In 1876, the National League of Professional Base Ball Clubs (later known as the National League or NL) was established after the NA proved ineffective. The league placed its emphasis on clubs rather than on players. Clubs could now enforce player contracts, preventing players from jumping to higher-paying clubs. Clubs were required to play the full schedule of games instead of forfeiting scheduled games when the club was no longer in the running for the league championship, which happened frequently under the NA. A concerted effort was made to curb gambling on games, which was leaving the validity of results in doubt. The first game in the NL—on Saturday, April 22, 1876 (at the Jefferson Street Grounds, Philadelphia)—is often pointed to as the beginning of MLB.