Despite returning only three starters and featuring two true freshmen in its lineup, the 2015 Florida State defense ended up being a surprisingly excellent unit. The Seminoles finished 10th in defensive S&P+ thanks to a stingy pass defense that helped the ‘Noles finish fifth on standard downs despite ranking only 33rd in rushing S&P+.

The two true freshmen who got in on the action were defensive end-linebacker Josh Sweat and free safety Derwin James. Both of them now return as likely anchors for 2016’s defense.

James’ role, in particular, will be enormous, because he’ll be the centerpiece of the position group that has defined Florida State’s success in the Jimbo Fisher era: the secondary.

One of the biggest advantages to being an in-state program in talent-rich Florida is the access to the absurdly large number of phenomenal skill athletes that come out of the state every year. The Fisher Seminoles have taken advantage, and their 2013 championship came largely thanks to a phenomenal nickel lineup comprised of NFL draft picks, none of whom went later than the third round. Three of the five primary secondary players that year were from Florida.

The 2015 Florida State secondary was built around the sole remaining member of that legendary 2013 crew: Jalen Ramsey, who’s now off to the NFL himself. You can follow the passing of the “alpha of the secondary” torch from Lamarcus Joyner in 2013 to Jalen Ramsey and now to James, whom Pro Football Focus recently suggested could be the best defensive player in the country this year.

The 2016 ‘Noles secondary will be built around maximizing James’ prodigious talents.

The brilliance of the 2015 Florida State defense was partly thanks to an ability to mix very conservative coverages with an extensive blitz package.

The ‘Noles’ favorite combination in 2015 was to mix a very conservative cover-6 base defense with a diverse and devastating collection of blitzes from that two-deep pre-snap look. All of it served to highlight Ramsey’s unique abilities at the boundary corner position.

From a pressing position on the boundary, the ‘Noles could count on Ramsey (No. 8) to do any number of things. He could play underneath coverage and force the run, rush the edge on a blitz package or lock down a receiver in standard man coverage to free up other blitzers or the strong safety to do other things.

James’ role on standard downs was to ensure Florida State could bend without breaking.

In last season’s Peach Bowl, James made 14 tackles against the Houston Cougars, with a sack and two tackles for loss to boot. His job was to play deep over the slot, permit the nickel cornerback to be aggressive against running plays, act as the free hitter against receiver screens and, in general, clean up any mistakes his teammates made.

Houston had a lot of success gaining leverage at the line of scrimmage with its spread-option plays but averaged only 5.7 yards per attempt and 3.5 yards per rush. This was largely thanks to James’ ability to make the saving tackle and to do it reasonably close to line of scrimmage. His 14 tackles were a combination of error erasures and occasional drive-killing plays when the nickel was successful in containing a play for him:

Unique athleticism and size are the defining characteristics of James’ game. At a SPARQ event in high school, he ran a 4.52-second 40-yard dash with a 4.32 shuttle run, 38′ power ball toss, and 34.9″ vertical leap, all at 197 pounds. Those are numbers comparable to what you might find from many NFL cornerbacks, but James is about 6’2 and now around 210 pounds or so and perhaps even stronger and quicker.

That speed allows James to close on the ball quickly from deep alignments and even change his track if the force play ahead of him isn’t particularly effective at containing the ball in the alley. That acceleration and lateral agility also allow James to line up extra deep and still break on passes to the slot or fill the alley on runs, which in turn allows the nickel to play more aggressively underneath.

Here’s how that looked against the Houston spread passing game:

It’s a simple enough formula, but it requires closing speed. James has it.

The ‘Noles are bringing a man/zone combo blitz from their cover-6 pre-snap shell. Ramsey blitzes the edge, and the strong safety and weakside linebacker are playing man coverage while FSU is playing cover 2 to the field side. Houston is running the “snag” concept, which gets a deep out route isolated against the free safety if the defense tries to cover up the underneath routes.

This play is generally designed to pick up easy yardage underneath when the corner or nickel drops deep to help the free safety, but that isn’t necessary here for FSU. Indeed, James nearly picks off the pass despite working from awful initial leverage.

Free safeties that can cover ground like this and free up the players ahead of them to play aggressively, while providing the security blanket of sure tackling, are exceptionally valuable. This is the kind of play that really helps defenses force passing downs, and normally that’s where a free safety’s impact starts to fade. Not for James, though.

James has extra motivation to force passing downs, because he’s a featured weapon in the Florida State pass rush.

Teams are always looking to find freak athletes who can rush the edge with speed and power but also have the flexibility to turn the corner on big, mobile offensive tackles. The guys who excel rushing the edge are often limited in performing the other duties of a defensive end, such as setting the edge and grappling with tackles on running plays, which means that guys who have natural ability to win the edge aren’t always put in position to do so.

James could never hold up as a DE or even an outside linebacker hybrid on regular downs, and he’s much more useful in those instances swooping down from his perch as a free safety. However, in obvious passing downs when he can be free to just focus on beating pass blocks, he can wreak havoc.

Derwin James.#FSU #DerwinJames #FSUvsUF pic.twitter.com/Ll9X8Bcp1G

— Cinefunk (@CineFunk) November 29, 2015

James had 4.5 sacks last year and will likely have a few more in 2016 as a more prominent part of the Seminole pass rush. That’s not even the only value James brings to the box on passing downs, though.

There are three different tasks that have to be executed to stop teams from converting on passing downs, and these tasks vary depending on the opponent and particularly depending on the QB.

The first task is pressuring the QB so he doesn’t have time to find a receiver or deliver the ball, and obviously James has a lot to offer in terms of bringing pressure.

The second is eliminating hot reads. Many offenses excel at beating the blitz by getting the ball out quickly to a receiver who’s working in isolation against a linebacker. James has a lot to offer here as well, because the ‘Noles will often plant him in the box on passing downs and sometimes use him to lock down a receiver rather than blitz the QB:

There’s no getting away from James. His acceleration and lateral quickness are too much for receivers to find many open windows. Ramsey once served in this role as a sophomore himself, and now James will.

Then there are the quarterbacks who will burn you with the scramble, and here again, James is the solution. Against dangerous scramblers, the ‘Noles would often bring just three rushers, drop seven men into coverage,and then spy the QB with James hanging around in the box. Scrambling QBs often like to use their legs to either get outside the pocket to create opportunities to throw or to take off and run, but both of these are frustrated if there’s a superior athlete nearby shadowing their movements and cutting off their angles. That’s James.

Florida State loses Ramsey this year, and he’ll be missed. But it’s hard to imagine the ‘Noles having a better fit in place to follow him than James. The torch has been passed, and the FSU secondary is still in good hands.