Stupid answer. Though a lot of fighters have built up inflated records over hyped opponents, quality of opposition still reveals more than anything else. In the majority of cases you beat the fighters you beat because you're better than them. How can you call one fighter 'A level' if as you insist anyone can beat anyone once they're in the ring? This isn't randomly throwing dice. Styles do often make fights of course and the 'triangle theory' doesn't always hold, but that styles make fights is the exception that proves the rule that more often better simply beats lesser.