Is Diamondbacks Vs. Rangers the Most Unlikely World Series Matchup Ever?

Let’s cut right to the chase (field): Is the matchup of the fifth-seeded wild-card Texas Rangers and the sixth-seeded wild-card Arizona Diamondbacks the most unexpected in World Series history?

The series starts on Friday as Texas seeks its first title and Arizona its first since 2001. (Get ready for a lot of David Freese and Luis Gonzalez highlights on the Fox broadcast.) And nobody expected this particular pairing of teams: not before the season, not before the postseason, and not even midway through last week, when both the Astros and Phillies, who’d clashed in a star-studded 2022 World Series, led their respective league championship series.

But the Rangers won Games 6 and 7 on the road in Houston, the Diamondbacks matched them with two road wins in Philadelphia, and now we’re set for a southwestern showdown for MLB’s most important piece of metal. Which raises the natural, aforementioned question: Is this the most unexpected matchup in World Series history?

It’s certainly unexpected based on each team’s recent history. Before this season, Texas hadn’t reached the playoffs or even posted a winning record since 2016, while Arizona hadn’t reached the playoffs since 2017. Both teams appeared to be in the process of heading back toward contention, at least: the Rangers by signing Corey Seager, Marcus Semien, and Jacob deGrom, among others, and developing prospects like Josh Jung and Evan Carter; the Diamondbacks by building a young core headlined by Corbin Carroll and Gabriel Moreno.

But it was hard to imagine that either team would return to contention so suddenly. In the 2021 season, the Diamondbacks lost 110 games—the most for a team two years before a World Series berth. Also in 2021, the Rangers lost 102—the second most by that same measure. FanGraphs’ preseason projections forecast the Rangers to win just 81.9 games and the Diamondbacks just 78.4, with each team ranked fourth in its own division.

Even during this season, as both teams exceeded those expectations, they endured long stretches of sub-pennant-level play. Locked in a tight AL West race, the Rangers suffered a 4-16 swoon from late August to early September. The only pennant winners with a worse 20-game span at any point during the season were the 2017 Dodgers (who had an inexplicable 3-17 run after an 89-35 start) and these very Diamondbacks, who had a 3-17 run of their own as part of a 16-34 stretch, which is the worst 50-game span for any eventual World Series squad.

But we can try to answer that initial question with a more rigorous approach than just comparing streaks. First, it’s important to define our terms. Mainly, are we judging against expectations from before the whole season or against expectations from before the postseason?

That distinction can matter a lot. Consider the two teams that met in the 2006 World Series. On one side were the Cardinals, who had won 100-plus games and reached the NLCS in both 2004 and 2005, and who still had the reigning NL MVP and Cy Young winners on their roster in Albert Pujols and Chris Carpenter, respectively. From a preseason vantage point, the Cardinals were definitely not an unexpected World Series contestant.

But despite further star performances from Pujols (second in MVP voting) and Carpenter (third in Cy Young voting), the Cardinals’ depth collapsed, and they scuffled through an 83-win regular season with the 15th-best run differential in the majors. Five different non-playoff teams had a better record than St. Louis. So on the eve of the postseason, the Cardinals would have looked like an unexpected World Series team.

Their opponent in that World Series, the Tigers, fit the opposite profile. Entering 2006, Detroit hadn’t had a winning season since 1993, with a 119-loss nadir in 2003. The Tigers certainly didn’t look like a championship contender—but then they won 95 games and posted the majors’ second-best run differential, so they would have seemed like a perfectly viable World Series squad by the beginning of the playoffs.

The 2023 pennant winners, though, were unexpected at every point. They seemed like World Series long shots both at the start of the regular season and at the start of the postseason.

FanGraphs projections gave the Rangers a 4.9 percent chance to reach the World Series (ninth best in the AL), which seems low but was much higher than the Diamondbacks’ mere 1.2 percent chance (10th best in the NL). Multiply those two probabilities together, and there was a 0.06 percent chance of this matchup, or about 1 in 1,700.

If you want a single answer for just how unexpected this World Series matchup is, that’s your number: about 1 in 1,700. In the 10 years of FanGraphs playoff odds data, dating back to 2014, that’s tied for the lowest probability of any eventual World Series matchup. Previously, in 2015, the projections didn’t believe in the Mets or the Royals (who had just made the World Series but were infamously undervalued by the computers).

By the time the 2015 playoffs rolled around, though, a Mets-Royals rumble looked considerably more likely. The Royals had sustained their 2014 momentum to win the AL’s no. 1 seed, while the Mets cruised to their first NL East title in nine years. So the FanGraphs playoff odds had warmed to the duo, giving them a combined 4.6 percent chance to meet for the title.

That wasn’t really the case for the 2023 Rangers and Diamondbacks. Sure, their odds had improved because they were two of 12 remaining teams that still had a chance, instead of two of 30. But even as the playoffs began, both teams ranked just fifth in their respective leagues in pennant odds, which came out to a combined 0.7 percent chance—or about 1 in 150—for their eventual matchup. That’s the lowest start-of-playoffs probability for any of the past 10 World Series pairings, with only one other matchup that comes close.

That one other matchup is 2014’s Giants-Royals pairing, which was, until this year, the only wild-card-vs.-wild-card World Series since 2012’s postseason expansion. Those two teams combined for a mere plus-78 run differential in the regular season, which is the lowest for any pairing in World Series history.

Even the 2023 contestants weren’t that mediocre in the regular season by that measure. The Diamondbacks actually had a worse run differential than their record suggests; at minus-15, they’re only the second World Series participant with a negative mark, joining the minus-20 1987 Twins. But the Rangers had a much better differential, at plus-165. By this metric, Texas was even better than the Orioles and Astros, the two teams it beat in the ALDS and ALCS.

Add those two marks together, and the 2023 pairing had a combined regular-season run differential of plus-150, which is the seventh worst in World Series history.

By raw record, though, the 2023 duo resides all by itself at the very bottom of the list. The 90-win Rangers and 84-win Diamondbacks won an average of 87 games between them—the lowest in World Series history (extrapolating shorter seasons to 162 games).

Unfortunately, FanGraphs wasn’t around with statistical projections in 1973 or 1987, so it’s hard to precisely compare those World Series possibilities to 2023’s. But it feels safe to say that neither of those admittedly unpredictable matchups was quite as unpredictable as 2023’s. That’s because of the smaller playoff field before the wild-card era: The 1973 Mets needed to win only one five-game playoff series to reach the Fall Classic, while the 1987 Twins needed to win only one best-of-seven.

By comparison, the 2023 Rangers and Diamondbacks had to navigate three rounds apiece just to reach the World Series. Winning one round against a superior opponent is standard fare in baseball; winning three in a row should be much, much harder.

Note that seven of the 10 seasons on that lowest-win-total chart come from the wild-card era, and an eighth—strike-shortened 1981—had a longer postseason as well. Until recent decades, mediocre teams rarely received a chance to make a Cinderella postseason run because they couldn’t make the playoffs at all, unless they played in a weak division (like the 1973 Mets, who claimed the NL East crown with just 82 wins).

Now, underdogs have more of an opportunity, and in a sport as random as baseball, they’re taking advantage. This century, there have been more World Series that have pitted wild card vs. wild card (three) than pitted no. 1 seed vs. no. 1 seed (two).

The newer playoff format doesn’t seem to have meaningfully reduced the odds that a wild card will appear in the World Series. From 1995 through 2011, when wild cards advanced straight to the divisional series, 29 percent of World Series contestants (10 of 34) were wild cards. Since 2012, wild-card teams have needed to win an extra round and have theoretically lost the ability to set their desired rotation for subsequent series—and in that time, 27 percent of World Series contestants (six of 22, not counting 2020) have been wild cards.

Even against that contextual backdrop, Rangers-Diamondbacks stands out because of how poorly the two teams—particularly Arizona, which would have missed the playoffs entirely before the addition of a sixth playoff team in each league—finished the season. But although they might collectively be the worst regular-season teams ever to meet in the World Series, that doesn’t mean they’re definitely headed for a lackluster season finale.

Many of the other series on that last chart produced considerable drama. The 1973 World Series went seven games and featured two extra-innings affairs, two pitching duels between future Hall of Famers Tom Seaver and Catfish Hunter, and the final games of Willie Mays’s career. The 2014 World Series went seven games and ended with arguably the most memorable pitching appearance of the 21st century. The 1997 World Series went seven games and ended with a Game 7 blown save and walk-off.

In 2023, perhaps the lack of reliable starters past each staff’s top two will lead to lots of high-scoring, back-and-forth contests. Perhaps the young sluggers on each team will enjoy the remainders of their coming-out parties. Perhaps the Rangers’ shaky bullpen will add to the long history of unreliable relievers who produce the best playoff drama.

And for whichever team emerges victorious from the next four to seven games, the very long odds that they overcame along the way will make the accomplishment all the sweeter. Everyone likes an underdog story, especially those living the tale themselves.