Monday, October 04, 2010

Past Performance Is No Guarantee of Future Results

One of the hoariest of hoary sports cliches is "you can throw the regular season record out when it comes to the playoffs." Fortunately (and perhaps surprisingly) for Twins fans, when it comes to Major League Baseball's playoffs that trope holds true (WSJ-sub req):

The New York Yankees lost Sunday, meaning they draw the Minnesota Twins in the first round of the American League playoffs. Even though they lost the division title in the process, they probably feel pretty good about playing a team that they've handled easily in the regular season the past few years. However, history shows that when October rolls around, you really can throw out the record books.

Since Major League Baseball expanded the playoffs in 1995, there have been 90 postseason series where one team had a head-to-head edge in the regular season. Of those times, each side has won the October series exactly 45 times. The correlation between head-to-head regular-season winning percentage and postseason winning percentage was 0.04, which means there was basically no relationship between the outcomes.

While Twins fans no doubt have bad memories from 2003 and 2009, when the Yankees dominated their team in the regular season and also bounced them from the playoffs, there are just as many examples of a team getting revenge in October. In 2008, the Red Sox beat the Angels in a first-round series despite Anaheim winning eight of nine games over Boston during the year. The Cleveland Indians had pulled the trick on the Yankees the year before, knocking off the Bronx Bombers after getting swept in six regular-season matchups.

Different players. New stadium. Home field. Plenty of reasons for Twins fans to hope for change.