The Book of Fangio

The 'Fangio Defense' has taken over the NFL. Shawn Syed breaks down Fangio's philosophy, core concepts, and the nuances of a scheme that has altered the geometry of the league.

The sun crests over eastern Illinois and the alarm on your phone blares. You wake up quickly to shut it off, but the headache from studying all of the install material rushes back. The date is July 27, 2017. It is the first day of training camp and your first day as an intern for the Chicago Bears. 

You hurry to the facility and make your way over to the defensive meeting room. As you groggily walk in, on your left is one day Los Angeles Chargers head coach Brandon Staley along with his future defensive line coach, Jay Rodgers. To your right is Sean Desai, future defensive coordinator for the Chicago Bears and one-day defensive assistant for the Seattle Seahawks. Next to Desai sits future Minnesota Vikings defensive coordinator Ed Donatell. Donatell, with his patented rectangular framed glasses, sits next to his future defensive backs coach, Roy Anderson. At the center of the table is Vic Fangio. Fangio, hat in hand, has been through more NFL seasons than you can remember watching. He has spent time with the Saints, Panthers, Colts, Texans, Ravens, 49ers, Bears, and one day will coach the Broncos before being a defensive consultant for the 2022 #1 seed Philadelphia Eagles. He also has spent time in the USFL, college football, and even coached high school ball.

The ideas discussed in the room that day were the product of endless tinkering by generations of gifted defensive minds. Five years later, the flexible two high structures that the 2017 Bears deployed would be commonplace across the league. No single coach has had a bigger impact on the structure – or aesthetics – of NFL defenses in the past 36 months as Fangio.

Fangio had been running them long before that season, and when he decides the time is right for him to return to an NFL sideline, he will run them again. 

This series is an ode to Fangio-ism and the schematic shift that the coach and his cohort have thrust upon the NFL. In it, we will discuss the macro philosophy and tendencies, as well as break down the nuts and bolts of the core coverages he uses.

The Philosophy

The name Vic Fangio is hallowed in defensive circles. “Fangio” is now shorthand for two-high structures, a base 3-4, light boxes, and modern defense. Fangio did not create any of those things. He does, however, deserve credit for using these now meta schemes before their influence blanketed the league. Fangio has worked with Steve Sidwell, Dom Capers, Jim Mora, Rex Ryan, and a laundry list of coaches currently employed by NFL teams. 

The “Fangio Defense'' has a few trademarks. Fangio’s defenses consistently are at the top of the league in two-high shells before the snap. The two-high structure allows for flexibility in the secondary. Safeties can move before or after the snap, react from depth, and ultimately be used as tools to attack the offense. The roll of the safeties often comes very late and can change the picture for quarterbacks who turn their backs to the defense in play action. As the wide-zone-then-boot offense became the orthodoxy for NFL offenses (again) with the rise of the Shanahan-McVay-Stefanski-LaFleur style of offenses, changing the picture on the quarterback while his back is turned to execute a play fake has become a go-to tool for coaches looking to disguise, bluff, and add extra beats to a quarterback’s decision-making process – beats that can lead defenders to crash the pocket or the quarterback to make a poor decision with the ball.

Dissecting what occurred on a play can even be difficult because of the way the safeties’ responsibilities vary so much depending on what the offense presents. To combat Sean McVay’s famed “illusion of complexity” (the idea that a few core concepts are presented in different ways), the Fangio Defense uses the appearance of simplicity. The same exact defensive look can end up in a plethora of coverages, pressures, and assignments.

At the first and second level, the modern iterations of the Fangio Defense are often at the top of the league in light boxes. This is part of a never ending cat and mouse game in football. The Fangio Defense has made the choice to use technique and depth instead of numbers at the point of attack to combat the run game. 

Generally, runs are less efficient than passes. Encouraging a team to run into a seemingly attractive look can help set the defense up for a 3rd and long. Defensive linemen are asked to eat up double teams and play with moveable leverage to keep linebackers clean, while safeties trigger downhill in the run game to make what looks like a light box play much heavier. Defenders often spill the ball to the edge and ask safeties to clean up the mess. Fitting the run from depth with safeties also allows the defense to be better suited to respond to play action and the passing game. The Fangio Defense has made a choice to put an umbrella over the offense. The generic strategy is to force teams into inefficient run plays, play coverage with four rushers when it is time to pass, be flexible with coverages that start out similar but end up different, and add enough depth to the proceedings to have the secondary read-and-react from advantageous positions versus the most lethal of offensive weapons: play-action.

The Fangio Defense is also not a huge blitzing scheme. On passing downs, there are usually four rushers and seven players in coverage. Coverages all look better when the four rushers get home, and elite edge-rushing talent is one of the hallmarks of a Fangio Defense. Blitzes are used at opportune times, “safe” pressures are used frequently, and fire zones can play out like man coverage.

The Main Packages

The main packages to know from the Fangio Defense are 3-4, Nickel/Sub, Penny, and 40. 

Base 3-4:

The base 3-4 look appears as you may expect it. A nose may shade a side at different times, and the defensive ends play tighter than some other schemes. Their alignment also can shift based on what formation the offense presents. Outside linebackers play on the line as edge setters for the defense, and deep safeties fill the box quickly.

Nickel/Sub:

Fangio’s Nickel or Sub personnel is technically a 2-4-5 but presents as a 4-2-5. The outside linebackers become edge rushers and they are given the chance to go and get after the quarterback. The interior defensive linemen are still double-team eaters and are key to allowing the defense to play with a light box. The nickel defensive back replaces the nose tackle and aligns to the passing strength (more below).

Penny:

Fangio’s Penny front uses 3-3-5 personnel but presents like a 5-1. This defense clogs interior gaps and makes running zone more difficult. Ed Donatell has liked to use this package in short-yardage situations with the Vikings. The front increased in popularity as Brandon Staley weaponized it with the Rams. Penny allows a defense to have a good look at the first level of attack while also having a nickel on the field in pass defense – a kind of best-of-both-worlds solution.

40:

The 40 package is a heavy run-stopping group that was key to Bill Belichick and the Patriots stopping Sean McVay’s offense in Super Bowl 53. Fangio’s Bears played the Rams tough and part of that is thanks to putting a player in every gap and having a middle linebacker tempo the running back — Belichick mimicked the gameplan in order to stop McVay’s go-go, jet-motion-heavy group in the Super Bowl. These days, it’s most commonly seen now on the goal line and in short-yardage situations.

The Personnel

Vic Fangio has coached some tremendous players. The players help push the scheme, and the scheme aims to put players in a position to succeed. There may be archetypes for roles within the Fangio Defense, but there is always room for talent. 

DL/EDGE: Though the Fangio Defense may be thought of back to front, the trenches are where the fun starts. In the base 3-4 that Fangio uses, the defensive line generally does not attack up the field aggressively in the same way as some single-high structures demand. Instead, high-level technique and an understanding of leverage  help clog up double teams while linebackers can leverage the running back for tackles. On the interior, Fangio has had players like Akeem Hicks and Justin Smith at the 3-4 defensive end spot while Eddie Goldman was a nose tackle for the Bears. The outside linebackers play standing up and help set the edge while also being asked to drop into pass coverage.

When the defense turns to their Nickel package, the most used package for Fangio, they deploy a 2-4-5 format. The two interior defensive linemen are generally the 3-4 defensive ends, and the outside linebackers become edge rushers. While it is technically a 2-4-5 by numbers, it will look like and play like a 4-2-5. The outside linebackers pass rush ability is key to speeding up the offense. Players like Khalil Mack succeeded in this role. 

LB: Fangio’s linebacker rooms feature a who’s who of the great and good. We’re talking Patrick Willis, NaVorro Bowman, Roquan Smith and on. Stylistically, the linebackers are often kept clean from double teams by the defensive line while also being asked to get depth in pass coverage. In pass coverage, having a linebacker that is athletic enough to play man coverage with faster-running backs is an essential part of coverage flexibility.

CB: Vic Fangio has recently coached cornerbacks like Patrick Surtain II and Chris Harris Jr. Cornerbacks need high-level coverage skills, but the Fangio Defense also uses cornerbacks as force defenders in the run game. 

S: The safeties are the queens on Vic Fangio’s chessboard. Players like Eddie Jackson and Justin Simmons thrived in a role that asks a player to fit the run from depth, cover large sections of the field, and be the hole player to take away crossing routes. Generally, the weak side safety has the most coverage flexibility, and holding one’s assignment until the last second is a trademark of a Fangio secondary.

---

The Passing Strength and Field Zones

In the NFL, the majority of snaps come from the hashes. As the hashes are not as wide as they are at lower levels, the ground to cover on each side is comparable. Thus, defenses can more confidently use halves coverages to sides without the same concern college teams may have about a player covering a ton of ground from the hash to the sideline. Instead of setting the defense to the wide or short side of the field, the Fangio Defense sets its secondary based on the passing strength. Simply put, the passing strength is the side with “more” or “better” receiving threats.

Though the Fangio Defense uses different matching rules and variations within coverage that combine man and zone coverages, a basic understanding of field zones is important as we start to dig into pass coverage. The general zone assignment can turn into a man assignment based on the formation or if certain players cross certain zones. Further, certain offensive looks can give a defender freedom to support another player’s responsibility. 

When discussing coverages, it is important to note that responsibilities and nuances can change by gameplan. Plus, the terms used are a combination of the verbiage the Fangio tree has used (and continues to use) and other terms that help to simplify the larger picture.

Zone Coverages

Cover 4 (Trix)

Cover 4 is a basic four deep, three under coverage. It is used in its purest form in the red zone. Offenses like to conflict the quarters flat defender or try to occupy a safety while taking advantage of the cornerback’s outside and deep responsibility. Offenses can try to make the linebackers’ lives hard by running routes above and below their zone. Also, an offense may be able to run the defense out of two-high or be happy with forcing a safety to make the tackle after a run has already gained yards from heavier personnel. Defenses that are forced to bring a safety down into the box before the snap open up other potential play action or matchup issues. Cover 4 is the base for putting a ceiling over the offense’s pass game and is pretty to watch when communication and execution is maximized.

Cover 4 also has an adjustment against 3x1 sets. A Trix call allows the back side safety to read the releases of 3 and 2 to the trips side to see if there are any vertical or deep crossing routes. This would allow the defense to play 3 on 3 against 4 verts and help the defense deal with teams that want to get their fastest receiver matched up on a linebacker. A Trix call would also require the linebacker to play man on the running back, while a cornerback is locked in man on the back side receiver. If the safety does not get a vertical threat, they could zone their quarter or hang in the window to rob a route breaking inside from the back side X receiver.

Cover 6 (Quarter, Quarter, Half)

In the Fangio Defense, Cover 6 and Cover 8 are closely related. The differentiation in the two comes from what is played to the passing strength or to the call. Both are played with a Quarters side and a Halves side. Cover 6 plays Quarters to the passing strength, while Cover 8 plays Halves to the passing strength. One might group these two as one coverage, but the goals, responsibilities, and strengths of the coverages are different and thus should be separated.

Quarter, Quarter, Half (what I will call Cover 6) plays Quarters to the passing strength and a Halves side away from it. The Halves side away from the passing strength is particularly helpful when the offense has a star receiver that the defense wants to cloud. Getting a press from a cornerback can help disrupt timing, and having safety help over the top encourages the offense to look elsewhere. This is of course an allocation of resources that may open up matchups elsewhere.

Cover 8 (Half, Quarter, Quarter, Trix) (Penny Sam 8)

Cover 8 (Half, Quarter, Quarter, Half to the passing strength) is a coverage that is becoming more popular across the league. It is a common coverage against 3x1 sets – and for good reason. 

Cover 8 puts a cloud corner over number one while the nickel defensive back and linebacker will play zone match rules. A safety will play deep half, and a trix safety will likely be in play. This lets the defense get five defenders over three receivers and is a key to how Brandon Staley likes to play coverage – lock the back side in man and flood the frontside in zone. Cover 8 is also commonly run from the Penny front. Cover 8 allows the cornerback to play aggressively in the shallow to the intermediate area while pushing the numbers in the defense’s favor. As always, one-on-ones on the back side can undo this coverage.

Cover 9

Cover 9 is a weak rotated Cover 3. One example of the defense having flexibility and multiple ways to play against the offense is an adjustment that the Fangio Defense uses similar to Nick Saban’s “Site”. Against a 3x1 set with the running back set away from the trips, the down safety would be rotating to the running back. Remember from some of our other coverages that the linebacker to the running back’s side may end up taking the running back man to man. 

Variations of Cover 3 against 3x1 sets face a core problem against 4 verticals. The biggest concern is known, in coaching parlance, as: “three up is three. Meaning: The weak hook player, who may be a linebacker not suited for the job, ends up having to chase a speedy receiver down the field. The weak hook player ends up responsible for this in coverages that exclude one of the safeties. The Fangio Defense has a different way of dealing with this.

In Cover 9, there are a few ways to take care of the running back and the third receiver. One way is to have the safety take the running back while the linebacker plays their usual three up is three responsibility. Another option would be to either flip it, or more interestingly to read it or game plan it based on the running back’s release and personnel. Site does just that. If a running back is less likely to go out for a pass or checks protection at the line, the linebacker can take the running back while the down safety becomes the three up player. This situation is more indicative of a deeper pass as the six blockers in protection give the offense a chance to develop routes. If the running back is either a significant passing game threat or is out to the flat fast, the safety could take the running back while the linebacker goes to their usual three up responsibility. This situation places the offense in empty pass protection and is more likely to be a quicker pass. 

The flexibility of Site allows a defense to leverage what an offense does as well as have the same presentation play out different ways. This adjustability is a way for modern defenses to fight back against offenses. Giving the same look that leads to different coverages is made possible by the two high structure and versatility of the secondary. Sure, there are tells such as alignment of the linebackers that leave space for a likely down safety, or cornerbacks pressed that indicate a likely cloud side, but Fangio’s defensive backs learn to become experts in waiting on when to show their intentions. Even if the coverage is not disguised, the different calls can make a defense less predictable and give the pass rush that extra tick to get to the quarterback.

Man coverage

Man coverage is one of the best tools to use when you are confident in your ability to cover the offense’s receivers. There’s a reason those branches that have fallen off the Saban tree call it “Cat” coverage. Our cat is better than your cat.

Along with pure one-on-ones, the Fangio Defense (and many others around the league) use different variations of cover 1 with a hole player to leverage against certain routes. Generally speaking, the hole player is able to provide inside help against in breaking routes at certain depths in the middle of the field. The hole player can work to a particular side, receiver, or area that is known to be an offense’s attack zone. The difference between the variations comes down to the responsibilities of the linebacker and the down safety. 

In 1 lurk, the down safety will be covering a receiver or tight end while the linebackers will leverage the running back. One linebacker will end up on the running back and the other will end up as the hole player. One way to play this out is to have the linebacker to the side of the running back’s release take the running back, while the other linebacker is the hole player. 

In 1 robber either the down safety or linebacker will take the running back based on their release and location. The other would become the hole player.

In what the Saban tree calls 1 cross, the down safety would be playing the hole at the first down marker. This helps particularly against teams that like to run a deep crosser on 3rd down. Some defenses have hole players take routes while the original defenders become the new hole player after the pass off occurs.

A bunch of opposing offenses have had difficulty navigating their way through the maze of 1-coverages. Where is the rotator coming from? Are my eyes lying to me? The late stages of the 2021 season were dominated by offenses being thrown off by the backside safety rolling into the robber spot to cut the crosser originating from the frontside. Jimmy Garoppolo, Dak Prescott, and a slew of on-time, in-rhythm, hit-the-back-foot, get-the-ball-out quarterbacks were stung by late rotation and being caught on the backside. These coverage structures, along with their disguise and flexibility, are partly why the 2022 season has seen a rise in the checkdown; quarterbacks are happy to get rid of the ball ASAP to a back underneath to move on with the game before worrying about squeezing the ball into ever shrinking windows deeper down the field.

Pressures

Before getting into pressure, we need a basic understanding of fire zone coverage. The most common fire zone has 3 deep 3 under coverage. 

Instead of dropping to a spot and hoping for the best with vision on the quarterback, Vic Fangio’s fire zones end up playing out with matching rules that can look like man. Droppers can carry the routes up the field and may match them going out. This bolsters the coverage and avoids common pitfalls of spot drop zone coverage.  

The Fangio Defense takes advantage of certain base pressure paths. The Whip path is one that you will see across the NFL on Sundays. Most defenses run some variation. Whip sends the will linebacker to the B gap while the defensive tackle rips to the A gap. The end away from the rush drops into coverage. The dropper is a “bonus” dropper and can be gameplanned to drop into certain problem areas of the fire zone coverage. The Whip path challenges the running back in pass protection, may force the offense to keep the back in, and also has 7 players in pass coverage. This often leads to 4 receivers against 7 coverage players for the defense; this is math the defense is happy to accept. It is thus a “safer” rush than true fire zones and is not technically a blitz.

Slug

Slug is similar to Whip, but instead sends the nickel off the edge. A safety will rotate down to replace the blitzer, and the end away from the Nickel will drop into coverage. The end dropping away from the Nickel may be a seam/flat player or could also be a bonus hook dropper. This is another example of sending a non-traditional 4 rushers, dropping 7 into coverage, and giving the offense another look to deal with.

Punch

Punch is a 3 deep 3 under fire zone that sends the nickel while also rushing the end away. This leaves only 6 droppers in coverage and is more of a “true” fire zone. 

These “basic” pressures don’t mean that the Fangio tree does not dig into the bag when it comes time to dial it up. Brandon Staley has done a tremendous job at attacking pressure this season. The top pressures are those that manipulate protection rules, make a running back’s life hard, and are well timed to give the defense the advantage.

So, What’s Next?

After being spotted hanging around practice in the fall, Fangio, a Pennsylvania native, was revealed to be a defensive consultant for the Philadelphia Eagles. His role is unclear, though it is likely current Eagles defensive coordinator and hot head coaching candidate Jonathon Gannon has been able to pick Fangio’s brain. Turn on the Eagles and you will see the coverages and fronts discussed in this series. With an impending Gannon departure, Fangio may find himself on a list of potential replacements including those already in the Eagles’ building. Fangio also has been linked to a future Sean Payton-led coaching staff.

Perhaps Fangio fancies the flexibility his schedule provides him as he visits friends across the country and plays golf in Florida. Maybe Fangio is reinvigorated by his coaching sabbatical and is ready to get back to work testing offensive coordinators and quarterbacks. No matter what is next for Vic Fangio, his fingerprints on the NFL history books have already been cemented. As offensive coordinators draw up quarters beaters and devise ways to get into heavier personnel to test light boxes, Fangio will be ready.

---

Editor’s Note: This was originally published as a multi-part series. Those pieces have been combined here into one, complete ‘Book of Fangio’ to make it easier to share over time.