Undefeated season

A perfect season is a sports season including any requisite playoff portion, in which a team remains undefeated and untied. The feat is extremely rare at the professional level of any team sport, and has occurred more commonly at the collegiate and scholastic levels in the United States. A perfect regular season (known by other names outside the United States of America) is a season excluding any playoffs, where a team remains undefeated and untied; it is less rare than a complete perfect season but still exceptional.

A perfect season may be part of a multi-season winning streak.

Exhibition games are generally not counted toward standings, for or against. For example, the 1972 Miami Dolphins (below) lost three of their preseason ("exhibition" games in 1972 NFL vernacular) games but are considered to have had a perfect season.

Since the National Football League began in 1920, only one team has played a complete perfect season (both regular season and playoffs): the 1972 Miami Dolphins, who won their fourteen regular season games and three postseason games, including Super Bowl VII, to finish the season 17–0–0.

The Dolphins briefly extended their winning streak before losing to the Oakland Raiders on September 23, 1973. It has often been reported that the surviving members of the 1972 Dolphins would either gather to drink champagne when the final undefeated team earned its first loss, or send a case of champagne to the team who beat this final undefeated team. The head coach of the 1972 Dolphins, Don Shula, denied this in a 2007 interview with ESPN. On August 20, 2013, four decades after their accomplishment, President Barack Obama hosted the 1972 Dolphins noting that they "never got their White House visit".

Prior to the development of a playoff system in the NFL in 1932, there were four teams who completed seasons undefeated, but with one or more tied games: the 1920 Akron Pros, the 1922 Canton Bulldogs, the 1923 Canton Bulldogs, and the 1929 Green Bay Packers. According to the 2012 NFL Record & Fact Book, under NFL practices at the time, from 1920 to 1971 tie games were not included in winning percentage (there was also no overtime to settle ties in the regular season until 1974) so, these four teams were recorded with perfect win percentages of 1.000.

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