The World Series was a baseball championship series on Earth during the 20th and 21st century. A best-of-seven playoff, the Series was contested between the winners of the two established leagues. The Series took place on a yearly basis (excepting 1904 and 1994) from 1903 to 2042.
According to Benjamin Sisko, game seven of the 1964 World Series was, in his opinion, one of the greatest baseball games of all time. In 2371, he suggested the holosuite program of that game as the venue for celebrating Julian Bashir's thirtieth birthday. (DS9: "Distant Voices") Later that year, Sisko intended to take Kasidy Yates to that game for one of their first dates. (DS9: "The Adversary")
In 2032, the New York Yankees won the Series in six games. John Kelly, trapped aboard the Ares IV in a graviton ellipse before the sixth game, regretted the fact that he would not be able to learn who the winner would be. (VOY: "One Small Step")
The final World Series took place in 2042. With the decline of the sport, only three hundred spectators attended the last game. The Series was won by the London Kings, the winning home run being struck by Buck Bokai. (DS9: "If Wishes Were Horses")