It is the ACC that is causing the issue. They have 3 guaranteed games with 1 or 2 of these being at home depending on the year. 5 ACC games with 2 to 3 at home.
Do you see the issue? At this point they have 4 home and 4 away, to get 7 home games 3 of the final 4 need to be at home. That is the issue.
8 or 9 games is just a crazy number. 9 home games with 3 away really does not work.