It seems that BYU's style (game management offense with solid defense) results in close games where one or two plays can make a big difference. It seems that everything is going BYU's way through four games and that is bound to change at some point.
BYU football has had a tendency to get cocky after some success and come out flat after big wins (see TCU last year, Oregon in 2022, Boise St in 2021, Toledo & USF in 2019, Cal & UW & USU in 2018, etc). I think both teams are probably evenly matched and but it seems that outside of momentum Baylor has a lot of advantages - homefield, early start, desperation, etc.
BYU has yet to win a Big 12 road game and lost by 28+ in three of their five road games so far.
I think this is going to be a low-scoring game where BYU's lack of offense finally comes back to bite the Cougars in a close one.