If frank goes on a mission he has no clue what he is coming back to at Duke. At BYU he knows a little bit more to what he will come back to.
At duke, he could come back to some good returning point guards. He will cone back to some incoming freshman who have been playing bball at a very high level with no two year break. The future is a little cloudy. No doubt his team will be good but the starting lineup is unknown. The level of guard play (his competition for PT) is unknown.
At byu frank will most likely be paired with emery, haws, mika, and dastrup. A top 25 team. He would most likely start and be given time to get his legs back and get into his groove..
.. A luxury he might not get at duke.
It is going to be a tough choice. Big choices for an 18 year old.