The New York Jets don't know how to quit Darrelle Revis.

After trading Revis to the Tampa Bay Buccaneers in 2013, the Jets' pass defense suffered. Now, after a year in New England and a Super Bowl title, Revis has returned to the team that made him the 14th overall pick in the 2007 NFL Draft. Is it the right move, though?

We'll evaluate this signing by using numberFire's Net Expected Points (NEP) metric. In every situation, a team has an expected number of points they will score during their current possession. A negative play such as an interception makes a team's NEP go down. A positive one such as a first down increases it. This gives us a reading of the efficiency of a team over the course of a season.

We'll look at this signing from two angles: first, what impact it'll have on the Jets' defense, and second, whether or not the Jets are in a position to capitalize on any improvement fully.

A Great Defense Fallen

This ain't your papa's Jets defense. Below is a chart of the Jets' pass defense over the past six years. For those first four, Revis was still on the team before departing in 2013. The column labeled "Adj D PNEP/P" stands for Adjusted Defensive Passing NEP per play. This is adjusted for strength of schedule and measures how good the Jets' pass defense was on a per-play basis.

As you can see, they missed their ol' buddy in his absence.

Basically, the brown stuff hit the fan after Revis tore his ACL during the 2012 season. The year they slipped to ninth was the Revis holdout season in which he missed three games with a bum hamstring. Outside of that, the team balled out with Revis' blanketing opponents.

Last year, the Jets drudged to a 21st-place finish in a category in which Rex Ryan used to thrive. They have a long way to go in order to regain their status among the league's best under Todd Bowles, but Revis has a track record of making defenses immediately better.

The chart below shows how the Bucs and Patriots fared before they had Revis and the year they had Revis. The chart shows where the teams ranked in Adjusted Defensive Passing NEP per play in each of those seasons.

Both teams also brought in additional help outside of Revis for their respective secondary, but it's not a coincidence that both improved. Tampa Bay subsequently fluttered back to a 23rd-place ranking in 2014 after Revis's departure. Revis makes a positive impact wherever he goes.

The rest of the secondary isn't exactly swimming in talent with Dee Milliner and Buster Skrine, but those three are immeasurably better than the revolving door the Jets started at corner last year. The team is going to improve significantly against the pass.

But are the Jets focusing too much on the near future given their grotesque past two seasons? That would be the $70 million question.

Chasing Down Competency

As shocking as this may be, the New York Jets, given their 4-12 record, were not a good football team last year. They finished 25th in numberFire's nERD stat at -4.27, which tracks a team's expected margin of victory or defeat against a league-average team on a neutral site. They have serious questions at quarterback, their offensive line has regressed from its glory days, and their linebacking core is aged at best, yet new general manager Mike Maccagnan is all-in.

Maccagnan is the anti-John Idzik. Idzik's thriftiness gave the team gobs and gobs of cap space, and now Maccagnan gets to play in it. He has done so already by bringing in Brandon Marshall via trade and Revis through free agency.

The problem is that these two guys aren't exactly spring chickens any more. Revis turns 30 in July, and Marshall will be 31 later in March. In order to fully justify these acquisitions, it would be logical that the Jets would need to succeed now before these guys get further into their years of decline.

As numberFire's Dan Pizzuta noted last week, even the 2014 version of Marshall is a significant upgrade over the receivers the Jets have featured recently. Marshall paired with Eric Decker, who actually had decent receiving metrics in his first year with Gang Green, and a more seasoned Jace Amaro gives Geno Smith plenty of weapons with which to work. Whether or not he properly utilizes them is a totally different question.

With Muhammad Wilkerson fully healthy and Sheldon Richardson doing his typical beastly things, the Jets may suddenly find themselves in a position where they are only a few pieces away from being competitive. Considering where they were when the offseason began, that's impressive.

The problem is that one of those pieces is a wee bit important. If the team sticks with Geno and he doesn't get it done again, they will run out of time with their new toys. If they roll with a rookie quarterback, they'd better get it right, or the same will be true. They were able to win when Revis was younger despite Mark Sanchez's struggles, but this Revis will be on the wrong side of 30 for Week 1. Thinking that is still a possibility would be a stretch.

Then you get to the money aspect. The Jets have cap space galore, but they're making Revis the highest-paid corner in NFL history. They can't afford not to succeed.

The positive in that aspect is the structure of the contract. The deal includes $39 million in guaranteed money but only $6 million of that comes after the second season according to this report from ESPN's Rich Cimini. Basically, they're locked in through the end of Revis's age-31 season but have increased flexibility after that. It's not a contract that is going to set the franchise back a decade if it doesn't pan out.

At the end of the day, Revis is going to make the Jets better -- and probably significantly so on the defensive side of the ball. There is little chance he can live up to a $70 million contract, but the team still has plenty of money to work with this offseason and the number-six overall pick in April's draft.

While plenty of questions linger on the offensive side of the ball, you can't fault the Jets for making a bid to be competitive again. This doesn't mean they'll push for a playoff spot in 2015, but the NFL is a strange, strange league. At least, unlike 2014, the Jets have given themselves hope of making a run.