Nine innings
Each team bats until it makes three outs. A complete game is nine innings, unless the home team is already ahead after the visitors bat in the ninth. Extra innings follow if the score is tied.
Baseball · 2026
MLB, explained.
Thirty teams. Twelve playoff clubs. One World Series. Here’s the quick guide.
Major League Baseball is the top professional baseball league in North America: 30 clubs in two leagues, a 162-game regular season, and an October playoff that ends with the World Series.
League contact
Commissioner’s Office details published by MLB. For tickets, accounts, or a specific club, use that team’s site — not the league office.
- Headquarters
- Office of the Commissioner of Baseball
1271 Avenue of the Americas
New York, NY 10020 - Phone
- (212) 931-7800
- Press
- (212) 931-7878MLB Communications
A short history
The National League dates to 1876. The American League began play in 1901. The two leagues met in the first modern World Series in 1903. They have operated under one commissioner since 1920; the organization fans now call Major League Baseball is that combined office and the 30 clubs.
Realignment into three divisions per league came in 1994, and the Wild Card joined the playoffs in 1995. Interleague play started in 1997. The field has been 30 teams since the Arizona Diamondbacks and Tampa Bay (then Devil Rays) joined in 1998. The Athletics are playing 2026 home games at Sutter Health Park in West Sacramento while a Las Vegas ballpark is built.
The 2026 regular season ends September 27. The World Series is scheduled to start October 23.
Current teams
Fifteen clubs in each league, five per division. Open a team for scores, the next game, and news.
American League
National League
NL East
NL Central
2026 schedule
The regular season runs March 25 to September 27, 2026. Each team plays 162 games. Opening Night was the Giants and Yankees in San Francisco; traditional Opening Day was March 26. The All-Star Game was July 14 at Citizens Bank Park in Philadelphia.
How the league works
Nine innings, three outs, and a 162-game standings race that feeds a 12-team playoff.
Balls, strikes, and the count
Four balls is a walk. Three strikes is an out. A hit that stays in play can be a single, double, triple, or home run — or an out if a fielder records it.
The designated hitter
Both leagues use the designated hitter: a batter who hits in place of the pitcher. That rule is league-wide, not just the American League.
Scoring
A run is one point: a player who reaches home legally. There is no equivalent of a field goal or a convert. The team with more runs after nine innings wins.
Extra innings
If the game is tied after nine, play continues. Regular-season extra innings start each half-inning with a runner on second. Postseason extra innings start empty.
Leagues
The American and National Leagues each have East, Central, and West divisions. Each division has five teams. Clubs also play interleague games during the year.
The season
Spring training in February and March, 162 games from late March into late September, then four playoff rounds for the World Series in October.
How the playoffs work
Twelve teams. Four rounds. MLB does not reseed after the Wild Card Series.
Who gets in
Six teams in each league: the three division winners and three Wild Cards. Seeds 1–3 are the division winners by record. Seeds 4–6 are the Wild Cards. The top two seeds get a first-round bye.
Wild Card, then Division Series
Best-of-three Wild Card Series: 3 vs. 6 and 4 vs. 5, all games at the higher seed. Winners meet the byes in a best-of-five Division Series — 1 plays the 4/5 winner, 2 plays the 3/6 winner.
LCS, then World Series
League Championship Series are best-of-seven. The AL and NL champions meet in the World Series, also best-of-seven. In 2026 Game 1 is October 23; a Game 7 would be October 31.
Home field: The higher seed hosts the Wild Card Series (all three games) and has home-field advantage in the LCS. In the World Series it goes to the pennant winner with the better regular-season record. The 2026 Wild Card Series begins September 29.
For the live table that feeds these seeds, see the MLB standings.
Office address, 2026 dates, and playoff rules checked September 24, 2026. Use the official MLB links if an address, number, or date changes.