Other than DamonD who atleast addressed some of the criteria I suggested but didnt add any I dont see how any of you can discuss ATG status if you have never really thought about it. I hope someone can add a respectable post to this thread.
The main thing is the quality of your opponents, and the timing of when you face them. Let's compare two fighters "noticeable wins", Ali had Foreman and Frazier/Liston, Calzaghe had Bernard Hopkins and Roy Jones jr. Timing and quality is vital.
So your down to only 2 criteria. Who you fought and where they are on their career ladder. I think again this isnt enough and rating people where they are on their career lends itself to too much subjectivity.
After thinking about this here is my opinion. Most Important Criteria1) Quality of opposition *Primary determination of ATG 2) People believe that you are nearly unbeatable in your weight class 3) Overall Record wins/losses 4) Quanitity of fights Less Important Criteria 5) Style of fighter/Punching Power Ko's 6) Popularity and Fame * 2) this is determined by your record and fan/expert opinion. An example of this would be duran at lightweight during his time. SRR at welter..Ray Leonard at welter etc. This is contextual based on your weight and your era. Another good example was bhop during his reign etc. *4 I consider this very important as it can help determine toughness. Look at a guy like Harry Greb 200 plus fights..then look at a guy like Tarver only 32 fights. *5 Brawler versus a Boxer, techincal *6 I think this is important for fighters to transcend the sport and become mainstream recognized. Thats what i have so far.
I like your list. Excellent. I would have said being able to be defeated and come back and win in the rematch. Some people might say being defeated just to come back is ridiculous, but I actually think losing and than winning is better than beating the guy in the first place. If you look at that list, Virgil Hill had the first 5. Level of opposition they beat can be said. Roberto Duran fought great guys, but didn't beat them all. Although most people believe he is great. I think also you have to have charisma like Duran. Charisma will boost a fighter 50 percent of their ATG's.