Originally, the term described a series of exhibition games played between the two clubs after the conclusion of spring training, immediately prior to the start of the regular season. It was first used to refer to the 1989 World Series which the Athletics won and the first time both teams had met since they moved to the San Francisco Bay Area. Today, it also refers to games played between the teams during the regular season since the commencement of Interleague play in 1997. Through the 2020 season, the A's have won 69 games, and the Giants have won 61.