High Quality Content by WIKIPEDIA articles! Interleague play is the term used to describe regular season Major League Baseball games played between teams in different leagues, introduced in 1997. Before the 1997 season, teams in the American League and National League did not meet during the regular season. AL/NL matchups only occurred during spring training, the All-Star Game, other exhibition games such as the Hall of Fame Game in Cooperstown, New York, and the World Series. Unlike modern interleague play, none of these contests, except for the World Series, counted toward official team or league records.