The Steel Curtain defense is regarded as arguably the greatest defensive unit in NFL history. Anchored by four Hall of Fame players and multiple other perennial Pro Bowl players, Pittsburgh's fabled Steel Curtain defense of the 1970s propelled the Steelers to four Super Bowl victories in a six-year span. In Super Bowl IX, the unit, spearheaded by arguably the greatest defensive line in NFL history (comprised of Dwight White, Ernie Holmes, Joe Greene and L.C. Greenwood), set Super Bowl records by holding the Vikings to 17 yards rushing and 119 total yards in the Steelers' 16-6 victory over Minnesota in Super Bowl IX. In Super Bowl X, they sacked Hall of Fame quarterback Roger Staubach seven times while intercepting him three times in Pittsburgh's 21-17 victory over Dallas.
Ironically, the Pittsburgh's 1976 defensive unit is considered the team's greatest defensive unit despite the Steelers falling that season to the Oakland Raiders in the AFC title game after Pittsburgh lost 1,000-yard rushers Franco Harris and Rocky Bleier the previous week during a playoff victory over the Baltimore Colts. After Pittsburgh fell to 1-4 to start the season, the Steelers' defense recorded five shutouts during the team's final nine games of the regular season while allowing just 28 total points during that span. Pittsburgh won each game while giving themselves a chance at becoming the first team in NFL history to win three straight Super Bowls. The Steelers' 1976 defense was recently voted as the greatest defensive unit in NFL history in a poll created by the Pro Football Hall of Fame's Twitter handle.
Pittsburgh's '76 defense received 39 percent of the vote, barely edging out the '85 Bears, who took home 38 percent of the vote. The '00 Ravens' defense finished third with 19 percent of the vote, while the '69 Vikings' won just four percent of the vote.
The turning point for the 1976 Steelers took place in Week 6. Pittsburgh, facing division rival Cincinnati, was down to their third string quarterback, Mike Kruczek. Jack Lambert, the Steelers' Hall of Fame linebacker, recalled what transpired after Kruczek received a cheap shot from Bengals' linebacker Bo Harris when Kruczek scrambled out of bounds.
"Mike was scrambling and he went out of bounds and Harris gave him a shot," Lambert told NFL Films. "It wasn’t a real vicious shot, but it was a pretty good shot. So I went down and gave him one back. At that time, all we were trying to do was survive.”
That moment served as a rallying cry for the Steelers, who defeated the Bengals that day while beginning the greatest stretch of defensive mastery in NFL history. Lambert was one of eight Pittsburgh defenders that were selected to the Pro Bowl that season, as the Steelers showed the NFL world the toughness and determination that made them the team of the '70s.
“There’s been a lot of great defenses over the years," Lambert said, "but I really and truly believe that the 1976 Steeler defense is the best defense in the history of the National Football League."