It's also more difficult to go 20 rounds if you're fighting a guy a foot taller than you, with a foot reach on you, who moves around the ring (when everyone else stands right in front of you) and who is hitting you in the face with 30-40 jabs a round from a distance when jabs were rare. The number of times Fury would have to go 20 rounds against 1900 heavyweights - defending his title once or twice a year - would be minimal to nil. I don't see any of the champs at the time beating him. Forget the guys who lost to those champs.
I wouldn't. Both would need a KO to win. Otherwise, Fury coasts to a decision with the jab and movement alone. Throw in Fury's clubbing shots, and I'd be surprised if either lasted 20 rounds with Fury. If those are the toughest guys he has to fight ... I'd say he'd remain champ for as long as he likes.
That's fair. And I've learned over the years that if a guy's only chance to win is by KO, then take the other guy. Fitz certainly isn't outboxing Fury. (And I don't see Jeffries doing so, either.) And if both have to set a trap in hopes of scoring a KO, forget about it.