Yeah, one of my favourites. :good Well, heavyweights come in different sizes. But size is definitely an advantage (up to a point). I dont think a significant size advantage is enough to overcome a significant deficit in quality in all or even most cases though (as I've stressed in Bruno-Marciano discussion). I will say, in this day and age even if there are 180 - 200 pounders around who can compete or dominate at heavyweight there is no harm in them moving up to 215 or 220 pounds or more through better-informed weight-gain programmes and competing at higher body weights. That doesn't prove that at their lower original body weight they would have failed though. Take Holyfield for example. If he'd stayed at 190 or sub-200 pounds I think there's a good chance he would have achieved a lot at heavyweight that he did in fact achieve at 202 - 220 pounds. Against some opponents he may have even performed better. But I think he was better than he would have been overall and did the right thing bulking up his weight and strength.
Because it makes more sense and is fairer for Chavez to fight Whitaker than it is for Chavez to fight Tyson?