Short answers, pulled from the story.
The Boston Americans and Pittsburgh Pirates met in 1903 to decide the first modern champion of Major League Baseball. This single best-of-seven series established a tradition that would last over a century without structural change.
Only four teams participated in the Major League Baseball postseason before league expansion to twelve teams in 1969. No other teams participated, and no intermediate rounds existed to filter entrants during this period.
The World Series awards home field based on regular-season records rather than the midsummer classic since 2017. Home-field advantage alternated between leagues annually until 2003 when the All-Star Game winner claimed the privilege.
The Atlanta Braves and San Francisco Giants finished with the two best records in 1993 yet only one could advance due to playing in the same division. The system created scenarios where high-performing teams missed the playoffs entirely if they failed to win their specific division.
The introduction of wild card spots occurred in 1994 and doubled the number of participating teams from four to eight per league. A second wild card team joined the bracket in 2012, triggering a controversial one-game playoff between the two non-division winners.