Baseball was a team-based sport of human origin, with nine or ten positions played, depending upon whether a designated hitter were used. Apart from the designated hitter, the other positions were pitcher, catcher, first base, second base, third base, shortstop, right field, center field and left field.
While professional baseball had died out on Earth with the last World Series in 2042, there were efforts to revive the sport (with apparently limited success) over succeeding centuries. In the 2150s, Titan had a baseball team called the Bluebirds, and the Boston Red Sox had changed their name to the New England Red Sox. (In Between Days: Reversal)
- In the TNG novel: Fortune's Light, it is mentioned that a 10-team interplanetary league existed for only two seasons in the 22nd century. These two teams may have been part of that league.
- In the ST novel: Federation, the last World Series was played before the Optimum Movement takeover at Battersea Stadium in the United Kingdom.
The game underwent at least a limited revival on Earth in the 23rd century. Old team names such as the New York Yankees and Atlanta Braves were brought back, and new ones -- such as the Moscow Mudhens -- created. (Orion Press)
A six-team league proved to be very popular on Cestus III during the 2370s, with such teams as the Cestus Comets and the Pike City Pioneers. (DS9: "Family Business", DS9: "The Way of the Warrior") On Deep Space 9, the captain and crew of USS T'Kumbra challenged the command crew of the station to a baseball game. (DS9: "Take Me Out to the Holosuite")
The sport was still popular on Simpson's Planet in the 2380s, with both minor and major leagues. However, few female Simpsons could play major-league baseball in that era. It was the object of much gambling over a variety of baseball-related items, such as the point spread and whether one could pitch a perfect game. (RIS Bouteina: "Black Sox", "Jockship")
Dhiemm was known to be completely neutral to hockey and indicated that he might have preferred baseball instead, when he said "Play ball!" during every face-off he had to preside over during the hockey game. (RIS Bouteina: "Ultimate Wager")
Due to a spatial and temporal interphase, Wesley Crusher and Geordi La Forge were sent to 1941 briefly, and took in a game between the Washington Senators and the Boston Red Sox, and saw Ted Williams hit two home runs. (In Between Days: "Crackerjack")
In the Mirror universe, baseball was played with twelve players. In addition to the above-mentioned nine (there was no designated hitter), mirror baseball also had a fourth base, second pitcher and second catcher. Pitchers and catchers were often designated as being "left" or "right", depending upon where they stood on the mound, with reference to the two hitters, who would also be designated as "left" or "right". Both pitchers would hurl at the same time as the two batters would attempt to connect and run the bases on the pentagonally shaped field (In Between Days: Temper). Knife fights were common, particularly during pitching changes or plate collisions (In Between Days: The Play at the Plate).
Two of the better mirror teams were the Ganymede Hunters and the South American Pistoleros. The Empress Hoshi Sato would encourage her crew to watch the various games, and she and her senior staff, and then eventually her children, would collect wagers and would exert physical pressure if debts were not paid on time (In Between Days: Reversal, The Play at the Plate).
In 2410 the two teams competing in the Bajoran World Series were the Warriors, from Kendra Province, and the Hara Cats. Vesin Kilros of the Warriors was at bat first in one game, and scored a hit off the opening pitch that went into right field. (Bait and Switch: "All's Fair in Love and War")