So it seems like we really are pretty close. The only thing that keeps throwing me off is your “12-8 or better” at 10%. That just seems ridiculously unlikely.
Even 11-9 at 15% seems pretty high. Look at those percentages you posted—to go 11-9 they need to go 4-3 in the toss ups, which either means sweeping the road games AND beating one of the toughest 4 at home, or beating two or more of those tough teams at home.
Boom. Nailed it. Georgia Tech goes 11-9 to finish 5th in the ACC.