Knockouts and knockdowns don't cause brain damage. It's individual punches that cause brain damage. You can never get knocked down in your whole career but it's the punches you take will mess you up. Even little tap punches to the head add up
I just took this opportunity to answer a question to our fellow forum member i'm still in favour of this thread being deleted given it's 14 years old!
To distill fourteen years' worth of valuable discussion, the leading proposed theories behind a combat athlete's capacity to withstand blows are: (note: in the case of most individuals, a confluence of these reasons is likely at play) Skull thickness Neck muscle strength/whiplash resistance Mental willpower/confidence/self-belief/determination Hydration/adequate levels of CSF Angle of impact (encompasses both riding/rolling with or partially deflecting shots, and static defensive positioning) Genetic mystery "good chin genes" x factor? A dynamic brain-based variable, perhaps? Less discussed but somewhat obvious: actual congenital TMJ, pterygoid muscle, and mandibular bone construction?
I'd say also just robust health and fitness in general. Someone who is anemic or with a very poor diet is going to be put to sleep with alacrity, I think. Many - but not all - known vegetarians and vegans (a population that medical professionals caution to be very mindful about ensuring they get enough heme supplementation) in the sport happen to have notably also suffered violent knockouts losses. Correlation of course doesn't imply causation, but...makes you wonder if the phrase "iron chin" may have an unintended double meaning, with ferritic deficiencies weakening resistance.
I don't have any real data to back me up, just an observation. It seems the guys that have real good reflexes don't have good chins(Roy Jones, Zab Judah etc) but guys like Canelo and Golovkin have great chins. I'm sure the more knowledgeable on this site will post 10 quick reflex guys with iron chins and 10 brawler, stocker type with glass.
I'd like to add my oft repeated observation on "the chinniness of youth," now with more evidence: https://journals.sagepub.com/doi/pd...iuHVez9mxwtIzsfZyzx-6I16H5Lc7tdO3HITQMMna5Skx https://www.ingentaconnect.com/content/wk/jsm/2016/00000026/00000005/art00011 Both show increased concussions in lower age groups. Makes sense when we think about Ali stunned by Doug Jones, Fury put down by Cunningham, and all the other examples of guys who later show iron chins having trouble early on.
Punch resistance seems to be related to the following: Physical factors - having a large head and thick neck (thick torso in general) tends to be better suited to absorbing damage than being a bean pole, although the springiness associated with the latter body type can be its own advantage in taking shots. So Canelo, Tua, Tyson, Miller all seem to absorb shots well. Some guys who are light on their feet also absorb shots well, especially when they seem naturally loose. Mental factors - how well you mentally react to getting hurt. Obviously if you panic when you get hit that's going to contribute to how well your body overall accepts and then recovers from the blow. Wlad's a good example of this: decent chin but horrible reactions that sapped his strength and made him come apart. Stylistic factors - how often you put yourself in harm's way, how recklessly you fight etc can all contribute. Obviously if you're a cagey dude who keeps his chin tucked away at all times you're going to be able to ride shots better versus some wild brawler swinging away with his chin in the air. Concentration levels - related somewhat to the above, fighters who are able to maintain their concentration get hurt less because they're more prepared for taking shots. Even the most iron-chinned opponents can be hurt and dropped if they're hit by something they're not expecting. I don't think Andre Ward had a particularly good chin but he rarely got hurt even when hit clean because of how razor-sharp his focus was.
Anybody ever notice that Hagler had an oddly shaped dome? Like his forehead seemed strangely shaped and his general skull didn't look normal.
It´s been said that he had a thicker skull than the average person. At least that´s how the story goes. However a thick skull is unlikely to correlate with how one takes punches, according to experts. But I would like to add my two cents: If a persons skull is thicker and stronger than the average, then what else about them might be above average? Hagler was undoubtedly built different.
There are people that can take punches without getting knocked out easily but nearly everybody that takes punches to the head for years will have brain damage. The people that have made it into their 60's and older without showing and cognitive decline are just the genetically superior ones. There are a lot of people that had a great chin but damage showed up quickly after they turned 40 years old. A lot of boxers in history already showed brain damage in their 20's, being aggressive and violent in regular life is usually a sign of frontal lobe damage.
This is true but, perhaps counterintuitively, I'm pretty sure most comparative studies done have shown that boxing (can't speak to any other combat sports, where you get slammed on the ground or kicked in the head) is less dangerous long-term for brain health than some full contact team sports, especially American football. You've got to figure an NFL player, to make the league, had to have at least played in college and high school and in most cases all the way back to PeeWee. Those coaches are notorious for competitively pushing those kids beyond their physical limits without regard for their safety, in a way that I don't think happens with young prepubescent amateur boxers who are brought along slowly under very careful supervision (again, speaking broadly). So it's apples to apples really - both a championship level pro NFL player and champion boxer will have on average been at their respective discipline from the age of, say 8 or so - but I'm pretty sure the former is statistically far likelier to develop CTE by middle age. That may of course vary a bit depending on position - punt kickers are probably at much lower risk than returners, for instance.
Sort of a candle burning at both ends, though, because accumulative wear and tear over the years can definitely lessen resistance. There may be a sweet spot somewhere in the middle where a chin has "matured" but not yet begun to suffer from erosion.