From the first World Series in 1903 through 1960, there were only 64 possible postseason matchups. With eight American League teams and eight National League teams and the club with each circuit's top record going straight to the World Series, the list of possibilities was relatively narrow.

That is no longer the case today. With MLB having gradually expanded its ranks to 30 teams and its postseason field to 12, there are now a whopping 435 possible playoff matchups (105 apiece in the AL and NL playoffs, plus 225 in the World Series).

Of those, more than half (237) have yet to happen. But each passing season brings another opportunity to shorten that list. In 2023, four matchups happened for the first time: Phillies-Marlins, Phillies-Diamondbacks, Rangers-Astros and finally, Rangers-Diamondbacks in the World Series.

Will the trimming continue in 2024? With eight days remaining in the regular season and the postseason field coming into focus, there are many potential first-time matchups that are realistic targets. Here is a closer look.

AL/NL PLAYOFFS

Mets vs. Phillies

Only about 100 miles separate these foes, who have tangled well over 500 times in the regular season since the Mets joined the NL in 1962 -- including across the pond earlier this season. Since 1969, both have been members of the NL East. Of course, it wasn’t until the Division Series began in 1995 that division rivals had the chance to clash in the postseason, but in that time, we’ve gotten two Mets-Braves series and two Phillies-Braves series. (The latter also happened in 1993, when Atlanta was still in the NL West.)

We’ve never seen Mets-Phillies, though that could change if New York can hold off Atlanta for an NL Wild Card berth. If it does, the atmosphere -- at either Citi Field or Citizens Bank Park -- promises to be electric. Imagine longtime Mets antagonist Bryce Harper facing Edwin Díaz with the game on the line or Pete Alonso trying to take former teammate Zack Wheeler deep in a high-leverage moment. The fans would be in a frenzy. That’s what it’s all about.

• Former Mets, Phillies greats reflect on rivalry

Astros vs. Orioles

These clubs have only been in the AL together since 2013, so the opportunities to go head to head in October have been limited. But while the history here is minimal, these teams do share some significant DNA. Current Orioles GM Mike Elias came from Houston, as did his two assistant GMs, Sig Mejdal and Eve Rosenbaum. Like the Astros before them, the Orioles went through three miserable seasons of more than 100 losses before emerging with a young, homegrown core capable of quickly reversing the franchise’s fortunes. For Houston, that has resulted in four World Series appearances and two titles since 2017. The Orioles haven’t reached the Fall Classic since 1983, and it would be interesting to see them try to go through the Astros to do it.

Brewers vs. Padres

The Rangers’ 2023 title run left only five MLB teams without a World Series triumph. The two that have been around the longest? Milwaukee and San Diego, who prior to 2024, had combined for 110 seasons, three league pennants and zero championship rings. This year, both clubs are prospering under new leadership: Pat Murphy for the Brewers and Mike Shildt for the Padres, both of them top NL Manager of the Year candidates. This also would be a matchup of two sensational rookie center fielders who happen to share a name: Milwaukee’s Jackson Chourio and San Diego’s Jackson Merrill. And perhaps best of all? A matchup between these clubs would guarantee that one would advance closer to that long-awaited championship.

Astros vs. Tigers

If the Tigers manage to complete their late-season surge toward the playoffs, they will snap a nine-season drought that is tied with the Angels for the longest in the Majors. That would be quite a story on its own, and with heavy AL Cy Young Award favorite Tarik Skubal fronting the rotation, Detroit would be a dangerous team. There’s also this: The Tigers are managed by A.J. Hinch, who previously had the helm in Houston (2015-19), where he won a title with Jose Altuve, Alex Bregman and company in 2017. Hinch, of course, was dismissed by the Astros and suspended for one year as a result of MLB’s sign-stealing investigation. And now he could find himself back in Houston with a lot on the line. Justin Verlander pitching in October for the Astros against the team he debuted with and won a Rookie of the Year, Cy Young and MVP would also be compelling.

Brewers vs. Mets

One man had a significant hand in building both of these teams. That would be David Stearns, who helped get the Brewers to the postseason each year from 2018-21, earning a promotion from general manager to president of baseball operations. He stepped down to an advisory role after the ‘22 season, then came home to New York to take over the Mets’ baseball operations last offseason. Stearns has quickly helped the Mets put their disappointing 2023 behind them, with savvy additions such as Sean Manaea, Luis Severino and Jose Iglesias. The Brewers, of course, have thrived under Matt Arnold, Stearns’ former general manager who was promoted in his stead. Now those two highly respected executives could watch their teams go head to head in October.

D-backs vs. Padres

NL West foes since the D-backs’ inaugural 1998 season, these teams have played each other tough over the past couple of years. Arizona took the 2023 series, 7-6, and this year’s rematch is tied at 5-5 heading into a season-ending three-game set next weekend at Chase Field. An October reunion would be intriguing as well, with Arizona’s high-powered offense (an MLB-best 5.5 runs per game) trying to fight its way past an imposing Padres pitching staff.

Guardians vs. Royals, Tigers or Twins
Royals vs. Twins

We’re lumping all of these AL Central-centric matchups together, because, well, there haven’t been many in the past. In fact, there has never been one since the AL Central was created in 1994. (The Tigers replaced the Brewers as a member when Milwaukee flipped to the NL in 1998.) While Detroit faced Kansas City in the 1984 ALCS and Minnesota in the 1987 ALCS, that was when the clubs were in separate divisions. Even when Wild Cards entered the playoff picture, and it became possible for division rivals to face off in October, it hasn’t happened for the AL Central.

That’s in part because the division has not sent multiple teams to the postseason very often in recent years, but that’s going to change in 2024, when it will very likely send three. Any of these four matchups would be interesting in its own right, but perhaps none more than Guardians-Twins. Those franchises have been facing off in the AL since 1901, when the Washington Senators were still 60 years away from becoming the Twins. This also would be a battle between two clubs that have controlled the AL Central in recent years, with 2024 being the eighth time in nine years one or the other won the division.

Note: The Mariners, who have considerably lower postseason odds, were not included above. But if Seattle manages to sneak into the field, it has never faced Detroit, Kansas City or Minnesota in a playoff series. The Mariners, with no World Series appearances, also have never faced any current NL team.

WORLD SERIES

There are too many potential first-time World Series matchups to go through each in detail, but here is a closer look at five of the juiciest, followed by a full list.

Orioles vs. Padres

It’s the Manny Machado Bowl! The star third baseman has played only five games back at Camden Yards since being traded before the 2018 Deadline, including three this season. He has gone 7-for-21 (.333) with a pair of homers in those contests. But Machado aside, the younger stars would make this a compelling Fall Classic: Gunnar Henderson and Adley Rutschman vs. Fernando Tatis Jr. and (Maryland native) Jackson Merrill? Sign us up.

Brewers vs. Guardians

If you want big-market coastal behemoths, well, this wouldn’t be the World Series for you. But it would be a fitting (and exciting) matchup between two smart, well-run clubs that in recent years have done an impressive job of squeezing the most out of their more limited resources thanks to savvy transactions and progressive player development. The thing that has eluded both despite that success? A ring. The Brewers, as mentioned, are looking for championship No. 1. The Guardians haven’t won since 1948. Something would have to give.

Dodgers vs. Royals

Which shade of blue do you like better? Aside from that burning question, there are other reasons this would make for a fascinating series. The Royals, who have stunned the baseball world in 2024 behind one of MLB’s best rotations, would put it to the test against a star-studded Dodgers lineup. Bobby Witt Jr., meanwhile, would take a shot at outshining the likes of Shohei Ohtani, Mookie Betts and Freddie Freeman.

Phillies vs. Twins

This pairing would bring a great sense of urgency. The Phillies have been in win-now mode in the Dave Dombrowski Era, and experienced close, ultimately painful, brushes with World Series titles in 2022 and ‘23. This year looks like their best shot. The Twins’ recent history is littered with postseason agony. The 2023 club finally snapped an historic playoff losing streak but still fell short of reaching the franchise’s first Fall Classic since it won -- for the second time in five seasons -- in 1991. Who would get the job done here?

Astros vs. D-backs

We were one Astros ALCS victory away from getting this World Series matchup in 2023, but having it come together in 2024 could be worth the wait. While Arizona snuck up on everyone a year ago, that’s not the case this time around. (The Astros, obviously, haven’t snuck up on anyone for a long time now.) Pitching has long been a key to Houston’s run of dominance in the AL, but Arizona’s bats -- including Ketel Marte and a resurgent Corbin Carroll -- would make life difficult for Framber Valdez and company. Meanwhile, a shaky Snakes staff would face a tall task in handling the postseason battle-tested Astros lineup, including Yordan Alvarez, Jose Altuve, Alex Bregman and Kyle Tucker.

Others

Here is a list, in alphabetical order, of other potential World Series matchups among teams with a significant chance to reach this year's postseason.

Note: Among that group, the Yankees are the only franchise not to appear anywhere in this article. The Yankees' only missing postseason matchups are with clubs not headed to the 2024 playoffs: the Blue Jays and White Sox in the AL, and the Nationals and Rockies in the NL.

• Astros-Brewers
• Braves-Orioles
• Braves-Royals
• Braves-Tigers
• Brewers-Orioles
• Brewers-Royals
• Brewers-Tigers
• Brewers-Twins
• D-backs-Guardians
• D-backs-Orioles
• D-backs-Royals
• D-backs-Tigers
• D-backs-Twins
• Dodgers-Tigers
• Guardians-Mets
• Guardians-Padres
• Guardians-Phillies
• Mets-Tigers
• Mets-Twins
• Padres-Royals
• Padres-Twins
• Phillies-Tigers