There were 40 bowl games this year (this is the high-water mark). Thus, 80 teams in the top tier of NCAA football played in a bowl game.
There are 130 Div-I FBS teams, spread out through ten conferences (four teams are independent of any conference for football). Thus, 80/130 teams played bowl games, or 61.5%.
When I was growing up in the '60s and '70s, substantially fewer teams played bowl games. There were ten bowl games after the 1970 season (not counting the three all-star bowl games). So only 20 teams participated in bowl games. However, there were significantly fewer teams who were likely to participate in bowl games back then (in 1970 there was no split of the NCAA into divisions, yet, as we know them; there was the “University Division” for larger schools, and the “College Division” for smaller schools, but no differentiation among these divisions in football for purposes of bowls). Roughly speaking, there would have been about 75-80 teams playing in conferences which could have expected possible bowl bids. So 20/80ish would be about 25% playing in bowls.
Obviously, things have changed.
Interestingly, of the ten bowls played after the 1970 season (Rose, Orange, Sugar, Cotton, Peach, Sun, Gator, Tangerine, Liberty and Bluebonnet), only one of them no longer is played in some form today. That would be the Bluebonnet Bowl, which was a Houston game. For those who do not know, the bluebonnet is the state flower of Texas. As a young person, I for some reason always thought it was referencing the margarine instead. :smack:
(For purposes of calculating “bowl-eligible” teams in 1970, I added up the membership of the following conferences: Pac-8, Big-8, Big-10, SWC, SEC, ACC (which were the “big” boys of the time), WAC, PCAA, plus independents (of which there were quite a few at the time). I may have managed to miss one or two conferences which occasionally sent members to bowl games back in the 60s and early 70s).