I don't see many tennis discussions and he was a hero from over 20 years ago.

Pele was over 50 years ago and for a sport that some americans purposefully avoid. We also get very nationalistic about our heroes so i could see a number of younger CBers not knowing anything about a Brazilian superstar.

Gretsky was the third but even if hockey isn't america's favorite pastime, most american should know who he is

the rest are american heroes and you'd have to be dead not to know who they are .