sentences:  Cassidy was a southpaw (left-handed) who was world-rated in the junior middleweight, middleweight, light heavyweight and cruiserweight divisions.In 1975, he was ranked number one in the world as a light heavyweight by the World Boxing Council.In 1963, Cassidy, from Levittown, Long Island, New York, scored a one-punch, 39-second knockout in his professional debut at Sunnyside Garden.