Because inclusion in the Major League Baseball postseason

Major League Baseball postseason

The Major League Baseball postseason is an elimination tournament held after the conclusion of Major League Baseball's regular season. It consists of one best-of-five series and two best-of-seven series...

 is based upon the teams' regular-season records, procedures exist to break ties between teams.

Two-way tie for the division or wildcard

One game tie-breakers are played between teams tied for a division championship or wildcard

Wild card (sports)

The term wild card refers broadly to a tournament or playoff berth awarded to an individual or team that has not qualified through normal play.-International sports:...

 berth on the day after the season was scheduled to end.

Two teams that are tied for a division championship play a tie breaker if such a game would eliminate the loser from the playoffs completely. This was the case in 2009 when the Minnesota Twins

Minnesota Twins

The Minnesota Twins are a professional baseball team based in Minneapolis, Minnesota. They play in the Central Division of Major League Baseball's American League. The team is named after the Twin Cities area of Minneapolis and St. Paul. They played in Metropolitan Stadium from 1961 to 1981 and the...

 and the Detroit Tigers

Detroit Tigers

The Detroit Tigers are a Major League Baseball team located in Detroit, Michigan. One of the American League's eight charter franchises, the club was founded in Detroit in as part of the Western League. The Tigers have won four World Series championships and have won the American League pennant...

 were tied at the end of the regular season for the American League Central

American League Central

The American League Central Division is one of six divisions in Major League Baseball. This division was formed in the realignment in 1994, and its teams are all located in the Midwestern United States...

 division title. Since the 2009 season, home advantage has been determined by comparing the teams involved in the tie by a set of performance criteria, with the first tiebreaker being head-to-head record. Accordingly, the first one-game playoff under the new rules, the AL Central playoff

2009 American League Central tie-breaker game

The 2009 American League Central tiebreaker game was a one-game playoff for Major League Baseball's American League Central divisional championship. The game took place on October 6, 2009 between the Detroit Tigers and the Minnesota Twins at the Hubert H. Humphrey Metrodome. It was necessary after...

 between the Minnesota Twins

Minnesota Twins

The Minnesota Twins are a professional baseball team based in Minneapolis, Minnesota. They play in the Central Division of Major League Baseball's American League. The team is named after the Twin Cities area of Minneapolis and St. Paul. They played in Metropolitan Stadium from 1961 to 1981 and the...

 and Detroit Tigers

Detroit Tigers

The Detroit Tigers are a Major League Baseball team located in Detroit, Michigan. One of the American League's eight charter franchises, the club was founded in Detroit in as part of the Western League. The Tigers have won four World Series championships and have won the American League pennant...

, was hosted by the Twins, who won the scheduled season series 11–7. The Twins won that game and advanced to the Division Series

2009 American League Division Series

The American League Division Series consisted of two concurrent best-of-five game series that determined the participating teams in the 2009 American League Championship Series. Three divisional winners and a "wild card" team played in the two series. The ALDS began on Wednesday, October 7 and...

, where they were swept by the eventual World Series

2009 World Series

The 2009 World Series was the 105th edition of Major League Baseball's championship series. The best-of-seven playoff was contested between the Philadelphia Phillies, champions of the National League and defending World Series champions, and the New York Yankees, champions of the American League...

 winners, the New York Yankees

New York Yankees

The New York Yankees are a professional baseball team based in the The Bronx, New York. They compete in Major League Baseball in the American League's East Division...

.

Two teams that are tied for the wildcard berth (such that both teams have a worse record than their division champion, whether in the same division or not), always play a tiebreaker game. Home field advantage in this scenario is given according to tie-breakers outlined in the next section.

Prior to 2009, home field advantage in the game was determined by a series of coin tosses that occurred a few weeks before the end of the season between teams that were close enough to each other in the standings where a tie becomes a significant possibility. If new situations occurred (i.e. a team quickly rises in the standings making another tie possible) more coin tosses occurred. Contrary to what some believe, home field advantage

Home Field Advantage

Home Field Advantage is a 2000 independent film starring Tony Award-winning actor Dan Fogler in the role of Charlie....

 was not determined by head-to-head record in the regular season until . For example, in 1995, the Seattle Mariners

Seattle Mariners

The Seattle Mariners are a professional baseball team based in Seattle, Washington. Enfranchised in , the Mariners are a member of the Western Division of Major League Baseball's American League. Safeco Field has been the Mariners' home ballpark since July...

 and California Angels

Los Angeles Angels of Anaheim

The Los Angeles Angels of Anaheim are a professional baseball team based in Anaheim, California, United States. The Angels are a member of the Western Division of Major League Baseball's American League. The "Angels" name originates from the city in which the team started, Los Angeles...

 played a one-game playoff to break a tie for the AL West championship. The Mariners hosted (and won) the one game playoff, but lost the season series 5 games to 7 games (excluding the one game playoff).

If postseason berths are not in dispute

No game is played if both teams are guaranteed to go to the playoffs. For example, the team that loses the tie-breaker game for the division would still go to the playoffs as a wildcard. In this case, the rules below are used to determine the division winner.

Two-way intradivision tie-breaker, with both teams already guaranteed a playoff spot with one as the wildcard and one as the division champion. The division title is awarded in the following priority:

1. The team with the best record in head to head play.
2. The team with the best overall record ignoring interleague play
   Interleague play
   Interleague play is the term used to describe regular season Major League Baseball games played between teams in different leagues, introduced in . Before the 1997 season, teams in the American League and National League did not meet during the regular season...
   
   .
3. The team with the best record in the final 81 games of the season, ignoring interleague play.
4. The team with the best record in the final 82 games of the season, extending backward until the tie is broken (since teams in the same division play each other as many as 19 times, this step is guaranteed to break the tie. Interleague games are skipped and ignored in this process.)

The loser of this tie-breaker goes to the playoffs as the wildcard team.

Ties between two division winners

If two champions from separate divisions have the same record, a tiebreaker is needed to determine seeding. With the current set-up of Major League Baseball

Major League Baseball

Major League Baseball is the highest level of professional baseball in the United States and Canada, consisting of teams that play in the National League and the American League...

 divisions, there are three possible scenarios.

1. The top two teams have the same record, and one of the teams is in the division with the wildcard. In this case, the team from the division that also contains the wildcard berth winner becomes the second seed and the other team becomes the first seed. This is a convenience based on the rule that two teams from the same division cannot play each other in the first round of the playoffs, the Divisional Series round.
   1. if these teams meet again in the League Championship Series
      League Championship Series
      The League Championship Series is the official name for a round of postseason play in Major League Baseball which has been conducted since 1969...
      
      , they would be re-seeded based upon the two way intra-division tie-breaker.
2. The top two teams have the same record, but neither team is in the division with the wildcard. Here, the intra-division tiebreaker at the bottom of the previous section is used. This determines the first and second seed.
3. There is a clear winner of the first seed, but the remaining two division winners have the same record. Again, the intra-division tiebreaker at the bottom of the previous section is used. This determines the second and third seed.

Three-way tie for the division or wildcard

If the three teams have identical records against each other in the regular season, the office of the commissioner conducts a draw with the teams designated as teams A, B, and C. First, team A plays team B with team A as the home team. The following day, the winner of the that game plays team C with team C as the away team. The winner of the game on the second day advances to the playoffs. The team designations are determined as follows:

• If the teams do not have identical records against one another, and one team has a best record against both other teams, and another team has a winning record against the final team, the first team shall get the first pick of their team designation, the second team gets the second pick, and the last team is assigned the remaining designation.

• If one team has a better record against both of the other teams, and the two other teams have the same record against each other, then the first team would get the first pick for team designation, and the other teams would draw lots. The winner of the draw would get the second pick, and the loser of the draw would be assigned the remaining designation.

• If two teams have the same record against each other, and both have a better record than the last team, then the first two teams draw lots, with the winner choosing their designation first, the loser of the draw picking their designation second and the final team being assigned the remaining designation.

• If each team has a winning record against one other team in the three team group, and a losing record against the other team in the three team group, the priority for choosing designations shall be chosen based on overall winning percentage within the three team group, any ties in winning percentage within the three team group will be broken by drawing lots.

"Mixed" three-way tie

The situation may arise that two teams from the same division are tied for the division championship, but they are also tied with another team from a different division, with that team not having the best record in their division, but having a better record than all of the other non-division winners.

In this case the two teams in the same division play a one game playoff, with the winner declared the division champion. The next day, the loser of the first game, and the other team from the other division play each other, with the winner declared the wildcard.

Three-way ties between division winners

If there is a three-way tie among all division champions, the team with the best record against both of the other division champion is given the top seed with the remaining teams seeded as follows:

1. Best record in games against own division.
2. Best overall record in the regular season ignoring interleague play.
3. The team with the best record in the final 81 games of the season, ignoring interleague play.
4. The team with the best record in the final 82 games of the season, extending backward until the tie is broken (since teams in the same division play each other as much as 19 times, this step is guaranteed to break the tie, with interleague games skipped and ignored in this process.)

If neither team has a better record against the other teams, immediately go to above tiebreaker.

Ties between four teams

The four teams draw lots, as teams A, B, C, and D. On the first day team B plays at team A and team D plays at team C. The next day the winners of these games play each other at the ballpark of either team A or B (depending on who won the game).