Fans on both sides of Missouri are seeing their Major League Baseball teams win at a higher rate than any of the other teams in their respective leagues. This has created an expectation for the World Series that almost was in 2014 and that made for a stellar series back in 1985, the last time the Kansas City Royals won a championship.
Recent history suggests that while it’s possible that one of those two teams may win its league’s pennant, it’s highly unlikely that both teams will. The likelihood is that for the second year in a row, either Kansas City or the St. Louis Cardinals will again fall just short.
Over the past 20 seasons, the teams with the best winning percentage in each league at the end of the regular season met in the World Series a grand total of twice. Just two seasons ago, the Boston Red Sox and St. Louis both finished with a .599 winning percentage to top MLB in that regard. They met in the 2013 Fall Classic and Boston won in six games. The only other time in the past two decades when this scenario played out was 1995, when the Cleveland Indians took their MLB-best .694 winning percentage into the playoffs to lose to the Atlanta Braves, who had a National-League best .625 winning percentage during that regular season, in six games of that year’s World Series.
In 18 of the past 20 seasons one of the two teams who finished their regular season schedule with their league’s best winning percentage failed to reach the World Series. That’s a strong negative correlation, but the correlation is weak when it comes to either one of those teams reaching the World Series (if you remember your statistics classes, a weak correlation doesn’t mean that it something is unlikely or likely to happen, only that the given scenarios don’t seem to influence each other). Over the past 20 seasons, one of the teams who finished their regular season schedule with the top winning percentage in their respective league and/or all of MLB reached the World Series a total of nine times.
This recent history sample tells us that finishing with the best winning percentage in the American League/NL/MLB shouldn’t have much effect on one of the two teams to earn that title making the World Series in 2015, but both teams winning their league pennants is unlikely.
The correlations for such teams are varied as you go further back into playoff series over the past 20 seasons. Over the past 20 seasons, 42 teams finished the regular season possessing or tied for the best winning percentage in their respective leagues and/or all of MLB. 24 of those 42 teams (57.1 percent) reached the League Championship series in that season, which is a weak correlation.
What’s most interesting about this statistic analysis is that the average ranking of the past 20 World Series teams in regards to best to worst MLB overall winning percentages in their respective seasons is exactly the same. The average ranking of the past 20 World Series champions is 4.5, and the average ranking of the past 20 teams to lose the World Series is 4.5 as well.
Recent history tells us that the strongest positive correlation between where a team falls on that list and getting to the World Series is to finish around fourth or fifth. Going into play on Saturday, Aug. 29, the Chicago Cubs have the fourth-best winning percentage in MLB at .575 and the Toronto Blue Jays are fifth at .562. Going by this statistical analysis, if those teams remain in those spots, we should expect a Blue Jays-Cubs World Series in 2015.
Of course, there is a great variance in those teams and rankings within the group that produced that average. In 2006, the Cardinals won the World Series in five games. St. Louis had the 13th-best regular season winning percentage that season. The Detroit Tigers won the American League pennant in 2012 with the 11th-best regular season winning percentage. The 2003 Florida Marlins won the World Series in six games with MLB’s ninth-best regular-season winning percentage.
The franchise with the strongest positive correlation between finishing with the best winning percentage in MLB in a particular season and postseason success over the past two decades is Boston. Both times in the past 20 seasons that the Red Sox have finished the regular season with baseball’s highest winning percentage (2007 and 2013), Boston also won the World Series.
Three things must be taken into account to put this analysis into its proper perspective. Correlation does not equal causation, there are a number of factors that couldn’t be quantified by this analysis that will go into determining which two teams reach the World Series each season, and the current records of MLB teams are not at the point of regular season finality yet.
With those things in mind, this analysis forecasts that either the Kansas City Royals or St. Louis Cardinals (if those two teams do indeed finish with the top winning percentages in the AL//MLB/NL) will likely lose in the LCS round. It also predicts that the Rogers Centre and Wrigley Field will host World Series games this season, should the Blue Jays and Cubs remain in their spots.