The Kansas City Royals just concluded the most improbable, exhilarating, agonizing and — ultimately — meaningful season in the franchise’s past three decades of existence. That they lost the World Series to the inexplicably dynastic San Francisco Giants in a memorable Game 7 that literally came down to the final out doesn’t soften the blow for Royals fans, but it does put in perspective what Kansas City accomplished this season: they essentially came as close as any team possibly could to winning the World Series without actually hoisting a World Series trophy.
(As Grantland’s Royals-fan-in-residence Rany Jazayerli put it: “[Kansas City] went 11-4 in the postseason. That’s not only the best postseason record any team has managed without winning the World Series — it’s the best possible record a team can have under the current format without winning the World Series.”)
And yet, as the Giants’ celebration was unfolding under the Kansas City sky Wednesday night, there was the distinct sense that the clock had also struck midnight on the Royals’ 2014 cinderella story. Kansas City had not won their division, narrowly finishing first in the American League wild card standings over two teams (the Oakland Athletics and the Seattle Mariners) who’d posted vastly superior run differentials during the regular season. Going into the playoffs, the probability of a team like Kansas City, with an 84-78 pythagorean record, getting through the AL’s postseason minefield to the World Series was just 6.3 percent.
It took a lot of good fortune for the Royals to even make it as far as they did. But can they make it back?
To (roughly) answer that question, I built a simple model predicting the probability of a World Series contestant making another World Series appearance at any point in the five seasons after its initial showing. (The ingredients for it can be seen at the bottom of this post.) That model says the Royals have just a 30 percent probability of going back to the World Series at any point in the next five seasons (the average World Series participant returns about 46 percent of the time).
Coincidentally, that 30 percent probability means Kansas City currently has roughly the same chances of a World Series return as the model assigned to the 1985 Royals (which had a similar age and weighted pythagorean winning percentage as the 2014 Royals). That version of the team, as Kansas City knows well, never made it back to the World Series. Other similar teams include the 2007 Colorado Rockies and 1984 San Diego Padres, both of which drew easy comparisons during the Royals’ October run — and both of which were World Series one-hit wonders. Of the 10 historical World Series contestants most similar to this year’s Royals, only one — the 1992 Atlanta Braves — ever found their way to another World Series within the next five seasons.
Then again, the model isn’t too much more optimistic about the Giants team that beat the Royals, assigning San Francisco a 34 percent probability of ever going back to the World Series with their current group. Yet the Giants have already bucked similar odds twice — they returned after the 2010 edition of the team appeared to have a 33 percent chance of doing so, and made another repeat trip after the 2012 edition was assigned a 37 percent probability of going back to the World Series. For their part, the Royals have the eighth-best farm system in MLB according to Baseball America, and have had top-10 prospect classes in three of the last four such lists issued by Baseball America. The talent is ostensibly there to keep the Royals’ 2014 run from being a total fluke.
The truth is that most World Series entrants fail to return within the next few years. It’s hard enough to make it to one World Series, let alone two in the span of five seasons. MLB’s current playoff structure ensures a high degree of randomness, with mechanisms in place to prevent the best teams from running the table. The Royals are most likely to fade away like so many other World Series teams have throughout baseball history.
For the model readers out there: I used data since MLB expanded its playoffs to include four teams in 1969, fitting a logistic regression model that used an average of the team’s previous five seasons’ worth of pythagorean winning percentages (weighted 5-4-3-2-1, from most recent to least recent, to give more influence to more relevant seasons) and the average of the team’s mean ages for its batters and pitchers. (I also considered additional variables, such as the market size of the team’s home city and whether or not the team actually won the World Series in question, plus dummy variables for MLB’s free agency and wild card eras, but none of those proved statistically significant.)
While Kansas City’s players were younger than the typical World Series team — their mean age was 28.3, compared to 29 for the average World Series team — their weighted pythagorean winning percentage (.497) was league-average at best over the previous five seasons. The pythagorean-record factor has historically been 50 percent more important than a team’s average age, and the Royals had the eighth-worst such mark of any World Series participant since 1969.