Question: Sydney Mervin "Merv" Batt was a frequent opponent for many foreign wrestlers travelling overseas including NWA World Heavyweight Champions such as one who was called, "probably the greatest champion of the 20th century." by who?
Sentence (from "National Wrestling Association"): The group created a number of "World" level championships as an attempt to clear up the professional wrestling rankings which at the time saw a number of different championships promoted as the "true world championship".
Relevant evidence: No