The Indianapolis Colts had allowed 58 points over their last four games. They allowed 51 to the Pittsburgh Steelers Sunday in what can only be termed an astonishing loss.
It had been a while since Colts fans saw this—both the Philadelphia Eagles and Denver Broncos carved up the Indy defense en route to the 0-2 start the Colts suffered. It certainly didn't help that cornerback Vontae Davis, outside linebacker Erik Walden and defensive end Cory Redding all came off the field at different points of the game for injuries.
The blitzes of defensive coordinator Greg Manusky, so instrumental in setting the pace for this defense, barely seemed to faze Ben Roethlisberger as he went off for 522 yards passing.
So that leaves us with a question: Which Colts defense is real?
The answer lies somewhere between the two extremes. The Colts have seen genuine improvement from edge-rusher Bjoern Werner. Davis has played like an absolute top-flight cornerback at times. While the Colts recorded zero sacks against the Steelers, they came into the game first in the NFL in adjusted sack rate, per Football Outsiders.
But Indianapolis' success was also fueled by an unsustainable defensive third-down conversion rate. Football statisticians have said for years that teams doing abnormally well on third down tend to regress toward the mean.
For instance, Football Outsiders had the Seattle Seahawks with the best third-down DVOA defense last season, at minus-55.6 percent. While Seattle still has a good defense this season, its minus-6.4 percent third-down DVOA defense is 16th in the NFL.
The Colts came into this game with a minus-49.5 percent defensive DVOA on third downs, second best in the NFL. Or, to put it in layman's terms, see this chart below:
|Colts Defensive Third-Down Conversions, Week 3-Present|
|Week||Opponent||Third Downs Faced||Conversions||Points Allowed|
This was always bound to fluctuate. There was some luck involved. That luck mixed with a dash of poor opponent offenses and a smidgen of injury-related fortune (a la the Cincinnati Bengals not having wideout A.J. Green) to create a defense that looked top of the line.
The fate of this defense going forward seems to be tied to how much pressure Manusky can generate via the blitz. The Indianapolis corners can play aggressive coverage well if the pressure can get to opposing quarterbacks.
While the Colts were leading the league in sack rate, they don't have anyone with more than four sacks. A look at Pro Football Focus' pass pressures also shows a pass rush that has spread the wealth around thus far:
|Colts Players by Hurries Through Week 7|
|Ricky Jean Francois||7||2|
|Source: Pro Football Focus|
While the Indy offense had its blemishes, including a throwback performance by an offensive line that seemed to want quarterback Andrew Luck to get killed, 34 points is going to win you a lot of NFL games.
The Colts probably would have slowed the ball down and not forced Luck's last interception had the game script not dictated otherwise. With less focus on wideout Hakeem Nicks and the development of rookie wideout Donte Moncrief, that unit even looks to have a little untapped upside.
But at the end of the day, this team's identity as a true AFC contender is going to hinge on if Manusky's blitzes can generate pressure. Werner has been much better this season, but he's not capable of putting this defense on his back a la outside linebacker Robert Mathis in 2013.
Was this game an aberration or the new normal for the Colts?
That answer will go a long way to determining how deep into January they play.