September is officially here. Not only are rosters being expanded, but the final month of the MLB regular season means we’re officially in the home stretch. We’re so close to finding out which teams will make the postseason and ultimately win the World Series.

The MLB playoff format has undergone several changes over the years. Previously, only the top-ranked teams from each league were allowed to participate, then there was one wildcard team, then two, and now three. Six teams from each league ultimately have a chance to enter and win the World Series.

In this article, you’ll learn everything you need to know about the MLB postseason, from the updated playoff format to important dates to how rosters work and more.

Overview of the current format

A total of 12 teams qualify for the MLB postseason – six from each league. Each league has its three division winners and three wild card teams – the teams with the best record among those that don’t win the division – that advance to the postseason.

The postseason consists of four rounds – the Wild Card Series, Division Series, League Championship Series and World Series.

Both the AL and NL use the same seeding format, which can be seen below:

Wild Card Series

The postseason begins with the Wild Card Series. Four of the six qualified teams from each league participate in this series and a spot in the Division Series is at stake. The top two teams from each league receive a bye, automatically advancing them past the Wild Card Series.

The format of the Wild Card Series in both leagues is as follows:

The number 3 and 4 seeds in each league will play a three-game series against the number 6 and 5 seeds, respectively, at their home stadium. All three games will be played on the field of the higher-seeded team and the winner of this series will advance to the next round.

Division Series (ALDS and NLDS)

The teams fortunate enough to advance beyond the Wild Card Series play in the Division Series, either the ALDS for the American League teams or the NLDS for the National League teams.

This series is a best-of-five series, meaning a team must win three games to advance to the next round, up from the two wins needed to advance past the Wild Card Series.

The top two seeds in each division will receive home-court advantage in this series, meaning three of the five games will be played at their stadium. The other two teams that advanced from the Wild Card series must win at least one away game to advance. The first two games and the fifth game (if necessary) will be played at the home stadium of the higher-seeded team.

League Championship Series (ALCS and NLCS)

After the Division Series we come to the League Championship Series. The LCS is the last round of the postseason before the World Series. It determines which team will represent its league (one each in the AL and NL) in the World Series.

This series is a best-of-seven series, one step above the Division Series. A team must win four of the seven games to win the championship and advance to the World Series.

Home court advantage in this series will again be with the highest ranked team in each division. The team with home court advantage will host the first two and (if necessary) the last two games of this decisive series.

While home field advantage is important, it is not the be-all and end-all. In last season’s ALCS, the visiting team won all seven games, leading to the Texas Rangers defeating the Houston Astros and ultimately winning the World Series.

The World Series

Once we have determined who wins which league, we move on to the World Series. This is where all the marbles are at stake. The winner of this series becomes the world champion for the season.

Like the League Championship Series, the World Series is played in a best-of-seven format, meaning a team must win four of the seven games to be crowned champion.

The format is exactly the same. The team with the best record of the two participants has home field advantage and that team gets to host the first two and (if necessary) the last two games of the World Series.

Postseason schedule

October is exactly when the MLB playoffs officially begin. They begin on October 1st with Game 1 of the Wild Card Series, and depending on how long the World Series lasts, the playoffs could last into November.

What sets MLB apart from the other major U.S. sports is that they play literally every day. During the regular season, there are stretches where teams don’t have a day off for two or three weeks. In the postseason, they don’t play every day, but they play very often.

Days off are due to travel (when the series moves to another city) or before a new series starts.

Broadcast schedule

For cable TV owners, MLB postseason games can be seen on numerous channels, depending on which round of the postseason we are in.

Those without cable can tune in on a variety of streaming platforms, including MLB.tv for those with active subscriptions and ESPN for the Wild Card Series.

MLB teams’ active rosters include 28 players in September, but once the postseason begins, the size of the active rosters is reduced back to the traditional 26 players.

Rosters are set before the first game of a series, but teams can apply to the Commissioner’s Office for permission to replace an injured player on the active roster. The downside to this is that the injured player cannot play not only in the current round, but also in the following round. Also, keep in mind that a pitcher who is taken off the roster due to injury can only be replaced by another pitcher. The same goes for fielders.

As for eligibility, any player who was on a team’s 40-man roster before 11:59 p.m. ET on August 31 is eligible to be named to the postseason roster. Players on the 60-day IL are also eligible if they were out for at least 60 days before being activated. Players signed in September are not eligible for the postseason, which is why players like Tommy Pham were released in August, not September.

Typically in the postseason, even though roster size stays the same, teams use four-man rotations, making bullpen depth all the more important. Teams may also value speed off the bench, as every late-game run that can be stolen is all the more important.

Unfortunately, MLB has taken away one of the game’s best moments, a potential Game 163. In the past, teams with identical records battling for either a division title or a wild card spot would play in a Game 163 to determine which team earned a certain spot. Now, tiebreakers are determined by other factors and there are no more Games 163.

Tiebreakers are most often determined by head-to-head matches. This is the only tiebreaker needed for a divisional race, as teams within the same division play an odd number of games (13, to be exact). However, things can get trickier for the Wild Card spot, as teams battling for those spots can’t always play an odd number of games against each other and finish with a head-to-head matchup.

The next factor is the record within the division. The team with the best record within its own division wins the tiebreaker. Yes, this even decides a tie between teams that do not play in the same division.

The next tiebreaker scenario is the record between divisions. When calculating the record within divisions, if there is a tie, the league will calculate which team has the best record against the other divisions in the same league. So if an NL East team is involved in a tie, their record against the NL Central and NL West teams will be considered in this scenario.

If there is still a tie after these three tiebreaker scenarios, we would look at the final half of the interleague games. For an AL team, this would calculate the games within its last 81 games of the season against NL opponents. Their record against NL teams within its last 81 games of the season would be their record in breaking the tie here. This process continues backwards until there is a winner.