Question: What was the country of origin of one of the major users of Butterfly style in 1980's hockey?

full_context: Document 1: Bobby Orr: 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. He holds the record for most points and assists in a single season by a defenceman. Orr won a record eight consecutive Norris Trophies as the NHL's best defenceman and three consecutive Hart Trophies as the league's most valuable player (MVP). Orr was inducted into the Hockey Hall of Fame in 1979 at age 31, the youngest to be inducted at that time. On January 27, 2017, in a ceremony during the All-Star Weekend in Los Angeles, Orr was part of the second group of players to be named one of the '100 Greatest NHL Players' in history. After his hockey career, he became a well-known scout for many professional teams. He also spends time talking to and mentoring young skaters.
Document 2: Roberto Luongo: Roberto Luongo ( ; born April 4, 1979) is a Canadian professional ice hockey goaltender for the Florida Panthers of the National Hockey League (NHL). Born in Montreal, Quebec, he is of Italian and Irish ancestry. He employs the butterfly style of goaltending and has previously played in the NHL for the New York Islanders and the Vancouver Canucks. Luongo is a two-time NHL Second All-Star (2004 and 2007) and a winner of the William M. Jennings Trophy for backstopping his team to the lowest goals-against average in the league (2011; with backup Cory Schneider). He has additionally been a finalist for the Vezina Trophy as the league's best goaltender (2004, 2007 and 2011), the Lester B. Pearson Award as the top player voted by his peers (2004 and 2007) and the Hart Memorial Trophy as the league's most valuable player (2007).
Document 3: Bernie Parent: Bernard Marcel "Bernie" Parent (born April 3, 1945) is a retired Canadian professional ice hockey goaltender who played 13 National Hockey League (NHL) seasons with the Philadelphia Flyers, Boston Bruins, and Toronto Maple Leafs, and also spent one season in the World Hockey Association (WHA) with the Philadelphia Blazers. Parent is widely acknowledged as one of the greatest goaltenders of all time. During the 1973–74 and 1974–75 seasons, in what many consider the finest consecutive seasons ever by a goaltender, the Flyers won two Stanley Cups and Parent won the Vezina Trophy and Conn Smythe Trophy both seasons. In that two-year run of dominance, Parent posted 30 shutouts in regular and post season play combined. A 1984 inductee into the Hockey Hall of Fame, Parent was rated number 63 on The Hockey News' list of "The Top 100 NHL Players of All-Time" in 1998. Parent remains an iconic fan favorite in Philadelphia more than three decades after his retirement. On January 27, 2017, in a ceremony during the All-Star Weekend in Los Angeles, Parent was part of the second group of players to be named one of the '100 Greatest NHL Players' in history.
Document 4: 2001–02 Colorado Avalanche season: The 2001–02 Colorado Avalanche season was the Avalanche's seventh season. At the end of the regular season, Patrick Roy had a goals against average (GAA) of 1.94 and a save percentage of .925. For his efforts, Roy earned the William M. Jennings Trophy and was a First Team All-Star for the fourth time in his career. The Avalanche beat the Los Angeles Kings in the first round in seven games, then San Jose in the second round in seven games, but lost to the higher-seeded Detroit Red Wings in seven games after being up 3–2 in the series and lost game 7, 7–0, against Detroit.
Document 5: Brett Hull: Brett Andrew Hull (born August 9, 1964) is a Canadian-born American former National Hockey League (NHL) player and general manager, and currently an executive vice president of the St. Louis Blues. He played for the Calgary Flames, St. Louis Blues, Dallas Stars, Detroit Red Wings and Phoenix Coyotes between 1986 and 2005. His career total of 741 goals is the fourth highest in NHL history, and he is one of five players to score 50 goals in 50 games. He was a member of two Stanley Cup winning teams - 1999 with the Dallas Stars and 2002 with the Detroit Red Wings. His championship winning goal for Dallas in overtime of game six of the 1999 Stanley Cup Finals remains the focus of debate over whether it was scored within the rules of the time. On January 27, 2017, in a ceremony during the All-Star Weekend in Los Angeles, Hull was part of the second group of players to be named one of the '100 Greatest NHL Players' in history.
Document 6: Dominik Hašek: Dominik Hašek (] ,    ; born January 29, 1965) is a retired Czech ice hockey goaltender. In his 16-season National Hockey League (NHL) career, he played for the Chicago Blackhawks, Buffalo Sabres, Detroit Red Wings and the Ottawa Senators. During his years in Buffalo, he became one of the league's finest goaltenders, earning him the nickname "The Dominator". His strong play has been credited with establishing European goaltenders in a league previously dominated by North Americans. He is a two-time Stanley Cup champion, both with the Red Wings. On January 27, 2017, in a ceremony during the All-Star Weekend in Los Angeles, Hasek was part of the second group of players to be named one of the '100 Greatest NHL Players' in history. He has the lowest career goals against average amongst goaltenders on the list.
Document 7: Rush goalie: Rush goalie, also known as a fly goalie or fly keeper, is a variation of football in which the role of the goalkeeper is more flexible than normal. The goalkeeper position is taken by any player who can run out of and leave his goal to actively participate in outfield play. However, when defending the player returns to his goal and takes up the role of goalkeeper once again, in rush goalie only one player can be the goalkeeper and handle the ball. Once the danger has passed, that player (the "rush goalie") returns to normal outfield play. Rush goalie is only played in informal football matches, usually by children, and often when the players want to play a more active role in the game than the position of goalkeeper would normally allow; it can also be applied when the number of players per side is low.
Document 8: Tony Esposito: Anthony James "Tony O" Esposito (born April 23, 1943) is a retired Canadian-American professional ice hockey goaltender, who played in the National Hockey League, most notably for the Chicago Black Hawks. He was one of the pioneers of the now popular butterfly style. Tony is the younger brother of Phil Esposito, a centre. Both brothers had notable careers and are enshrined in the Hockey Hall of Fame. On January 27, 2017, in a ceremony during the All-Star Weekend in Los Angeles, Esposito was part of the second group of players to be named one of the '100 Greatest NHL Players' in history.
Document 9: Wayne Gretzky: Wayne Douglas Gretzky {'1': ", '2': ", '3': ", '4': "} ( ; born January 26, 1961) is a Canadian former professional ice hockey player and former head coach. He played twenty seasons in the National Hockey League (NHL) for four teams from 1979 to 1999. Nicknamed "The Great One", he has been called "the greatest hockey player ever" by many sportswriters, players, and the league itself. He is the leading scorer in NHL history, with more goals and assists than any other player. He garnered more assists than any other player scored total points, and is the only NHL player to total over 200 points in one season – a feat he accomplished four times. In addition, he tallied over 100 points in 16 professional seasons, 14 of them consecutive. At the time of his retirement in 1999, he held 61 NHL records: 40 regular-season records, 15 playoff records, and six All-Star records. As of 2015, he still holds 60 NHL records.
Document 10: Butterfly style: In ice hockey, "butterfly style" is a technique of goaltending distinguished by the goaltender guarding the lower part of the net by dropping to the knees to block attempts to score. The butterfly style derives its name from the resemblance of the spread goal pads and hands to a butterfly's wings. The "butterfly style" is contrasted with stand-up style, where most shots on a goal are stopped with the goaltender on their feet. Many factors helped make it a "de facto" standard style of play today, including the popularization of the goalie mask by Jacques Plante, Vladislav Tretiak's outstanding use of the style at the 1972 Canada–USSR Summit Series, the National Hockey League (NHL) emergence of Tony Esposito in the 1970s and Patrick Roy in the 1980s, the development of lightweight materials for pads and the influence of professional goaltending coaches such as Warren Strelow, Benoit and François Allaire. There are few who exclusively employ a stand-up style in the NHL.
Document 11: Terry Sawchuk: Terrance Gordon Sawchuk (December 28, 1929 – May 31, 1970) was a Ukrainian-Canadian professional ice hockey goaltender who played 21 seasons in the National Hockey League (NHL) for the Detroit Red Wings, Boston Bruins, Toronto Maple Leafs, Los Angeles Kings and the New York Rangers.
Document 12: Patrick Roy: Patrick Jacques Roy (] ; born October 5, 1965) is a Canadian former professional ice hockey goaltender and the former head coach and vice-president of hockey operations for the Colorado Avalanche of the National Hockey League (NHL). He is regarded as one of the greatest goaltenders of all time. On January 27, 2017, in a ceremony during the All-Star Weekend in Los Angeles, Roy was part of the second group of players to be named one of the '100 Greatest NHL Players' in history. Patrick is the brother of Stéphane Roy.
Document 13: 200-foot game: A 200-foot game is an expression used in ice hockey to describe a forward's ability to have strong play at both ends of an ice rink, which is standardized at 200 feet long. Players who can play a 200-foot game are contrasted with players who score a lot of points by avoiding hard forechecking or backchecking, cherry picking their plays perhaps for breakaways, and avoiding fighting for the puck in the corners of the rink, such as Pavel Bure or Brett Hull. Playing a 200-foot game means fighting for each part of the ice, fighting for control of the puck whether it's in one's possession or not, and engaging using your body in traffic. Some examples of players who play or played a 200-foot game include Sidney Crosby, Mike Richards, Marian Hossa, Jonathan Toews, Pavel Datsyuk, Auston Matthews, and Gordie Howe.
Document 14: Guy Lafleur: Guy Damien "The Flower" / "Le Démon Blond" Lafleur, OC, CQ (born September 20, 1951) is a Canadian former professional ice hockey player who was the first player in the National Hockey League (NHL) to score 50 goals and 100 points in six straight seasons. Between 1971 and 1991, he played for the Montreal Canadiens, New York Rangers and Quebec Nordiques in an NHL career spanning 17 seasons, and five Stanley Cup championships (all with the Canadiens). On January 27, 2017, in a ceremony during the All-Star Weekend in Los Angeles, Lafleur was part of the second group of players to be named one of the '100 Greatest NHL Players' in history.
Document 15: Glenn Hall: Glenn Henry "Mr. Goalie" Hall (born October 3, 1931) is a former professional ice hockey goaltender. During his National Hockey League career with the Detroit Red Wings, Chicago Black Hawks, and St. Louis Blues, Hall seldom missed a game and was a consistent performer, winning the Vezina Trophy, which at the time was awarded to the goaltender on the team allowing the fewest goals against (a distinction that now results in being awarded the William M. Jennings Trophy), three times, being voted the First Team All-Star goaltender a record seven times, and winning the Calder Memorial Trophy as best rookie. Nicknamed "Mr. Goalie", he was the first goaltender to develop and make effective use of the butterfly style of goalkeeping. On January 1, 2017, in a ceremony prior to the Centennial Classic, Hall was part of the first group of players to be named one of the '100 Greatest NHL Players' in history. He is the grandfather of Grant Stevenson.
ground_truth: Canada