The similarities don't exactly stick out.
Seattle's Pete Carroll played in the secondary at University of Pacific and his coaching career started on the defensive side of the ball, while San Francisco's Jim Harbaugh is a former quarterback from Michigan who went on to play in the NFL.
Carroll has never met an interview he can't talk around, while Harbaugh hasn't found a conversation he can't make agonizingly, haltingly awkward.
But someone who has played for both coaches said that as different as they were to play for, there is a common ground between the two head coaches in Sunday's game between the top two teams in the NFC West.
"Their personalities are completely different," said Seattle receiver Doug Baldwin, who played for Harbaugh in college. "Coaching style is completely different. But there's a strategic way that they go about running their teams."