The New York Jets lead the league in run defense. You probably already knew that. What you may not know is the Jets own one of the top run defenses in recent memory.

They're allowing 2.85 yards per rush. Some perspective: Since 2000, only three teams have allowed fewer yards per carry: The 2000 Baltimore Ravens (2.69), the 2006 Minnesota Vikings (2.83) and the 2007 Ravens (2.84).

As a side note, Rex Ryan was an assistant coach in Baltimore in '00 and '07; defensive-line coach Karl Dunbar served in the same position for the '06 Vikings. Is it a coincidence they're both heavily involved in another great run defense? No way. It would be a tremendous accomplishment if the Jets could somehow lower their average below the '00 Ravens, widely regarded as one of the top defensive outfits in history.

"I think right now, if you look at our team, we’re a dominant run defense," Ryan said. "There’s nobody close to us in this league and when you look at it, saying from a statistical standpoint, I think we give up 2.8 or 2.9 a rush, when the next closest team is maybe 3.5 or 3.4 per rush. I think that’s a separation that you don’t see very often in this league."

Ryan's numbers are accurate. The Cleveland Browns are second at 3.43.

In one year, the Jets managed to turn a weakness into a strength. They dropped to 21st last season (4.32), an embarrassing low for a Ryan-coached defense. How'd they improve so much so fast? Four reasons:

An immovable nose tackle: First-year starter Damon Harrison is a significant upgrade over Sione Po'uha, who was rendered ineffective last season because of a back injury that has forced him out of football. The Jets allow a paltry 2.5 yards per rush when Harrison is on the field, 2.9 when he's not. Enough said.

The Sheldon Factor: Mike DeVito was a solid, blue-collar run stuffer for the Jets, but they let him walk in free agency and replaced him with rookie Sheldon Richardson, who wasn't regarded as a superior run defender in college. Richardson has altered that reputation. He leads all rookies with 10.5 backfield stops -- 7.5 tackles behind the line and three sacks. He brings athleticism to the position, allowing Ryan to play an attacking style. The Jets aren't your typical 3-4, read-and-react scheme.

Mo better: Muhammad Wilkerson was a good player last season. Now he's a very good player, having improved his quickness and stamina. He can wreck any blocking scheme.

Faster linebackers: Last year's linebacking corps was dinosaurish. Graybeards Bart Scott and Bryan Thomas were too slow, one of the reasons why the defense allowed so many long runs. They were replaced by Demario Davis and Quinton Coples, who often plays in a three-point stance as the "rush" linebacker. Nothing helps a front seven like youth and speed. "Mike" linebacker David Harris dropped weight in the offseason, improving his lateral quickness. As a result, the Jets have allowed only 16 runs of 10+ yards, the fewest in the league.