(and I'm not really trying to help out B12/PAC here - just making a note)

ACC = 8 conference games
B1G = 8 conference games
SEC = 8 conference games
PAC = 9 conference games
B12 = 9 conference games

ACC = 21 / 14 = 1.5 + 8 = 9.5 Avg P5 opponents
B1G = 19 / 14 = 1.36 + 8 = 9.36 Avg P5 opponents
SEC = 12 / 14 = .86 + 8 = 8.86 Avg P5 opponents
PAC = 11 / 12 = .92 + 9 = 9.92 Avg P5 opponents
B12 = 8 / 10 = .8 + 9 = 9.8 Avg P5 opponents

Final average rank order...
PAC = 9.92
B12 = 9.8
ACC = 9.5
B1G = 9.36
SEC = 8.86

But when you get down to talking champions of the conferences you'll also give each participant in the title games another 1 for their individual final average for all conference except the B12 - so when talking playoffs add 1 more to PAC, ACC, B1G & SEC top team...