The most common way of utilizing 2x2 formations is to pair concepts that attack well against different defensive coverages. In this way, depending on if the QB reads a single-high safety or a two-high safety defense, the QB can determine which side of the field is best suited for attacking. These concepts can be found in the TE-Flanker and Twins Concepts. These can be longer developing route concepts or shorter developing concepts, just understand that you can only utilize a maximum of a 6 man protection scheme. Because of this, you want the option to adjust to a hot route or build in a hot route. This means most play action situations should be at most a standard fake at most, but often a weak fake simply in an effort to freeze the defense to better diagnose the coverage.
Below, I've paired a standard double slant and a smash concept. At the snap, if the QB reads a single high-safety, he will look first to his left, to the double slant; if the defense is in a two-high safety coverage, the QB will look to his right, to the smash concept.
These concepts can be paired out anything from 10 personnel to 12 personnel to 31 personnel, which allows the offense to give a lot of different looks (increasing the complexity for the defense), but keeps the offense simple for the QB and receivers. In all the cases below, the offense is in a 2x2 formation, regardless of personnel. The formation is balanced, just understand which of the standard concepts work well with your personnel and their split (attacked to the LOS or split wide), and you can simply adjust your offense based on personnel strengths or run game preferences.
Here, we'll look at pairing a standard single-high safety beater concept (slant) with a standard two-high safety beater concept (smash). Out of the different personnel groupings, the concepts hardly change, but the look for the defense can change a lot.
11 Personnel - Ace Right
A 2x2 formation with three WRs, a TE, and a RB. You can run the ball successfully, particularly if your zone based, but you threaten the field with 4 vertical threats.
12 Personnel - Ace Right Wing
Another 2x2 formation, this time with two WRs and two TEs. This puts a lot of strength to the right side of the formation to create a serious run threat, either by outflanking the defense or merely adding additional gaps to the mix. However, the twins set on the left side still allows for a number of concepts, including WR screens and rub routes (the smash has been changed to a China concept, but the goal of the two concepts is the same, you can run either in this situation but my personal preference is the China concept).
12 Personnel - Dot
A favorite of a lot of zone run based, pro-style teams, this provides a lot of gaps for any 7-man defensive front to control. But an offense can still feel comfortable utilizing standard 2x2 concepts to have success.
10 Personnel - Doubles
The standard spread offense, with 4 WRs and a RB. From Air Raid to Spread-to-Run offenses, this simple use of pairing concepts can be very effective at simplifying QB reads and getting the ball out on time.
31 Personnel - Pistol Diamond Right
But run heavy teams, including wishbone or flexbone teams, can utilize the same concepts. Here, you obviously have the capability to utilize a lot of run game variety, but mixing in standard pass concepts reduces the amount of practice time needed that has to be devoted to the pass game. Include a few standard concepts in your system and you can continue to focus a lot of your time on the variety of run threats you need to establish within your offense.
It doesn't have to be these two concepts by any means that are paired. Any single-high safety beater and any two-high safety beater can be paired, that's the beauty of it. It just depends on how many concepts you want to implement.
There are also quite a few standard mirrored concepts that teams like to utilize. This doesn't have the same advantages as the paired concepts does above, but there are a few advantages. As a play caller, if you are confident in what the team will run, you minimize your QB's thought process and allow him to get into his reads quicker and be more confident in his reads. Also, if you run a standard set of routes, they should be able to be effective regardless of the coverage, assuming you are capable of mixing up concepts to keep the defense honest. Additionally, this allows you an easier ability to pick on a defense's weakness, either a specific player or a specific side of the field (right and left, or field and boundary). Lastly, if you run these concepts enough, you should begin to be able to run route adjustments to better attack the defense. This again forces both QBs and WRs to make sight adjustments during the play, but as long as they are on the same page, it's a simple and effective way of attacking defenses.
Double slants is typically considered a 2-high safety beater, while Slant is typically a better single high safety beater, but both can win against either coverage. In this case, I consider this a mirrored concept, because All-Slants (next play) can cause congestion in the middle of the field, so some prefer to run this version.
As I said, it can beat any coverage. Just make sure you have wide enough splits so that your receivers aren't running into each other and putting the QB in a position where he doesn't see a defender falling off another defender. Make sure your QB quickly identifies his movement key and throws to an aiming point defined by the defense, you don't want to lead your receiver into the middle when defenders are quickly diverging.
If you have a vertical passing attack or are able to suck defenders into the box, this is a quick and easy way of overloading underneath zones and spreading the field laterally. Likewise, defense's that are forced to play off will give up run after the catch. Just make sure the ball gets out quickly, as if the defense recognizes this route it can become a dangerous pick-6 throw.
Similarly, this is a great intermediate throw that gives the QB a similar movement key read as the all-slants. Here, your receivers are running away from the interior defenses, which gives your QB a clean throwing line and leads him and the receiver away from the wash. Help your QB by running play action or rolling him in the direction of the throw so that the ball doesn't have to travel as far and allow the defense to break on it.
All verts is one of the scariest concepts any defense goes up against. It forces the defense to be sound fundamentally, as any receiver has the potential to get behind the defense and get a big play. It overloads deep zones and puts man defenders in one-on-one situations. Utilize MOFO/MOFC (Middle Of Field Open/Middle Of Field Closed) rules to make this an even greater threat.
You can pretty much utilize the entire route tree here if you want, but the above are the most common. All Comebacks, All-Ins, etc, can also be effective, as long as the QB has the arm, accuracy, and gets the ball out on time.
This works in the same way that the mirrored routes works above, except now we are using concepts that combine specific routes to be effective. We mirror those concepts on both sides of the field to have the advantages described above.
A very effective two-high safety beater, attack a certain defender or a certain side of the field. If a safety is weak in man coverage, pick on him with the corner route. If a CB is playing off because he's afraid of the WR speed, pick on him with the smash route. These "match-ups" allow this to be effective against man coverage as well, and understanding how defenses rotate in Cover 3 can leave that outside smash open to boot. Or just let the QB decide pre-snap based on feel and open grass.
Double Crease works great because it can be effective against either coverage because of the MOFO/MOFC rules. Against the single high safety, both vertical threats put that center field defender in a bind, while often times seeing the hook/curl zone defender follow deep. The inward breaking route provides a clear throwing lane and a fairly short throw for an intermediate route, while clearing out the inside defenders. Because the dig can settle between zones, it works equally well against man and zone.
The corner routes provide the benefit described in the Double Smash concept, but the snag allows the outside receiver to run a bit of an option route against zone heavy defenses. He can settle in any weak spot of the defense, and a quick, short throw underneath (where the corner route has vacated the defense) can allow for nice completions.
This is similar to double crease, but this runs off the outside receivers while forcing the center field player to cover even more ground (forcing one-on-one match ups. You can find one-on-one match ups on the outside because of that, or you can find ways to get LBs matched up on receivers, that should be able to utilize their athleticism to beat them to the sideline. More of a two-high safety beater, you can run it against man or zone, but just be aware that the out is a long throw that can be undercut, so make sure your QB is comfortable looking for man coverage coming from inside-out, or zone coverage jumping from underneath.
Essentially the same as Double Smash, but this provides a bit more of an intermediate threat to pick up those third and 7+.
Double 9 Out
A very effective way of running 2x2 sets is by utilizing option routes. This really takes advantage of the mismatch between your receiver and the defenders. It allows the receiver to break in multiple ways, depending on the view of the defense, in order to get open.
Previously described, but this gets the outside receivers matched up with interior players a lot. The snag can break back outside or continue inside if need be.
Double 9 Option
The option route is a quick, 4-6 yard route that allows the receiver to hitch or break inside or outside depending on the weakness of the defense. It often sees slots/TEs matched up against LBs and sometimes safeties. The 9 Route on the outside is a very good way of clearing out the outside defenders while holding the safeties over the top to prevent them from crashing down on what is perceived to be an opening in the defense. This makes life easier for both the receiver and QB to be on the same page.
Double 3 Option
The out route doesn't hold the safety, but it does hold the outside defenders further outside. One of the main threats of running the go route is that the outside defender may pass the receiver off and come down on what looks like an opening on the out route. This makes sure the outside receiver is held off, so if that Cover 4/Cover 2 uncertainty is there, this can mitigate that. Just be sure to maintain a vertical threat so safeties don't come into play.
Double Stick Out
Works the same as Doulbe 3 Option, but from a tighter formation (often referred to as a DOS set), typically with bunch routes. If the arrow route wins immediately, that's a nice throw to be able to make and allow your receiver to turn up field and run down the sideline, otherwise, look to the option route. Works well additionally because of the threat of crossing routes that are often seen from this type of formation.
While we won't cover the middle of the field threats yet, that is a primary threat from this look. However, because of the tight formation, teams often can get out-leverage on the outside and get beat with outward breaking routes as well. These mirrored concepts do just that.
Double Stick Out
Essentially a Double China route, works the same as Double Smash in that it provides a high-low read on the outside.
I want to keep most double moves to a separate post, but the swirl gets teams peaking outside that want to jump the arrow route, and provides a nice throwing window for the inward breaking route (and most inside defenders have already passed him off and are no longer as focused in coverage).
Rather than attack with the corner route, this utilizes a post or deep cross from one of the receiver. In this way, you keep the safety play honest, while putting a lot of stress on one safety in a two-high look. This works well to hold a single safety and provide a one-on-one match up with the corner route breaking to grass, or it overloads a two-high safety who often isn't looking for routes coming from the far side of the field. This works great with play action and a roll out, as all three receivers can be hit with the roll out and it overloads a side of the field (made easier by the tight formation, meaning the deep cross doesn't need to travel as far).
Base Concepts are typically three man concepts, though blockers can eventually leak out and become threats for dump offs. But typically, this utilizes a standard "route tree" route on the outside, along with one of a few routes from an interior receiver, either a slot or a TE, or even potentially a back. I won't go through all the combinations here, but instead look at the standard Base routes and the inside receiver options.
Base 3 Y Cross
The deep cross from the inside receiver is often difficult for defenses. It forces the deep safeties to be aware of the whole field and see routes coming from the far side, when the immediate threat is typically the receiver to their side. It can also lead to confusion. In the example of Base 3 Y Cross, the CB may have the responsibility to sink into the deep cross, but if he doesn't see him and tries to jump the out, a deep threat is wide open. But this can also be paired with something like a Go route, in which the receiver runs off a deep third defender or something of that nature. That's the beauty of the "Base" concept, is it works a few different routes in which the QB knows what to look for, so that the QB can get the ball out quickly based on simple reads. It's simple, but can see defensive confusion.
Base 4 Y Mid-Read
The Hook route is a standard Base Concept, as it works as a viable one-on-one beater. But an "alert" with the inside receiver running a Mid-Read is a nice way to keep the vertical threat alive, despite only one receiver running vertical. Here, based on the MOFO/MOFC rules, the TE can threaten the field in a number of ways. But if the safeties start creeping down due to run game success or because they are tired of being dinked and dunked, the TE or slot because a serious mismatch issue with a LB running with him in man, or because he can get behind the safeties in zone.
Base 5 Y Drive
Base 7 Y-Stick
The 7 route works away from inside-leverage defenders and is typically a safe throw that runs off the underneath defense. This allows the Y-TE in this example to run a stick route, which starts as a hitch but then works outward to get open. This is great from a match-up perspective, as either the quick hitch is open between zones, or the TE can wall off and outrun the LB in space.
I'm typically not a fan of mirrored concepts, but they do have their place in football and they can be very effective. These examples simplify the game for the QB and often times the receivers, in that they ask them to do a limited number of things, and it takes some of the thought and decision making out of the QB's hands, which can be very good for young QBs that don't have the full grasp of the playbook down. Likewise, the 2x2 paired concepts can be a staple at any level. You're simplifying the playbook by working with a limited number of concepts that work in tandem to beat essentially any defensive call, and besides the simplified read the concepts themselves provide, the only additional thing you levy onto your QB is a read of the number of safeties (which isn't the most difficult thing to teach). You will see this from the High School level to the pro level, and for good reason. They are effective and they get the ball out of the QB's hands and into the hands of the playmakers.