Namath, who had famously guaranteed a Jets win before the game, and former Colts head coach Weeb Ewbank, and their victory proved that the AFL was the NFL's competitive equal. This was reinforced the following year when the Chiefs defeated the NFL's Vikings 23–7 in Super Bowl IV. 1970s: Dominant franchises After the AFL–NFL merger was completed in 1970, three franchises—the Cowboys, Miami Dolphins, and Steelers—would go on to dominate the 1970s, winning a combined eight Super Bowls in the decade. The Baltimore Colts, now a member of the AFC, would start the decade by defeating the Cowboys in Super Bowl V, a game which is notable as being the only Super Bowl to date in which a player from the losing team won the Super Bowl MVP (Cowboys' linebacker Chuck Howley). Beginning with this Super Bowl, all Super Bowls have served as the NFL's championship game. The Cowboys, coming back from a loss the previous season, won Super Bowl VI over the Dolphins. However, this would be the Dolphins' final loss for over a year, as the next year, the Dolphins would go 14–0 in the regular season and eventually win all their playoff games, capped off with a 14–7 victory in Super Bowl VII, becoming the first and only team to finish an entire perfect regular and postseason. The Dolphins would repeat as league champions by winning Super Bowl VIII a year later. In the late 1970s, the Steelers became the first NFL dynasty of the post-merger era by winning four Super Bowls (IX, X, XIII, and XIV) in six years. They were led by head coach Chuck Noll, the play of offensive stars Terry Bradshaw, Franco Harris, Lynn Swann, John Stallworth, and Mike Webster, and their dominant "Steel Curtain" defense, led by "Mean" Joe Greene, L. C. Greenwood, Ernie Holmes, Mel Blount, Jack Ham, and Jack Lambert. Many of the team's key players were selected in the 1974 draft, in which Pittsburgh selected four future Hall of Famers, the most for any team in any sport in a single draft. A fifth player, Donnie Shell, was signed by Pittsburgh after going unselected in the 1974 NFL Draft; he too was later enshrined in the Hall of Fame. The Steelers were the first team to win three and then four Super Bowls and appeared in six AFC Championship Games during the decade, making the playoffs in eight straight