I would put Ali from 1964-67 up there. It is true that fundamentally there were flaws in his defence such as holding his hands too low. And yet he was so hard to hit because of how lightning quick he was. His foot movement combined with head movement, pulling back , sliding out of corners etc. puts him there. He is my 1 here. I will put the Tyson of 1985-88 here. He ducked, bobbed and weaved and dodged punches with ease. The fact that he was an outstanding counter puncher contributed to his defence since guys were reluctant to commit due to the fear of being counter puncher. If your offence makes guys hesitate , I consider that part of your defence. Prime Tyson was hard as hell to hit. Usyk is my number 3 pick. Technically I rate his defence better than Ali and Iron Mike. Usyk keeps his hands up all the time, moves his head well, circles to the opposite side of his opponents power hand, etc. He is quick but not lightning quick like peak Ali and peak Tyson. This is the only reason I have him at 3; despite his better fundamentals , he is a little easier (though not easy) to hit because he does not have the supreme reflexes and athleticism that peak Ali and Tyson had. After that, in no order; Byrd, Witherspoon, Charles, maybe Jack Johnson if we are going way back.
Vitali Klitschko. Great radar. Almost impossible to land a combo on. He had that footwork and upper body movement that got opponents to try to land but they would have to go off balance badly.Terrific concentration and he followed corner instructions as well as anyone. And punching up to hit him didn't make it easier.
Ezzard Charles*4 Rex Layne Joe Baksi Lee Q Murray Elmer Ray*2 Joe Louis*2 Rocky Marciano*2 That's 13 fights against rated, dangerous punchers. Walcott got knocked out 3 times. Once by Louis after 10 rounds of avoiding numerous offensive advances in the rematch. Twice by Marciano, the first time after surviving a 13 round shelling by a prime Marciano and the second time getting one punched in his last fight at 39 years old. Had Walcott not had effective defense he wouldn't even go so many rounds against Louis and Rocky. The first fight with Louis is a masterclass in defense.
I'd take Holmes out and replace him with someone like Tyson or Ali. Holmes had a good defense but could be prone to lapses of concentration that saw him get tagged hard and clean.
Ali during his peak was absolutely elite. He and Jones were a bit alike, their otherworldly speed and reflexes made them two of the most "effective" defensive fighters you would ever want to see. For a smokey with greatly underrated defense i'll throw up Sonny Liston. His defense was multi layered and surprisingly good considering it barely ever gets acknowledged.
That's 3 fellow journeymen, a LHW great above his best weight and past his best days, a lazy hype job, an ancient ex-great and a limited skilled but force of nature upstart. Losing 1/3 of your fights shows you have definite limitations for which you do not compensate in other areas, at least if we are judging upon the highest criteria.
That's three fellow ranked guys, in the top 5 at the time of beating them, a LHW goat who was in his prime for the first two fights, potentially prime for the third and just out of it for the 4th fight, an ancient great who had recently crushed his number 1 contender like a soda can, a prime force of nature knockout machine and Rex Layne. I'm just counting the punchers here, if I include the other guys it gets even more dire for your case. Jimmy Bivins, Joey Maxim, Harold Johnson, useless journeymen the lot of them. Most of his losses are pre 1944, therefore, discarded. Not the same Walcott, I couldn't give less of a damn about them.
Walcott took fights at the last minute, sometimes fought on an empty stomach, and possibly threw some fights because of his mob connections. He has a real hard-knock life. Wins are wins, and losses are losses...is what it is. But let's not forget that this is the guy who knocked down Louis twice in a fight 70% of people thought he won. He's a great with a lot of asterixes, but he was great. And his defense was attested to by everyone who saw him. He did a lot of weird things not only to avoid the punches, but totally confuse his opponents, like just walking away when they were getting hot. Ring master. Fun little video, here... jersey_joe_walcott_footwork_and_defense
Yes, we have determined that he was uniquely effected by the time, the Depression and the Second War, the only fighter to ever fight on an empty stomach (and weirdly still weirdly weigh in at a good number), the only guy ever asked to throw a fight or apparently 20 fights. Wins are definitely wins. And he was able to win about 68% of the time. And that is his level. Pointless dance steps aside.
No, it's pretty much his history. Louis never fought on an empty stomach and was never asked to throw a fight.
There were dozens, if not a hundred, other fighters on Walcott's level during his time. I'm not talking Louis but them. They all had to endure, as do so many today from places in Asia, South America and Eastern Europe. Name me the fight with weigh ins where Walcott was malnourished.