against the other 3 teams
BYU vs Houston
BYU vs Cincinnati
UCF vs Houston
UCF vs Cincinnati
Those are the 4 additional games that are needed with each of those schools only playing 2 games against the "new" schools and leaving the remaining 7 agains the "old" schools. I assuming you didn't factor in that it only takes 1 game to use up 2 of the "spots" in those ones since they are "new" vs "new" games instead of "old" vs "new" games.