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 from 1902 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 Bashirs thirtieth birthday. (DS9: "Distant Voices") Sisko later intended to take Kasidy Yates to that game for one of their first dates, later that year. (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 wouldn't be able to find out the winner. (VOY: "One Small Step")
The final World Series took place in 2042. With the decline of the sport, only 300 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")