In regular season games, (if you count the first game of the 2008 season) Brady's overall winning percentage as a starter is .809. Without that start, Tom Bradys career winning percentage is .781. Brady is 14-3 in the playoffs, a .823 winning percentage.
New England Patriots regular Season records/Winning Percentages Year Record Win %
1960: 5-9 .357
1961: 9-4-1 .692
1962: 9-4-1 .692
1963: 7-6-1 .538
1964: 10-3-1 .769
1965: 4-8-2 .333
1966: 8-4-2 .667
1967: 3-10-1 .231
1968: 4-10 .400
1969: 4-10 .400
1970: 2-12 .143
1971: 6-8 .429
1972: 3-11 .214
1973: 5-9 .357
1974: 7-7 .500
1975: 3-11 .214
1976: 11-3 .786 1977: 9-5 .643
1978: 11-5 .688
1979: 9-7 .563
1980: 10-6 .625
1981: 2-14 .125
1982: 5-4* .556 ---- *9 game season
1983: 8-8 .500
1984: 9-7 .563
1985: 11-5 .688
1986: 11-5 .688
1987: 8-7* .533 ------ * 15 game Season
1988: 9-7 .563
1989: 5-11 .313
1990: 1-15 .063
1991: 6-10 .375
1992: 2-14 .125
1993: 5-11 .313
1994: 10-6 .625
1995: 6-10 .375
1996: 11-5 .688
1997: 10-6 .625
1998: 9-7 .563
1999: 8-8 .500
2000: 5-11 .313
2001: 11-5 .688
2002: 9-7 .563
2003: 14-2 .875
2004: 14-2 .875
2005: 10-6 .625
2006: 12-4 .750
2007: 16-0 .1000
2008: season underway
Regular Season: 376-355-9
Playoffs: 21-14
The Philadelphia Eagles have a .483 all-time winning percentage.
No, Ohio State's winning percentage is 71.6%. It is the fifth highest of All-time. The University of Michigan holds the highest winning percentage of 74%
The Cleveland Brown's all time historical winning percentage was .535 which has topped the franchise's winning record and is high against other NFL teams.
Through the 2012 season, the San Francisco 49ers have a .555 all-time winning percentage.
University of Idaho .362 winning percentage (Kansas State has most all-time losses.)
From 1933 to 2010, the Steelers are tied for 14th overall in the NFL with a .520 winning percentage.
The New Zealand rugby team, the All Blacks, have an all-time 74.49% winning percentage.
Depending on specificity of the question (ie. overall record or winning percentage) the answer will vary. Overall wins would be the Bears (712), winning percentage all-time is the Bears as well .575. The Bears hold combined regular & post-season wins, and the Bears and Cowboys share combined winning percentage (.575). Single regular season is Patriots at 16-0 followed by the undefeated Dolphins team of '73 at 14-0 (obviously both 100% but Pats with two more wins). Complete season (including playoffs) is the Patriots at 18-1 followed by the '73 Dolphins with a record of 17-0.
According to the Pro Football Hall of Fame, as of the start of the 2007 season the team with the best all time regular season winning percentage was the Miami Dolphins whose all time regular season record was 368-252-4 for a winning percentage of .593. Second was the Chicago Bears with an all time regular season record of 670-482-42 for a winning percentage of .579.
Through Week 9 of the 2008 season, that would be the Broncos. The Broncos all time record is 382-340-10 for a winning percentage of .529 and the Eagles all time record is 484-527-25 for a winning percentage of .479.
According to Basketball Reference, the Lakers all time regular season record through the 2007-08 season is 2905-1824 for a winning percentage of .614.
Michigan