<P> The National Hockey League has always used a playoff tournament to determine its champion, generally opening up its playoff games to a much larger number of teams, including those with a losing regular season record in some years (the most recent being the seventh and eighth seeded San Jose Sharks and Edmonton Oilers, respectively, in 1999). </P> <P> From the NHL's inception to 1920, when ownership of the Stanley Cup was shared between the NHL and the Pacific Coast Hockey Association the regular season was divided into two halves, with the top team from each half moving on to the league finals, which was a two - game total goals series in 1918 and a best - of - seven series in 1919 . In 1920, the Ottawa Senators were automatically declared the league champion when the team had won both halves of the regular season . The two halves format was abandoned the next year, and the top two teams faced off for the NHL championship in a two - game total goals series . </P> <P> At the time, the NHL champion would later face the winners of the PCHA and, from 1921, the Western Canada Hockey League in further rounds in order to determine the Stanley Cup champion . During this time, as the rules of the NHL and those of the western leagues differ (the main difference being that NHL rules allowed five skaters while the western leagues allowed six), the rules for each game in the Stanley Cup Finals alternated between those of the NHL and the western leagues . Before the WCHL competed for the Stanley Cup, the Cup championship series a best - of - five series . Following the involvement of the WCHL, one league champion was given a bye straight to the finals (a best - of - three affair starting in 1922), while the other two competed in a best - of - three semifinal . As travel expenses were high during these times, it was often the case that the NHL champions were sent west to compete . In a dispute between the leagues in 1923 about whether to send one or both western league champions east, the winner of the PCHA / WCHL series would proceed to the Stanley Cup Finals, while the loser of the series would face the NHL champion, both series being best - of - three . </P> <P> In 1924 the NHL playoffs expanded from two to three teams (with the top team getting a bye to the two - game total goal NHL finals), but because the first - place Hamilton Tigers refused to play under this format, the second and third place teams played for the NHL championship in a two - game total goals affair . The Stanley Cup Finals returned to a best - of - five format the same year . </P>

How many games does a hockey team have to win to win the stanley cup