There are a lot of interesting angles to take on this year’s Astros-Nationals World Series. From the potential all-time pitching matchups between Justin Verlander, Gerrit Cole, Zack Greinke, Max Scherzer, Stephen Strasburg, and Patrick Corbin; to the David-and-Goliath angle of the MLB-leading Astros finishing 14 games ahead of the Wild Card Nationals; to the novelty of the two sharing a Spring Training complex.
But to me, one of the more interesting quirks of this match is that both the Nationals and the Astros are expansion teams. It might not seem that notable, given that this describes about half of the league for the past twenty seasons, but in fact this is only the second time in history that it’s ever happened; the first was in just 2015, when the Royals took their second-ever title against the Mets.
As a quick history, for those who don’t know, the NL and AL were both eight-team leagues at the turn of the twentieth century (the NL had fluctuated in size before then, but usually stabilized close to eight). From 1903 until 1960, Major League Baseball stayed at sixteen teams across the two leagues, but in 1961, the AL finally added their ninth and tenth teams (the Angels and Senators, later Rangers), starting the modern expansion era. The Astros and Mets were added to balance out the NL the following season. There have been four waves since then, with two teams each being added in 1977, 1993, and 1998. 1969 saw the only four-team expansion in league history, including the Montreal Expos, who would later move and become the Washington Nationals.
With that history out of the way, let’s do some quick, back-of-the-envelope math: if about half the league is now expansion teams (close enough), and everything else is equal, then the chances of an all-expansion series in a given year should be just below one-in-four, meaning the 2010s are the first decade where we’re right around our expected number of all-expansion matchups. Sure, there wasn’t a near-even split until 1998, but even as far back as 1969, both leagues were one-third expansion. That still works out to about one every nine years, which the league clearly wasn’t matching given the nearly five decades between 1969 and 2015.
The obvious answer is that the playoff odds aren’t even for every team; sure, if we’re trying to predict a team’s chances of appearing in the 2030 World Series, we might as well go with that, but that doesn’t describe the odds that we’ve seen to date. Expansion teams have consistently underperformed those chances; since the Angels and Senators first took the field back in 1961, expansion teams have represented 610 of 1538 team-seasons, of just a hair under 40%. In that same time frame, there have been 336 playoff spots, and expansion teams have taken just 95 of them, or 28.3%. Going up the ladder even further, expansion teams have taken just 26 of 116 pennants in that time, or 22.4%.
Granted, some of that is on expansion as a process, as teams used to be very protective about losing their players to new teams in expansion drafts, resulting in some rough early seasons for new franchises. Teams in 1961 could protect eighteen players from their twenty-five man roster, and the draft results for the Astros and Mets the following year were so bad that they allowed them extra compensation picks a few years later to make up for it. Things have gotten considerably smoother since then (protections for existing teams have loosened considerably, plus the Rockies and Marlins got to participate in the June 1992 Rule 4 draft to help them start building farm systems ahead of the actual expansion draft; after that, the Rays and Diamondbacks got two years of picks before their actual expansion draft), which helps partially explain how teams like Florida (five seasons to win a World Series) and Arizona (four seasons) could turn things around so much quicker.
In contrast, the Astros and Expos each took a full decade to even post a winning record. The Astros would take another nine years from there to actually make the postseason, with most of the years in between being mediocre-to-bad, but in 1980, they became just the second NL expansion team and fourth overall to make the playoffs, losing to the eventual-champion Phillies in the NLCS (back before the Division Series was a thing, making that the first round).
In a weird twist, both the Astros and future-Nationals would make the playoffs the following season, which added a one-year Division Series due to a strike splitting the season into two halves. Unfortunately, both would lose in that round to avoid giving us a prophetic NLCS, and it marked the only playoff appearances for Montreal prior to their move to Washington.
Despite all of those historical struggles, Houston and Washington are still two of the most successful examples from the expansion bunch. The Astros’ franchise .496 winning percentage puts them second among all expansion teams, just behind the Angels’ .499 mark, and they’re still in the upper half of the league in franchise winning percentage at 14th overall. On top of that, their 107-win mark this year is third all-time behind only the 2001 Mariners (116) and the 1986 Mets (108) for single-season totals. The Nationals, despite their singular post-season appearance prior to 2012, are still fifth out of the fourteen expansion teams and ahead of four of the original sixteen (Oakland, Minnesota, Baltimore, and Philadelphia) with a .489 winning percentage.
But all of that trivia aside, even after working past those initial blues for a lot of the 1960s newbies, there still seems to be something working against expansion teams. Even just going back to the Wild Card era (1995 to present) to cut out the initial struggles for the earlier new franchises, expansion teams make up over 46% of seasons, but still only 32% of playoff appearances and 34% of pennants in that time frame. Maybe some of that is the teams added in the ‘90s dragging things down, but then again, those four newest teams actually account for five pennants, three World Series titles, and a handful of other playoff appearances.
On that note, the expansion struggles also shows up when you look at World Series droughts. When the Astros won in 2017, it ended a 55-year titleless run stretching back to the origins of the franchise. At the time it ended, it was the third-longest active drought of it’s kind, and it still stands as the ninth-lonest one in MLB history. The Nationals now are tied for the third-longest active World Series drought, along with their fellow 1969 additions the Brewers and Padres. Only the Indians (going back to 1948) and Rangers (no wins since they began in 1961) have longer active runs, and five of the six longest current winless streaks are expansion teams with no title to their name. Should the Nationals pull off the upset, they’ll beat six other expansion teams to their first title.
On the flipside, the Astros are just one of two expansion teams to win it all in the past decade and a half (seven have won the pennant but failed, including the 2005 ‘Stros), and given the other title was the Royals in the aforementioned first all-expansion series, Houston’s win over the Dodgers in 2017 still stands as the only time since the Marlins beat the Yankees in 2003 that an expansion team has beaten one of the original 16 (and only the tenth such occurrence in history).
2019 represents their third pennant, behind only the Mets (5) and Royals (4) among expansion teams, and if they can close it out, they’ll become just the fifth expansion team with two World Series under their belt (every original team has two or more, with the Phillies and Indians the only ones without a third). And not to get too ahead of ourselves, but considering the four teams currently in that group are the Mets, Marlins, Royals, and Blue Jays, you’d have to like their odds at being the first to three; but let’s wait to cross that bridge until we come to it.
I don’t know that I have a good answer to all the factors that make things difficult specifically for expansion teams even years after they join the league, or whether this series and the four years before it mark some turning point in this regard, or any other big questions this raises. But it’s fascinating to see it all laid out, and it definitely makes for a lot of good trivia. So since we have almost two full days to wait until baseball resumes, it’s a good time to just sit back and appreciate how unusual this series is historically even before it starts.