Short answer: The World Series is a best-of-seven format, so a team must win four games to become champions. Details:
- In a best-of-seven World Series, the first team to reach four wins takes the title. This means anywhere from four to seven games can be played, depending on how the wins are distributed between the two teams.
- Historically, the format has always been seven potential games, with actual play stopping once a team reaches four wins.
- The number of games actually played depends on the series outcome:
- If a team goes 4-0, only four games are played.
- If it goes to the maximum, the series goes seven games with a 4-3 final.
If you’d like, I can pull up current-season specifics (which teams are in the World Series and how many games have been played so far) or discuss probabilities of different series lengths given various per-game win probabilities.
