… than just who has the most viewers per game.

1) The network the game is on is a HUGE factor in viewership.

Tiers:
CBS/ABC
Fox
ESPN
ESPN2
FS1/ESPNU (some of these games don’t even rate enough viewers)
CBSSN (ratings not reported)

2) The time slot is very important. The latest time slots (Usually starting after 9:00 Eastern and ending after midnight) have many fewer viewers because so much is the east coast and Deep South has gone to bed. Noon eastern isn’t a great one either as many our west miss out those.

3) The opponent played. P5 conference games are bound to have a higher average since TCU and Kansas St (et al) get to count their games vs OU and Texas towards their average every year, despite the fact that the vast majority of those viewers are not TCU fans or KSU fans, but Sooners or Longhorns. Playing teams with non-existent fan bases hurts the viewership a lot.

4). The ranking of the teams when the game is played. If either team is ranked, the viewership tends to be much higher. If both are ranked, then the game is usually put on a major network and a lot of average CFBnfans are more likely to tune in.

5) Outliers: things like the annual Army/Navy game, or when a non-P5 gets into a NY6 bowl, the viewership is through the roof. Again, this is mostly general/casual CFB fans tuning in and doesn’t mean that team has loads of their own fans watching.