When it comes to sports statistics, we make do with what we've got. In college football, we've got more than ever before -- better and more detailed passer and pass-rushing data, better predictive analytics, etc. But when it comes to measuring team experience, we've been stuck primarily with one measure: returning starters.
There are worse numbers, of course. If you return 19 total starters, you're probably going to improve, while if you only return seven, you will probably struggle. Still, one offense's seven starters aren't another's, and we instinctively understand that some positions are probably more important than others.