In the unlikely event that you require another reason to root against that most loathsome of teams, remember what happened last time they won the World Series.

A National League team has won the World Series 33 times dating back to 1936. In the year following an NL victory, the S&P 500 has averaged a 14.3% gain, according to the data-crunching prowess by Richard Peterson, a director at S&P Capital IQ. That includes this year’s 24% rally after the San Francisco Giants, a National League squad, won the 2012 World Series.

By comparison, the S&P 500 has averaged a 9.3% increase in the 43 years after an American League franchise claimed the World Series….

Still, a deeper dive into the data shows bullish investors should support St. Louis. When the Cardinals have been victorious in America’s pastime, the S&P 500 has averaged an 8.3% gain. In the two instances in Mr. Peterson’s dataset when the Red Sox won the World Series – 2004 and 2007 – the stock market has generated mixed results.

The S&P 500 rose 3% the year after the Red Sox broke their 86-year curse in 2004. But the market plunged 38% in the year after Boston’s 2007 victory due to the financial crisis. That marked the worst performance following a World Series win at least since 1936, Mr. Peterson said.

On the other hand….

When a World Series lasts six games, the S&P 500 goes on to average a 15.3% gain over the next 12 months no matter which league is victorious, Mr. Peterson says. When the series goes the full seven games, the average return is 8.4%.

Which is not good, but which is not a 38% decline. Go Cards.

Morning MoneyBeat: For the Love of the Markets, Root Against the Red Sox [WSJ MoneyBeat blog]