Complex sentence: William Earl Casper, Jr. (June 24,1931--February 7,2015) was an American professional golfer who was one of the most prolific tournament winners on the PGA Tour from the mid- 1950s to the mid- 1970s.
Split into simpler sentences: William Earl Casper, Jr. (June 24,1931--February 7,2015) was an American professional golfer. He was one of the most prolific tournament winners on the PGA Tour from the mid- 1950s to the mid- 1970s.