The greatest rival of the Kansas City Royals is the St. Louis Cardinals. The I-70 Series, sometimes known as the Show-Me Series, is a Major League Baseball series that pits the St. Louis Cardinals of the National League against the Kansas City Royals of the American League.

The series is played every year between the two teams. This rivalry is named “Show Me State” because both cities are located in the state of Missouri,  and because both cities are located along Interstate 70, which connects the two cities.

During the 1985 World Series, which the Royals won in seven games, they faced off against each other for the first first time. They play each other every regular season in interleague play as a result of their close geographic closeness.

This long-running rivalry began with the Royals’ early-’80s accomplishments and was intensified by the Royals’ World Series victory against the Cardinals in 1985, which cemented the Royals’ position as the best team in baseball.

In the minds of many fans, the series is still a subject of dispute, particularly after a contentious decision in the bottom of the ninth inning of game 6 in which Jorge Orta was declared safe on a play that was proved to be incorrect on review. A rally by the Royals enabled them to tie the game and ultimately win it, as well as win the series.