In 1986, "Parcells changed little about the team from the previous year, relying on a fearsome defense and ball-control attack on offense," Puma wrote. The Giants sported a league-best 14-2 record during the regular season, then dominated San Francisco and Washington in the playoffs for the franchise's first National Football Conference (NFC) championship since 1956, when it was the premerger NFL. In the NFC title game against the Redskins, Parcells opted for New York to kick off to start the game rather than receive, but with a 30 miles-per-hour wind at its back in the first quarter. New York dominated early and won 17-0. In Super Bowl XX at the Rose Bowl in Pasadena, California, the Giants scored 30 second-half points to defeat the AFC champion Denver Broncos 39-20.
Parcells, whom the Giants denied permission to speak to Atlanta about a coaching vacancy shortly after wining the title, returned the team to the Super Bowl in January, 1991. At Tampa Stadium, the Giants knocked off the Buffalo Bills, 20-19. Though most remember Super Bowl XXV ending on Scott Norwood's missed 47-yard field goal attempt for the Bills, Parcells and his staff, especially defensive coordinator Bill Belichick, got credit for limiting Buffalo's high-powered offense. New York held the ball for two-thirds of the game.
Bill Belichick, as New York Giants defensive coordinator, helped Bill Parcells win two Super Bowls. Fired as head coach by the Cleveland Browns in 1995, Belichick rejoined Parcells in New England, where the two, in the same roles, went to another Super Bowl; then, they nearly went back with a third team, the New York Jets.