 The NHL added another six teams by 1974 to bring the league to 18 teams. This continued expansion was partially brought about by the creation of the World Hockey Association (WHA), which operated from 1972 until 1979 and sought to compete with the NHL for markets and players. Bobby Hull was the most famous player to defect to the rival league, signing a $ 2.75 million contract with the Winnipeg Jets. When the WHA ceased operations in 1979, the NHL absorbed four of the league's teams — the Edmonton Oilers, Hartford Whalers, Quebec Nordiques and Winnipeg Jets. This brought the NHL to 21 teams (the Cleveland Barons had ceased operations in 1978), a figure that remained constant until the San Jose Sharks joined as an expansion franchise in 1991.
