There are pleanty of ultra runners who are bigger blokes, including a lot of ex army types. Some of them have problems with their knees, but it usualy manifests itself later in life. Jeffries was probably doing most of his running off road, which would have taken a lot of the sting out of it. He would have been wearing a running flat, which would have induced him to strike on the forefoot. This would have taken the pressure off his knees and thrown it more on the halves.
Michael Spinks ruined his knees running on hard surfaces. The British Army did away with the stamp of the right foot when a soldier came to attention precisely because it was found to do damage to joints.
I'm sorry, but I don't think 15 rounds against Byrd would be enough to break Byrd down at the pace Jeffries fought at. And it hugely works against him the fact that he by all accounts wasn't much of a clincher. This means he couldn't impose his greater power as well as partially negating his questionable footwork. Nope, I think Byrd takes this all the way.
You don´t think Jeff would be intelligent enough to figure out that he would have to change his approuch over the shorter distance when he wants to succeed?
Foreman, knowing he was in a longer scheduled fight against a durable guy, might conceivably pace himself don't you think? I allways thought Lewis's foot work was pretty poor actually. Ali had magnificent stamina in his prime , "dance all night". The pedestrian pace of the old timers would likely have sent him to sleep from boredom. Corbett was 33 years old, and had been retired for 2 years plus he was giving away 30 lbs . How about a 27 year old Lewis , 6 foot 5in, 30lbs heavier than Jeffries, strong as an ox, hit like a train , with his right ,plus a very good jab? Jeffries would look like a traffic accident against all of these men, even if he beat some of them, because he had no jab ,and little defensive skills. On film, his head is stationary, it's there to be hit ,and it would be hit by super heavyweights ,something he never experienced. His bravery could rebound on him, imo.
Bad bad science, they're measuring force and not power or how fast the force is transfered from the glove to the surface, which is what causes a concussion. Imagine for a miniute your boxing an opponent, would you choose 8oz gloves or the 40oz celebrity boxing gloves? Which do you choose? Why do you think there are less KO's in the amateurs?
Johnson's defense seemed to work fine at a similar distance. I'm not entirely convinced Byrd wins this actually, he's not that good, I lean towards him though due to his defense/technique