The fact that boxers fight with their shirts off makes it tempting to explain their power with reference to their physique. Like, in mainstream sports writing, how many column inches have been devoted to Fury's switch to Kronk vs his fluctuating physique and how it compares to Joshua etc? It's a bit of a shame we don't get more discussion of, er, mechanics like this one about Rory Mcilroy (5'9", 160lbs golfer enjoy who's consistently been one of the biggest hitters on the pro tour for a long time). Mechanics are every bit as relevant to boxing. https://golf.com/news/taylormade-3d-technology-reveals-the-secrets-to-rory-mcilroys-swing/
There's this misconception about "God given" power that falls apart when it comes to physics: whenever you concentrate the kinetic energy gained from proper footing, transfer of weight, timing and accurate placement, the weakest WW puncher of all time has the same % of chance at doing the damage the hardest KO artist can deliver. The only logical conclusion is that the lacking comes down to improper punching technique, and that's probably goes back to early muscle memory days either in the gym or on the streets, depending where the kid first got into punching other kids in the face. Looks are obviously deceiving, as some knocking ppl. out seemingly without much effort or accuracy (say Randall Bailey) while others put their whole body into it and still need perfect timing and placement (Vasyl Salido Jr.). But if you had the chance to analyze the full muscle movement breakdown, you'd see at the time of connect, a true puncher is more properly concentrating that energy to the given point than another... and that's both technique and ability, both to be learned and polished in the gym.
In my opinion it’s a combination of technique (use of weight, legs, twisting of the torso, punching being “intended“ to hit the BACK of the head, with deliver more power then being delivered to the face (Closer)) physical strength genetics
Disagree work in the gym can increase physical strength many times over, and that can be carried forward to punching power granted, it’s not the ONLY factor, but it is one of the prominent faactors
All those repetitive motions and gradually moving small to medium amounts of weight with evert muscle of your body greatly increases functional strength. Farm work, swimming, moving couches, loading trucks, laying bricks, etc. You can take a skinny tooth pick or an overweight fatass and have them do that stuff for a year and they may still be fat or skinny but they will be VERY strong and have a subtle increase in both red muscle and fast twitch muscle for a unique explosive burst allowing them to work or exercise longer than the average person. It carries over into sports quite well and, in my unprofessional but fairly well informed opinion, can actually be more effective in building the muscles you need for athleticism and burst of power than lifting weights or using weight machines (initially). It targets almost everything every time so you don't even need to keep track as much. Eventually you do hit a ceiling if you are too used to the work rate and load, and you will either need to increase it or supplement it with weights to get the areas the labor isn't improving.
What you say about proper technique & concentrating energy upon impact is very true. The part about early daaaze experience is insightful, & some of this is also intuitive athletic ability. But what you claim about the weakest WW puncher being able to do the damage the hardest (presumably HW or SHW) fighter can is way, way off. That is basic physics too-mass & speed is essential, & we can easily measure the force registered as higher n average with bigger guys, all other things being equal. Though as Janitor once said some machines are nonsense, girls just slapping at them get high scores. Force must be measured, not just speed. Also someone recently was astute in talking about what goes into being "heavy handed: thick bones & joints more effectively transfer/do not lose much force & energy. And a larger fist makes a difference, there are many factors. But we have not properly isolated or predicted exactly who can hit how hard. It is assuredly in good part genetic, not just technique & practice, which helps. Just like I do not care how much training does for a lifetime or even how effective a PED regimen an average man takes, they will never run the 100 Meters in under 10 seconds, likely not even close. And short of a game changer such as gene therapy (where you can essentially become someone else vis a vis specific attributes) just an *average* major league fastball of 92 MPH will never ever be reached by someone without very good genetics for throwing a baseball.
I occupy a middle position. Getting stronger can increase punching power, but much less than a 1 to 1 ratio. And you can become too stiff & rigid which may hurt it. Also "many times over"? I lifted for years & read many sources, from what i can tell the average man can get twice as strong as an *average* many naturally. Now if you start off as weak or say a skinny kid, you may reach near or over 4X what you were. OR if you use PEDs: that number goes up somewhat more. Start off weak & use PEDs effectively in cycles stacked with potentiators like insulin for years, then you might exceed 10X what you were. I am strongly against any use of PEDs even recreationally as they are unnatural & bad for your health + nobody can find a safe dosage, may damage the major organs fuhgettibout stuff like 'roid rage acne shrunken balls & rebounding with high estrogen levels when you go off steroids, seperate gruesome HGH side effects... I am just stating the facts.
I think guys like saddler,inoua and Tysons power are all genetics I don't you can develop their type of power but you can definitely build serious power just by lifting weights and doing power drills