Danny Williams and Terry Norris are probably two of the best examples that i have overlooked.. Perfect examples in fact....
great example ruben olivares in his later years was another on/off performer. he was frightenly consistent in his younger days though junior jones is another one
Like mentioned earlier, a lot of the 80's fighters. Jersey Joe Walcott seemed to fight up and down to competion. He looked great in the first Louis fight, he had great fights with Charles, and was very impressive in the first Marciano fight.
Don't actually follow the logic. Why lose to the second raters? Consistently fighting top men will lead to defeats, though, unless one is a super fighter in the Sugar Ray Robinson mode.
mike weaver corrie sanders ron lyle jerry quarry eddie machen razor ruddock ray mercer and many7 more..............
A few more: Jack Sharkey, Evander Holyfield (at HW), Emile Griffith (relatively speaking given his talents).
I was unaware Duran took drugs ,what is your source? Duran was undisciplined as he got older ,loved his food and would gorge himself ,he was a known **** swordsman too,I think a lot of his losses can be blamed on the fact he was not in top shape and fighting above his best weight.Ray Arcel said he could have stayed at Lighweight ,but his eating habits pushed him to Welter.
Jack Sharkey is a good shout ,as is James Toney.I don't see how Holyfield ,who was rated in the top 10 for over 10 years can be classed as inconsistant though.