Let me begin by stating that this is a bit of a random topic that may have been fueled by a bit of insomnia. But last night I saw a (fairly typical) comment lamenting the history of our beloved Amazins. Admittedly this franchise has had more downs than ups, but it has had two world championships, four pennants, and seven trips to the post-season. That last number is kind pathetic in light of post-season expansion, but they're actually not terrible numbers compared to the rest of their expansion brethren. In fact, the Marlins and Blue Jays are the only other expansion franchises to win two World Series, and only 6 of the 14 franchises that joined the Major Leagues beginning in 1961 have ever won a world title, and a couple haven't even been to the World Series. When you take a closer look, the record of the expansion franchises is pretty bad.
If we count the modern era of baseball as beginning in 1901, Major League baseball had 16 original teams, or 8 in each league. Those 16 franchises - with some territorial movement - were the only franchises until the leagues expanded in 1961. The American League expanded first, adding the Los Angeles (then California, then Anaheim, then Los Angeles of Anaheim) Angels and Washington Senators (who replaced the franchise that moved to Minnesota and became the Twins. The Senators themselves to moved to Texas a little over a decade later and became the Rangers). The National League expanded in 1962 with the Mets and Houston Colt 45s (soon renamed the Astros). Two teams in each league were added in 1969 - the Kansas City Royals, Seattle Pilots (who moved to Milwaukee and became the Brewers) in the American League, and the San Diego Padres, and Montreal Expos (later the Washington Nationals) in the NL. In the year of my birth, 1977, the Blue Jays and Mariners were added. There was no more expansion until 1993 when the Colorado Rockies and Florida Marlins were born. And the last bit of expansion took place in 1998 with the Tampa Bay Devil Rays and Arizona Diamondbacks.
First of all, there's a historical curiosity about these expansion efforts. Only one franchise from each round (counting the 1961 and 1962 expansions as separate rounds) has won a world title: the Mets, Angels, Royals, Blue Jays, Marlins, and Diamondbacks. Cumulatively they have won nine world titles. Being generous and counting only from the point when the Mets became the first expansion team to win it all, that's nine championships in 42 years, or less than one in four titles won in that time period. Considering that expansion teams make up nearly half of all teams, that's a less than stellar record.
Of course not all teams have been playing for that entire time period. If you add up the number of seasons for the 14 expansion teams since 1969, it equals 492 total seasons, whereas the number of cumulative seasons for the original 16 in that same time period is 704. Even granting the expansion teams a few years to get themselves to the point where they could field a competitive teams (although the Diamondbacks did win a division in just their second year), the share of expansion teams that have won it all is quite low, all other things being equal.
Even getting beyond just world titles, the history of these teams is not sparkling. Not one of them owns a winning all-time record, though both the Angels and Diamondbacks would go over .500 if they win more than 86 games this year. The cumulative winning percentage of the teams is .480 (the Mets are a notch below at .478). Only the Orioles (who languished as the St. Louis Browns for half a century) and Phillies have worse marks among the original 16. Again, we'll grant that the teams should have some growing pains, but generally the expansion teams have not done well. On top of the collective 9 world titles, they've only appeared in a collective 20 World Series (and the Mets are alone at the top with four appearances). Really only the Angels qualify as mediocre, as they've been a first division club for most of their history. The Royals started strong, becoming competitive fairly quickly, but have stunk since their lone world title. The Mariners have been awful throughout their history save for the late 90s and early part of this century. The there are the Rays, who have become a model franchise only after an initial decade of futility. And on and on.
Honestly, I don't know what to make of this. Perhaps it's just random coincidence. It can't be explained by location or finances, as many of these teams, other than the Royals, are in big markets such as New York, Los Angeles, Phoenix, and Dallas. And while I concede again the reality of growing pains, a majority of the expansion teams have been around for approximately half a century, and only four are younger than me.
Though I haven't studied the other sports leagues in depth, it's noticeable that the same pattern rings true in the NFL and NBA. The most successful AFC franchise (Pittsburgh Steelers) is one that was an original NFL franchise, and NBA expansion teams have only won a small handful of titles - though most of all the NBA titles have been won by two teams - the Lakers and Celtics. The NHL is the only sports league where expansion teams have won a bunch of titles, but there were only six original franchises to begin with.
So what does all this mean? Probably nothing. If there's no other takeaway it's that the Mets have actually been one of the more fortunate of franchises of a subset of all major league franchises. So we've got that going for us. Which is nice.