Now maybe you don't agree with BYU's 4th down philosophy and how that influences 3rd play calling, but that appears to be the horse they've hitched themselves to.
BYU has gone for it on 4th down in 10 of the 28 times this season we didn't convert 3rd down. BYU has converted 4th down 8 out of 10 times.
So of the 39 times we've reached 3rd down this year, BYU picked up a first down 19 times (48.7%)