"All he does is fight bums", we hear this a lot. I, personally, feel like this word is tossed around so loosely that it no longer holds any value. So I want everyone to lay it out and stick to your guns: What constitutes a "bum" in boxing? What's your "bum checklist"?
Oxford Concise English Dictionary definition reads as such.... 1. the large muscles at the base of the vertebrae 2. the majority of Mayweather's opponents in the last decade
I guess someone who is very far below your skill-level that you choose to fight. An obvious and extreme mismatch of an opponent who is underserving whether it's because of their lack of skill, experience, current ranking/level, or all three.
Someone who is irrelevant at the weight. Someone who achieves nothing at the weight. Someone who doesn't perform to their best at the weight.
Basically this, along with someone you have no excuse for fighting. If it's an unavoidable mando for guys that want to keep their titles (such as Kovalev recently v Mohammedi) then there is no problem with that. If the opposition is weak because you can't get anyone else willing to fight you (like some of GGG's opposition) that is fine. But guys like Wilder and Stevenson have no excuse whatsoever.