Is James J. Jeffries the most underrated HW champ?

"Performing well doesn't mean you are in your prime"

Prime doesn't matter. Performing well does. Take the Archie Moore-Harold Johnson fight in 1954. Johnson at 26 was certainly in his physical prime. Moore at 37 or 40 was not by your take. But results are results. Moore was better, regardless if he meets your prime criteria. Performance is a real thing. Prime is not or at least isn't what really matters.

"he has retained some of the ability that they never possessed in the first place"

And if he retains enough ability to win, why does being past prime matter? Was Holmes prime for Cooney? Was Cooney? Holmes was pushing 33, so perhaps not in his case. What I do know is that in the event Holmes was better.

"Old Louis was kept away from punchers"

???? You mean Marciano wasn't a puncher? Don't forget Savold had scored 72 KO's, and against tough competition. Bivins has recently stopped Clarence Henry and would stop Coley Wallace the next year. Agramonte had a lot of KO's. I think this statement is just wrong.

"Tom Sharkey"

I usually don't debate pure opinions, as everyone has his own. You think Sharkey KO's Louis. I don't think Sharkey was even at the same level as Bivins, Savold, and Brion. Pumping Sharkey up as a proto Marciano is silly. Even in his physical prime at 27 he was getting starched by Fitz and Ruhlin.

The facts about Louis is that he was beaten in his comeback only by the best fighters in the world, Charles and Marciano. He won 8 straight, 7 of which were against men who had been recently rated, were rated, or would soon be rated. Obviously this was not the great Joe Louis of the pre-war years, but still a tough fighter who was a skilled boxer and a big man for his era. That he would have lost to this or that contender he didn't fight is unsupported opinion.

"one-armed"

The films of the Agramonte and Savold fights show Louis still had a right. It was just not the old Joe Louis right. He was not a one-armed fighter. By the way, that was a common criticism made of Jeff.