Not many players start out with reputations as enforcers and end up with equal billing for their goal scoring and puck handling abilities. While playing for St. Catharines and the Buffalo Bisons, Hadfield regularly posted far more penalty minutes than points. He continued in his tough guy roll for the New York Rangers after they claimed him from Chicago in the 1961 Intra-League draft.
Except for a brief stint with the Baltimore Clippers during the 1962-1963 season, Hadfield played for the Rangers from 1961 until 1974. In 1963-64, Hadfield posted a league-leading 151 penalty minutes in 69 games. He stayed in the triple digits in the pim column for the next three seasons but started to increase his point totals during the 1967-68 season. Hadfield credited a new curved stick recommended by friend Bobby Hull; but the Rangers' acquisition of some additional tough guys helped as well. So did being put on a line with Jean Ratelle and Rod Gilbert, creating a combination so effective that they were nicknamed the Goal-A-Game line.
That was the first year that his point total came close to equaling his penalty minutes. He consistently scored twenty or more goals a season for the rest of his career. However, he still found time to entertain his teammates by "allegedly" nailing a defenseman's shoes to the floor of the dressing room. He also managed to steal Bernie Parent's mask during a game against the Leafs and toss it into the crowd at Madison Square Garden. Hadfield posted a personal best during the 1971-72 season with 50 goals and 106 points. During this same season he was again in triple digits in penalty minutes, with 142, demonstrating that it was possible to do it all. The Rangers made him their captain in 1971, a position he held until being traded to Pittsburgh in 1974.
Although he was a perennial fan favourite, Hadfield drew a lot of criticism during the 1972 Summit Series while representing Team Canada. Having been used sparingly during the first half of the series, Hadfield traveled with the team to Moscow only to learn that he would probably not be dressing for any of the remaining games, in spite of having just come off a fifty goal season with the Rangers. Hadfield was understandably upset and promptly packed his bags and caught the first flight home.
His defection was not presented to the media in anything resembling a sympathetic light; and Canadians were unforgiving. While Hadfield felt that his time was better spent getting ready for the Rangers camp and making sure he earned his high salary, those who weren't close to the situation viewed his decision as a selfish act based on a bruised ego.
Hadfield remained with the Rangers through the end of the 1973-74 season, when financial pressures led the team to trade him to the Pittsburgh Penguins. Although surprised by the trade and coping with a series of injuries, Hadfield went to Pittsburgh, posting two consecutive 30-goal seasons before suffering a knee injury that eventually ended his career. Having worn out his knees, Hadfield retired in 1977.