How MLB Playoffs Work

How MLB Playoffs Work: New Postseason + a History

We are reader supported. When you purchase through links on our site, we may earn an affiliate commission. Also, as an Amazon affiliate, we earn from qualifying purchases.

Major League Baseball fans know their season takes up half of each year, but there is a particular time of year when they pay extra special attention: October. That month hosts the MLB postseason, a playoff tournament to determine a world champion.

How the MLB playoffs work has evolved tremendously in recent years. After making no changes for almost a century, starting in 1969 the modern major league playoff system began, leading up to today’s tournament style featuring multiple division winners and “wild card” teams.

In fact, for the past two decades (through 2022) the MLB experimented and expanded a championship play process that previously was unchanged for 92 years. Then, for the 2023 season, they changed the playoff format again. Back-to-back years with playoff changes was unprecedented.

Big MLB Playoff Format Changes 2022 and 2023

In 2022, the MLB playoffs officially expanded to feature 12 teams total, 6 from each league, up from 10 teams the previous year. The big change is addition of a 3rd wild card qualifying team, and first-round byes for division-winning teams that finish with the best regular season records.

The big 2023 change was adding games in the first round, known as the wild card round.

Starting with the 2023 season, once again 12 teams again qualify for the MLB playoffs, six from each league. Again the two teams from each league (division winners with the best records) still get first-round byes ~ a concept to keep top teams playing hard through season’s end even if they already clinched a playoff spot.

The remaining four teams from each league now compete in the Wild Card round. Big change: the Wild Card round is now a best-of-three format. (Single-game wild card contests were eliminated.)

The League Championship Series and World Series remain unchanged, at a maximum 7 games, best-of-four format.

MLB Playoffs Up to 2021

Through 2021 (excluding the short 2020 season, explained below), the playoffs featured an exciting single-game playoff between the 2 wild card teams, with winners moving on to join a straight 8-team tournament through the World Series.

From 2022 and beyond, expect more teams participating, with the overall system looking more like the tournament brackets you might see in NCAA championship events.

MLB Postseason Now Like Tournaments of Other Sports

Are the playoffs in Major League Baseball that complicated now? Not really. Let’s take a look at what to expect with the new format (approved during the Collective Bargaining Agreement of early 2022), plus a detailed look at the history of the MLB’s championship play.

Remember, from 1901 to 1968, only 2 teams made the postseason. If teams finished atop their league at the conclusion of regular-season play, they met in a 7-game series and the winner claimed the championship. (On a few occasions the World Series was a best-of-9 games ordeal, like in 1919).

The World Series was the only postseason in the MLB from 1903 to 1968.

Now, teams must survive rounds of play against the best teams, in a bracket format seen in tournaments of other sports (college sports in particular). It is quite hard to make it to the World Series nowadays, let alone win it.

The 2022 MLB playoffs featured 12 teams total for the first time. (Immediately prior to that, 10 teams made the playoffs, with the big difference being the previous 1-game playoff between 2 wild card teams to fight over which would be the final team allowed into the brackets. That 1-game playoff is eliminated, in favor of seedings, including 3 wild card teams).

To summarize, instead of 1 of the 2 wild card teams in each league getting eliminated immediately, all the wild card teams automatically join the championship bracket. Each team’s final regular-season record dictates seeding, and when and who teams play.

In each league, of the 3 division winners, the 2 teams that finished with the best regular-season records get a bye in the initial round of playoff play. That is, they get the time off while 4 other teams battle. So, it’s very important to claim a No. 1 or No. 2 seed.

Then, the division winner with the worst record of those titlists joins the 3 wild card teams to create a 4-team bracket. Here’s how the brackets are scheduled:

#1 seed = Best record in either the National or American league, 1st-round bye

#2 seed = Division winners with the 2nd-best record in either league, also 1st-round bye

#3 seed = Division winners with 3rd-best record, vs. #6 seed (Wild Card team with 3rd-best record)

#4 seed = Wild Card teams finishing with the best record among the Wild Card teams in each league, vs. #5 seed

#5 seed = Wild Card teams with 2nd-best record among Wild Card teams in each league, plays #4 seed

#6 seed = Wild Card team with the 3rd-best record of the Wild Card teams, to face #3 seed

The 1st round is known as the Wild Card games, and they begin Oct. 7, with matchups between the #3 vs. #6 and #4 vs. #5 seeds in a best-of-3 series. The winner of the #3 vs. #6 game plays the overall #2 seed, and the victor of the #4 vs. #5 game faces the #1 seed.

That 2nd round, called the Division Series, are best-of-5-game affairs; then the remaining champion of each league battles in the World Series in a best-of-7-game format.

It was not all that long ago (1993) when the Major League playoffs involved 4 teams and 2 rounds: the winner of each division in each league battling for the right to play in the World Series. There were only 2 divisions each, and no Wild Card teams.

For the 1995 season, both leagues were split into 3 divisions (there were no playoffs in 1994 due to the players’ strike). That’s when a single wild card entrant was added in each league, dropped into the equation with the division winners.

That’s quite a bit of change for the MLB playoff format in a scant couple of decades ~ after 27 years of no changes. Let’s dig into the details.

A History of Playoffs in Major League Baseball

The same baseball you see on television today began as a professional enterprise in 1876 ~ only 11 years after the end of the Civil War.

Until the end of the 19th century there was just 1 official major league (at the time), the National League. While up until the turn of the century a few other leagues claimed professional status, it was not until formation of the American League that an operation proved successful enough to compete with the Nationals.

So from 1876 to 1902 there was no World Series. Yet, the National League had to have champions each year. With no playoffs or World Series, how?

Major League Baseball Championships Before the World Series


Until 1969, high-level professional baseball leagues did not have enough teams to split into divisions. Basically, most of the time before 1901, whoever finished the season with the best regular-season record was named champion.

The team that today is the Chicago Cubs (then called the White Stockings) won the first MLB championship in 1876, with a record of 52-14. There were 8 teams (compared with 30 now), with squads from Hartford (Conn.), St. Louis (but not the Cardinals), Louisville, Boston (not the Red Sox), New York, Philadelphia, and Cincinnati.

While the White Stockings/Cubs won the regular-season championship that is recognized by the MLB, that inaugural year of 1876 did see a post-season: an exhibition series between those White Stockings and the Brown Stockings of St. Louis. In this case, the team that finished with the 2nd-best record, St. Louis, won the series 4 games to 1.

From that point until 1882 there were no MLB postseasons.

Competition Professional Baseball Leagues of the Late 1800s

During the latter part of the 19th century, what today are called “upstart” pro leagues surfaced to challenge the “senior circuit” National League. Most of those leagues were not recognized by the “major” National League, until 1882 when MLB officials agreed to a championship series against the champion of the American Association.

The first 2 were deemed exhibitions, with the first ending in a tie, while the other was canceled. It was not until 1884 that the baseball-loving public saw championship competition between the majorest of the leagues.

For a few years, in fact, that championship series between the N.L. and A.A. champions was promoted as the “World’s Championship Series” (WCS). Even though some shortened it to call the match a World Series, currently the MLB does not officially recognize them along with the championship series that arrived with the 20th century.

Champions of Other Major Professional Baseball Leagues

There are some notable high-level professional baseball leagues that remain notable in history books, namely because they were formed by MLB players.

Prior to the National League even being formed, the National Association of Ball Players named champions, from 1857 to 1870.

From 1871 to 1875 there was a different yet similarly named National Association of Professional Baseball Players. The last 3 champions of the old NAPBBP were named the Chicago White Stockings, Philadelphia Athletics, and Boston Red Stockings.

The before-mentioned American Association attracted a considerable amount of MLB talent and generated some following in the press of the day. That league ran from 1882 to 1891, and its champion got to play the National League Champion from 1884 to 1890 (mentioned above as the World’s Championship Series). There was no series in 1891 before the AA went defunct.

The only AA champions to beat their NL counterparts at the end of the season were the St. Louis Browns of 1886, and the Louisville Colonels of 1890.

The National League was the preeminent baseball league in the world until the 20th century.

Very First MLB Playoffs

The 1884 championship series between the National League’s Providence Grays vs. the American Association Metropolitans (of New York), won by the NL team in a 3-game sweep, can be considered the first “playoff” series in major league baseball.

History of the American League

Most knowledgeable baseball fans know the first official “World Series” was played in 1903.

Then, there was no N.L.-A.L. matchup in 1902 because the New York Giants refused to acknowledge the upstart A.L. and its champion.

However, both leagues ceased animosity by 1905 the World Series as we know it resumed.

The American League did not just pop into existence with the World Series. It was originally a league called the Western League, which featured play from 1885 to 1899 in cities around the Great Lakes region (which at that time was considered the western United States!).

That circuit changed its name to the American League for the 1900 season, and by the next year grew into a true competitor for the “senior circuit” NL ~ and ultimately a 2nd “major league.” Though the leagues merged in 1901, there was no World Series until 2 years later.

Baseball World Series History


The first official World Series was won by the Boston Red Sox, playing in 1903 as the Boston Americans, backed by the stellar pitching of Cy Young, over the favored Pittsburgh Pirates of the National League. The 1st World Series was a best-of-9-games affair; it was switched to a 7-game series in 1905.

The World Series switched back to 9-game affairs from 1919 to 1921.

The championship series was a contest between the winners of each league, with no pre-playoffs, through the 1968 season. The next season each league was divided into 2 divisions, and an additional playoff round was added.

The World Series was played exclusively in daylight until 1971, when the Pittsburgh Pirates turned on the lights for a night game vs. the Baltimore Orioles. Game 6 in 1987 was the last World Series match played under the sun.

Starting in 2003, the winner of the mid-season All-Star Game decides home-field advantage in the World Series. This practice was abandoned starting in 2017, when the team with the best record gets 4 World Series home games, while the other team gets 3.

There was no World Series in 1994 due to a players’ strike.

Notable MLB Postseason Moments through the Years

1903 ~ First World Series between Boston Americans of the American League (AL) vs. the Pittsburgh Pirates of the National League (NL)

1908 ~ Fred Merkle’s bonehead play forces replay of game at end of season, becoming 1st 1-game playoff ever (though not officially since it was a made-up regular-season game). Merkle’s New York Giants lost out on the pennant to the Chicago Cubs ~ who ultimately won the Merkle game.

1918 ~ Babe Ruth of the Boston Red Sox sets the record for most consecutive scoreless innings in World Series play; the 29⅓ scoreless innings began in the 1916 World Series.

1919 ~ World Series returns to best of 9 format, won by the Cincinnati Reds but later immortalized by the Black Sox gambling scandal.

1920 ~ Bill Wambsganss of the Cleveland Indians turns the only unassisted triple play in MLB postseason history, in Game 5 of the World Series versus the Brooklyn Robins.

1923 ~ World Series returned to best-of-7 affair; first World Series in Yankee Stadium.

1932 ~ Babe Ruth has his “called shot” in Game 3 at Wrigley Field vs. the Cubs.

1946 ~ First-ever contest between the regular season and World Series to determine a league champion; the St. Louis Cardinals top the Brooklyn Dodgers in a 3-game playoff series.

1948 ~ First single-game, “elimination game” between the regular season and World Series: Boston Red Sox lose heartbreaker 1-game playoff to the Cleveland Indians.

1947 ~ Jackie Robinson breaks the color barrier in the World Series.

1951 ~ Bobby Thomson hits a playoff series-ending home run to propel the New York Giants to the World Series, over the Brooklyn Dodgers.

1956 ~ The Yankees’ Don Larsen throws the first and only perfect game in MLB history.

1959 ~ 1st World Series game played west of the Mississippi River (at the Los Angeles Coliseum, where the Dodgers hosted the Chicago White Sox).

1960 ~ Bill Mazeroski of the Pittsburgh Pirates hits a Game 7 home run to end the series clincher, as the first walk-off series ender, against the New York Yankees.

1969 ~ First year of divisional playoffs, the New York Mets sweep Hank Aaron’s Atlanta Braves, then shock the heavily favored Baltimore Orioles in the World Series.

1972 ~ Players strike shaves a game from the regular season, resulting in the Detroit Tigers winning the A.L. east by a half-game.

1975 ~ Cincinnati Reds top the Boston Red Sox in Game 7 in what many still call the Best World Series Ever.

1977 ~ Reggie Jackson hits 3 home runs in a series-clinching Game 6 vs. the Los Angeles Dodgers.

1981 ~ Players strike results in 2 halves of the season, and 8 teams qualifying for the playoffs.

1986 ~ Dave Henderson saves the Boston Red Sox with a 2-out, 2-strike 9th-inning home run in Game 5 of the A.L. playoffs, pushing his team on to the championship series.

1986 ~ Bill Buckner of the Red Sox misses a 2-out, 2-strike 9th-inning ground ball that let the New York Mets tie Game 6, and eventually win the Series.

1988 ~ Kirk Gibson of the Los Angeles Dodgers shocks the heavily-favored Oakland Athletics with a 2-out, 2-strike 9th-inning home run in Game 1 of the World Series.

1989 ~ The Loma Prieta earthquake disaster in the Bay Area of California delays the “subway” World Series between the teams based there, the Oakland Athletics and San Francisco Giants.

1992 ~ Toronto Blue Jays become the first non-U.S. team to win an MLB championship.

1994 ~ Mid-season players strike causes cancellation of entire MLB postseason.

1995 ~ New playoff format with 2 “wild card” playoff teams added, and extra 3rd division added in each league.

2004 ~ Boston Red Sox end 86-year championship drought by defeating the St. Louis Cardinals in the World Series.

2005 ~ Chicago White Sox end 88-year championship drought by defeating the Houston Astros in the World Series.

2010 ~ In Game 1 of the National League Division Series, Roy Halladay throws the 2nd no-hitter in MLB postseason history.

2016 ~ Chicago Cubs top the Cleveland Indians to claim first World Series championship since 1908.

2017 ~ Houston Astros defeat the Los Angeles Dodgers in 7 games in a World Series later tainted by claims of cheating by Houston.

2020 ~ Coronavirus pandemic shortens season to 60 games, and creates expanded playoffs of 16 teams, eventually won by the Los Angeles Dodgers.

Baseball Elimination Playoff Game History

National League

The National League used a 3-game playoff until 1969, when teams were split into divisions and a 1-game elimination game was ordered.

Through 1968:

1969 to Today:

American League

The American League always instituted the 1-game playoff to determine who moves on to the World Series. It occurred 6 times:

Related Questions

Question: It says new baseball leagues formed to compete with the National League were called “upstarts.” What does upstart mean?

Answer: An upstart is a person (or thing, like a league) that is cocky, arrogant, and/or disrespectful of others. That’s what major league club owners thought of new leagues when they were formed by past colleagues or disgruntled players.

Q.: Which MLB team has won the most postseasons?

A.: New York Yankees, with 27. The St. Louis Cardinals hold the record for National League teams, with 11 world championships.

Q.: Why were there 3 playoff rounds in 1981?

A.: A player’s strike wiped out games in the middle of the season. Upon conclusion of the strike, the league set up the postseason among the teams that finished first before the strike, then after the strike. Basically 2 separate seasons of games. While the post-season returned to normal in 1982, that 8-team championship tourney of 1981 planted the seeds in the minds of owners that resulted in the expansion into 6 total divisions in 1995. (That change, too, was at least partially the result of a player’s strike, of 1994).