Well, a lot.
As they try to build an offense from scratch and retool a defense that has lost several key veteran players, the Jets have and will continue to undergo a tremendous amount of change that we have not seen from this franchise in nearly a decade.
Here is a look at what will be new for the Jets in 2013.
As of this writing, a starting quarterback for Week 1 has not yet been announced—but change at the position is inevitable.
Even if Mark Sanchez is the starter for Week 1, unless Sanchez emerges as a competent quarterback who could put the Jets into contention, it would be irresponsible if the Jets did not play Geno Smith enough to see if he has what it takes to lead a franchise for the next decade.
The early returns on Smith have been a bit disappointing. His three-interception debut in the third week of the preseason showed that he still had a long way to go in terms of his development, but he did flash his potential on a handful of deep throws into tight coverage.
Smith was a second-round pick for a reason—unlike Andrew Luck or RGIII, he has significant flaws in his game that will prevent him from having a historic rookie season as Luck and Griffin did. With a tendency to stare down receivers and mechanical inconsistencies, Smith will need a bit more time to show what he is capable of doing.
The good news is that Smith's flaws are correctable, but he will need time to work through them.
Either way, change at the game's most important position is inevitable for the green and white.
Last year, the Jets made the elementary mistake of trying to build a run-first offense without a dynamic threat from the running back position—and finished 30th in the NFL in total offense as a result.
No one knows exactly how much the Jets are going to run the ball this year under new offensive coordinator Marty Mornhinweg, but new general manager John Idzik needed to at least fill the void left in the wake of Shonn Greene's departure.
Idzik found a way to upgrade his running back situation after exchanging a fourth-round pick for Chris Ivory.
Ivory is a talented runner who has been the victim of injuries and depth chart politics. No longer buried behind a slew of talented runners in New Orleans, Ivory will get his chance to prove that he can be a bell-cow runner who can stay healthy.
However, Ivory will not be the team's every-down back. He will split many of the carries with Bilal Powell, who has yet to surrender his position atop the depth chart. Powell excels in pass protection and is a bit more decisive in making his cuts than Ivory, despite being a bit less physical and easier to bring down.
There will also be a changing of the guard at fullback, where seventh-round pick Tommy Bohanon will take over for the injured Lex Hilliard. Bohanon lacks Hilliard's experience, but he makes up for it with his ability to contribute in the passing game.
Rex Ryan's defense in New York has been built around his stellar secondary anchored by Darrelle Revis. However, now that Revis is no longer in the picture, the Jets must build their defense in a more conventional style that is more centered around generating pressure than playing stellar coverage.
Realizing his need to retool his defense, John Idzik used a first-round pick on a pass-rusher in Sheldon Richardson and signed third-down specialist Antwan Barnes to pick up the slack on the edge.
Richardson may not be the edge rusher in the mold of Von Miller that fans have been clamoring for, but he is an athletic specimen who moves like a linebacker at the size of a defensive tackle. Richardson, along with Quinton Coples (when kicked inside) and Muhammad Wilkerson, will generate a devastating interior pressure that will disrupt the elite pocket passers like Tom Brady.
Tom Brady can step away from outside rushers. However, there is no running from a 300-pound defensive tackle that is three yards from his nose.
The Jets still need an young, dynamic presence at the outside linebacker position but for now, the pass rush is set to take a big step forward from last year.
No team trades away a player of Revis' caliber and gets better, but the Jets are one of the few teams that are built to sustain losing such a tremendous player.
One of the driving factors that facilitated the Revis trade was how well Antonio Cromartie played in his absence. After Revis was hurt in Week 3, the Jets made Cromartie the "new Revis" of their defense, following around the opposition's top receiver everywhere he went with minimal safety help.
While he did not completely eliminate these top receivers from the game in the same way Revis did, he certianly minimized their effectiveness. Opposing quarterbacks had just a 69.7 quarterback rating when throwing to Cromartie, who defended 12 passes in the process (via Pro Football Focus).
However, teams have now had an entire offseason to dissect the Jets' new method of playing defense without Revis and will certainly have a plan to beat Cromartie. It is now up to Cromartie to rise to the occasion and prove that last year was not a fluke.
"Ground and pound" is dead.
Unlike Rex Ryan, Marty Mornhinweg is not interested in "setting a tone" with a strong running game. Instead, he is more interested in doing whatever it takes to move the ball and score points—which he believes is through the passing game, as he told Rich Cimini of ESPN.com:
You score points throwing the ball. Now you're getting into a philosophical situation. Look it, we don't care how we get it done -- running, passing, we don't care who gets the credit. It's whatever it takes to win the next game.
Mornhinweg, who was the Eagles' offensive coordinator for six seasons, was often criticized for abandoning the running game when calling plays for the Eagles. His critics may have had valid complaints, but his offenses were certainly better than what the Jets have put on the field during that time.
Don't expect the once-porous passing game of this ironically nicknamed Jets team to turn into the greatest show on turf anytime soon. Rather, it appears as if Rex is finally willing to concede that winning on a consistent basis with just a strong running game is not realistic in today's NFL.
Plus, having to convert a third down every series because you ran the ball on first and second down is taxing on any offense.
The running game will still be a significant aspect of the Jets' offense, but they will definitely take on Mornhinweg's philosophy as a pass-first offense.
Perhaps the most "underrated" change for the Jets this season is at the guard position, where they will field two new starters at the position.
For the first time since 2003, the now-retired Brandon Moore will not be on the Jets' roster. Meanwhile, Matt Slauson signed with the Chicago Bears in free agency.
With limited cap space, John Idzik had to take a chance on players with less-than-perfect injury records such as Willie Colon. Colon was a quality right tackle and guard for the Steelers but was never quite the same player after he tore his triceps in the first week of the 2011 season.
Despite his injury risk, Colon could turn out to be one of the best bargain buys of free agency if he can avoid the trainer's table and solidify the right guard spot.
The left guard position, however, remains much more of a question mark. The Jets hoped third-round pick Brian Winters would have seized the job by now, but it appears as if Vladimir Ducasse, the disappointing second-round pick from 2010, will be the opening day starter now that Stephen Peterman is out of the picture.
Ducasse has plenty of athletic ability to get the job done, but he has struggled with the mental aspects of the game. Now in his fourth year, it's now or never for Ducasse to prove that he can be a viable starter.
No position has seen less stability in the Rex Ryan era than the safety position.
After finally seeing some success with the pairing of LaRon Landry and Yeremiah Bell a year ago, the Jets must make yet another transition to a completely new starting safety tandem.
The solid-yet-unspectacular Dawan Landry (LaRon's brother) has been inked as the starter at strong safety since the day he was signed. Although not an ideal player to have in coverage, Landry is a smart veteran who will lean more on his experience than his physical ability to get the job done.
The free safety spot is much more of a question mark, with Antonio Allen and Jaiquawn Jarrett still battling for the starting job. As of this writing, no decision has been made for the opener, but this is a battle that will last into the regular season and could vary from week to week.
Either way, both players will see the field plenty with the expanded use of three-safety personnel groupings.
If neither Allen nor Jarrett are able to prove that they are capable of starting for the long term, the Jets could see yet another overhaul at the position next spring.
There are many different factors that go into how a defense performs form year to year, but there is a direct correlation between how much the Jets blitzed and where they ended up in annual defensive rankings.
Here is a breakdown of the Jets' blitz percentage (via Rich Cimini ESPN.com) and their rankings:
|Blitz Percentage||Blitz Rank||Team Defense Rank|
Mike Pettine's influence was the biggest reason why the Jets abandoned their aggressive ways. As he gained more control of the defense, the Jets blitzed less and less.
Now that Pettine is in Buffalo, Rex is free to return to his recklessly aggressive ways—something the locker room has been clamoring for, according to Cimini. David Harris hinted at a desire to do less dropping into coverage and more getting after the quarterback:
We're going to do a lot of blitzing and getting after people. There should be a different brand of football than you were used to seeing the last couple of years. We played more coverage. It wasn't like '09, that's obvious. That's all I'll say about that.
No defense loses a player like Darrelle Revis and gets better, but perhaps a more aggressive approach will help reverse the Jets' gradual decline on the defensive side.
The Jets are set to retain all three specialists (kicker Nick Folk, punter Robert Malone and long snapper Tanner Purdum), but there will be many subtle changes behind the scenes and in the return game that will give the special teams unit a new feel for the first time in a long time.
Since 2001, Mike Westhoff was the captain of a well-respected special teams unit for the Jets. Now that Westhoff has retired, his apprentice Ben Kotwica will have to fill the shoes of one of the best special teams coaches of all time.
From a tactical or schematic standpoint, not much should change from years past—the Jets have been grooming Kotwica for several years now. Still, Westhoff's Yoda-like presence is no longer around to guide the often young and inexperienced group of men that make up the special teams group.
There are some more visible changes coming for special teams as well, most notably the kick return spot. After releasing Joe McKnight, the Jets will lean on either Clyde Gates or Kyle Wilson to continue McKnight's success in the return game.
Thanks to Westhoff's genius, the Jets have been successful in the return game whether it was McKnight or Justin Miller returning kicks. A new return man will test the skills of Kotwica right off the bat.