Originally Posted by Mustard
A 53 match clay-court winning streak, which lasted until Nadal beat it in 2006. This streak also included 2 clay-court grand slam victories at the French Open and the US Open. It's plain to see who had the best results in 1977.
I believe that Vilas had, by default, better green clay results than Borg in 1977 due to Borg's absence in the summer when most of the har-tru events were played.
However Borg clearly had better red clay results, meaning that there is evidence that he was better on red clay than Vilas.
Overall, Borg was far superior than Vilas due to his excellence on grass and carpet. Surfaces that Vilas avoided - when he didn't, he performed far worse on them than Borg.