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The calendar has flipped to October, and the 2021 MLB playoffs are set to start on Tuesday. But despite it being the final day of baseball's 162-game regular season, we still have to sort out races in the the NL West and the AL wild card. So what happens if 162 games aren't enough to provide sufficient clarity on these fronts? Tiebreakers, that's what. 

With chaos possible on the regular season's final day (follow the action here), let's break down MLB's tiebreaker scenarios one by one. 

NL West, two teams tied for division title

This one's pretty basic. Should the Giants and Dodgers end the regular season tied for the NL West crown, then they'd play a one-game tiebreaker on Monday, Oct. 4 to determine the winner. Since the Giants (narrowly) prevailed in the head-to-head season series, they would host said tiebreaker.

The winner of that 163rd game would be NL West champion for 2021, clinch top seed throughout the postseason, and advance to the NLDS to face the winner of the NL Wild Card Game. The loser of that game would become the top NL wild card team and host the Cardinals in the NL Wild Card Game on Wednesday, Oct. 6. The Giants, it should be noted, have won seven in a row entering Saturday and their magic number to clinch the division is one.

AL wild-card tiebreakers

Here's where things get a bit more complicated. Right now, four teams -- the Yankees, Red Sox, Mariners, and Blue Jays -- are jostling for two wild card spots in the AL. Before we dive in to the tiebreaker scenarios, here's a look at those AL wild-card standings entering the final day of the regular season: 

N.Y. Yankees9170--

With one game left in the regular season schedule, chaos is still possible. Let's take each possible scenario one by one. 

Before we plunge in, though, let's explain how three- and four-team tiebreakers work. If we need to sort out a tie that involves more than two teams, then teams will be assigned a letter designation. A three-team tiebreaker would involve Teams A, B, and C. A four-team tiebreaker -- still gloriously possible at the moment -- would involve Teams A, B, C, and D. Tied teams are ordered based on combined head-to-head winning percentages -- e.g., the Red Sox' combined 2021 record against the Mariners and Blue Jays would be their figure if they were involved in a three-team tiebreaker with those two squads. The team with the best combined head-to-head record gets choose A, B, or C. The team with the next best head-to-head record chooses second and so on. Here's how a "three teams for one spot" tiebreaker would work, for the sake of an example:

  • Team A hosts Team B.
  • The winner hosts Team C.

If you get first choice, then you're picking A or C. Picking A would mean having to win two games but getting to host both of them (assuming you win the first one). Picking C would mean having to win only one game but also having to do so on the road. In a four-team tiebreaker, the top three teams have a choice to make, while the fourth team is left with the only letter designation remaining. The team picking third in that situation in essence has to choose which of the top two teams it wants to play on the road. 

Here's what happens next: 

  • Two teams tie for one wild card: Very straightforward. One-game tiebreaker with home-field advantage going to the team with the better head-to-head record.
  • Three teams tie for one wild card: Teams A, B and C are assigned as noted above and they play as noted above -- i.e., B at A, followed by the winner of A-B at home against C with the bid at stake.
  • Four teams tie for both wild cards: Team A plays Team B, and Team C plays Team D. The winners of those two games meet in the AL Wild Card Game.
  • Three teams tie for both wild cards: Game 1: Team B at Team A, winner gets wild card; Game 2: Team C at loser of Game 1, winner gets remaining wild card.

In the event that two teams are tied for the top wild card spot, no tiebreaker game is played. Instead, here's what happens to determine which of those two teams will host the Wild Card Game: 

  • Team with the best head-to-head record plays at home.
  • If that's tied, then the team with the best division record (e.g., the Yankees' record against AL East teams) would play at home. 
  • If that's tied, then the team with the best intraleague record (i.e., NL vs. NL and AL vs. AL) would play at home. 

Finally, let's lay out a grid that details each of the four wild card contender's records against the other three teams. That way you can calculate those combined 2021 head-to-head records on your own depending on which teams are involved in the tiebreaker(s). Forthwith: 


vs. Yankees

vs. Red Sox

vs. Mariners

vs. Blue Jays






Red Sox










Blue Jays





In the event of a massive four-team tie, the Yankees would go to Boston and the Mariners would go to Toronto. MLB has already run through the scenarios so teams could arrange travel, and in this case, the Yankees chose to go to Boston over going to Toronto. Seattle was then left taking whatever was left over.

All of the AL wild-card possibilities were picked by the teams before Sunday's games and can be found here.

Got all that? Good.

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