Phil Steele recently released this year's version of his "Experience Chart," in which he goes school-by-school and breaks down the depth chart for every team in the country by position and year.
To formulate a point system, I awarded 3 points for every senior starter (2.5 for every additional senior in the two deep) 2 points for every junior starter (1.5 for every additional junior in the two deep) 1 point for a sophomore starter (0.5 for every additional soph in the two deep) then subtracted 1 point for every frosh starter and .5 for every frosh in the two deep. The total points column uses that formula to figure out the points awarded to a team.
It's an interesting way to preview teams, albeit not the be-all, end-all because the Pac-12 will have plenty of sophomore starters (and players in the two-deep) this season who will be more valuable -- and experienced -- than senior starters at other positions or senior starters on other teams. A senior isn't necessarily going to be more "experienced" than a sophomore just because he's a senior. Case in point: In this system, UCLA quarterback Josh Rosen receives one-third the points of a first-year senior starter. (Hey, better than last season, when he would've subtracted points from the Bruins' final tally!)
Also, Steele's ranking doesn't take into account Pac-12 coaches who like to constantly shuffle players through the lineup. So, you might have a lineman who plays nearly as many reps as the starter, but Steele will consider them first and second string, while the coach -- and how the reps break down -- really might look at them as 1A and 1B.
Because of that, it's probably more useful to look at this ranking as an "Age Chart," rather than an overall look at experience, since we so commonly use that word to mean playing experience/game experience and not just how many years a player has been on campus.
Here's where the Pac-12 teams fell nationally in Steele's ranking:
T-76. Oregon State, Washington State
T-87. Arizona State, Cal