Super Bowl defenses are battle tested

The Indianapolis Colts are 6½ to 7-point favorites in Super Bowl XLI, but most people won't appreciate how the odds of them making the Super Bowl were stacked against them. You can say the same for the Chicago Bears.

This wasn't the year a light, quick Cover 2 defense was supposed to thrive. The New York Times was the first to do a study of how games were officiated this season. The results, published this week, were not only fascinating, but they make you appreciate even more how tough it was for the Colts and Bears to meet in Super Bowl XLI.

According to the Times, officials called 876 fewer penalties this season, an average of 3.5 fewer a game. Only 11.9 penalties were called in each game, and the number dropped to single figures in the playoffs. Overall, that's a good thing. Fewer penalties mean more action, and it led to one of the league's most competitive seasons and clearly one of the closest playoffs in NFL history.

But a look inside the Times' numbers reveals how the odds were against a passing offense such as the Colts' and two light, Cover 2 defenses surviving 20 weeks of football. The penalty numbers, in fact, explain a lot of things about how the 2006 season concluded.

Peyton Manning relies on precise routes and timing to get Indy's offense going. For years, Bill Belichick countered that by having his Patriots defensive backs be as physical as possible with Marvin Harrison and Reggie Wayne. Manning put up crazy numbers during the first two years officials emphasized calling more illegal contact and interference penalties.

But this year, defensive pass interference penalties dropped 16.7 percent (227 to 189) and illegal contact dropped 25.3 percent (162 to 121). Though it was a struggle, the Colts and Manning survived and other quarterbacks handled adversity well. Passing yards leaguewide increased slightly from 406.9 to 409.6 a game, while the average length of completions went up from 11.4 to 11.5.

The real telling story was the 34.4 percent decrease in offensive holding calls (861 to 578). Although it can be said there is holding on every play, the fact fewer holding penalties were called certainly made it tougher on the light, Cover 2 defenses. It also explains why it was such a good season for running backs. Total rushing yards rose almost 10 yards a game from 224.9 in 2005 to 234.6 season.

To be a light defense in this environment is tough.

The Colts finished the season with a defensive front seven that averages 253 pounds per player. In a season in which blockers can get away with a little bit extra, the Colts were the little kids on the block being pushed around by bullies.

That's no excuse for the Colts giving up 173 rushing yards a game. Poor tackling and poor defensive execution were at fault for the defense being that bad against the run. But if a light defense is going to be banging away at 320-pounders 60 plays a game, it's pretty easy to see that those defenses will wear down.

The Colts ranked 16th in overall defense in the second half of the season, giving up 327.4 yards a game in total offense, including a staggering 180.6 on the ground. The Eagles wore down in the final eight games, giving up 340 yards a game, including 155 yards on the ground. The Bears suffered, too, giving up 337.6 yards (22nd in the league) a game during the final eight weeks.

For a while, it looked as though the Cover 2 was unraveling.

"People like to bring a lot of the stats up on the Colts, but that was the regular season," Colts defensive end Dwight Freeney said. "It was about keeping our poise. You can't lose your cool. It's all about intensity and it's all about attitude. It's not always about X's and O's and drawing up the perfect defense."

The Colts' defense improved during the playoffs and stuffed the run instead of being run over. The Bears' defense, despite the loss of defensive tackle Tommie Harris, held up well through two playoff games.

"I was never panicked about our run defense," Colts coach Tony Dungy said. "When we have all our tacklers out there, and we play fast and play hard, we did fine. We just weren't consistent in the playoffs. We're going to be tested when we play Chicago because those two backs [Thomas Jones and Cedric Benson] can pound it."

It the Colts win the Super Bowl, a 24-year-old stat will end. The Colts could be the first team to win a Super Bowl with a defense that didn't rank in the top 10 in points allowed. The last team to do that was the 1983 Raiders.

All season, I had a feeling that stat could be in trouble. Five of the six NFC playoff teams didn't rank in the top 10 in scoring defense. The Colts won their final two playoff games against teams with the stingiest defenses in football -- the Ravens and Patriots.

That the Colts and Bears made it to the Super Bowl shows how well some teams can fight the odds. Little teams can win in a season that favors the bigger teams.

Nevertheless, expect the Cover 2 teams to make adjustments during the offseason. If the trend to call fewer holding penalties continues, the light defenses will need to add some bulk. But don't expect teams to start junking the Cover 2 scheme.

Instead, watch for the Colts and others to find bigger backup linemen and linebackers who can be used in early-down run packages. It helped the Colts when Rob Morris, a 243-pound linebacker making minimum wage, replaced 228-pound Gilbert Gardner on the strong side. Having a couple 300-pound backups will help the lighter teams match up better against running teams.

The Colts and Bears survived the tough odds. Now, they can make the adjustments.

John Clayton is a senior NFL writer for ESPN.com.