Is that other teams probably have to take a large chunk of their practice time to prepare for them. We run maybe 1-3 a game, but with the possibility of them being big gains I’m sure opposing coaches have their guys nailed down on what to look out for. This gives them less time to prepare for BYU’s high octane offense’s “normal” plays.
Despite that, they are still generally successful. The fake fumble near INT in the red zone is the only trick play I can think of that hasn’t worked yet this season.