Not my practice to call out players or coaches for their performance, but I've seen enough from parker to know he isn't the answer.
Someone nailed it when they mentioned every yard seems so hard. That happens when the opposition knows your tendencies and you don't have or haven't shown any counters to that particular play. The defense can just diagnose and attack.
Clemson has a good D, but there were a lot of points left on the field. Parker l lacks the feel for calling a week timed counter and on the off chance he guesses right, someone doesn't execute their assignment which blows up the play. Again, needing everyone to doi their job perfectly is not a recipe for success...