How much better is Rex's defense with the Jets? Scheme and coaching-wise, the only way to really tell is to compare each coaches' production with as similar a depth chart as possible. That would be the 2008 Jets defense vs. 2009. And when broken down, pass defense was the biggest difference.
Ryan took the third-worst passing defense in the league and made it the best. In 2008, Eric Mangini's passing D gave up 234.5 yards per game. In 2009, Rex's squad gave up 157.7 per game, a difference of 76.8 yards. Take away nearly 80 passing yards from an opponent's game, and you're facing at least two, if not three, fewer redzone trips per contest.
The Jets were also the seventh-worst team in preventing first downs through the air in 2008. Ryan made the NYJ the best in that department a season later. Offenses converted first downs on 36.5 percent of their passes against the Jets in Mangini's last year. In Rex's first year, the Jets defense gave up first downs on just 25.5 percent of passing plays.
Big picture, in 2008, Mangini's defense surrendered 81 more first downs through the air than Rex's in 2009 – that's 5.1 extra first downs per game. Rex was able to get his defense off the field five more times per game than Mangini.
New York prides itself on stuffing the run and playing hard-nosed ball. But the moneymaker in this pass-crazed league is shutting down the aerial attack. That's what Rex can do, and Mangini couldn't.
Nick St. Denis covers the Jets for GreenAndWhiteReport.com. Follow him at Twitter.com/nickstdenis