That was the difference between them.Williams resume is a bit thin on quality wins but was that his fault? I can't imagine many were queuing up to fight him.
Williams was a big man and a puncher in a time with few. His main problem was he had the durability issues, and simply could not take a punch. His heart though was very good. His resume of top wins is very thin.
Liston's famous quote: "Williams can hit as hard as I can; but he can't take it as well as I can". (Liston respected Williams....and actually refereed one or two of Cleve's fights.