Born in
Kirkland Lake, Ontario, in 1936, Duff was one of 13 siblings. He began playing hockey at a young age with his brothers. At 15, he moved to Toronto to attend
St. Michael's College School and play for the school's team, the
Toronto St. Michael's Majors. After two years at St. Michael's (1953–1955), Duff joined the NHL, playing his first game in 1955 in a scoreless match between the Montreal Canadiens and the Toronto Maple Leafs. He opted to join the NHL full-time for the 1955-56 season, forgoing his final year of junior eligibility. A highlight of Duff's stint with the Maple Leafs was the
1962 Stanley Cup playoffs where Duff contributed three goals and ten assists in 12 games. He scored the Cup-winning goal to give Toronto their first championship in ten years. After eight and a half seasons with the Maple Leafs, he was traded to the
New York Rangers in February 1964 in a major seven-player trade, bringing
Andy Bathgate to Toronto. Later that year, the Rangers traded Duff to Montreal for
Ernie Hicke. Duff would play for the Canadiens until 1970, a part of four championship teams. In 1970, he was traded to the
Los Angeles Kings and later traded to the
Buffalo Sabres in December 1970. After finishing the 1970-71 season, he returned for a final 11 games in 1971-72 before retiring. After retirement, Duff was an assistant coach for three seasons from 1979 until 1981 with the Maple Leafs. This included a stint for two games as head coach during the
1979-80 season. Duff won the
Stanley Cup six times—twice with Toronto and four times with Montreal. He was inducted into the
Hockey Hall of Fame on November 13, 2006, and into the
Ontario Sports Hall of Fame in 2014. His brother
Les Duff also played professional ice hockey, and his great-nephew
Cody Goloubef has played in the NHL. ==Career statistics==