Jim Henderson had experienced plenty of frustration during his quarter century as a radio announcer for the usually hapless New Orleans Saints. So he was understandably excited when the Saints won the National Football Conference title game in January, qualifying for the first Super Bowl in their 43-year history.

"Pigs have flown,” Henderson yelled. “Hell has frozen over. The Saints are on their way to the Super Bowl." They completed their dream season two weeks later, defeating the Indianapolis Colts, 31-17, to claim the championship of the National Football League.

It was the ultimate feel-good story. The Saints had been mired in the doldrums for decades, and the city of New Orleans was still recovering from the devastation wrought by hurricanes Katrina and Rita in 2005. Who could deny that they had now achieved the pinnacle of NFL success?

A new study by Portfolio.com and bizjournals, that’s who.

Our breakdown—released as the 2010 pre-season gets underway this week—shows that the Dallas Cowboys were the NFL’s most successful franchise a year ago. The Saints took second place in the rankings, followed by the Indianapolis Colts, New England Patriots, and New York Jets.

Portfolio.com and bizjournals analyzed the overall performances of all 32 NFL teams last season. The top scores went to those franchises that were strongest at the twin missions of professional sports—winning games and making money. The Saints were clearly No. 1 on the field, posting an impressive 13-3 regular-season record and taking home the Super Bowl trophy. Dallas was two games back with an 11-5 mark, good enough to make the playoffs.

But the Cowboys—who opened a mammoth new stadium in Arlington, Texas, last year—easily led the league in attendance, drawing 89,756 fans per home game. They also ranked first in net worth, with Forbes magazine estimating the value of the Dallas franchise at $1.65 billion. New Orleans did not finish in the top 10 in either category.

These were the 10 most successful organizations in the NFL in 2009. Click on a team's name to get more details from Sporting News:

1. Dallas Cowboys
2. New Orleans Saints
3. Indianapolis Colts
4. New England Patriots
5. New York Jets
6. Philadelphia Eagles
7. Green Bay Packers
8. Minnesota Vikings
9. Baltimore Ravens
10. San Diego Chargers

And these were the 10 least successful (with No. 1 in this list being at the bottom of the 32-team list):

1. Detroit Lions
2. Oakland Raiders
3. St. Louis Rams
4. Jacksonville Jaguars
5. Kansas City Chiefs
6. Tampa Bay Buccaneers
7. Cleveland Browns
8. Seattle Seahawks
9. Buffalo Bills
10. Miami Dolphins

Explore the statistical profiles of all 32 NFL franchises by clicking on this interactive, or get a breakdown by clicking here.

Half of each team’s score was determined by its level of success on the field. The formula used by Portfolio.com and bizjournals considered each franchise’s win-loss record, average margin of victory (or defeat), and playoff results.

The other half was based on each team’s relative success in business. The formula analyzed average home attendance, the percentage of available seats sold for home games, and the franchise’s financial value, as estimated by Forbes. Further details about the formula are available in the methodology sidebar.

The Portfolio.com/bizjournals study shows that the on-field gap between the NFL’s haves and have-nots is enormous. The top 10 teams in the rankings won 113 of their 160 regular-season games last season, posting a winning percentage of .706. All 10 of these elite franchises qualified for the playoffs. The 10 worst teams, on the other hand, won only 45 games, for a .281 percentage.

The same disparity exists off the field. The top 10 teams drew an average of 71,447 fans per home game, compared with 60,302 for the bottom 10. And the typical elite franchise was worth $98 million more than the typical bottom-feeder.

The following were the best and worst teams in the six categories encompassed by the study. All figures are for the 2009 season:

• Regular-season winning percentage: Indianapolis Colts, .875; St. Louis Rams, .063.
• Average margin of victory: New Orleans Saints, 10.56 points per game; St. Louis Rams, -16.31 points per game.
• Playoff results: New Orleans Saints, Super Bowl champions; 20 franchises (tied), did not qualify for playoffs.
• Average attendance per home game: Dallas Cowboys, 89,756; Oakland Raiders, 44,284.
• Percent of capacity: Eight franchises (tied), 100 percent; Oakland Raiders, 70.3 percent.
• Franchise value: Dallas Cowboys, $1.65 billion; Oakland Raiders, $797 million.