Best heavyweight record any fighter could have plausibly amassed with great luck?

A Lennox Lewis who didn't delay his career because he wanted to win a gold medal, who was trained by Emmanuel Steward from early on. He'd have steamrolled the entire division from young until his late 30s.

Note: very important he has Steward for a while before fighting a young Tyson.

 

If he had beaten Tyrell Biggs in the '84 Olympics and went on to win a Gold Medal he would have turned pro in '85. By the time 1993 came around he would have faced at some point Tyson, Holyfield, Bowe and Mercer. He's not running a clean sweep on them especially the Pre-Steward version.

 

this is why in my hypo he needs Steward from an early age. but give him that, and give him the luck this thread hypothesizes, and I think he cleans out the division, retires undefeated in his late 30s.

 

I think Tyson would need to be at his very best to beat Lewis. Anything but that looks something like what actually happened when they fought.

 

While not "MOST IMPRESSIVE RECORD OF ALL TIME!"

Ken Norton.

 

Ken Norton is best positioned. Give him the chin to withstand Foreman, and the nods against Holmes & the Great One thrice over, and have both he and friend & Futch teammate Frazier get over their reluctance to fight each other ... add Joe's name to George's, Larry's and Muhammad's, going 6-0 against those four - yeah, that's as great as it could possibly get in the history of the HW division, methinks.

 

Another easy contender. Larry Holmes. Wins both Spinx fights, retires undefeated with 50-0. Depending on how far we want to go with the luck, draws Tokyo Tyson, wins a decision against him. Knows to quit while ahead, retires 51-0 after beating Marciano's record and dethroning Iron Mike.

 

Ali.

No exile. Is faster with footwork and reaction time. Trained 100% every fight.

Most of his loses he claimed he just didn't take them and training seriously (also because the Frazier, Norton, and somewhat Spinks loses were great opposition obviously )

 

Or, well - even without modifying his chin, let's say a more realistic approach would be give him a strategy to avoid getting creamed by George over 15 and pot shot to a decision, even if a boring and unsatisfying one. That along with Frazier and Holmes and getting a clean 3-0 sweep versus Ali with maximal benefit of doubt from the judges, and his is the probably forever untouchable GOAT record.

Otherwise...you'd have to say Dempsey, if he didn't "forget to duck" in Tunney I and the count wasn't "long" in the rematch ...he'd need to be considered up there.