baseball, the reserve clause meant that he would have to play for the Expos. McNally, a strong union supporter, joined Messersmith to ensure the case went to arbitration rather than letting the Dodgers negotiate independently. In October 1975, the MLBPA filed grievances on behalf of Messersmith and McNally, arguing that their contracts with the Dodgers and Expos had expired after the 1975 season, leaving both players essentially free agents. The central argument around Messersmith's case regarded the Uniform Player's Contract of the Basic Agreement, which stated that "the Club shall have the right ... to renew his contract for the period of one year on the same terms". Messersmith understood the contract to mean that the Dodgers had the right to extend his contract unilaterally for the 1975 season, but now that the season had passed, he was no longer under contract with the team. The Dodgers front office argued that renewing Messersmith's contract also renewed the one-year option, and that they could continue to extend his contract in perpetuity. On December 23, 1975, Seitz ruled in favor of the two pitchers that the Basic Argument only allowed unilateral extensions for a period of one year. Moments after issuing his ruling, the owners fired him as an arbitrator. Seitz's decision was based on the question of whether the reserve clause extended to players whose contracts had expired. Rule 4-A(a) suggested that reservations only applied to players under active contract, while Major League Rule 3(g) prohibited opposing owners from approaching reserved players regardless of their contract status. Seitz rested his decision on the Cincinnati Peace Compact that had united the National and American Leagues in 1903, which applied the reserve clause only to players under active contract. Seitz never addressed the antitrust exemption in his ruling, focusing on the CBA, particularly this provision of the 1970 version: "Regardless of any provision herein, this Agreement does not deal with the reserve system." Because the CBA did not directly deal with the system, any challenges to it were allowed to pass through arbitration. After Seitz's ruling, the owners challenged his decision in federal court for the Western District of Missouri before Judge John Watkins Oliver. The case turned on the three 1960 Supreme Court cases known collectively as the "Steelworkers Trilogy", which define the role and scope of arbitration in resolving labor disputes. MLB, through the plaintiff Kansas City Royals, argued that a