As mentioned, BYU has won 38% of their P5 matchups over the last decade.

Without going into the same level of detail, I figured I'd look at some of the other G5 schools we're most often compared to when discussing expansion (UCF, Cincy, Houston, Memphis, Boise St)

Houston has won 62.5% (10/16)
Cincinnati has won 55.6% (15/27), but only 53% since going AAC (8/15) so definitely eased up on the scheduling
Boise State has won 52.6% (10/19)
UCF has won 42.9% (9/21)
BYU has won 38.1% (16/42)
Memphis has won 33.3% (5/15)


First off, major credit to BYU for playing so many. At first glance, the quality doesn't seem to differ too much between most of the schools - BYU had LSU and Notre Dame, UCF had LSU and Ohio State, Cincy had multiple against Ohio State, Houston beat Florida State (back when they were good) + Oklahoma. Boise State is maybe a slight step below with games against Oregon and a post-peak Florida St and Memphis basically only beat bad P5 teams (including Kansas twice). In any case, BYU has played twice as many as any other team (discounting when Cincy was in the Big East before it imploded). BYU has really taken advantage of independence to schedule way more P5s. I've been an advocate for trying to join AAC, but this paints a slightly different picture.

Secondly, BYU has to find a way to win more of these games. BYU isn't competing with Rutgers or Oregon State to get into a P5, they're competing with these teams. Even if we ignore all the 8 losses to Utah, BYU only moves up to 47%. BYU has a stronger history/tradition, but is less geographically convenient (except for Boise) so needs to show out on the field.