The OP is about Alistair Overeem, but the thread is about the question in the title and less about Overeem. There are two main questions that need to be asked: 1. On average, how much harder does a HW fighter hits in compassion to a LHW fighter? 2. How much does a fighter's hitting tolerance (Chin) improve while gaining weight? As for the first question, it's easy to see why the bigger the fighter, the harder he hits. More weight behind the punch means more power. Obviously there are freaks of nature in every division (LHW's that hits harder than most HW) but this are exception to the rule. As for the second question, that's a bit more controversial. One the one hand a fighter can gain muscle almost every where, but he obviously can't grow muscle on the chin. One the other hand, is someones "chin" only consists of his chin? Or is it also neck and shoulder muscles that adds to the equation? I believe muscles have a lot to do with it and Overeem's neck and shoulder muscles have become gigantic, but does it really cover the gap in the power differences between the divisions? Overeem had been stopped by several LHW in his career, most notably Chuck, Lil nog, Shogun and Arona (No shame in any of those loses). And as far as i can remember, in his short HW career no one hit him flush. This is not a thread about Overeem's chin. At least not in the conservative "Is it good or bad?" kind of way. What i'm trying to ask is does Overeem have any disadvantage, considering his opponents power, combined with his history of being smaller and being stopped by smaller guys (Smaller than his current opponents)? Discuss.. PS, please be kind with any grammar mistakes. It's not my first language.