For decades, Major League baseball clubs only played teams from their own league during the regular season and most of the playoffs, with only their champions facing off in the World Series. This separation gradually caused the leagues to develop slightly different strategies and styles of play. The National League was long considered the more "traditional" league, a reputation most exemplified by the NL's more prevalent use of "smallball" tactics and lack of a designated hitter rule, which the AL implemented in 1973. However, with the advent of free agency in the 1970s allowing for more player movement between leagues, and the introduction of regular season interleague play in 1997, the difference in play between the two major leagues has diminished considerably. The NL's adoption of the designated hitter rule in 2022, and the expansion of interleague play to 46 games beginning in 2023, has further blurred the lines between leagues.
For decades, Major League baseball clubs only played teams from their own league during the regular season and most of the playoffs, with only their champions facing off in the World Series. This separation gradually caused the leagues to develop slightly different strategies and styles of play. The National League was long considered the more "traditional" league, a reputation most exemplified by the NL's more prevalent use of "smallball" tactics and lack of a designated hitter rule, which the AL implemented in 1973 However, with the advent of free agency in the 1970s allowing for more player movement between leagues, and the introduction of regular season. interleague play in 1997, the difference in play between the two major leagues has diminished considerably. The NL's adoption of the designated hitter rule in 2022, and the expansion of interleague play to 46 games beginning in 2023, has further blurred the lines between leagues.