The Big 'D': Broncos defense in midst of staggering turnaround

If your friendly neighborhood Broncos fan seems disoriented this week, you'll have to forgive him.

There's the sudden shock of an unexpected 4-0 start, the budding pangs of puppy love for Josh McDaniels, the joy of this week's orange-splashed Sports Illustrated cover,and, of course, the famously thin Mile High air.

But Broncos fans are also suffering from the disorienting statistical whiplash caused by the sudden u-turn of the Denver defense that was one of the worst units in football last year. This year it's one of the best.

You probably know the basics:

• The 2008 Broncos surrendered 374.6 yards per game (29th overall); the 2009 Broncos surrender 239.8 YPG (2nd)

• The 2008 Broncos surrendered 28.0 points per game (30th); the 2009 Broncos surrender 6.5 PPG (1st)

But the power of the Denver defense is even more impressive when viewed through the pigskin periscope of the Quality Stats that we use to rate teams at ColdHardFootballFacts.com. Quality Stats are those indicators that have a direct correlation to team-wide success.

Here are five that highlight in no uncertain terms the dramatic improvement of the Denver D:

1. Defensive Hog Index -- This is our measure of each team's defensive front. And it offers very, very encouraging news for the Broncos, for there is no better indicator of postseason success in sports over the past two years.

• The 2008 Broncos ranked 31st in this indicator, ahead of only the pathetic Chiefs.

• The 2009 Broncos rank 1st in this indicator, ahead of everybody.

ColdHardFootballFacts.com contributor Jonathan Comey developed the Defensive Hog Index concept in 2006 and, after some tweaking for 2007, it's proven a huge indicator of success.

• The 2007 Giants finished No. 1 in the Defensive Hog Index. They won the Super Bowl.

• The 2008 Steelers finished No. 1 in the Defensive Hog Index. They won the Super Bowl.

• The 2009 Broncos, for now anyway, rank No. 1 in the Defensive Hog Index. They're 4-0.

Just as impressively, over the past two years, teams with the better Defensive Hogs are 20-2 in postseason games.

2. Negative pass plays -- Forcing opposing passers into critical mistakes such as sacks and interceptions is a huge indicator of team success. Consider the impact of interceptions alone: each pick by a defense increases that team's chances of victory by about 20 percentage points. It's a huge play. And the Broncos have suddenly blossomed in this area.

• The 2008 Broncos ranked 30th in this indicator, forcing opponents into negative pass plays on just 6.1 percent of drop-backs.

• The 2009 Broncos rank 2nd in this indicator, forcing opponents into negative pass plays on 14.8 percent of drop-backs.

3. Third-down success -- Third-down success is an obvious indicator of a team's success: you stop the other team's offense and turn the ball over to your own. Again, the Broncos have risen from one of the worst teams in football to become one of the best.

• The 2008 Broncos ranked 25th, allowing opponents to convert 44.1 percent of their third downs.

• The 2009 Broncos rank 2nd, allowing opponents to convert just 26.4 percent of their third downs.

4. Defensive Passer Rating -- DPR simply takes the formula used to compare quarterbacks and applies it to defense. It's always been a huge indicator of team-wide success, a much better indicator than passing yards allowed. In fact, passing yards allowed is a virtually useless indicator of team success. If you see a pigskin "pundit" compare passing defenses by yards allowed, move on to something else. He/she has no idea and should be banished to the soccer beat.

If you look at most any of the great dynasties in history, you'll always find outstanding Defensive Passer Ratings. The 1960s Packers, the 1970s Steelers and the 1980s/90s 49ers, among others, were all outstanding in this indicator year after year. And, yet again, this is good news for the Broncos.

• The 2008 Broncos ranked 31st in Defensive Passer Rating (98.5); only the 0-16 Lions, with the worst pass defense in history, were lower on the list (110.8).

• The 2009 Broncos rank 2nd in Defensive Passer Rating (56.0); only the powerhouse 4-0 Saints are better (51.3).

The Broncos excel in this area because they're they only team in football that's yet to surrender a TD pass. They've also nabbed six interceptions. Only two teams (New Orleans, Green Bay) boast more picks.

5. Bendability -- The Bendability Index is our attempt to chart the "bend-but-don't" break concept. Essentially, it's our measure of defensive efficiency, telling us how many yards opponents must generate for every point they score.

• The 2008 Broncos ranked 28th in this indicator. They forced opponents to march the equivalent of 93.8 yards for every seven points they put on the board.

• The 2009 Broncos rank 1st in this indicator, and nobody's even close. They force opponents to march the equivalent of 258.3 yards for every seven points they put on the board.

That's a shocking number of efficiency. So far, Denver's opponents must march up and down the entire length of the field two and a half times before they score a single touchdown. In fact, we've never seen anything remotely close to this mark since we created the Bendability Index in 2004.

What it tells us is that the Broncos are good in many other areas, because the Bendability Index is not just a defensive measure. It takes into account a variety of team-wide factors, including the efficiency of the offense and special teams, red zone defense and turnover margin. Essentially, even when opponents can generate yards against Denver, they're usually in no position to turn those yards into points or they simply leave those points on the field.

The irony of the sudden rise of the Denver defense is that new head coach Josh McDaniels joined the team with a reputation as an offensive specialist. After all, he was the offensive coordinator for the 2007 Patriots, the highest scoring team in NFL history.

But he and his staff, including new defensive coordinator Mike Nolan, immediately went to work remaking the Broncos defense.

At one point in the spring, the Broncos were singularly responsible for one of every four signings in the free-agent market. They picked up three of their four current starters in the secondary in the space of a few days in February and March: cornerback Andre Goodman and safety Renaldo Hill, both from Miami, and safety Brian Dawkins, who was a legend with the Eagles. The Broncos did not re-sign one of their own free agents. So it was spring-cleaning time in Denver.

So far the plan has worked brilliantly. But there are two caveats:

1. On Sunday, McDaniels meets his master, Bill Belichick, the guy who's largely responsible for much of what he knows about pro football. We'll know much more about the Denver defense by the end of the day.

2. We saw this same type of early-season performance out of Denver just three years ago. The 2006 Broncos began the season 5-1 and had surrendered just 44 points, easily the best mark in the league through six games. But that unit unexpectedly disintegrated into nothing. Denver lost 34-31 to the Colts in Week 7 and suddenly couldn't stop anybody over the final 10 games. The 5-1 Broncos of October turned into the 9-7 Broncos of December and didn't even get to play in January.

If that happens again, your friendly neighborhood Broncos fan will be more than disoriented at season's end.