I can understand the “ceiling” thing, but Do some QBs have more room for improvement than others? Imo, yes. Josh Allen’s potential has barely been scratched given his limited exposure to coaching, camps, experience, etc., whearas Rosen has been on the star QB track since high school. Rosen is leaps and bounds ahead in those areas. Yes, Rosen can still improve and improve a lot, but given their relative starting points, Allen has more room.