When the Jets traded Darrelle Revis, it spelled the end of an era. Revis was the lynchpin for some of the best defenses in the NFL early in Rex Ryan's tenure. He was by far the most valuable player on the Jets defense and arguably the most valuable defensive player in the league.

Here are just some of the ways he provided value:

Single-handedly eliminated game-changing offensive weapons like Andre Johnson, Calvin Johnson, Randy Moss, etc.

Took other offenses and quarterbacks out of their comfort zone by forcing them to run their offense through secondary options, not the elite number one receiver.

Allowed safeties to provide help in run support because of how little help he needed.

Allowed the Jets to move defenders who would be helping clogging passing lanes on his side of the field to help other defenders.

Allowed the coaching staff to be very aggressive and creative with blitz calls, knowing the coverage would hold if the pressure did not get there.

Gave pass rushers extra time to get to the quarterback with great coverage.

Took young teammates under his wing and taught them how to train.

Made everybody better by demanding the best in practice. If a practice squad receiver didn't come close enough to imitating the way an opposing receiver would run a route, he would stop practice and make them do it over.

How much was the defense based on Revis? Consider this. In the last five years, the Jets were one of only five teams to have more than one top five defense. Sometimes you can have a flukey good year and catch the right opponents. If you do it more than once in a short span, you have built a legitimately good unit. Only the Jets, Steelers, Ravens, Packers, and 49ers have done it at least twice in the last five years. Green Bay's defense fell off a cliff, but there was a stretch where it was a legitimately very good unit.

How much could one star be expected to carry the load for a top defense? Let's take a look. Ultimately you have a top defense because you have top players. Looking at All Pro teams is a good way to judge where the elite talent is. We will be very liberal with All Pro designation. If you made the first or second team from the AP, PFWA, or the Sporting News, you will be designated an All Pro for that year.

How many top of the line players did these units have? How much of the load did the top guy carry?

Team Number of top five defenses since 2008 Average number of All Pro's in peak years Players who have made at least one All Pro team in peak years Percentage of team's All Pro appearances in peak years represented by the top player Jets 3 1.33 2 (Darrelle Revis, David Harris) Revis 75% Steelers 5 1.60 4 (Troy Polamalu, James Harrison, Lamarr Woodley, James Farrior) Polamalu/Harrison 37.5% Ravens 3 3.33 4 (Haloti Ngata, Ray Lewis, Terrell Suggs, Ed Reed) Ngata 30% Packers 2 2.50 3 (Charles Woodson, Nick Collins, Clay Matthews) Woodson/Collins 40% 49ers 2 5 7 (Justin Smith, Patrick Willis, Navarro Bowman, Carlos Rogers, Aldon Smith, Ahmad Brooks, Dashon Goldson) J. Smith/Willis/Bowman 20%

This shows the extent to which the Jets leaned on Revis. David Harris' 2009 second team AP nod made him the only other Jet in that span to crack an All Pro team. Every other team on the list had at least two players make multiple appearances. The Jets have two of the four seasons on this list with one or fewer All Pro player.

It's difficult to compare the value of players across positions. How can we really tell quantify what Revis brings to the table against what Polamalu or Lewis does? This is a decent look. This doesn't necessarily mean Revis would be less valuable if he was put on a defense loaded with talent like San Francisco. What it means is the Jets arguably got more value out of Revis than any team got out of a player the last few years.

The Jets didn't have Revis last year, and it showed. Yes, they might have ranked eighth in the league on defense and second against the pass, but that alone was a dropoff. It also was a tad deceiving when you consider the Jets were the number nineteen defense before playing Ryan Lindley, Chad Henne, Jake Locker, and Ryan Fitzpatrick in four of the last five games. This defense feasted on atrocious quarterback play to pump up its stats. The Jets also benefited statistically on defense because of how frequently they played from way behind. Other teams didn't have to pick up big chunks of yardage or run quick successions of plays. For long stretches, the opponents would look to eat up the clock and avoid costly mistakes. Antonio Cromartie had a good year, but the Jets couldn't trust him the way they trusted Revis. They couldn't redeploy their players to help those struggling in other areas, like the run game, to the same extent. The numbers were also deceiving because the aforementioned Murderers Row of quarterbacks left some big plays on the field. Philip Rivers did not in the Jets-Chargers game Week 16. Cromartie and Kyle Wilson were not weaknesses, but their numbers would have looked a lot worse against better quarterbacking. This wasn't a bad defense, but it wasn't the kind of defense that dragged the Jets to success (or at least respectability) by overcoming a suspect offense like in the past.

Revis, however, is not coming back because of a combination of salary, injury, and personality. The merits of these have been debated endlessly. There is no need to rehash them. The Jets now need to figure out how to replace this great value Revis represented.

The Jets cannot expect one player to replace Revis. That is not realistic. They do not need one player to do that, though. I have seen some claim Dee Milliner will replace Revis. Others say it will be Antonio Cromartie. Neither of these is really accurate. The Jets aren't just replacing Revis the cornerback. They are replacing the value Revis provided. While the cornerbacks will be part of the equation, they have players in other spots who can help make up the difference.

The early Rex Ryan defenses were top of the line because they were overwhelming in coverage. Without Revis, that will not be the case. The Jets do have Milliner, though, who hopefully will grow into a player who can provide a large percentage of what Revis used to be able to do. It's not fair to Milliner to expect him to get all the way to Revis level, but that is not what the Jets need. The Jets can afford to be a little less stifling in coverage if they can make up for it by improving in other areas.

The area that really sticks out is the defensive line as Gang Green has invested three first round picks since 2011. The defensive line was never a weakness in the Revis years. There were good players there like Sione Pouha, Mike Devito, and Shaun Ellis, but there is now potential with all of the top end young talent for the unit to become a game-changer in a way it wasn't. Muhammad Wilkerson is already on an All Pro type career trajectory. He is currently one of the very best at his position. Wilkerson's emergence takes some of the pressure off everybody else on the defense. He commands double teams and keeps the second level clean.

The Jets also hope Sheldon Richardson can turn into an impact player. He has top notch athletic potential. If he develops properly, he could turn into a very disruptive force pushing the pocket and getting into the backfield.

Quinton Coples might be the guy who could go the furthest in making up for a downgrade in coverage without Revis. He has flashed potential to be a lethal pass rusher. He's incredibly fast and athletic for a man of his size and strength. He has the tools to become a dangerous pass rusher.

The Jets have announced that Coples is moving to outside linebacker in the 3-4. It was kind of a curious decision in the abstract. Usually when you have somebody stand up in the 3-4, it is because they can't win a one on one lined up directly across from somebody else as a pass rusher. You stick them further away from the quarterback and linemen so that they can use speed and athleticism to finesse their way to the passer. Coples doesn't have this problem. He's at his best going one on one.

The move to outside linebacker is a misnomer to some extent, however. As you are probably sick of hearing me say after all of these years, the Jets are not purely a 3-4 team. They show a ton of fronts and like to have players line up in all kinds of different spots and roles to confuse the offense. I am hoping Coples moves around on the defense. He will undoubtedly spend a lot of time standing up as an outside linebacker. The Jets seem willing to live with him struggling in space and in coverage because they feel he is athletic enough to get to the quarterback from that position. He can line up in other spots, though. He can be a defensive end. He can be a defensive tackle. If Coples can reach his potential as a pass rusher, his versatility makes him dangerous. The Jets want him to be a guy for whom the offense always has to account. Once you start moving a guy like that around, it can unnerve blockers. They have to find the pass rusher in short time. Everybody has to adjust their assignment to account for the gamebreaker lining up in an unexpected place. This can lead to favorable one on one matchups for other players and blown assignments, especially when a defense compounds things by blitzing from unexpected angles as Rex Ryan's unit does. It has a complimentary effect. With Revis, the Jets didn't need a great pass rush. With Coples, the Jets might not have to cover quite as well.

Individually none of these young guns, Milliner, Wilkerson, Richardson, or Coples will ever be as valuable as Revis. Collectively, though, they could match the collective production of the top four players during the Revis years. Think of it like a baseball lineup. From 2009 to 2011, Revis was exceptionally valuable. He was able to carry other parts to a top five ranking on defense. Two, three, and four were less valuable on the whole than you would expect from an elite defense. Milliner+Wilkerson+Richardson+Coples might end up providing similar value to Revis+2nd best+3rd best+4th best. That's the hope.

Even had the Jets kept Revis, it was always going to be important to get more diverse on defense. It's bad practice to depend too much on one person, especially in a sport like football where injuries are a fact of life. As Revis ages, he will be able to do less. The idea would have been for Revis to carry the load as the young guys matured. As Revis aged, and the young guys got more seasoned, they could take on more of the load. By the time they hit their second contracts, the Jets could now part ways with Revis and use the savings to give the youngsters a raise. So even if Revis was still here, you would be seeing the Jets go in this direction. It is a good thing.

In the short term, the Jets are probably taking a step back on defense. It is too much to ask too much of rookies like Richardson and Milliner. Richardson in particular plays a position where transitions to the NFL are difficult. He is probably going to be a downgrade from Devito this year, possibly a big one. The hope is the experience and seasoning he gets will translate into bigger things down the road. While improvement for Coples is the hope, the 10 sack figure might be more realistic in his second year than the 15-20 range.

Hopefully by 2014, these guys will be seasoned and ready for big things. The pie in the sky hope is Wilkerson, Milliner, Richardson, and Coples will have become elite level players by then. David Harris will have rebounded. He and Antonio Cromartie will represent the fifth and sixth best players on the defense. Demario Davis will blossom, and there will plenty of cap space to find quality supporting players to round out the defense. Admittedly, it's a lot to ask, but it is where we are.

Rex Ryan defense 2.0 is not going to be based on otherworldly coverage. It is going to be based on very good coverage and very good line play. Nobody will ever provide as much value from the number one spot, but one to eleven, the Jets might be able to match the total value of the Revis defenses. Instead of leaning on a once in a generation player, this defense could be more balanced, which could be a better formula.