MLB, Major League Baseball, is the top professional baseball league in North America, made up of 30 teams split between the American League and National League. The two leagues have operated as a single unified organization since their administrative offices merged in 2000, and MLB crowns one champion each year through the World Series.

MLB currently has 30 teams, 15 in the American League and 15 in the National League. The league has discussed expanding to 32 teams, with Nashville and Salt Lake City viewed as the leading candidate cities, though new franchises are not expected to begin play until around 2032 or 2033 at the earliest.

Rob Manfred has served as MLB Commissioner since 2015. He has said his current term, which runs through January 2029, will be his last, meaning he plans to retire from the role once it ends.

Each MLB team plays 162 regular-season games, typically running from late March or early April through late September or early October, followed by a postseason that stretches into late October or early November.

The AL and NL are MLB's two leagues, each made up of three divisions, East, Central, and West, with five teams apiece. The leagues once had different rules, most notably the designated hitter, but since 2022 both use identical rules leaguewide.

No, MLB does not use a hard salary cap. Instead it applies a Competitive Balance Tax, commonly called a luxury tax, that financially penalizes teams for exceeding a set payroll threshold without actually stopping them from spending beyond it. Whether to introduce a real salary cap is a central, contentious issue heading into the next round of labor negotiations.

MLB is run by the Commissioner's Office on behalf of the 30 team owners, working alongside the MLB Players Association, the players' union, on labor matters. On-field playing rules are set by a Joint Competition Committee made up of owners, active players, and an umpire representative.

Teams play an unbalanced schedule weighted toward divisional opponents, with interleague games against teams from the other league spread throughout the entire season rather than confined to a separate interleague stretch, which was the case before 2023.

AL East: Baltimore Orioles, Boston Red Sox, New York Yankees, Tampa Bay Rays, Toronto Blue Jays. AL Central: Chicago White Sox, Cleveland Guardians, Detroit Tigers, Kansas City Royals, Minnesota Twins. AL West: Houston Astros, Los Angeles Angels, Athletics, Seattle Mariners, Texas Rangers. NL East: Atlanta Braves, Miami Marlins, New York Mets, Philadelphia Phillies, Washington Nationals. NL Central: Chicago Cubs, Cincinnati Reds, Milwaukee Brewers, Pittsburgh Pirates, St. Louis Cardinals. NL West: Arizona Diamondbacks, Colorado Rockies, Los Angeles Dodgers, San Diego Padres, San Francisco Giants.

The New York Yankees have won 27 World Series championships, far more than any other franchise, with their most recent title coming in 2009.

Several current National League franchises trace their roots to the league's founding in 1876, including the Atlanta Braves, originally the Boston Red Stockings, and the Chicago Cubs, making them among the oldest continuously operating professional sports franchises in North America.

The Arizona Diamondbacks and Tampa Bay Rays, both added in 1998, are MLB's newest franchises. The league has not expanded since, though a move to 32 teams is under discussion for the early 2030s.

The franchise dropped Oakland from its name after leaving the city following the 2024 season. For 2025 through 2027 the Athletics are playing as a temporary tenant at Sutter Health Park in West Sacramento, California, including a handful of home games in Las Vegas in 2026, ahead of a planned permanent move to a new Las Vegas stadium expected to open around 2028.

Hurricane Milton badly damaged Tropicana Field's roof in October 2024, forcing the Rays to play their entire 2025 home schedule at Steinbrenner Field in Tampa. After roughly a year of repairs costing about 60 million dollars, the Rays returned to a renovated Tropicana Field for their 2026 home opener.

Yes, though it is uncommon. Recent examples include the Cleveland Indians becoming the Guardians in 2022 and the Athletics dropping their Oakland affiliation in 2025 ahead of a planned Las Vegas move. Earlier relocations include the original Washington Senators becoming the Minnesota Twins in 1961 and the Montreal Expos becoming the Washington Nationals in 2005.

Teams carry a 40-man roster of players eligible to be called up during the season, but only 26 of them, with a maximum of 13 pitchers, can be on the active game-day roster for most of the season. That active limit expands to 28 players, with up to 14 pitchers, for the month of September.

Opening Day typically falls in late March or the first days of April, the 162-game regular season runs through late September or very early October, and the postseason concludes with the World Series in late October or early November.

MLB's Commissioner's Office sets the non-waiver trade deadline on a date between July 28 and August 3 each year. In 2026 it falls on August 3 at 6 p.m. ET, after which players on 40-man rosters can no longer be traded between teams for the rest of the season.

The All-Star Game is played in mid-July at a rotating host ballpark. The 2026 All-Star Game is scheduled for Tuesday, July 14, at Citizens Bank Park in Philadelphia, the Phillies' fourth time hosting the event and their first at that ballpark.

The MLB Draft, officially the Rule 4 Draft, is now held during All-Star week in the same host city as the All-Star Game. The 2026 draft ran July 11 to 13 in Philadelphia and lasted 20 rounds.

The offseason runs roughly from the end of the World Series in early November through the start of spring training in mid-February, and includes free agency, the Winter Meetings, the Rule 5 Draft in December, and Hall of Fame voting results in January.

The current collective bargaining agreement between MLB and the players' union expires on December 1, 2026. Given the sides' sharp disagreement over introducing a salary cap, a lockout similar to the one that delayed the start of the 2022 season is widely expected, and a new deal would likely need to be reached by around March 2027 to avoid losing regular-season games.

The designated hitter, or DH, allows a player to bat in place of the pitcher without playing a defensive position. Since 2022, the DH has been used leaguewide in both the American League and National League, ending decades of differing rules between the two leagues.

Introduced in 2023, the pitch clock requires pitchers to begin their motion within 15 seconds with the bases empty or 20 seconds with runners on base, and batters must be in the box and alert with time remaining. It was credited with cutting average game times by roughly 25 minutes in its first season.

Since 2023, defensive positioning rules require two infielders on each side of second base with all four infielders positioned with both feet on the infield dirt at the moment of the pitch, effectively banning the extreme defensive shifts that had become common against pull-heavy hitters.

Yes, MLB increased base size from 15 inches square to 18 inches square starting in 2023, which slightly shortened the distance between bases to improve player safety around the bags and modestly encourage stolen base attempts.

MLB places a runner on second base to start the 10th inning of a regular-season game, and every extra inning after that, until a winner is decided, which speeds up extra-inning games. The rule is permanent for the regular season only; it is not used in the postseason, which is played with traditional extra-inning rules.

The Automated Ball-Strike, or ABS, challenge system debuted during the 2026 regular season, letting the batter, pitcher, or catcher challenge a ball or strike call in real time using tracking technology. Each team starts a game with two challenges, keeps a challenge if it succeeds, and loses it if it fails; MLB's own data shows challenges succeed a little over half the time.

It is available in all standard MLB ballparks but is not used for a handful of special events, including the Mexico City Series, the Field of Dreams Game, and the Little League Classic, due to technical limitations at those non-standard venues.

Managers can challenge certain umpire calls, such as safe or out calls on the bases and boundary calls, sending the play to an off-site replay official for a video review. Each manager starts a game with one challenge and is awarded an additional one if the first challenge is upheld.

Twelve teams qualify for the postseason, six from each league: the three division winners and three wild card teams per league.

The top two division winners in each league receive a bye directly into the Division Series. The third division winner and the three wild card teams play a best-of-three Wild Card Series, and the four winners advance through a best-of-five Division Series, a best-of-seven League Championship Series, and finally the best-of-seven World Series.

In the Division Series and League Championship Series, the higher seed gets home-field advantage. In the World Series, home-field advantage has gone to the team with the better regular-season record since 2017, a change from the earlier rule that awarded it to whichever league won that year's All-Star Game.

The Los Angeles Dodgers won the 2025 World Series, defeating the Toronto Blue Jays four games to three, capped by an 11-inning Game 7 win on November 2, 2025. It was the Dodgers' ninth championship and the first time a team repeated as World Series champion since the New York Yankees in 2000.

The Wild Card Series is the opening round of the MLB playoffs, a best-of-three series played entirely at the higher seed's ballpark between the third-place division winner and the three wild card qualifiers in each league.

MLB expanded to a 12-team postseason field starting with the 2022 season, up from the 10-team wild card format used from 2012 through 2021.

The Rule 4 Draft is MLB's primary mechanism for teams to acquire the rights to amateur players from U.S. high schools and colleges, along with players from Canada and some U.S. territories. It runs 20 rounds, with the draft order generally based on the previous season's standings, and is now held during All-Star week.

Most international players, from countries such as the Dominican Republic, Venezuela, Japan, and South Korea, are not draft-eligible and instead sign as international free agents under a bonus-pool system. MLB has repeatedly proposed adding a separate international draft, but the league and the players' union have not reached an agreement to implement one.

Held every December at the Winter Meetings, the Rule 5 Draft lets teams select certain players left unprotected on another team's 40-man roster. A player selected this way must stay on the acquiring team's active 26-man roster for the entire following season or be offered back to his original team.

Players generally become eligible for free agency after accumulating six years of major league service time, at which point they can sign with any team. A team that extends a qualifying offer to a departing free agent may receive draft-pick compensation if that player signs elsewhere.

Players with between three and six years of service time, along with the top tier of two-plus-year players known as Super Two players, who are not yet eligible for free agency can go through arbitration, where an arbitrator picks either the player's or the team's proposed salary figure if the two sides cannot agree.

Active rosters carry 26 players, including no more than 13 pitchers, from Opening Day through August 31. The limit expands to 28 players, with up to 14 pitchers, for September and the remainder of the season.

The 40-man roster is the full pool of players a team controls and can call up to the majors at any point in the season, including the 26 or 28 active players plus additional players on the injured list or optioned to the minors.

The major league minimum salary for the 2026 season is 780,000 dollars, a figure that rises annually under the current collective bargaining agreement.

The average MLB salary reached about 5.34 million dollars in 2026, though the median salary is far lower, close to 1.5 million dollars, because a relatively small number of very large contracts pull the league average upward.

The Competitive Balance Tax, commonly called the luxury tax, charges teams a penalty on every dollar their 40-man roster payroll exceeds a set threshold, which is 244 million dollars for the 2026 season. Additional surcharge tiers apply near 264 million, 284 million, and 304 million dollars, with tax rates ranging from 20 to 50 percent depending on how many consecutive years a team has exceeded the threshold.

No, teams can spend as much as they choose and simply pay the tax on the amount over the threshold; there is no hard cap preventing further spending. Teams that finish more than 40 million dollars over the threshold do face an added penalty of having their top amateur draft pick moved back 10 spots.

The current collective bargaining agreement expires December 1, 2026, and owners are expected to push for a hard salary cap for the first time since 1994, a proposal the players' union has strongly opposed. Given how far apart the two sides are on this issue, a lockout affecting the 2027 season is considered likely unless a new agreement is reached first.

The New York Yankees and Los Angeles Dodgers are consistently ranked as MLB's two most valuable franchises, both valued well above 7 billion dollars depending on the valuation source, with the Boston Red Sox, Chicago Cubs, and San Francisco Giants also regularly ranking among the league's most valuable teams.

The Most Valuable Player award, voted on by the Baseball Writers' Association of America, is given annually to one outstanding player in each league, the American League and the National League.

The Cy Young Award is given annually to the best pitcher in each league, as voted on by the Baseball Writers' Association of America. It is named after Cy Young, the all-time leader in career pitching wins.

Beyond MVP and Cy Young, MLB hands out Rookie of the Year, Manager of the Year, and Executive of the Year awards in each league, along with Gold Glove Awards for the best defensive players and Silver Slugger Awards for the best offensive players at each position.

Fans vote to select the starting position players for each league, while pitchers and the remaining roster spots are filled through a combination of player voting and selections by team managers and the Commissioner's Office, with every team guaranteed at least one representative.

Retired players become eligible for the writers' ballot five years after retirement and need at least 75 percent of the vote from the Baseball Writers' Association of America to be inducted, with a maximum of 10 years of eligibility on that ballot. Separate Era Committees periodically reconsider older players, managers, executives, and umpires who were passed over by the writers.

The National Baseball Hall of Fame and Museum is located in Cooperstown, New York, and holds its induction ceremony there every summer, typically in late July.

Barry Bonds holds the career home run record with 762, a total that has stood since he retired after the 2007 season.

Barry Bonds hit 73 home runs in 2001, the all-time single-season record. In the American League specifically, Aaron Judge holds the record with 62 home runs, set in 2022.

Pete Rose holds the career hits record with 4,256, a mark that has stood since he retired in 1986.

Cy Young holds the career record with 511 wins, compiled in the late 1800s and early 1900s, a total widely considered unreachable under the modern five-man starting rotation. MLB's annual award for the best pitcher in each league is named in his honor.

Nolan Ryan holds the career strikeout record with 5,714, roughly 900 strikeouts ahead of the next closest pitcher.

Rickey Henderson holds the career stolen base record with 1,406, along with the single-season record of 130 stolen bases, set in 1982.

As of the 2026 season, 24 perfect games have been thrown in MLB history, out of well over 200,000 games played since 1871. The most recent came from Domingo German of the New York Yankees on June 28, 2023.

In 2024, Shohei Ohtani became the first player in MLB history to hit at least 50 home runs and steal at least 50 bases in the same season, doing so while playing for the Los Angeles Dodgers, a milestone widely regarded as one of the sport's most remarkable modern achievements.

The longest MLB game by innings was a 25-inning contest between the Chicago White Sox and Milwaukee Brewers on May 8 and 9, 1984, which was suspended overnight and completed the following day.

MLB's national games are spread across several platforms for the 2026 to 2028 seasons: NBC and Peacock carry Sunday Night Baseball and the first round of the postseason, ESPN carries weeknight games plus the MLB.TV out-of-market streaming service, Netflix airs marquee events such as Opening Night and the Home Run Derby, and FOX, TBS, and Apple TV+ round out the remaining national windows, alongside each team's local regional broadcasts.

MLB.TV is the league's subscription streaming service for out-of-market games, meaning games not broadcast by a fan's local regional sports network. Games involving a fan's home teams are usually blacked out on MLB.TV within that team's local broadcast territory.

The World Baseball Classic is a separate international tournament rather than an official MLB competition, but it features many active MLB players representing their home countries and is organized in cooperation with MLB, the players' union, and the WBSC.

Nearly every MLB team operates or is affiliated with a chain of Minor League clubs at levels such as Triple-A, Double-A, High-A, and Single-A, where prospects develop before potentially being called up. Since 2021, Minor League Baseball has operated under direct MLB oversight rather than as an independent organization.

Yes, MLB regularly schedules regular-season games abroad, including an annual series in Mexico City and periodic series in cities such as London, Tokyo, and Seoul, as part of its effort to grow the sport's global audience.