Some things will never die. Like Clint Eastwood, for example, or the belief that defense wins championships.
However, both have seen better days. In fact, if you want to earn a fistful of dollars in the Super Bowl, defense is not the sure bet it once was. 
Sure, playing better defense will help you win any given game. Hauling in interceptions is the single most important thing a defense can do. Teams that win the INT battle are a perfect 10-0 here in the 2009 postseason. A pick-six in the Super Bowl, meanwhile, is a virtual guarantee of victory – as our pal Kurt Warner learned the hard way against the Patriots in Super Bowl XXXVI and the Steelers in Super Bowl XLIII. Teams that return an INT for a touchdown are a perfect 9-0 in Super Bowl play.
But that's like saying if you score more points and you'll win the game.
Here's what has changed, though: a tough regular-season defense that carries its team into the Super Bowl is quickly becoming a quaint vestige of the past rendered meaningless by the evolution of football. 
Sure, the 2008 Steelers won the Super Bowl with a defense that dominated virtually every statistical indicator in the NFL. The 2000 Ravens and 2002 Buccaneers captured championships with second-rate offenses and shutdown defenses. But stellar championship defenses are becoming the exception, not the rule.
We're now in the midst of a four-year run that has given us Super Bowls with many of the worst defenses in the 44-year history of the game.
The breaking of the 300-point barrier
Three-hundred points used to be something of a magic barrier. If you surrendered more than 300 points, you were rarely a contender, even with a great quarterback. If you surrendered fewer than 300 points, and had a good  quarterback, you probably were a contender.
In fact, in one of our all-time favorite Cold, Hard Football Facts, the 49ers never gave up 300 points during their 16-year dynastic run of the 1980s and 1990s. Sure, they had Joe Montana and Steve Young. But they fielded champion-caliber defenses for an amazing stretch of nearly two straight decades.
Those laws of football physics all changed drastically with the 2006 Colts. They surrendered 360 points (22.5 PPG) – still the most points allowed by any Super Bowl champion. Even worse: Indy's defense surrendered an awful 5.33 YPA to opponents on the ground.
It was not just the worst run defense of any Super Bowl contender or of the 2006 season, it was one of the worst ever: just six teams in the entire history of the NFL, almost all expansion teams, fielded run defenses worse than the 2006 Colts. Yet this team with a historically dysfunctional defense held on long enough to capture four playoff wins and hoist a Lombardi Trophy.  The most notable game was a victory over the Patriots in an AFC championship game when they surrendered 34 points.
Then along came the 2007 Giants, who surrendered 351 points – the second most by any Super Bowl champion. Yet they somehow turned it on in the playoffs and ended the year by shutting down the highest-scoring offense in history from New England.
The 2008 Cardinals lost to Pittsburgh in last year's Super Bowl, but it was a historical miracle that they reached the big game after a season in which they surrendered 426 points – easily the most by any team that's ever played for a championship, going all the way back to the first title tilt in 1933.
The Saints this year surrendered 341 points. If they win Sunday, only the 2006 Colts and 2007 Giants will have captured Super Bowls with defenses that were worse. And the Saints, like the 2006 Colts, entered the postseason with a very poor run defense – New Orleans surrendered 4.52 YPA on the ground this year. Only five teams were worse in 2009.
Even the 2009 Colts, who have improved dramatically on defense in recent years, don't exactly have what we'd call a shutdown defense. They surrendered 307 points this year – good enough for eighth in the NFL.
But that used to be a number that precluded teams from contention: before the 2006 Colts, only three teams had surrendered 300 points in the regular season and went on to win a Super Bowl. Now it's a regular occurrence.
The Colts even have one glaring weakness that conventional wisdom tells us would be impossible to overcome: they can't get off the field on third down. Opponents converted 45 percent of their third-down attempts against Indy this year. Only the Falcons were worse.
The futility of defensive success as an indicator
The diminishing importance of defense as an indicator of Super Bowl success is evident in a little exercise we conducted last week.
We looked at the success of identifying winners here in the 2009 postseason of 20 different offensive and defensive indicators.
Scoring defense finished last as an indicator of success: it accurately identified the eventual winner in just four of 10 playoff games this year. Two of those wins were by the Jets, the team that fielded the stingiest defense by almost every measure in 2009. The Jets were eventually blown out, 30-17, by the Colts in the AFC title game.
What the Colts and Saints do have in their corner is obvious, and it's the most important piece of any title contender: a spectacular quarterback. Indy's Peyton Manning, as we all know, won league MVP honors in 2009 for a record fourth time; New Orleans' Drew Brees led the league with a 109.6 passer rating and set an NFL record by completing an amazing 70.62 percent of his passes.
Quarterbacks have always been important: consider that just 10 of them have captured 26 of the previous 43 Super Bowls.
But the formula used to be this: great quarterback + great defense = Super Bowl success.
Now it seems a quarterback is more than enough to carry a team on his own.