seasons. Pittsburgh still remains the only team to win back-to-back Super Bowls twice and four Super Bowls in a six-year period. The Steelers' 1970s dynasty was interrupted only by the Raiders' first Super Bowl win in Super Bowl XI and the Cowboys' second Super Bowl win in Super Bowl XII. Conversely, the Vikings, with their Purple People Eaters defense, were the only other team to appear in multiple Super Bowls (IV, VIII, IX and XI) during the decade but failed to win each one. 1981–1996: The NFC's winning streak In the 1980s and 1990s, the tables turned for the AFC, as the NFC dominated the Super Bowls of the new decade and most of those in the 1990s. The NFC won 16 of the 20 Super Bowls during these two decades, including 13 straight from Super Bowl XIX to Super Bowl XXXI. The most successful team of the 1980s was the 49ers, which featured the West Coast offense of Hall of Fame head coach Bill Walsh. This offense was led by three-time Super Bowl MVP and Hall of Fame quarterback Joe Montana, Super Bowl MVP and Hall of Fame wide receiver Jerry Rice, running back Roger Craig, and Hall of Fame defensive safety/cornerback Ronnie Lott. Under their leadership, the 49ers won four Super Bowls in the decade (XVI, XIX, XXIII, and XXIV) and made nine playoff appearances between 1981 and 1990, including eight division championships, becoming the second dynasty of the post-merger NFL. The 1984 San Francisco 49ers were the first team to achieve an 18–1 record, doing so under Walsh. The 1989 San Francisco 49ers, under first-year head coach George Seifert, posted the most lop-sided victory in Super Bowl history, defeating the Denver Broncos by a score of 55–10 in Super Bowl XXIV. The 1980s also produced the 1985 Chicago Bears, who posted an 18–1 record under head coach Mike Ditka; quarterback Jim McMahon; and Hall of Fame running back Walter Payton. Their team won Super Bowl XX in dominant fashion. The Washington Redskins and New York Giants were also top teams of this period; Washington won Super Bowls XVII, XXII, and XXVI. The Giants claimed Super Bowls XXI and XXV. Both teams won multiple Super Bowls with different starting quarterbacks; Washington won with Joe Theismann (XVII), Doug Williams (XXII) and Mark Rypien (XXVI), and the Giants with Phil Simms (XXI) and Jeff Hostetler (XXV). As in the 1970s,