When you look at a Vegas line, its easy to assume bettors are putting money on their fandom. I just wonder how often that is true. Some people like to bet to make the game more fun to watch, and they want to make the smart bet independent of any fandom they have.

We assume most BYU fans don't bet, so that any team they come against has more fans betting against BYU. But if the bettors aren't laying money based on their fandom anyway, the notion of BYU fans being less likely to bet money would mean nothing.

This study (done in 2020 so it's kind of recent), seems to indicate fandom isn't a motivating factor: