Ice hockey is a contact team sport played on ice, usually a rink, in which two teams of skaters use their sticks to shoot a vulcanized rubber puck into their opponent’s net to score points. In Canada, the United States, and some European countries such as Latvia and Sweden, it is known as “hockey”; the name “ice hockey” is used in places where “hockey” could also refer to field hockey, such as South America, Asia, Africa, Australasia, and some European countries like Germany, the Netherlands, Spain and the United Kingdom. Ice hockey teams usually consist of four lines of three forwards, three pairs of defencemen, and two goaltenders. Normally, each team has five players who skate up and down the ice trying to take the puck and score a goal against the opposing team. Teams normally have a goaltender as their sixth on-ice player, whose job is to prevent the puck from entering the goal. A fast-paced physical sport (leading to the nickname “The Fastest Game on Earth”), hockey is most popular in areas of North America (particularly Canada and the northern United States) and Europe. In North America, the National Hockey League (NHL) is the highest level for men’s hockey and the most popular. The Kontinental Hockey League (KHL) is the highest league in Russia and much of eastern Europe. Ice hockey is the official national winter sport of Canada, where the game enjoys immense popularity. The International Ice Hockey Federation (IIHF) is the formal governing body for international ice hockey. The IIHF manages international tournaments and maintains the IIHF World Ranking. Worldwide, there are ice hockey federations in 73 countries. Ice hockey is believed to have evolved from simple stick and ball games played in the 18th and 19th century United Kingdom and elsewhere. These games were brought to Canada and the United States and several similar winter games using informal rules were developed, such as “shinney” and “ice polo”. The contemporary sport of ice hockey was developed in Canada, most notably in Montreal, where the first indoor hockey game was played on March 3, 1875. Some characteristics of that game, such as the length of the ice rink and the use of a puck, have been retained to this day. Amateur ice hockey leagues began in the 1880s, and professional ice hockey originated around 1900. The Stanley Cup, emblematic of ice hockey club supremacy, was first awarded in 1893 to recognize the Canadian amateur champion and later became the championship trophy of the NHL. In the early 1900s, the Canadian rules were adopted by the Ligue International de Hockey sur Glace, the precursor of the IIHF and the sport was played for the first time in the Olympics in the Olympic Games of 1920. In international competitions, the national teams of six countries (The “Big Six”) predominate: Canada, the Czech Republic, Finland, Russia, Sweden and the United States. Of the 69 medals awarded all-time in men’s competition at the Olympics, only six medals were not awarded to one of those countries. In the annual Ice Hockey World Championships, 177 of 201 medals have been awarded to the six nations. Teams outside the “Big Six” have won only 5 medals in either competition since 1953: All 12 Women’s Olympic and 36 IIHF World Women’s Championships medals have been awarded to one of these six countries, and every gold medal in both competitions has been won by either Canada or the United States.