INDIANAPOLIS – When trying to dissect the reasons why the Colts currently lead the NFL in time of possession by a staggering number of nearly two minutes more than any other team (36:28), the results lead you to an unfamiliar place.

Offensively, the Colts offense is sustaining drives at a high rate (2nd in the league with 26.7 first downs per game).

That is known.

What is beginning to be uncovered is the Colts defense starting to become dominant in third-down situations.

In the last three weeks, the Colts have been down right stifling when the No. 3 appears on the chains.

Greg Manusky's unit has run off the field on 25 of its last 28 third downs faced, a percentage that dwarfs any other in the league during that span.

The Colts have allowed just one third-down conversion in each of the last three games, which no NFL team has done since 1992.

"They are playing extremely aggressive. The guys are doing a great job of not only putting together a great plan for defense but executing it," Chuck Pagano says.

"They are coming together and you can really see what we envisioned a long time ago. The type of defense that we wanted to have out there week in and week out."

Behind that 10.7 percent conversion rate, the Colts defense sits atop the NFL in allowing just 29.7 percent of third downs through six weeks.

What is most impressive about this stretch is the Colts are dealing with some changes at each level of their defense.

Versatile lineman Art Jones remains out with a high ankle sprain, forcing the Colts to constantly shuffle bodies in across the three-man front.

At linebacker, leading tackler Jerrell Freeman played a complete game on Thursday night for the first time in 2014.

And then in the back end, special teams ace Sergio Brown has had to transform into a starting safety the last two weeks without LaRon Landry.

The Colts are also getting after the passer at an extremely high rate. In the last four weeks, the Colts are tied for the NFL lead with 16 sacks.

"The back end's doing a great job of playing tight coverage, taking away first reads, making it really hard to get the ball into tight windows, making the quarterback hold the ball just long enough to get those pressures home," Pagano says.

"We're being very, very aggressive, which we want to be in (that) package."

The pass rush has benefited from staying ahead of schedule in early downs, allowing the unit to flourish on third down.

While Andrew Luck and the Colts offense continues to lead the league in scoring, that side of the ball can thank the defense for giving them plenty of chances.

"That's something definitely we've been emphasizing the last few weeks," D'Qwell Jackson says of the third-down success.

"We've just got to continue to have a collective effort getting after the quarterback. Right now we're doing a good job of getting the guy down and getting pressure in his face, and that's what's in my opinion is making a difference on third down."