Do we do redshirting backward? Most guys that play as true freshman perform in some type of limited duty. Justin Jackson, Dan Vitale... are the exceptions. Let's take Garrett Dickerson. Last year, he played and had 4 catches for 44 yards. I can't really quantify how valuable he was a blocker. I'd think he would be far more valuable in year 5 than in year.
Basically, if we project a player to be a complete stud in the future, but don't have a full time starting type spot for him, I say redshirt him. If you need someone to fill in as a role player because you need another body, then play the guy that doesn't project to a 5 year player. If the kid develops better than expected, you'll have a redshirt down the line if he's injured and you most likely have a stud at that position anyway because that's the guy you redshirted as a freshman.
Basically, if we project a player to be a complete stud in the future, but don't have a full time starting type spot for him, I say redshirt him. If you need someone to fill in as a role player because you need another body, then play the guy that doesn't project to a 5 year player. If the kid develops better than expected, you'll have a redshirt down the line if he's injured and you most likely have a stud at that position anyway because that's the guy you redshirted as a freshman.