Complex sentence: Barthès was one of the Handsome Eight and reached a career high singles ATP ranking in 1974 of World No.54 but before the creation of the ATP ranking he was one of the best twenty players in 1971.
Split into simpler sentences: Barthès was one of the Handsome Eight and reached a career high singles ATP ranking in 1974 of World No.54. Before the creation of the ATP ranking, he was one of the best twenty players in 1971.