Portfolio.com and bizjournals set out to identify the most successful franchises in the National Football League. Here are the details:

Goal: The study’s objective was to measure the effectiveness of all 32 NFL franchises at reaching their twin goals of winning games and making money.

Sources: The study analyzed statistics from four sources. Winning percentages, point margins, and playoff results came from the NFL itself. Attendance and percent-of-capacity data came from ESPN.com and SportsBusiness Journal. Estimated franchise values came from Forbes.

Factors: Half of a team’s score was determined by its level of success on the field in 2009. The other half was based on its relative success in business during the same season.

These were the factors:

1. Winning percentage in regular season (20 percent)
2. Average margin (difference between points scored and points allowed per game, 20 percent)
3. Playoff performance (sliding scale from the Super Bowl winner to teams that did not qualify for the playoffs, 10 percent)
4. Average attendance at home games (15 percent)
5. Percent of available seats occupied at home games (15 percent)
6. Estimated value of franchise (20 percent)

Success Scoring: Each team’s results were compared against the study group’s averages in all six categories. Above-average performances received positive scores, while below-average results received negative scores. The first three factors determined the on-field half of each team’s final score, while the latter three factors accounted for the business half. Raw scores were converted to a 100-point scale, ranging from 84.96 for Dallas to 9.49 for Detroit.