The New England Patriots have the best win percent since 2011, with a 3 season average winning percentage of .771.
New York Giants!!!
According to today's Baltimore Sun, "The Steelers have the best home winning percentage (.722) in the NFL since 1970." http://www.baltimoresun.com/sports/football/bal-ravensscout0928,0,734965.htmlstory Must be a steelers fan since he doesn't include the year 66,67,68,69 in which the Steelers were terrible. Include those numbers and the steelers do not have the best home winning percentage. Since 1966 the Kansas City Chiefs have the best winning percentage followed by the Packers.
The University of Notre Dame has the highest winning percentage during that time. They have had 875 wins, 305 losses and 42 ties.
New York Yankees.
Ben Roethlisberger (Pittsburgh Steelers) has the best winning percentage by far.
Through the 2007 season, the American League team with the most wins in a regular season was the 2001 Seattle Mariners with 116. The American League team with the best winning percentage in a regular season is the 1954 Cleveland Indians who went 111-43 for a winning percentage of .721. Seattle's record in 2001 was 116-46 for a winning percentage of .716.
Highest Winning Percentage, Regular Season Miami Dolphins .580 Highest Winning Percentage, Overall Dallas Cowboys .577
Boise State has the best with a record of 112-17 for an .868 winning percentage. After that is Texas (110-19) and Oklahoma (110-24).
In addition to the most wins, 560, Oklahoma also has the best winning percentage, at .74835.