Probably a combination of the atmosphere and taking a bit to adjust to the speed & strength of the opposing players, but for whatever reason, BYU seems to fall behind early to P5 teams, then at some point they realilze "Hey, we can totally play with these guys" and they make a game out of it.

My hope is that the wins at AZ and Wisconsin last year will give the team some extra confidence going into the Tennessee game and prevent the usual "fall behind and then come most of the way back" scenario.