That depends on what kind of boxing "expert" your talking about? A historian? Means little to nothing!

A modern boxing analyst with no idealogical axe to grind will look at the footage of Louis, notice his rudimentary boxing skills in a sport that wasn't even technically complete yet (more of a barn yard brawl) coupled with his lack of speed, size, conditioning and power and conclude that Joe Louis would probably not be advised to box as a professional today (assuming he did not receive the same training and diet a guy like Haye has which changes the whole scenario).

To be simple, I give Louis about... FIVE SECONDS before Haye finds his jaw and KHTFO!

Louis fought not a single opponent who has any relevance to modern boxing at all.

Could you imagine how hard you would be laughed at were you to claim that a football lineman from 1930 could win best on ground in 2013 on a football forum? Sorry but comedy gold mate!