Pass defense wins championships, as Steelers, Packers proving

The NFL is all about the passing game. And it always has been, at least since the dawn of the T-formation in the 1940s, which made the quarterback the centerpiece of the offense.

Great offenses are those that pass effectively. And great defenses are those that make life hell on opposing quarterbacks. You can talk about "establishing the run" and "stopping the run" all you want, but history proves it's all about the passing game.

Super Bowl XLV provides plenty of evidence. You already know Green Bay and Pittsburgh boast great, efficient, productive passers. Aaron Rodgers is the highest-rated passer in NFL history (98.4). Ben Roethlisberger is far more prolific than anybody gives him credit for: he's No. 5 in career average per attempt (8.04) and No. 8 in career passer rating (92.5), just one spot ahead of -- gasp! -- Joe Montana (92.3) on the all-time list.

But more importantly, both teams dominate on pass defense, too -- especially when measured by what we call Defensive Passer Rating, perhaps the most important indicator in football. We simply apply the formula used to rate quarterbacks to pass defense. It has an incredibly high correlation to team success.

Throughout history, teams that dominate in Defensive Passer Rating dominate on the field. The Steelers and Packers continue the trend.

Pittsburgh was No. 1 this year this year in scoring defense (14.5). Green Bay was No. 2 (15.0 PPG).

Green Bay, meanwhile, was No. 1 in Defensive Passer Rating (67.2) -- in other words, quarterbacks combined to post a humble 67.2 passer rating against the Pack this year. Pittsburgh was No. 2 in Defensive Passer Rating (73.8)

Their effectiveness on run defense, meanwhile, varied widely. Pittsburgh surrendered just 3.01 yards per attempt on the ground this year. That effort was spectacular: the fifth-best run defense in the Super Bowl Era.

Green Bay against the run? The Packers, to steal one of this postseason's most famous lines, "couldn't stop a nose bleed." They surrendered 4.64 ypa on the ground this year. Only four defenses were worse against the run.

The common denominator between the league's two stingiest defenses was an ability to frustrate opposing quarterbacks. Just look at this year's final four: Green Bay No. 1 in Defensive Passer Rating; Pittsburgh No. 2; Chicago No. 3 (74.4); and N.Y. Jets No. 6 (77.1).

Notice a trend? By the way, only three defenses this year boasted more interceptions than touchdown passes allowed. Two of them are in the Super Bowl. The other was Chicago -- a team which, if it had a healthy quarterback, might be playing in Dallas instead of the Packers.

But here's the most compelling part: The dynastic histories of both the Packers and Steelers prove the importance of the passing game in general and Defensive Passer Rating in particular.

The 1960s Packers paired a consistently great pass defense with Bart Starr, the highest-rated passer in postseason history. The result of great passing offense and great passing defense was an unprecedented five NFL championships (and two Super Bowl victories) in seven years.

The Packers led the NFL in Defensive Passer Rating in 1962 (43.4), 1965 (48.2), 1966 (46.1) and 1967 (41.5). They won NFL titles all four seasons. They finished second in Defensive Passer Rating in 1961, their first championship year of the Lombardi Era.

The 1970s Steelers paired a consistently great pass defense with Terry Bradshaw, one of the great big-game gunslingers of all time. Bradshaw averaged a mind-boggling 11.1 ypa in the Super Bowl. The result was an unprecedented four Super Bowl victories in six years.

The Steelers led the NFL in Defensive Passer Rating in 1972 (47.0). It's no coincidence that the 1972 season was highlighted by the very first postseason victory in franchise history (the Immaculate Reception win over the Raiders).

The 1973 Steelers were even stingier, with a 33.1 Defensive Passer Rating -- the best pass defense in modern history.

Quarterbacks could do nothing against Mean Joe Greene & Co. that year: completing just 46 percent of their passes with 11 TDs and an incredible 37 interceptions. The 1973 Super Bowl champion Dolphins, by the way, were No. 2 in Defensive Passer Rating (39.9) and allowed just five touchdown passes all year (against 21 picks). Wow! Times have changed.

But Pittsburgh struggled to pass the ball well on offense in 1973 (Bradshaw played poorly) and the season ended with a playoff loss to the Raiders.

So the Steelers stocked up in the passing game in 1974 with the greatest draft class of all time. They added Hall of Fame receivers John Stallworth and Lynn Swann on offense, and Hall of Fame linebacker Jack Lambert on defense. Pittsburgh was off to the races, led by a Steel Curtain defense that consistently made life tough for quarterbacks.

The Steelers led the NFL in Defensive Passer Rating in 1974 (44.3) and 1979 (56.4) and were high among the league leaders in 1975 (42.8) and 1978 (51.8). They won Super Bowls all four years.

The 1960s Packers and 1970s Steelers, believe it or not, were not particularly stout against the run year to year. But they were always dominant on pass defense.

Now take a look at Bill Walsh's 49ers of the 1980s and 1990s. These teams are truly misunderstood. Walsh is remembered for popularizing the so-called West Coast offense and reinventing the modern passing game into the one of low risk/high efficiency that we know today. But Walsh's true genius is that he quietly created the longest-lasting defensive dynasty of all time -- a dynasty of pass defense that bookended the team's on-field dominance perfectly. And nobody knows it, because the defense was overshadowed by the offensive fireworks of Joe Montana, Roger Craig, Jerry Rice, Steve Young and company.

During a 17-season period of greatness from 1981 to 1997, the 49ers never surrendered 300 points in a single year. Not once.

The Steelers are the closest thing we have to a contemporary defensive dynasty. But they surrendered more than 300 points in 2006 (315) and again just last year (324). The 49ers went nearly two decades without allowing opponents to top 300. (Keep in mind that scoring, on average, was just as high in the 1980s and 1990s as it was in the 2000s).

And what did the 49ers consistently do well? That's right: they consistently frustrated opposing passers and consistently posted an incredible Defensive Passer Rating.

The 49ers were dead last in Defensive Passer Rating in 1980 (95.7, an abysmal number). They went 6-10 as a result in what was the second year for both Walsh and his young quarterback, Montana. Walsh saw the problem with the team and went all in on defensive backs in the 1981 draft. His 1981 team famously started three rookies in the secondary: Carlton Williamson, Eric Wright and the team's future Hall of Fame No. 1 draft pick, cornerback Ronnie Lott.

The results were immediate and dramatic: the 49ers improved by an incredible 35.5 points in Defensive Passer Rating in the space of a single season, from 95.7 in 1980 to 60.2 in 1981.

The result was a 13-3 record, San Francisco's first championship and the birth of a two-decade dynasty in which the 49ers consistently paired a productive quarterback with an elite pass defense. The dynasty officially ended in 1999 -- the year the team went 4-12 and surrendered a 99.8 Defensive Passer Rating. It was San Francisco's worst team since 1980. It was San Francisco's worst Defensive Passer Rating since 1980, too.

The Packers and the Steelers continue to prove the singular importance of pass defense today. In fact, no matter who wins Super Bowl XLV, we'll be able to use the new cliché, "Pass defense wins championships."