How the MLB Playoffs Work

How MLB playoffs work

LiveAbout / Alex Dos Diaz

The Major League Baseball (MLB) playoffs mark the end of the sport's 162-game regular season, typically beginning the first full week of October. It's a time of excitement for baseball fans when league leaders can collapse and wild-card teams can surprise everyone. 

Ten teams make the playoffs—five each in the American and National Leagues. The playoffs for each league consist of a one-game playoff between two wild-card teams, two best-of-five Division Series playoffs (DS) featuring the wild-card winner and the winner of each division, and finally the best-of-seven ​League Championship Series (LCS).​

The winners of the American League Championship Series (ALCS) and the National League Championship Series (NLCS) play each other in the best-of-seven World Series. 

Wild Cards

The wild card rule was first introduced in 1994 when Major League Baseball expanded the American and National Leagues from two divisions to three each. One wild-card team—each with the best record that didn't win its division—was added to the playoffs in each league.

Beginning in 2012, a second wild-card team was added. The two wild-card teams play each other in a winner-take-all game two days after the regular season ends. The winner of that game advances to the Division Series to face the No. 1 seed. 

Wild cards have been a force to reckon with in recent World Series playoffs. In 2014, the wild-card San Francisco Giants went all the way to the title series, beating the Kansas City Royals (also wild-card winners) in the seventh and decisive game of the World Series. 


Within the Division: If there is a tie at the conclusion of the regular MLB season for any of the divisional or wild-card positions, a one-game playoff will be held the day after the season to determine the team that advances. If there is a tie for a division and the losing team is assured of winning a wild card, there is no one-game playoff. The team that won the season series between the two is named the division champion.

Within the Series: If the teams split their seasonal series equally, the team with the better record overall within the division wins the title. And if they're still tied, the team with the better record in the final 81 games is declared the winner. If they're still tied, that scenario is extended back to 82 games, 83 games, 84 games, and so on.

Division Series (ALDS and NLDS)

The Division Series is a best-of-five series. The team with the best overall record gets the top seed and home-field advantage in the playoffs. It hosts Games 1, 2, and 5 in the Division Series round and faces off against that league's wild-card team. 

The remaining two divisional champs also square off against one another in a best-of-five matchup. Home-field advantage in that series is given to the team with the second-best season record; it hosts Games 1, 2, and 5 in its series. The two winning teams advance to the League Championship Series.

League Championship Series (ALCS and NLCS)

The winners of the Division Series then advance to the best-of-seven American League and National League Championship Series. The team with the best record in each league will have home-field advantage.

In the event that a wild-card team has the better record than the other qualifying team that is a division champion, the division champion still gets the advantage and hosts Games 1, 2, 6, and 7.

The Milwaukee Brewers, who moved from the American to the National League in 1998, and the Houston Astros, who moved to the American League from the National League in 2013, are the only teams to have appeared in both the ALCS and NLCS.

The World Series

The winners of the ALCS and NLCS advance to the World Series, the best-of-seven-game playoff. Prior to the 2002 season, a home-field advantage (games 1, 2, 6, and 7) alternated every year between the leagues. A rule change that year altered that approach, giving home-field advantage to the league that won that year's All-Star Game. MLB changed the rules again in 2017. Now, the home-field advantage goes to the team that has the better overall regular-season record. 

The first team to win four games in the best-of-seven-game series becomes the Major League champion. The 2016 World Series, pitting the Chicago Cubs against the Cleveland Indians, was noteworthy because it was the first time those two teams had met in the championship. It was also Chicago's first World Series title since 1908. 2017 was the Houston franchise's first-ever World Series win.

History of the Playoffs

The first World Series was played in 1903, and the winners of the American League and National League met in what was then a best-of-nine series. That year, the Boston Americans (who later became the Red Sox) won the title. Two years later, the World Series was pared back to a best-of-seven contest. 

When the AL and NL split into separate divisions in 1969, the ALCS and NLCS were formed, and four teams made the playoffs. When the leagues adopted a six-division alignment in 1994, another round of playoffs was created with the Division Series.

A fifth team was added from each league to the playoffs before the 2012 season.

Baseball commissioner Rob Manfred in 2018 said he is kicking around ideas to expand to 32 teams, 16 in each league, enabling each to have four divisions. That alignment could potentially eliminate the wild card and winner-take-all one-game playoff rounds.