Muhammad Ali, yes he did focus mitts, I know this because I have seen his training videos. As for Ray Robinson, I'm not too sure but the focus mitts are probably the most commonly used training exersises and I know as a former boxer, that they are extremely useful and almost everyone I know/knew has used mitts at some point in their lives and I would be willing to bet my life on the fact that they still do. This is what my bet for Ray Robinson having used them would be.
Hope I helped... :)
Charlie Goldman used mitts with Marciano in the 50's made then , probably special order, by Everlast. . I never saw either Robinson or Ali use them.
I don't think these mitts were invented when Robinson was boxing.
I boxed in the 60's and early 70's and never saw a pair at any gym.
