It's not just the neck .
The added weight / strength along the whole posterior chain is what helps.
I don't know why some guys are bringing up fat guts etc etc
Are posters really that simple or is it just to be contrary ?
A fighter moving up in weight , won't gain a 40lb beer belly.
I think ppl are mistaking that I'm saying you'll get a Mark Hunt style chin if only u get heavier.
No , it will help . That's it.
It'll help in absolute terms . ABSOLUTE terms.
You know that lil guy who can drop your middleweight ass on the floor with a good punch , do u think he could do that if u went up to heavyweight ?
Now those OTHER HEAVYWEIGHTS might because pound for pound , your chin isn't as good but if u gain some muscle YET STAY IN THE SAME WEIGHT CLASS u don't see how it'll help ?
And , while its widely accepted in fight circles , I'm also basing this on personal experience where a gym mate of mine fought a guy , got dropped 3 times in 3 minutes . Fought him again 8 months later only this time , instead of being right at the weight limit , he put on 10 - 12 solid pounds , cut weight and went in there the bigger man and lost a SD in an all out war. The only reason he lost was a tad hesitant in the first round (obviously) trying to gauge his power or more accurately , his resistance to it. Came back after the first round "how you're feeling ?" "he hits like a bitch." and just took it to him.
You can disregard such personal experiences or twist it to your beliefs and/or u can maybe stop n think that hey , maybe theres something to it.
Ps - I'm using caps to stress a point or phrase. The mobile site doesn't have italics or bold fonts.