Must be a reason, right?

For 25 years - longer than it took soap star Susan Lucci to win an Emmy - Philadelphia has failed to win a championship in any of the four major team sports.

Count two misses caused by strikes, and that's 100 seasons.

Such a streak that defies the odds, said Dennis DeTurck, chairman of the University of Pennsylvania mathematics department.

Assuming each sport has 30 equally competitive franchises - an admittedly dubious assumption - the chances of such a frustrating fate happening here is only 4 percent, he calculated.

The problem is not getting to the Big Game.

Seven times, since the Sixers took the NBA crown in 1983, a Philadelphia team has reached the finals - and lost.

That number was actually better than expected, DeTurck said. But assuming each of those teams had a 50-50 chance - again, a big assumption - the odds of losing all seven are only 1 percent, he said.

"We're really unlucky or inept, one or the other," he said.

Based on numbers alone, there's "no way to tell," he added.

So for answers, we turned to a former general manager, a sportswriter in football's hall of fame, and a local sports psychologist.

Let's wade through the theories.

The Curse of Billy Penn's Hat. In 1984, the city agreed to let One Liberty Place rise higher than Penn's statue atop City Hall, and no Big Four team has won a title since. Putting a Phillies cap on Penn in 1993 and a Flyers jersey on him in 1997 backfired. To counter the jinx, a smaller Penn statue has even been placed atop the Comcast Tower, now the city's tallest building.

Anybody buying this theory? "I don't believe an ounce of that," said NFL Films' Ray Didinger, co-author of The Eagles Encyclopedia.

Like Chicago's billy goat and Boston's Curse of the Bambino, such legends are fun to talk about - but silly, said Philadelphia psychologist Joel Fish. "These are attempts to make sense out of what can be a frustrating and apparently illogical reality," he said.

Note that the theory fails to explain why indoor lacrosse's Wings, minor-league hockey's Phantoms, and indoor soccer's Kixx have all won titles since.

The Revenge of Santa Claus. Is St. Nick still steamed over fans pelting him with snowballs at halftime during a 1968 Eagles game? Scratch this idea as applying to the Sixers, Phillies and Flyers, since they all won titles since. The Eagles, though ... hmmm. No trophy since 1960. Only two Super Bowls since - and both were losses.

There's something in the water. It's not not the city, said Pat Williams, general manager of the Sixers team that won in '83. "It has nothing to do with cheesesteaks, Tastykakes or Goldenberg's Peanut Chews," he said.

Negadelphia's nasty fans. Does booing makes athletes choke - or less motivated to win? Surprisingly, Didinger, Fish and Williams all poo-poo this theory, too. "I think Boston fans and Boston media are every bit as tough and it hasn't kept Boston from winning," said Didinger. Besides, as local teams succeed, desperate local fans get more and more gung-ho. "That passion is fueled into increased cheering and increased enthusiasm when things are going our way," said Fish, director of the Philadelphia-based Center for Sports Psychology. Since athletes worry most about game situations, fans probably depress each other more than they do the teams, he said.

Yes, players hear boos. "It affects them," said Williams, senior vice-president for the NBA's Orlando Magic. "But the great ones are able to block that out."

Sports-talk radio. "It has nothing to with WIP. Howard Eskin is not to blame," said Williams. Even if Eskin started his afternoon WIP gig in 1986.

Losing begets losing. Losing isn't a disease, though it can be an attitude, said Fish. So the trick is to turn misfortune into motivation. "The teams that win in markets that break long streaks are teams that don't avoid talking about this, but find a way to use it to their advantage," he said. The proper attitude: "Why not us? We can do this." As for almost winning being deflating, playoff experience is beneficial. "I think getting close oftentimes is a help," he said.

Cheap owners. Maybe Philly lacks home-grown owners with the deep pockets of a George Steinbrenner. Ruly Carpenter, who owned the World Series-winning 1980 Phillies, and Harold Katz, who signed difference-maker Moses Malone in 1982, had local ties.

This theory has flaws as well. Ed Snider, whose Flyers won in '74 and '75, has been a big spender while running both the Flyers and the Sixers. The Eagles, in a hard-capped league, have given mega-money to the likes of Jon Runyan, Donovan McNabb, Jevon Kearse and Asante Samuel. The Phillies have recently outspent most major-league teams as well.

"This is no backwater port," said Didinger. Philadelphia has plenty of rich people, and fans who fill the seats and generate "huge" radio and TV ratings, he said.

Besides, teams with below-average payrolls can and do win championships. Examples: 2002 Anaheim Angels, 2003 Florida Marlins, and the 2004 Tampa Bay Lightning (who beat the Flyers in the conference finals).

The refs hate Philly. Officials hold grudges against the city for surly fans and unruly players, going back to Broad Street Bully days, the theory goes. More likely long-frustrated fans blow questionable calls out of proportion, Fish said. Why would ratings-greedy leagues not want teams from a big, sports-crazy market to prosper in the playoffs?

So Philadelphia's not to blame? Forget city-centric theories, all three analysts said. Blame the problems that teams everywhere face: Picking players, getting them to outperform opponents, and just plain being lucky.

Everything has to come together, Fish said. "It's a hard thing to win a championship." Patterns - like 25 years, zero parades - don't have to have easy explanations.

Besides, luck matters. Take 1983. "Everything was perfect. Everything broke right," said Williams, who wrote about that season in Pat Williams' Tales from the Philadelphia 76ers. The Sixers were injury-free, with key players were at the peak of their careers, he said, while the Los Angeles Lakers had to cope with injuries to James Worthy, Norm Nixon and Bob McAdoo.

Maybe the 2005 Super Bowl, for instance, would have been different if pass-catchers Terrell Owens, Chad Lewis and Todd Pinkston had all been healthy - or MVP Deion Branch had been hurt.

"This gets down to the basic reasons why teams don't win anywhere," Didinger said. Teams generally fail because they're "poorly managed, poorly coached, or they don't have enough good players."

Each franchise is different, he said. The Phillies seem to have undervalued pitching. The Sixers have failed to land that second great star. The Eagles rely tremendously on the quarterback, but don't give McNabb supporting casts and game plans he needs to win it all.

"The Flyers are moving in the right direction," Didinger said. "For them to have made the progress that they made in one year's time is certainly very encouraging."

"At the end of the day, it all comes down to talent," said Williams. That's why scouting and drafting are so important. Obtaining Julius Erving and Moses Malone was crucial for the Sixers, but was so the drafting - at the urging of scout Jack McMahon - of Mo Cheeks and Andrew Toney.

"Talent, talent, talent." That's the key, he said.