The New England Patriots when they have Tom Brady under center
the Pittsburgh steelers
Through the 2010 season, it's the Chicago Bears. They have a record of 704-512-42 for a winning percentage of .579.
a winning season is when a team has more wins than losses. For example a team with a 9-7 (or better) record has had a winning season.
A team can secure a division title in the NFL by finishing the regular season with the best record in their division. This is typically achieved by winning more games than the other teams in the division.
49ers
Titans.
Among existing teams, the Cowboys have the best winning percentage. As of the beginning of the 2010 season, Dallas is 467-339-6 all-time, for a .579 winning percentage.
The 5-4-1 team has the better record. When figuring winning percentage, a tie is considered a half win and half loss. So, where the winning percentage of a team 5-5 is .500, the winning percentage of a team 5-4-1 is .550.
As of the current season, the New England Patriots have the best overall winning percentage in NFL history, making them statistically the best team in the league.
the New England Patriots had the best record in 2010 (14-2)
Pittsburgh Steelers
The 1983 Washington Redskins hold the record for the best turnover differential in NFL history.