Example of an ATG.
JMM!

Wins vacant IBF title, defends and gains WBA from Gainer. Successfully defends both belts twice before losing to Chris John.
Beats the Lineal Champ, Casamayor.
Wins LW for the WBA, WBO, IBO.
Humbled by PBF, then rebounds and wins 2 titles yet again WBA & WBO champ.
Final fight of his career he wins WBO welter.


He didn't just win titles moving up in weight, he came as close as one can to when it is about cleaning out the division. Now had he done an AJ, won multiple belts early on and never did it again, not sure how I would rate him.

But because he faced the best from Feather & Up and won in every weight class, holding multiple titles at the same time, is a testimony to that of a ATG!