right tackle over Jason Fox (25).

Meanwhile, starters from the Minnesota Vikings and Green Bay Packers rank among the NFL's nine youngest.

Making a value judgment here is much harder than compiling the figures. Younger isn't necessarily better, especially at key positions, unless it represents a longer-term fixture at the position. And in some cases, age represents the staying power of an elite player. For 2013, at least, I'm sure the Bears would prefer Briggs over, say, the Lions' DeAndre Levy (26) or the Packers' Nick Perry (23).

NFL team-building can be cyclical, however. What we can say, I think, is that teams with older starters have more urgency to identify and develop their next generation of players. Presumably, those with younger starters have already begun that process.

Related: The Packers and Vikings lead the division, respectively, with draft picks remaining on their roster.