About 20 years ago Chuck Norris wandered into the Gracie dojo and promptly got his butt handed to him. He was so impressed that he embarked upon adding grappling to his skills.
Everyone who goes there walks out saying that Rickson tooled them and he is the best ever.
Even at going on 50 years old I could definitely see Rickson beating Fedor or Brock.
Sure wish he would fight again and prove the myth.