Transcription
A lot of people are interested in learning about and analyzing football in a more in-depth way, but the amount of confusing terminology creates an intimidating barrier of entry. Broadcasters assume that you know nothing, so they give a very surface-level analysis. But most books and coaching clinics assume that you know everything, so they're incomprehensible to the average football fan.
This video is an attempt to bridge the gap between casual and serious football analysis and give you a starting point to becoming a more informed viewer. Whether you're wanting to get into football analysis as a hobby or career, or you just want to be the most pretentious person at a Super Bowl party, this video should be a helpful resource. In the description, I've also included a sort of master list of books, clinics, channels, and a lot of other resources that I've used to learn more about football.
Also, for this video, I'm assuming that you know the basic rules and strategy of the sport.
A 4-3 defense uses two interior defensive linemen, two edge rushers, and three off-ball linebackers. A 3-4 defense uses three interior defensive linemen, two edge rushers, and two off-ball linebackers. Base defense is the standard personnel package with 4 linemen, 3 linebackers, and 4 defensive backs. Nickel defense replaces a linebacker with another defensive back, usually a slot corner. Dime, quarter, and dollar defense each add one more defensive back onto the field. Nickel, dime, quarter, and dollar are referred to as sub personnel, but quarter and dollar aren't used very often. Sub personnel is used when the offense is more likely to pass the ball.
The strong side of the formation is the side of the formation with the tight end. If there's no tight end or two tight ends on opposite sides, the strong side is the side with the running back or fullback. And if the formation is perfectly symmetrical, the strong side defaults to the right side. The Sam linebacker is the linebacker on the strong side of the formation. The Will linebacker is on the weak side, and the Mike linebacker is in the middle.
Offensive personnel is designated by a two-digit numbering system where the first digit indicates the number of running backs and the second digit indicates the number of tight ends. So, for example, 12 personnel is one running back and two tight ends, and 11 personnel is one running back and one tight end. 11 personnel is the most common grouping in the NFL, followed by 12, 21, and 22.
The X receiver lines up wide on the line of scrimmage. This is usually a team's top receiver. The Z receiver, also called the flanker, lines up off the line of scrimmage and can be sent in motion pre-snap. The wide receiver is the tight end, and he lines up off the tackle, either on the line of scrimmage or flexed slightly back. A Y-flex player is often called an H-back, and they line up offset behind the offensive line. And then the U and M are the second and third tight ends, respectively.
An offensive formation is defined by three components: quarterback, backfield, and receivers. The quarterback will either be under center, in shotgun, or in pistol. Single back is self-explanatory with one running back who can be behind the quarterback or off to the side. And shotgun empty is another easy one, which just means no one's in the backfield. I-formation means a running back and fullback are lined up directly behind the quarterback, and offset I means the fullback is slightly to the left or the right. A split backfield means there are two backs lined up on either side of the quarterback, and a flex backfield looks similar to an offset I, but the tight end or H-back lines up behind a guard.
A balanced formation means the same number of receivers are lined up on each side of the formation. Twins is a two-receiver set with an outside receiver and a slot receiver on the same side. Trips is a three-receiver set, all on the same side, and trips has a couple of variations. Trips with one tight end and two receivers is called Trey, and trips with two tight ends and one receiver is called Trio. Bunch is similar to trips, except the three receivers are set close to one another, and the middle receiver is on the line of scrimmage. Slot is a three-receiver set with two receivers on one side and one receiver on the other side. Quads is very uncommon, but it means there are four receivers on one side.
Jet motion is motion across the formation where the ball is snapped right before the receiver reaches the quarterback. Fly motion is exactly like jet motion, except the ball is snapped after the player crosses the quarterback. Glide motion is when a player with an outside alignment moves inside about halfway towards the ball. In motion is when a player from the outside motions into the backfield. Over motion is motion from one side of the backfield to the same spot on the other side. Return motion is when a player crosses over to the opposite side of the formation and then back to their original alignment. Exit motion is when a player in the backfield moves to an outside alignment. Orbit motion is when a player in the backfield moves behind the quarterback to the opposite side and continues moving laterally until the snap. Rocket and laser motion is the same as orbit, except the player doesn't pass behind the quarterback. If they motion left, it's laser, and if they motion right, it's rocket. And finally, slide motion is when a running back starts beside the quarterback in shotgun and then moves up and out.
The route tree refers to all of the routes that a receiver can run. Receivers, running backs, and tight ends all have different route trees, but we'll mainly focus on receivers for this video. The initial vertical segment of a route is called the stem, and the second segment is called the brake. The standard route tree consists of the flat, slant, comeback, curl, dig, out, corner, post, and fly route, and they're often referred to by the numbering system that I have on the screen. These nine routes are the foundation of every route a receiver runs, but there's a ton of variations that build off of these core concepts.
A swing route is usually run from the backfield, and the player releases towards the sideline and bends slightly upfield. A wheel route, which can be run by a receiver or running back, starts like a swing or flat route and then breaks vertically. A pivot or whip route begins like a slant, but the receiver will then cut back towards the sideline. A sluggo route also begins like a slant, but the receiver breaks his route vertically. A dyno stem is a technique receivers will use at the top of a dig or a post where they take a few steps to fake an out or corner route and then break inside. A seam route is a go route that is executed by the tight end or slot receiver. An option route is a route where the brake is determined post-snap. Usually, the receiver will release vertically, read the coverage, and adjust his route depending on what he sees. Option routes are effective because they preserve the efficacy of a play regardless of what coverage a defense runs, but it's crucial that receivers and quarterbacks are on the same page.
Routes are usually packaged together into passing concepts that work well against different coverages. A lot of times, you'll have a concept that's good against man on one side and one that's good against zone on the other. Stick is a three-receiver concept where one receiver runs to the flat and another runs vertical, stretching the defense in both directions. The number three receiver runs a stick route, which is an option route that's either a quick hitch against zone coverage or a quick out against man. The dagger concept attacks the middle of the field by running the inside receiver vertically while the outside receiver runs a dig. The vertical route is intended to occupy the safety, leaving the dig route open. The Mills concept combines a post and dig route on the outside. The Mills concept is sort of the inverse of the dagger because the dig route is meant to bait the safety into biting forward, leaving single coverage on the post route. The drive concept is a high-low passing concept with a deep dig and a shallow dig. The quarterback has a simple read here; he just needs to throw whatever route the linebacker doesn't pick up. Four verticals, or four verts, is pretty self-explanatory; it's just four straight go routes. The goal here is to create as many tough decisions and two-on-ones for the deep defenders and hit whoever's open. Mesh is an Air Raid concept with two receivers running shallow crosses from opposite sides. The point where they meet is called the mesh point, and teams will often use option routes that break at this point. If the receivers read man coverage, they'll continue straight and take advantage of the traffic that the mesh point creates. If they read zone, they'll sit down in the soft spots. Sail is a three-level passing concept with a vertical route on the outside, a deep out, and a shallow or a flat. The vertical route stretches the safety and corner downfield, leaving a simple two-on-one high-low concept. Scissors is the most common way offenses attack Cover 2 and Cover 4, and it's just a corner route from the inside and a post route from the outside. This intersection creates physical and mental difficulties for two-high defenses. The smash concept combines a corner route with a hitch or a curl, which forces defenders in zone coverage to make a choice on which receiver to cover. White Cross combines a deep route from the outside to occupy the safety with a deep cross from the tight end or slot receiver. And finally, Yankee is a two-man concept with a deep post on one side and a deep cross on the other. This is usually combined with play action to ensure that both routes can get behind the defense.
Screen passes take advantage of an offense's athletic playmakers and can punish defenses that blitz too aggressively. On a bubble screen, the receiver bubbles backwards and outside, and the receivers block underneath him. A jailbreak screen involves the receiver coming back towards the quarterback, and the offensive line leaking outside to block. On a tunnel screen, the player fakes downfield and then cuts directly backwards as the blocks develop in front of him. The crack screen is a running back screen where the outside receiver cracks inside on the defender who's responsible for guarding the running back.
Gaps are designated by letters, starting with the A gap on either side of the center. The B gap is between the guard and the tackle. C-gap is between the tackle and the tight end, and the D-gap is outside the tight end. A defender's alignment is designated by a numbering system depending on which gap they're covering. So, a defender lined up directly over the center would be playing zero technique. Between the center and guard is a one technique. On top of the guard is the two technique, and so forth. If the defender is lined up on the inside shoulder, their technique is a number followed by an "i," so a player lined up on the tackle as a four technique, but a player lined up on the tackle's inside shoulder is a four-eye. A wide nine is a pure pass rusher who's lined up with a lot of space between himself and the tackle.
The front is the pre-snap alignment of the defensive line, and I'll quickly go over how to identify the most common ones. An over front places a 3 technique on the strong side of the formation, and the backside defensive tackle plays an "i" or one technique. An under front places a one technique on the strong side of the formation, and it's the only front that does this. Okie, Eagle, and Stack are so similar that it's not worth discussing the difference, but this is essentially the base 3-4 front. You have a true nose tackle playing zero technique and edge rushers playing five technique. The tight front has a zero technique as well, but the edge rushers are in a 4i, meaning inside shade of the tackle.
There are two broad types of run blocking schemes: gap blocking and zone blocking. Gap runs are built around taking advantage of the defensive line's leverage, and they're usually just targeting one gap. Let's look at power as an example, which is the staple run of any gap scheme. The linemen on the play side will down block, meaning they're blocking away from the ball carrier towards the center, which seals off the first side of the gap. And then at least one lineman from the backside will pull play side and perform a kick-out block to seal off the other side. The running back's read here is simple; since there's really only one gap he's going to run through, he just needs to wait for his blocks to develop and follow the puller through the designed gap. With gap runs, every lineman is responsible for a single defender. But with zone runs, every lineman is responsible for an area.
On zone runs, a lineman will either be covered, meaning there's someone in their play-side gap, or uncovered, meaning their play-side gap is open. If they're covered, they will reach block the lineman that's covering them. On a reach block, the lineman is moving play-side and trying to attack or reach the defender's playside shoulder. If a lineman is uncovered, he steps play-side and double-teams the first defender he finds, and then one of those two linemen move on to the second level to block a linebacker. The most common zone runs are inside zone and outside zone. Outside zone attacks off tackle and then works back inside to the cutback lanes. Inside zone attacks the play-side B gap and then the backside A-gap. If the B-gap is covered, zone runs require running backs to have really good vision because there are several gaps that they can choose. The easiest way to differentiate between zone runs and gap runs is that in a zone run, the offensive line moves in unison towards the play side, and in a gap run, the linemen are down blocking away from the play. Also, if there's a lineman pulling to the backside, it's most likely a gap concept.
An ace block is a combo block between the center and the guard. A deuce block is a combo block between the guard and the tackle. And a tray block is a combo block between the tackle and the tight end. A chip block is when a tight end or running back quickly blocks a pass rusher before running his route. A trap block is when an offense intentionally leaves the defender unblocked on a run play and then a lineman pulls from the backside to block him.
Two-gapping is a technique where a player is responsible for two gaps instead of one. The only players you really ever see two-gap are nose tackles in a 3-4, and they need to be disciplined to not pick a side too early, but they need to read the blocking quickly to figure out which of their gaps is most vulnerable.
Stack and shed is the technique linebackers use to engage blocks. Stacking requires making forceful contact and extending the arms to maintain separation from the blocker. While the linebacker stacks, he reads the run and he sheds and disengages the block once the ball carrier reaches him.
The read option is the most common option play, and it's run out of shotgun with the running back on the quarterback's side. The read player is the player that the quarterback's reading, and it's usually the edge defender. If the read player crashes, the quarterback keeps it and runs outside, and if he stays home, the quarterback hands the ball off. On a speed option, the quarterback runs wide immediately after the snap, and the running back follows the same path behind and outside of the quarterback. The quarterback reads the unblocked defender and either keeps it or pitches it. A triple option sort of combines the read option and the speed option, meaning the quarterback will have two reads and three options on this play. He reads the first defender and either keeps it or hands it off, and if he keeps it, he reads another defender further outside and either pitches it or runs.
An RPO, or run-pass option, combines an option run with a quick passing concept. The quarterback puts the ball on the running back's stomach while reading a linebacker or safety on the play side. If the defender bites on the run, the quarterback passes the ball, and if not, he hands it off.
A stunt is when two defensive linemen switch gaps, with one player essentially setting a screen, allowing the other to get to the quarterback. A fire zone blitz is when a linebacker or defensive back blitzes, and another player drops into coverage and replaces the blitzing player's zone. Zone blitzes can trick quarterbacks into throwing towards the blitz without realizing that someone's replacing that player's zone. A green dog blitz is when a player in man coverage blitzes the quarterback after realizing that his coverage assignment is staying into pass block.
Man coverage is pretty simple; one player is responsible for covering another player. Zone coverage is a spot-drop coverage, meaning the player drops into a specific location, reads the quarterback's eyes, and tries to disrupt passing lanes. Match coverage, or pattern match coverage, is what most defenses run nowadays, and it essentially means that a player has an initial assignment which can change depending on what a receiver does.
Press coverage is when a cornerback lines up right on the receiver and tries to disrupt his route. Off coverage is a less aggressive technique where the corner leaves up to 10 yards of cushion between himself and the receiver. This offers more protection against deep routes but leaves shorter routes open. Trail technique is when the defender plays a step behind the receiver. This added step gives the defender more protection against routes that break quickly in either direction, but it gives the receiver an advantage on vertical routes. Bail technique is when a corner faces inside towards the quarterback instead of facing the line of scrimmage and runs backwards at the snap instead of backpedaling. It's mostly used in zone coverage and it's almost always used from an off-coverage alignment.
Cornerbacks will play with different leverage depending on where they have help and what direction they want to funnel a receiver's route. Outside leverage means the corner is lined up on the outside of the receiver and he wants to force him to release inside. Inside leverage is the exact opposite; the corner is lined up on the inside and he wants to force his route outside. The leverage that a cornerback plays with depends on the coverage and what routes the defense wants to take away. A boundary corner is a corner lined up on the short side of the field, assuming the ball is on one of the hashes, and a field-side corner is lined up on the wide side of the field.
For the most part, pass coverages are named according to the number of deep defensive backs. Each zone coverage divides these underneath zones differently depending on how many underneath defenders there are. As the number of underneath defenders decreases, the zones get combined and become more difficult for one player to cover.
Cover zero, or zero blitz, is an all-out pressure with man coverage across the board and no safety help. Cover zero is very uncommon, and no team ran it more than one percent of the time in 2020.
Cover one, or man-free as most call it, is man coverage with one safety deep. Assuming a four-man rush, man-free will always have one extra defender, and that defender's role defines the different variations of this coverage. Most often, teams will play Cover 1 Hole, using the extra player as a hole defender who's responsible for picking up underneath routes over the middle of the field. There's usually a system of passing off routes with the hole defender. For example, if the slot corner gets beat on a slant inside, the hole defender will pick up the slant route, and the slot corner becomes the hole defender with the same responsibilities. If a linebacker is playing hole coverage, it's called Cover 1 Rat, and if the safety is playing hole coverage, it's usually called Cover 1 Robber. If the opposing quarterback is a threat as a runner, the extra defender might spy the quarterback. The extra defender can also bracket a tight end or slot receiver, so the primary defender will play with outside leverage, and the other defender will bracket the inside. The extra defender can also be sent on a blitz, and there's obviously a ton of different blitz packages that a defense could call. The strengths of Cover 1 are that you're accounting for every receiver, you can pressure with five players pretty seamlessly, and if your secondary is solid across the board, it's the most suffocating defense that you can run. But if you have even one weak link, the quarterback can identify it pretty easily and take advantage of it all game. You also need a free safety with elite speed since he's the only deep defender and he's responsible for the entire field, and you can't really count on great run support from your defensive backs because they're locked in on their man, so receivers can run deep routes to clear them out of the run fit.
As we get into zone coverages, keep in mind there's infinite pattern match rules that defenses utilize, and this video would exceed YouTube's time limit if I mentioned all of them, so I won't really be discussing those. But if you're interested in learning about those, check out the Pass Coverage Glossary by Cameron Soren. Link in the description. It's legitimately the most essential book that I own.
Cover 2 is a 2-deep zone coverage with 5 underneath defenders. In straight-up Cover 2, you've got the cornerbacks covering the flats, the outside linebackers covering the hook-curls, and the Mike linebacker covering the middle hole. Instead of having to cover the entire field, Cover 2 splits the field into two deep zones that the safeties are each responsible for. Tampa 2 is the Cover 2 variation that the Bucs popularized in the early 2000s, and the only difference is that the Mike linebacker takes a deeper drop. The soft spots of Cover 2 are the void behind the linebackers and between the safeties, and the deep sidelines behind the corners. Tampa 2 is designed to alleviate those weaknesses by bringing the Mike into the middle void, which in turn allows the safeties to cheat over to the sidelines. Two Robber sends a safety into the hook-curl zone, the cornerback into the deep half, and the linebacker into the flat. In Cover 2 Invert, the cornerback and safety switch responsibilities; the safety covers the flat, and the corner drops deep. Two-man is just man coverage with two safeties deep. Aside from the soft spots I already mentioned, Cover 2 can be weak against the run because with two safeties deep, you're gonna have a lighter box, especially with Tampa 2. The strength of Cover 2 is that it takes away pretty much everything short because you've got five defenders underneath, and corners can get an easy pick-six by playing off and baiting the quarterback into throwing into the flat.
Cover 3 is a 3-deep zone coverage, but now you've only got 4 underneath defenders, and they'll usually divide the underneath zones into the curl-flats and the hooks. In most defenses, this is the straight-up vanilla version of Cover 3, where you've got the free safety and the two corners covering the deep thirds, and the strong safety moving up into the curl-flat. But some teams that use a different variation as their base Cover 3 will call this 3 Sky. If you were to flip the safeties' responsibilities so you have the strong safety dropping deep and the free safety taking the curl-flat, that's usually called 3 Week. You've also got 3 Buzz, where the free safety and the outside corners cover the deep thirds, and the strong safety comes up into the hook zone, and then the linebacker takes the curl-flat. There's also 3 Cloud, where now you've got both safeties dropping deep, and one of the corners covers the curl-flat. With all these variations, at its core, it's the same coverage; you're just rolling into it differently and trying to keep the offense from knowing what defense you're in. Cover 3 is a balanced defense because there's three deep defenders to cover vertical routes, and you still have eight in the box, so you can be solid against the run. But Cover 3 just has so many weaknesses that it's really hard to run it very often and be successful. The first weakness is the seams, right in between the deep thirds, because you can create a two-on-one with the free safety, and he has to leave someone open. And then with only four defenders underneath, you're gonna give up a lot more in the short passing game, especially in the flats, because the curl-flat defenders will take a few seconds to get over to their spot. Also, just like Cover 1, your free safety needs to have a ton of range to cover the entire field. You can also have a really tough time running Cover 3 against an unbalanced formation because the offense can run four verts out of 3x1.
Cover 4 is usually called quarters coverage, and it's pretty much only run as a pattern-match defense. Quarters is usually diagrammed like this with four defenders deep, but it's almost never actually played like that for the entire play. The four deep defenders might drop deep to start out, but once the receiver in front of them gets 8 to 10 yards downfield, it turns into man coverage, and if everyone runs vertical, it's basically Cover 2 man.
The final coverage we'll discuss is Cover 6, which is Cover 2 on one side and Cover 4 on the other. This is also called quarter-quarter-half, and it's a good solution if you want to run a two-high defense but the opposing offense is using a lot of unbalanced formations.
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