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January was a fun month. The playoffs were compelling and ended on a huge defensive play made possible by preparation and execution -- you know I can't resist pointing that out -- and I spent time with lots of great friends watching the Senior Bowl practices and talking football over barbeque. You can read my practice reports on the defensive prospects at Matt Waldman's Rookie Scouting Portfolio blog here. And if you're into detailed analysis of the incoming draft prospects, Matt's fantastic Film Room series has covered many players on both sides of the ball.

I'll have much more on the incoming draft prospects in March and April, with draft previews by position, and my combined draft board to follow the NFL draft in early May. I'm also hoping to join Matt to talk about some prospects in the coming weeks, too.

coaching and scheme changes

January and February coaching changes give us our first look at how teams plan to attack 2015. Good teams need to replace valued coordinators. Bad teams are overhauling the front office and coaching staff. While the term "base defense" is more misleading than ever, it gives us an idea of what kind of player a team wants to roster and how they'll be used.

As late as mid-December, the prevailing speculation was that few teams would change coaches and it would be a relatively quiet transition. Six weeks later, twelve teams have new coaches and/or coordinators. Some won't involve any significant philosophical changes, but that's over a third of the league in transition. 

There are some interesting coaching changes this year to discuss -- particularly Vic Fangio in Chicago, Wade Phillips in Denver, and Jim Tomsula in San Francisco -- especially because the bulk of this year's new hires were defensive-minded coaches. But I still feel the scheme discussion is less critical to fantasy value than it once was. If you'll excuse the copy-paste, I think the following paragraphs from last year's scheme change feature are very relevant.

Defenses in the NFL aren’t that straightforward anymore. Most coordinators used to work with a playbook with a single primary base defense and a single primary nickel package. We could label a defense as a 1-gap 3-4 or a Tampa-2 leaning 4-3 and have a good idea about how a player would be used for the vast majority of his snaps.

Not anymore.

The term “multiple” started to creep into the table I would produce in the IDP forum highlighting each team’s defensive scheme three or four years ago. A small handful of teams would use both 3-4 and 4-3 concepts, but would still predominantly lean one way.

Now every team is “multiple.” And today’s “multiple” is a much more complicated term. A predominantly 3-4 (or 4-3) team may utilize both 1-gap and 2-gap concepts – on the same snap. Nearly every coordinator uses a variety of situational subpackages. Some never use the once-traditional 4-2-5 nickel formation at all. Many teams use a situational defense more often than their base defense. Coverages are multiple, too, with some teams using man concepts on one side of the ball and zone on the other.

It’s still important to consider the coach or coordinator’s preferred philosophy. But knowing each team’s base defensive front is no longer as critical. Snap counts and knowing which players on a given defense will see the most subpackage opportunity are growing more important.

Here's the table listing each team's head coach, defensive coordinator, and base defense. Changes are in CAPS. Of note, I removed the terms 1-gap, Tampa-2, multiple, etc from the scheme column. Again, that's because very few coordinators run the same base scheme on every down. Some may be more multiple than others, but all are multiple.

Scroll down for extended discussions on all the coach and coordinator changes.

Chicago hires John Fox as head coach and Vic Fangio as defensive coordinator

(replacing Marc Trestman and Mel Tucker)

Fox told reporters he wasn't tied to a specific defensive front in his press conference and has long experience with the 3-4 front. However, Fangio is a long time 3-4 coordinator and the Bears changed the title of their defensive line coach to outside linebacker coach. I think it's very likely the Bears are planning to be a 3-4 base.

Fangio uses multiple concepts but favors an aggressive 3-4 with lots of fire zone concepts and a 2-4-5 nickel package. Such a combination would leave room for multiple every down linebackers.

With D.J. Williams, Lance Briggs, and Darryl Sharpton all free agents, Jon Bostic and Christian Jones are heavy early favorites for the inside linebacker jobs. Both have every-down upside. I've been hard on Bostic, but he showed the ability to translate his athleticism into good linebacker play last year. Jones was inconsistent, but his size and speed are a good fit for Fangio's defense. There's a chance Briggs could return to Chicago with the new coaching staff, but don't bet on him being a key cog in this group.

The current defensive line and outside linebacker groups do not fit easily into Fangio's scheme. Jared Allen and Willie Young are the Bears' best returning pass rushers but aren't good fits as 3-4 outside linebackers on base downs. Both look like situational players on passing downs to me. Shea McClellin is the most versatile edge player on the roster, but he's a below replacement level talent. Lamarr Houston will work well as a 5-technique weak side 3-4 end, but it's questionable whether he'll be able to handle 700+ snaps coming off an ACL injury.

The Bears are flush with undersized, penetrating tackles -- Jay Ratliff, Will Sutton, Ego Ferguson, Stephen Paea. Ratliff was successful in Wade Phillips' 1-gap 3-4, but Fangio likes a bigger nose. Expect to see acquisitions at tackle, with Fangio taking a long look at who succeed in rotation at tackle or end.

Free agency and the draft will better define Fangio's plan. For now, I expect to slot only Bostic and Jones in my pre-draft tiers. 

Denver hires Gary Kubiak as head coach and Wade Phillips as defensive coordinator'

(replacing John Fox and Jack Del Rio)

The Phillips playbook has long been full of aggressive 1-gap 3-4 concepts. He's also long preferred a traditional 4-2-5 front on passing downs. The Broncos were a 4-3 front under Del Rio, but they have the pieces to transition quickly to Phillips' preferred fronts.

Denver has two edge rushing talents (DeMarcus Ware and Von Miller) that would reduce easily to defensive ends in subpackages, two aggressive inside linebackers with the ability to play downhill against the run and cover (Danny Trevathan and Brandon Marshall), and a mix of strong 3-4 line prospects (Terrance Knighton, Sylvester Williams, Derek Wolfe, Malik Jackson).

I think Williams may look better as a rotational end, but could also work as a 1-gap nose. I'm most interested in seeing what Phillips decides to do with Jackson and Quanterus Smith. Jackson may need to gain weight to play more than 500 snaps at 5-technique and I'm not sure Smith can transition to a standup outside linebacker role.

San Francisco hires Jim Tomsula as head coach and Eric Mangini as defensive coordinator

(replacing Jim Harbaugh and Vic Fangio)

January was filled with speculation the Niners would transition to a 4-3 front. Much of that speculation was fueled by a report by Bleacher Report's Matt Miller, who tweeted he'd been told Tomsula was interested in moving to a 4-3. On the surface, the speculation made sense. If the Niners get Patrick Willis and NaVorro Bowman back to full health, they have three off the line of scrimmage linebackers for only two spots in a base 3-4 front.

But don't jump to any conclusions yet. Tomsula said he favored the 3-4 in his opening press conference. He then hired Eric Mangini, whose coordinated and coached 3-4 fronts in New England, New York, and Cleveland. Until the Niners specifically show otherwise, expect them to remain a 3-4 base.

If healthy, Willis and Bowman are near locks to start, with Borland playing a reserve role. Mangini (coming from the Belichick tree) is more of an execution coach then an aggressive coach, but the inside linebackers will still be productive here. Speculation that Justin Smith will retire and Ahmad Brooks released means the Niners could lean more on Tank Carradine and Aaron Lynch in 2015.

BUFFALO HIRES REX RYAN AS HEAD COACH AND DENNIS THURMAN AS DEFENSIVE COORDINATOR

(REPLACING DOUG MARRONE AND JIM SCHWARTZ)

Ryan will bring his aggressive 3-4 front to Buffalo. It shouldn't be a major transition, as the Bills' personnel functioned well of a 3-4 under Mike Pettine in 2013 before bringing on Jim Schwartz last year after Pettine left to take over in Cleveland. Pettine worked under Ryan for years in Baltimore and Pettine's defense featured many of the same concepts Ryan prefers.

It won't be a major stretch for Mario Williams and Jerry Hughes (if the Bills bring him back) to become outside linebackers again.  And Marcell Dareus and Kyle Williams can handle defensive line roles in a 3-4 front.

The inside linebacker battle will be interesting, with Brandon Spikes a free agent, Kiko Alonso recovering from an ACL injury, and Preston Brown and Nigel Bradham strongly in the mix. A helathy Alonso will be an every-down player and I'd give the early edge to Brown over Bradham at the other spot. Ryan has used two inside linebackers in his subpackages, so it's possible both Alonso and Brown will hold every down roles next year.

Atlanta hires Dan Quinn as head coach and Richard Smith as defensive coordinator

(replacing Mike Smith and Mike Nolan)

The Falcons used a 3-4 front as their primary base last year after adding bulk to the front line, but didn't have the pass rush to make it work. Dan Quinn is the latest defensive mind in the Pete Carroll coaching tree to move out of Seattle. Quinn will bring the Seahawks' physical and fundamental brand of defense to Atlanta.

Though Quinn will work from a 4-3 front, we'll see some under front concepts with a Leo -- a standup weak side pass rusher -- and other defined roles along the defensive line. The Falcons don't have a great Leo candidate (e.g. the Chris Clemons / Cliff Avril role in recent years), so you can expect them to shop for one in free agency and/or the draft. Last year's first round draft pick, Ra'Shede Hageman has the ability to drop inside as a penetrating tackle. The scheme change may pay dividends for him.

It's likely Paul Worrilow will stay inside as Quinn's middle linebacker, but we won't know exactly how the linebacker group (which also includes Prince Shembo, Marquis Spruill and Joplo Bartu fighting for spots) will align until we see whether Atlanta wants recovering free agent Sean Weatherspoon back this year.

Washington hires Joe Barry as defensive coordinator

(replacing Jim Haslett)

Jay Gruden was clear about his preference to stay with the 3-4 defense after Washington fired Jim Haslett. After a flirtation with Vic Fangio, Washington's hiring of Joe Barry away from San Diego was hailed as a great decision. Barry had a long 4-3 history with Tampa Bay and Detroit in the mid-2000s, but has swung firmly toward the 3-4 playbook later in his career.

Barry will have a number of strong pieces to work with in Washington. Barry will need to decide whether to pursue Brian Orakpo (or another edge rusher opposite Ryan Kerrigan), but I don't expect any major depth chart or role changes to the tackle producers in the front seven.

Oakland hires Jack Del Rio as head coach and Ken Norton, Jr. as defensive coordinator

(replacing Dennis Allen and Jason Tarver)

There were rumblings about a move to a 3-4 (or at least some kind of multiple front) look from the moment Dennis Allen was hired as the Oakland head coach. Del Rio looked at many defensive coordinators, but his desire to be the de facto coordinator reportedly kept names like Mike Smith and Todd Grantham from signing.

Del Rio has said Norton will be the play caller on game days, but this will be Del Rio's scheme. Despite having two-way edge players like DeMarcus Ware and Von Miller with the Broncos, Del Rio chose to work from a 4-3 in Denver. I expect the same in Oakland, where Khalil Mack compares favorably in many ways to Miller. Sio Moore's role should also be safe. I'd argue the Raiders may want to add a middle linebacker -- which could threaten Moore's every-down upside -- but Del Rio didn't prioritize the position in Denver and has other holes to fill.

New York Jets hire Todd Bowles as head coach and Kacy Rodgers as defensive coordinator

(replacing Rex Ryan and Dennis Thurman)

The methods of aggression may change in New York this year, but the transition from Ryan to Bowles isn't likely to have a major impact on the defensive playbook. Rodgers coached with Bowles in Arizona and both share the same philosophy. Ryan preferred bigger bodied players and was willing to sell out with various overload blitz packages. Bowles has seemed to prefer speed in his career when given the option.

David Harris fits the Rex Ryan playbook a little better, but Bowles was very comfortable with Larry Foote in the middle after losing both Daryl Washington and Karlos Dansby last offseason in Arizona. We may see the Jets prioritize bringing Harris back in free agency. I don't expect any of the other front seven roles to change significantly and there's nothing in Bowles' playbook that will make Demario Davis a more consistent tackle producer.

New York Giants hire Steve Spagnuolo as defensive coordinator

(replacing Perry Fewell)

When the Tampa-2 and 'Miami' based 4-3 fronts were the rage last decade, Steve Spagnuolo (and his mentor Jim Johnson) was known as one of the most aggressive 4-3 coordinators in the league. That won't be the case in Spagnuolo's latest go-around in the NFC East. While we may see a more varied blitz package and the potential for a left/right interchangeable alignment at outside linebacker, there isn't likely to be much difference in the Giants' front this year.

There's still much to be determined in the linebacker group, with Jon Beason's health an unknown and Jacquian Williams and Spencer Paysinger both free agents. Devon Kennard could get a long look as a potential every-down player during OTAs.

Pittsburgh hires Keith Butler as defensive coordinator (replacing Dick Lebeau)

Arizona hires James Bettcher as defensive coordinator (replacing Todd Bowles)

Seattle hires Kris Richard as defensive coordinator (replacing Dan Quinn)

All three of these hires are promotions from within. There may be minor changes in depth charts and game day playcalling decisions, but I don't expect much to be different in Pittsburgh, Seattle, and Arizona.

Follow and ask questions on Twitter @JeneBramel. Reading the Defense will be back throughout the offseason with free agent commentary, draft prospect previews, tier discussion, links to our offseason IDP roundtable podcasts and much more. Subscribe to The Audible on iTunes or download our weekly IDP podcast here.