The NFL is entering its 104th season and will be holding the 58th Super Bowl in Las Vegas in February. Twenty NFL franchises have won at least one Super Bowl, but only one of those teams was perfect.

Even taking into account the NFL’s pre-Super Bowl era history, dating back to 1920, no team has ever completed a perfect season, winning every single game on their schedule — except one.

The 1972 Miami Dolphins made history and changed the game.

The Dolphins, entering 1972, were only a seven-year-old franchise, starting in the American Football League, and coming into the NFL as part of the NFL-AFL merger in 1970. They were also coming off a Super Bowl loss to the Dallas Cowboys after the 1971 season and there were increasingly critical comments that head coach Don Shula, entering his third year with Miami, could not win the “big one.”

The Dolphins, and Shula, were determined to put right what went wrong the previous year. Nothing less than a Super Bowl was acceptable in South Florida, and the only way to ensure a Super Bowl championship was to win every game. Miami did that.

They started the season by beating the Kansas City Chiefs 20-10 in the opening game of Arrowhead Stadium. They backed that up with a 34-13 victory over the Houston Oilers in Week 2 in Miami, then beat the Minnesota Vikings 16-14 in Minneapolis. The New York Jets were next to be dispatched, falling 27-17 to Miami in Shea Stadium before the juggernaut that was the Dolphins rolled through the San Diego Chargers 24-10 and the Buffalo Bills 24-23, both in Miami.

Week 7 featured Shula’s former team, the Baltimore Colts, in the first of two meetings, with Miami traveling to Maryland to win 23-0. Miami finished their home-and-home series against the Bills in Week 8, coming away with a 30-16 victory. The New England Patriots proved to be no obstacle for the Dolphins, who defeated them 52-0 in Week 9 in Miami before cleaning up the second half of the Jets series with a 28-24 victory. Carrying the momentum into Week 11, Miami beat the St. Louis Cardinals 23-10 before the second Patriots game and a 37-21 win. In Week 13, Miami beat the New York Giants 23-13 before finishing off the Colts 16-0, completing a perfect run through the regular season with a 14-0 record.

Miami was on a winning streak that wouldn’t end

That wasn’t the only story surrounding this team, though. Other than the wins, Miami’s biggest storyline of the season was an injury to starting quarterback Bob Griese. In the team’s Week 5 game against the Chargers, San Diego’s Deacon Jones stepped on Griese’s leg, breaking it and dislocating the ankle. Shula was prepared, however, having convinced veteran Earl Morrall to sign with the Dolphins in the offseason just in case he was needed. In the last significant playing time of his career, Morrall, then 38 years old, started the final nine games of the regular season for the Dolphins, then carried the starting role into the playoffs.

The 1972 regular season ended with the Miami Dolphins holding a perfect record of 14 wins and 0 losses. The team had dominated the entire season, with an average margin of victory of 15.2 points per game, and only three games were won by less than 10 points.

The team had two 1,000-yard rushers (Larry Csonka with 1,117 and Mercury Morris with 1,000 — the first time in league history that feat was accomplished); Jim Kiick had another 521 yards, which combined to set the franchise’s single-season team rushing yardage record. The offense was the top-ranked offense in the league (first in the rush, 16th in the pass, 1st in scoring), racking up 5,036 yards of total offense and 385 points. The Dolphins also had the league’s top defense (third against the run, fifth against the pass, first in points allowed), giving up only 3,297 yards and 171 points.

How the Dolphins pulled it off

In the postseason, Miami beat the Cleveland Browns 20-14 in Miami before having to play the AFC Championship game on the road, despite having a better record than the Pittsburgh Steelers. The league’s rotation system of hosting playoff games put Miami in Three Rivers Stadium, where the Steelers opened the scoring with a first quarter touchdown.

After tying the game before the half, the Dolphins found themselves facing a 10-7 deficit in the third quarter before Shula made the tough call. Having healed from his leg injury, Griese retook control of the Miami offense and proved to be the spark they needed. Miami escaped Pittsburgh with a 21-17 victory and were headed to their second straight Super Bowl.

The final win for the 1972 Dolphins

Super Bowl VII was held in Memorial Coliseum, Los Angeles, Calif. on Jan. 14, 1973. Over 90,000 fans packed into the stadium for an afternoon kickoff between the Dolphins and the then-Washington Redskins. Despite their dominance all season, oddsmakers did not seem to trust the Dolphins, and Washington was favored in the game by 1.5 points.

Miami dominated the game on both offense and defense. The Dolphins’ legendary “No-Name Defense,” led by linebacker Nick Buoniconti who was calling out defensive adjustments faster than the Washington offense could react, was so effective defensive tackle Manny Fernandez finished the game with 17 tackles.

Washington’s only points from the game came after one of the most infamous plays in Miami history. With just over two minutes to go in the game, the Dolphins lined up for a 42-yard field goal and what appeared to be a 17-0 lead as Miami looked to finish their 17-0 Perfect Season.

Kicker Garo Yepremian connected on a low line drive, and the ball was blocked. Morrall, backing up Greise and serving as the holder on placekicks, attempted to reach the ball, but Yepremian beat him to it and attempted to throw a pass to Csonka.

The ball slipped out of Yepremian’s hand, flying straight up into the air. Yepremian stayed with the ball and attempted to hit the ball out of bounds, but wound up batting it back into in the air, allowing Washington cornerback Mike Bass to grab it. Yepremian made a kicker’s tackle attempt, but Bass avoided it and returned the ball 49 yards for a touchdown. Suddenly, instead of having the only shutout in Super Bowl history, the Dolphins were clinging to a 14-7 lead with 2:07 left in the game.

Washington chose to kick the ball deep rather than attempt an onside kick. The defense held the Dolphins to a five-play drive, but they were forced to use all of the team’s timeouts. Miami punted from their own 36-yard line, a punt that was nearly blocked, with just over one minute left on the clock. However, the No-Name Defense was not going to let the dream of a Perfect Season die. After two straight incomplete passes, the defense forced a 4-yard loss on a swing pass. Facing fourth down with 14-yards to go, the Redskins came out looking to pass but Washington quarterback Billy Kilmer was sacked as time expired. The Dolphins won the game 14-7, in the lowest scoring Super Bowl ever.

The 1972 Miami Dolphins completed their Perfect Season, ended discussion of Shula’s record in the “big one,” and cemented themselves into NFL history. The 1972 Perfect Season remains the only such season in NFL history. The closest teams were the 1934 and 1942 Chicago Bears, both of whom lost the Championship game to the Giants and Washington respectively, and the 2007 New England Patriots, who were embarrassed by the Giants in Super Bowl XLII, one of the biggest upsets in NFL history.

Following the season, many Dolphins received awards and honors. The team had nine players named to the Pro Bowl. Quarterback Earl Morrall won the inaugural edition of the NFL Comeback Player of the Year. Eight members of the 1972 Dolphins team have been inducted into the Pro Football Hall of Fame: director of player personnel Bobbu Beathard, linebacker Nick Buoniconti, running back Larry Csonka, quarterback Bob Griese, center Jim Langer, guard Larry Little, head coach Don Shula and wide receiver Paul Warfield.

The Dolphins’ 1972 undefeated season remains the greatest season in NFL history. The 1972 Miami Dolphins team remains the greatest team in NFL history. And the game of football was forever changed by the Dolphins’ Perfect Season.