For the second straight year, the New York Yankees have missed the playoffs, abdicating one of their most important social responsibilities: giving America an obvious team to root against in October.

So, as a public service to fans looking for pleasure in the misery of others, The Wall Street Journal has assembled its second-annual Major League Baseball Hateability Index, ranking this year's 10 playoff teams in order of general loathsomeness. The rankings are based on how many points teams racked up in 10 contempt-worthy categories,...