Sorry but I don't get that line of thinking. I always thought of development as tied to a player's age, not the years he's playing. i.e. that's why 22 year old Internationals hardly improve at all. So to me, if you don't play an 18 year old draftee when he's 18, all it means is that he starts playing when he's 19. But I don't think you get that 18 year old year "back" anytime.