Robert Gordon Orr, OC (born March 20, 1948) is a Canadian former professional ice hockey player, widely acknowledged as one of the greatest hockey players of all time. Orr used his ice skating speed, scoring, and play-making abilities to revolutionize the position of defenceman. He played in the National Hockey League (NHL) for 12 seasons, starting with 10 with the Boston Bruins followed by two with the Chicago Black Hawks. Orr remains the only defenceman to have won the league scoring title with two Art Ross Trophies.

Orr joined the Bruins for the 1966-67 season, his first as a professional. The Bruins were not convinced Orr belonged on defence, trying him out at centre first. Through the pre-season, Orr was given jersey number 27. At the season's start, the Bruins offered him jersey number 5, that of past Bruins star Dit Clapper, but Orr chose jersey number 4. Orr made his NHL regular-season debut on October 19, 1966, against the Detroit Red Wings, getting one assist. On October 22, he scored his first NHL goal against the Montreal Canadiens. It was a slap shot past Gump Worsley and the Boston Garden crowd gave Orr a standing ovation.  In that first season, Orr was challenged by the veterans, and he earned respect by defeating Montreal tough guy Ted Harris in his first NHL fight. On December 4, 1966, Toronto Maple Leafs' defenceman Marcel Pronovost checked him into the boards, injuring Orr's knees for the first time in the NHL. He would miss nine games and the Bruins would lose six of them. The team finished with a 17-43-10 record, leaving the Bruins in last place. However, attendance at Boston Garden increased by forty-one thousand fans.  For the season, Orr scored 13 goals and 28 assists, one of the best rookie seasons in NHL history to that point by a defenceman. Orr won the Calder Memorial Trophy as the league's outstanding rookie and was named to the NHL's Second All-Star team. New York Rangers defenceman Harry Howell won the Norris Trophy as the league's best defenceman that year. In accepting the award, Howell said he was glad to win when he did, predicting "Orr will own this trophy from now on." Orr was runner-up in voting.

Where did he play before October 19, 1966?
Orr joined the Bruins for the 1966-67 season, his first as a professional.