decided to continue with play, Livingstone and Quinn threatened injunctions to stop the NHL from operating. However, the threats were not followed through on and the NHL season began on schedule. The NHA organization itself was not formally dissolved for several years afterwards and Frank Calder held the presidency in both organizations. Legacy The NHA was innovative for its time. The league put forth several innovations, among them the abolition of the rover position in 1912 (a labour-saving measure), the institution of match penalties, and allowing line changes on the fly. While the originator of jersey numbers in ice hockey is disputed, the NHA is commonly cited as the first to use them, requiring players wear numbered armbands beginning with the 1911–12 season. The championship trophy of the NHA was the O'Brien Cup, made of solid silver, donated by the O'Brien family. It survived as the championship trophy of the NHL until the Western Hockey League, the successor to the PCHA, folded after the 1925–26 hockey season. This left the NHL as the only professional league that competed for the Stanley Cup. Thus starting in 1926–27 season, the Stanley Cup became the championship trophy of the NHL. The O'Brien Trophy was then awarded annually as an NHL trophy afterward before being retired in 1950. Two current NHL teams, the Canadiens and Maple Leafs, have roots in the NHA. While the Canadiens acknowledge their NHA history and records, the Maple Leafs do not claim the Blueshirts' history as their own. A third, the Ottawa Senators, borrows its name and heritage from its NHA counterpart, but is a separate expansion franchise founded in 1992 while the original Senators ceased operations in 1934. Teams Season by season record † Stanley Cup Champions. In 1910, both the Wanderers and Senators are considered champions. *228th Battalion was from North Bay, Ontario, training at Camp Borden and in Toronto at the time. It dropped out after first half of season. Toronto was suspended by league after first half. Team history NHA presidents Frank Robinson submitted his resignation letter during an NHA's meeting on October 20, 1917. However, his resignation was not considered and he was voted as NHA president for another term. In Robinson's absence, the secretary-treasurer of the league, Frank Calder, chaired NHA meetings and served as the acting president of the NHA. See also 1918–19 NHL season List of ice hockey leagues List of