Once, the New England Patriots in the 2007-2008 season, the continued to go 18-0 but lost to the Giants in the Superbowl attempting to go an unheard of 19-0.
Uconn women has won 7 championships went 39-0 whole season. They also went 4 season undefeated, and won 78 games in a row.
The Green Bay Packers won 5 NFL championships in 11 years between 1929-1939 and had an overall regular season record of 98-35-5 during those 11 years. The Chicago Bears won 6 NFL championships in 15 years between 1932-1946 and had an overall regular season record of 122-36-13 during those 15 years. The 1934 Bears were the first team in NFL history to go through the regular season undefeated and untied (13-0-0). They lost the championship game to the Giants. The 1942 Bears also went undefeated and untied during the regular season (11-0-0) and lost the championship game to the Redskins. Incredibly, both times the undefeated/untied Bears had to play the championship game on the road.
In 2009, Peyton Manning was sacked 10 times in the regular season.
They play twice each season during the regular season as divisional match ups
The Kansas City Chiefs have played the Indianapolis Colts 16 times in the regular season.
that depends
The Steelers swept the Baltimore Ravens during the regular season, four times (1997, 1998, 2002 and 2008).
An undefeated regular season is 16-0. A "perfect" season would be 19-0.A team that was undefeated in the regular season would certainly earn a bye in the Wild Card round, then would have to win in the Divisional Round, the Conference Championship, and the Super Bowl.
3
The Steelers and Raiders have never played each other twice in the regular season.
Twelve - the Broncos and 49ers are tied 6-6 in regular season games.
450 times total - 426 in the regular season, 24 in the playoffs.