take a look at the other thread running around about SH approaches
I think most folks give freshmen at least some minutes at the start - 10 is probably the high end, 5 probably the low end. Views vary and how much folks adjust for high school gpa varies.
For your guy, since he was at zero, 20 is nice big jump. I bet you will be okay. if your team falls apart without him, you might go to 25.
IFFF he got a 1.3 gpa even with 10 mins of study hall, I would be saying that you have a chance that he'll be okay at 20 but less confident
at least thats my view
Dean Wormer really likes us to keep those GPAs up - our primary mission is education!