Barney Ross & Tony Canzoneri - Greatest Lightweight Rankings

[abeattell77]

Why does it seem that every greatest lightweight list ranks Canzoneri above Ross?

I have studied Ross' career in great depth, including his two fights with Canzoneri. I have not studied Canzoneri's entire career. However, I believe it is safe to say he was still in his prime when he met Ross. Both those fights were very competitive, but Ross won both decisions.

What I am I missing in arriving at the conclusion that Ross was the greater lightweight?