The Dallas Cowboys may have been America's team, but the Pittsburgh Steelers are Wall Street's team.

In the five years the Steelers have played in the Super Bowl, the Standard & Poor's 500 has advanced an average of 22 percent annually, more than double the 8.6 average annual gain the index has racked up since the game was first played in 1967.

While the Steelers lost in their most recent Super Bowl appearance, the market has never had a losing year when the Steelers appear in the game. The S&P's worst performance for a Steelers year was 1979, when it advanced 12.3 percent after the Steelers beat the Cowboys in Super Bowl XIII, 35-31.

That's more than can be said for the San Francisco 49ers, who are 5-0 in the Super Bowl but only 4-1 on Wall Street thanks to a 6.6 percent slide in the S&P 500 in 1990.

"Maybe Steeler fans buy more beer to propel the economy," says Louis Stanasolovich with Legend Financial Advisors in the North Hills.

The perennial powerhouse that brings out the worst in the index is the Oakland Raiders. The S&P 500 has advanced an average of 2.8 percent in the five years the team has appeared, with the index doing better the two years the Raiders lost than it did in the three years they won. The Dow Jones industrials have averaged a small loss in the five years the Raiders played on Super Sunday.

The S&P 500 has done fairly well when such teams as the Seattle Seahawks play in their first Super Bowl, with the index advancing an average of 10.6 percent whenever the game features a first- time team or teams. It does better when a first-time team wins (14 percent average advance) than loses (8.9 percent advance).

"The fact that the Steelers are in it and the fact that they're playing a first-time team suggests that no matter what happens, it's going to be a good year for the stock market," says Geoffrey Gerber of Twin Capital Management in McMurray.

Michael Adams, a Seattle financial adviser, says he'd be happy with the 14 percent return that, statistically at least, can be expected if his Seahawks win.

"But if we get a 22 percent gain and the Seahawks lose, it's a win-win situation," says Mr. Adams, who earned his master's degree in business at Carnegie Mellon University.

An 8.9 percent advance following a Seahawks loss would make the game's outcome easier to swallow for Seattle money manager Michael McBride of McBride Financial Advisors.

"We'd be happy with that return considering that most people have the market pegged for less-than-average returns this year," says Mr. McBride, a contrarian investor in that he's backing the underdog Seahawks.

In Boston, fans "are still crying in our Sam Adams because the [New England] Patriots aren't in it," says Eaton Vance chief equity investment officer Duncan Richardson.

Investors can be thankful for that since the S&P 500 underperformed in years when the Patriots played in the Super Bowl. When they did play, the S&P 500 did better when the Patriots lost.

Mr. Richardson, a Pittsburgh native, says it's rare for the market to post single-digit returns for two consecutive years, as it did in 2004-05. While many are expecting similar returns this year, he says the odds of that happening are low. Mr. Richardson believes there's more of a chance of a double-digit advance than a decline.

"The market could well surprise on the upside," he says.

Statistically speaking, how big of a surprise depends on whether the Seahawks or Steelers win.

"It looks good all the way around, no matter what," says Seattle financial planner Cheryl Kitashima. "I'm a little torn. I'm from Denver and they're out of it."

While the statistics are interesting, especially from a Steelers fan's perspective, advisers say investors shouldn't base their strategy on Super Bowl trivia. Instead, they should save regularly and have a diversified portfolio that reflects their objectives, stage in life and risk they are willing to bear.

"Statistics are fun," says Mr. McBride, "but the reality is, it's a crap shoot."

Just like the Super Bowl.