The rival American Football League arose in 1960 and challenged the NFL's dominance. The AFL began in relative obscurity but eventually thrived, with an initial television contract with the ABC network. The AFL's existence forced the conservative NFL to expand to Dallas and Minnesota in an attempt to destroy the new league. Meanwhile, the AFL introduced many new features to Professional Football in the United States: official time on the scoreboard clock, rather than on a watch in the referee's pocket, as the NFL did; optional two-point conversions by pass or run after touchdowns; names on the jerseys of players; and several others, including expansion of the role of minority players, actively recruited by the league in contrast to the NFL. The AFL also signed several star college players that had also been drafted by NFL teams. Competition for players heated up in 1965, when the AFL New York Jets signed rookie Joe Namath to a then-record US $437,000 contract. A five-year, $40 million NBC television contract followed, which helped to sustain the young league. The bidding war for players ended in 1966, when NFL owners approached the AFL regarding a merger, and the two leagues agreed on one that would take full effect in 1970. This agreement provided for a common draft that would take place each year, and it instituted an annual World Championship game to be played between the champions of each league. That game began play at the end of the 1966 season. Once the merger was completed, it was no longer a championship game between two leagues, and reverted to the NFL championship game, which came to be known as the Super Bowl.