Complex sentence: Robert Lansdorp (born 1938, Semarang, Indonesia) is a professional tennis coach who first rose to international fame in 1979 when his student Tracy Austin became the youngest US Open Women's Singles champion in history at age 16.
Split into simpler sentences: Robert Lansdorp (born 1938, Semarang, Indonesia) is a professional tennis coach. He first rose to international fame in 1979 when his student Tracy Austin became the youngest US Open Women's Singles champion in history at age 16.