Fluid isn’t really a factor if the fighter isn’t cutting extreme weight The temple shot is effective they say because it gives leverage to whip the head more same with the chin and because the head wips more the brain gets shaken more causing concussion that’s the common understanding But there are fighters that get their head violently spun on impact and nothing happens and there are fighters where there head doesn’t move much (so not a lot of movement in the brain ) but they go down There is a theory that it may explain it that the knockout may be caused not by the brain but by the head jamming into their Spine because in knockout what you often see is when they get punch despite if their head is rotating or not that their head goes back into their spine and if you look at shots where the head rotates but they still keep standing (example The clip of margarito getting punched by Cotto which i posted ) you don’t see their head go back into their spine is what I noticed so maybe that’s the reason the ko happens but it’s just a theory I don’t know if this is true or not but A punch directly to the neck which you said won’t jam the head towards the spine so that doesn’t disprove the theory
So with regards to the genetics, bone density, muscle strength at the neck (think Mike Tyson, who barely had a neck), even space inside the cranium which the brain can move around in the skull, all factor into the ability to naturally be able to take a shot. If you look at the very best fighters who could take a shot, George Chuvalo, Oliver Mccall - both were thick heavy set guys with big iron looking heads. If you could picutre someone that looks like they could take a punch, you'd picture either of those men. Cultural factors are (and perhaps more controversial) more of a placebo, as if someones self-talk is that they have a good chin and it's impossible to knock them out, they'd usually be more mentally resistant to being KO'd. Less panic, less tension and more calm when absorbing the shots. Just to be clear, I am not saying this is some magic switch that makes a fighter iron chinned, but it can support them in their overall punch resistance.
That head snap back is crazy But that’s not what I meant what I meant was is that with what you see with knockouts that it looks like their head jams into their spine and it look like their spine bulges the example you posted was a head snap so far back it that it looked it touched it’s back but you don’t see the neck bulging I talk a about so maybe that’s the reason he kept standing but that’s just a theory
i understand what your saying And the big iron looking heads can take more punishment sounds logical But despite that there are example with boxer with heavy set faces neck etc and yet they don’t have the best punch resistance There needs to be a explanation for that but it’s a mystery to this point I agree that mentality can help also but in more in the sense of if your hurt to push through etc but that’s more mentally toughness than having a good punch resistance