The National Hockey League began its first season with four teams, but the Montreal Wanderers were forced to withdraw when their rink burned down after just six games.
The league played a split season. Montreal won the first half, Toronto the second half, and Toronto then won the playoff and the right to play the Pacific Coast Hockey Association champion for the Stanley Cup.
The PCHA still played seven-man hockey and allowed some forward passing, which wasn't legal in the NHL until its second season. The teams alternated between NHL and PCHA rules during the five-game series. Toronto won all three games played under NHL rules and the Vancouver Millionaires won both played under PCHA rules. (The entire series was played in Montreal, but the team under whose rules the game was being played was designated the home team.)
The Seattle Metropolitans had won the PCHA regular-season championship, but Vancouver beat Seattle in the playoffs to win the right to challenge for the trophy.