Miami Dolphins coach Don Shula waves the Super Bowl trophy for a crowd for of some 2,000 fans as the team arrived in Miami after winning the Super Bowl, January 15, 1973. Shula's son David looks on at right. No team went undefeated before them, and no one has done it since. The 1972 Miami Dolphins, the NFL's only unbeaten team, celebrates 30 years of perfection.(AP Photo/file)