MLB playoff tiebreakers, explained: Postseason clinching scenarios for AL, NL teams in 2023

The 2018 MLB season came down to a pair of pivotal Game 163s: a matchup between the Brewers and Cubs for the NL Central and a clash between the Dodgers and Rockies for the NL West. The Brewers and Dodgers wound up winning to advance to the playoffs, though the two runners-up went to the playoffs as wild cards.

The days of a Game 163 are over. Major League Baseball will now turn to a tiebreaking system to determine which teams head to the postseason and which ones are headed home.

And that system could be put to the test in 2023. Heading into the final weekend of the regular season, the races for the AL West, final AL wild-card spot and the last two NL wild-card spots are both wide open, with several teams vying for the playoffs.

The tiebreaking system has many layers to it to ensure there is no way teams can remain tied by the end of the process. 

What is that system, and which teams are currently in the driver's seat in a tiebreaking scenario? Here's what you need to know.

MORE: Updated MLB magic numbers for 2023 playoffs

How do MLB tiebreakers work?

In the event teams are tied after Game 162, MLB will turn to its tiebreakers to decide the teams headed to the playoffs.

There is a set order for handling the ties:

1. Head-to-head record
2. Intradivision record
3. Interdivision record
4. Last half of intraleague games
5. Last half of intraleague games plus one

The first tiebreaker is simple enough. If one team has a winning record against the other, it heads to the playoffs over the other. It gets more complicated if there are three teams tied for the same spot. In that case, the head-to-head record would look first to see if one team has winning records against the other two. If two teams have identical records against each other, but both have winning records over the third team, those two teams would advance to intradivision records and the next wave of tiebreakers. If they are all still tied at that point, it looks at overall winning percentage against the tied teams; if the tie still exists, it moves to intradivision records.

Next up is the record teams posted within their own division. This applies even if teams play in separate divisions, e.g. the Cubs would look at their NL Central record while the Marlins would look to their NL East record.

Then it looks at the records for teams outside their own division, but still inside their own league. For example, the Cubs would look at their record against NL East and NL West teams, while the Marlins would look at their wins and losses against the NL Central and NL West.

The final two, and beyond, all involve intraleague games. The first is that teams would look at their records against all teams inside their league during the last half of the season. If there is still a tie from there, the tiebreaker would go back one further game on the schedule to see if that would resolve the tie. MLB would continue to look a game back in the intraleague records until it is resolved.

Current MLB tiebreaking scenarios

Some tiebreaking scenarios are already convincing enough that the remaining games of the season won't impact the remainder of the year.

Heading into the final weekend of play, updated with games ending as of Sept. 28, here's a look at how the tiebreakers are shaping up.

Head-to-head record

NL wild card

AL West

*Rangers have clinched the record against Seattle prior to season-ending series against Mariners.

AL wild card

*Rangers have clinched the record against Seattle prior to season-ending series against Mariners.

Intradivision records

NL wild card

*Cubs end season with a three-game series vs. Brewers
**Reds end season with a three-game series vs. Cardinals

AL West

*Rangers and Mariners end season with a four-game series against each other

AL wild card

*Blue Jays end season with a three-game series vs. Rays
**Rangers and Mariners end season with a four-game series against each other

Interdivision records

NL wild card

*Marlins end season with a three-game series with the Pirates

AL West

AL Wild card

Last half of intraleague games

NL wild card

*Cubs end season with a three-game series with the Brewers
**Marlins end season with a three-game series with the Pirates
***Reds end season with a three-game series with the Cardinals

AL West

*Rangers and Mariners end season with a four-game series with each other

AL wild card

*Blue Jays end season with a three-game series vs. Rays
**Rangers and Mariners end season with a four-game series with each other

Last half of intraleague games plus one

NL Wild Card

*Cubs end season with a three-game series with the Brewers
**Marlins end season with a three-game series with the Pirates
***Reds end season with a three-game series with the Cardinals

AL West

*Rangers and Mariners end season with a four-game series with each other

AL wild card

*Blue Jays end season with a three-game series vs. Rays
**Rangers and Mariners end season with a four-game series with each other