But 'or is a member of the IBHOF' might un-cancel it! If you're a HOFer, you don't have to have fought for a world crown.
Ross-Canzi-McLarnin-Petrolle-Fuller, I think. Was thinking that group might have been bigger but got to dash for the time being.....
Another five: Mauriello, Louis, Savold*, Nova and Bivens Savold was recognised as Heavyweight Champion of the World in Britain and Europe for a period, and it is noted in boxrec.
If Mayweather hadn't ran off into retirement you could have had.... Mosley Mayweather Cotto Margarito Pacquiao Plus DLH has fought three of those five..... I've got loads of fours..... Cintron Williams Martinez Margarito Clottey Pacquiao Margarito Cotto Tyson Lewis Holyfield Botha Holyfield Moorer Foreman Cooper [Alex Stewart fought three of those] Bonecrusher Smith Frank Bruno Tim Witherspoon Mike Tyson Jose Ribalta ^ surely there's a 6th that will fit here, maybe take Ribalta out to find another option for 5th.
Let me guess... you're not a huge Mayweather fan, are you? Yes, there are lots and lots of fours out there... and it's really amazing, how difficult it is to find just one more name to make it 5. Time and again you think you've got it - only to realize that one measly pairing is missing. Like in your last group of 5 - almost there, but not quite.
There must be a six amongst the heavyweights of the last 20 years. People like Savarese, Barrett, Ribalta, Sanders, Purrity seem to have fought everybody, and many of them have fought each other too. Or amongst the middles, Barkley, Nunn, Toney, McCallum, Kalambay etc.
I think I've found a group of seven. It could be even more for all I know, but I couldn't be arsed to dig any further. Anyway.... Leonard - Kansas - Welsh - Dundee - White - Mitchell - Kilbane. A few others like Ever Hammer, Lockport Jimmy Duffy and Willie Ritchie just missed out on this group via the odd name too.
I havent got time to look, but i will be stunned if the highest entry does not contain the names Langford, McVey, Jeanette, Jim johnson, bill Tate, Harry wills, Jack Thompson. And you can also add Kid Norfolk, depending on whether you consider his fight with Battling Jim Johnson as an exhibition or a proper fight. There maybe some others to add to this also. Jeff Clarke can swap with Bill Tate and can be added if a Jeff Clarke vs bill tate matchup is ever found, which is not beyond the realms of possibility. And Jack Johnson can easily be replaced with Harry Wills, so it is a shame we never saw Johnson Wills, although they were sparring partners at one stage.