Race for last? How the new MLB playoff format creates surprising odds for Mariners, Rays in AL wild-card hunt

“If you ain’t first, you’re last.” - Ricky Bobby

A race — as in pennant race — implies a certain singularity of purpose. There’s no next thing to consider. You want to finish first, or as close to first as possible. For as long as there have been playoff races in baseball, that’s been structurally true. The bracket was never big enough, the permutations never complex enough to alter the most fundamental consideration. Better regular season standing meant a better chance at the World Series.

As soon as the new MLB postseason format was unveiled at the end of the lockout, it was clear that wouldn’t necessarily be true anymore. The new playoff structure added a wild card to each league, meaning three division winners and three wild cards will make the field.

Now, here’s where it departs from the traditional equation, and from the other major American sports leagues: To accommodate a six-team bracket, it gives byes to the top two division winners. The division winner with the worst record and the three wild cards face off in three-game sets to determine who makes the Division Series. Unlike in the NBA, that last division winner gets the No. 3 seed, regardless of whether it actually has a better record than the wild card teams. And after the wild card series are decided, the bracket does not reseed like the NFL. A No. 6 seed that conquers the No. 3 gets to play the No. 2 division winner instead of being routed to the No. 1 seed.

It wasn’t a given that the new setup would produce a more complicated set of incentives for teams in this, its first season, but the matchup permutations that could shift World Series odds are now thoroughly in play for wild-card contenders in both leagues.

It’s becoming clear that if you’re not first, you might actively want to be last.

Astros or Yankees? Why AL wild-card contenders may want to finish last

Let’s take a look at the issues here through the very evenly matched AL wild-card race. At this stage, it’s less a battle to make the playoffs and more a battle for positioning. It’s also very evenly matched. The three wild-card teams are the Toronto Blue Jays, Seattle Mariners and Tampa Bay Rays.

As of Thursday morning, they are within 1.5 games of each other. Their run differentials are within 18. The No. 4, No. 5 and No. 6 seeds in the AL are going to be extremely interchangeable over the last 18 or 19 games of the season, and the way the clubs finish will have huge implications for their path in the playoffs.

Whichever way they line up, the numbers say the No. 4 seed has the best chance at reaching the World Series, but the No. 6 seed has the next best shot, followed by the No. 5 seed.

Why? Let’s break it down.

As No. 4 seed, the top wild card would host the entirety of the best-of-3 wild-card series against the second wild card, the No. 5 seed. The winner would be locked into an ALDS date with the No. 1 seed Houston Astros.

As No. 6 seed, the last team in would travel for a wild-card series against the relatively weak AL Central champ. Right now, that’s the Cleveland Guardians, who are 2.5 games worse than the worst of these wild-card teams. Whoever prevails would move on to face the No. 2 seed New York Yankees.

Even a gut-level overview of the potential paths makes the appeal of the No. 6 seed obvious.

No. 5 seed: On the road against the Blue Jays, Mariners or Rays, then an ALDS matchup with the powerhouse Astros, who are 34-18 since the All-Star break.

No. 6 seed: On the road against the Guardians — a worse team than any of the wild cards, then an ALDS matchup against the Yankees, whose struggles in a 23-28 second half are well-documented.

It wouldn’t be crazy to think the same dynamic could emerge in the NL, not because of the weakness of the New York Mets or Atlanta Braves (who are fighting for the No. 2 seed), but because of the utter dominance of the Los Angeles Dodgers.

Numbers give No. 6 seed an edge in most scenarios

With the help of Baseball Prospectus and its PECOTA system, I plugged the AL wild-card scenarios into a simple tool to put odds on each team in each path and test that gut-level assessment. Predictably, all three teams would have a better chance of reaching the ALCS as the No. 6 seed, and at least an equal chance of advancing to the World Series.

Take the current order — Blue Jays, Mariners, Rays. If they started the playoffs today, the projection would give the No. 6 seed Rays an 45.4% chance of beating Cleveland, while the No. 5 seed Mariners would have a 42.8% chance of toppling Toronto.

Let’s focus on the Mariners. So as the No. 5 seed, they would have 42.8% odds of reaching the ALDS against the Astros. Their ALDS odds would be 16.4% and their World Series odds 7.1%.

But if everything remains the same except, say, Seattle loses a tiebreaker to the Rays and the Mariners wind up as the No. 6 seed, their chances of escaping the wild-card round improve to 46.5%. Their ALDS odds — with the Yankees now set as their potential opponent — rise to 18.6% and their World Series odds are virtually the same at 7.2%.

Variations on that math holds true for all three clubs, no matter how you line it up. The model gives the No. 6 seed better World Series odds than the No. 5 seed in every scenario except where the Blue Jays are the No. 5 seed. Those numbers hover just north of 7%, where the No. 4 seed will likely have World Series odds between 9.5% and 10% entering the playoffs.

Plus, the projections are working off the Yankees’ full season strength. It’s possible everyone around Aaron Judge kicks it into gear and New York proves a daunting October foe, but if you’re wary of the recent slump, you may choose to mentally adjust those percentages even further in favor of the No. 6 seed.

Records and vaccine records: Toronto could pose problems

There’s one other thing the math can’t know, and it only accentuates the divergent incentives of the season’s final weeks. Players who aren’t vaccinated for COVID-19 can’t travel to Toronto. So if the Blue Jays secure the No. 4 seed, their opponent would be without any unvaccinated players for the whole series.

As far as we know, that would take starting pitcher Robbie Ray out of the equation for the Mariners. It’s less disruptive due to the addition of Luis Castillo and the emergence of George Kirby alongside Logan Gilbert, but it’s a consideration nonetheless. The Rays would have to play without Brooks Raley, who has been the best left-hander in their bullpen. They have dropped three of the first four games of a five-game series in Toronto this week as Raley sits on the restricted list back home.

On the strength of Bo Bichette’s scorching bat, Toronto currently leads the wild-card race by a half game over Seattle. The best thing any of these teams can do is win a home wild-card series with the No. 4 seed. It may be that they’re all playing for the top spot in a gripping sprint all the way through Game 162 on Wednesday, Oct. 5. But if one team not named the Blue Jays does fall off the pace, don’t expect them to be too upset.

Thanks to Robert Au of Baseball Prospectus for research assistance.