MIAMI — Mark Richt’s eyes light up, and he slides himself forward in his chair so that he’s nearly perched on the edge. He leans in, conspiratorially, to share one of his guiding principles.



This is his specialty. This is something he cannot mess up, something he cannot get wrong. This is about something maybe more important than football. Miami’s head football coach turns to his wife of nearly 30 years, Katharyn.



“She didn’t believe me in the beginning about how to make a sandwich, that it really made a difference,” Mark Richt says. “Didn’t you eventually say, ‘You know what, honey …’ ”



With an ever-so-slight roll of her eyes, Katharyn Richt says, “I mean, a sandwich is a sandwich. I was like, ‘What are you talking about?’ I never paid attention. Whatever was closest I just put on my sandwich. But then he was like, ‘Let me just make you a sandwich. You make...