Super Bowl curse
The Super Bowl curse or Super Bowl hangover is a phrase that refers to one of three phenomena that may occur in the National Football League (NFL). First, that host teams rarely qualify for the Super Bowl during the year their city will host. Second, that teams rarely win consecutive Super Bowls. Third, that a participating team will follow their Super Bowl appearance with sub-par seasons. These interpretations of the Super Bowl curse are not mutually exclusive.

The term has been used since at least 1992, when The Washington Post used the term in print. Former NFL General Manager Charley Casserly attributed the curse to such factors as "a shorter offseason, contract problems, [and] more demand for your players' time". Casserly also noted that "once the season starts, you become the biggest game on everybody's schedule," suggesting that pressure from fans and spectators may also affect a team's performance.

The Home Field Advantage Curse
The home field curse affects the host team of the Super Bowl. So far no team has yet managed to reach the Super Bowl in their home stadium. Five teams with Super Bowls in their home venue have qualified for the divisional playoffs: the 1994 Miami Dolphins, the 1998 Miami Dolphins, the 2016 Houston Texans, and the 2017 Minnesota Vikings, the Vikings being the first to qualify for their conference's title game. From 1966–2011 (excluding the six Super Bowl games held in a stadium without a professional team), the Super Bowl host team has had 11 winning seasons, four split seasons, and 25 losing seasons. Mathematically, the probability of that many losing seasons or more occurring by chance (assuming a 50 percent chance of having a losing season (disregarding .500 seasons)) is 7.69 percent. The Super Bowl host stadium is selected several years before the game is played, without regard to the teams that qualify.

Only two NFL teams have reached the Super Bowl hosted in their home region: the San Francisco 49ers, who played Super Bowl XIX in Stanford Stadium, rather than Candlestick Park, and the Los Angeles Rams, who played Super Bowl XIV in the Rose Bowl, rather than the Los Angeles Memorial Coliseum. Besides Stanford Stadium and the Rose Bowl, the only other Super Bowl venue that was not the home stadium to an NFL team at the time was Rice Stadium in Houston: the Houston Oilers had played there previously, but moved to the Astrodome several years prior to Super Bowl VIII. The Miami Orange Bowl was the only AFL stadium to host a Super Bowl and the only stadium to host consecutive Super Bowls, hosting Super Bowl II and III. MetLife Stadium in New Jersey, which hosted Super Bowl XLVIII, is the home stadium of two NFL teams: the New York Giants and the New York Jets.

This list of examples is not exhaustive; no team has ever qualified for the Super Bowl played in their home stadium.

The Non-Repeat Curse
Since 1993, few winning teams have followed up their Super Bowl appearances with a second Super Bowl appearance, or even advanced to a conference title game in the subsequent season (the 1994 Dallas Cowboys qualified for their conference title but did not qualify for the Super Bowl). Only seven teams have won back-to-back Super Bowl championships, and only one of these seven have made more than two consecutive winning appearances in the Super Bowl. The only franchise to reach more than three straight title games was the Buffalo Bills who lost four Super Bowls in a row from 1990–93. The salary cap, draft, free agency and the schedule makes it more difficult to win repeat league championships in the NFL, compared to other major North American professional sports leagues (MLB, NBA, and NHL) where dynasties have been prevalent. 

Since 2005, no incumbent holder has managed to successfully defend their title. Between 2006 and 2013, every defending Super Bowl champion would conclude the following season either losing their opening playoff game or failing to qualify for the playoffs.

This list of examples includes every team that has ever had back-to-back appearances at the Super Bowl.

The Losers' Curse
Although many teams experience this phenomenon, it is certainly not the rule. There are many speculations made about potential causal factors for this trend, including the team having a shorter offseason due to their extended postseason play, difficulty settling contracts, more pressure on the players, and an increase in visibility, which could contribute to nervous playing. Only the 1971 Dallas Cowboys, 1972 Miami Dolphins, and 2018 New England Patriots have followed up a Super Bowl defeat with Super Bowl win the following season.

One piece of the Super Bowl curse asserts the team that loses the Super Bowl will go into losing seasons overall. The trend was especially evident during the early 2000s.

This list of examples is not exhaustive.

Further reading