“How Do You Play Trips?” Pt. 3 – Defending the Run

Defending a spread offense’s 3×1 package run game from a two-high shell.

When developing a defense it is important to start with the front and work back. Lining up correctly to formations, understanding keys, and developing a plan to stop the run all starts with the front seven. In a 4-3/4-2-5 (or 3-4 Hybrid) defense, the secondary players become the adjusters. Playing a single-gap defense and using formations to dictate alignments allow defensive players to see the formation quicker and align correctly. Each player in a defense is anchored to one another in some way. Understanding these anchor points, and how they change depending on formations, is crucial to the success of any defensive unit.

The Spread’s utilization of space has put aligning correctly every play at a premium. It is easy to align to a simple 2×2 formation, but when offenses utilize 3×1 formations (primarily Trips Open) the defense must understand how it adjusts will dictate their areas of weakness. Offenses make use of Trips formations because it forces the defense to give something up. To gain a six-man box a defense must spin, either to the Trips or away. 

01-spotTo keep the front side pass distribution (and a four-over-three pass distribution) the defense can insert the backside safety into the box (see left). This allows the frontside Mike to cover down to the #3 WR. The Down Safety (DS, or backside safety), inserts into the box and will relate to #2. This creates a Cover 3 scheme to the single WR side and places a secondary player as a primary fitter (he is responsible for a single gap). The issues with this are obvious, most defensive coordinators do not want to put a safety in the box. The defense is also susceptible to any backside vertical route by #2. Traditionally, offenses have used the “X” WR in Trips to gain one-on-one advantages because many DCs chose to “kick” to Trips or spin to single-high to gain a six-man box. The point of stay in a two-high shell versus Trips is to protect the easy vertical throw to “X.”

05-cov-3The more frequently used adjustment to teams that run out of Trips formations is to spin to single-high and run a Cover 3 scheme over the formation (see right). Spinning to the Trips side allows the Mike to work back into the box. The front side safety works down on top of the #3 WR. The Sam works to his typical cover down to #2 and plays a two-on-two over/under scheme with the CB. Both safeties will bracket the #3 WR in a similar fashion. If the RB flares to the field, the spinning safety and Sam will exchange any push or rub routes. The main advantage of this scheme is the Mike is now in the box and only responsible for a gap (though he must push with the RB to the field) and the defense has created a six-man box. The Will is responsible for #2 weak if the back flares to the boundary. Like the weak spin discussed earlier, the disadvantage of this scheme is the manned CB on the single WR (“X”). The vacating boundary safety creates an easy throw to the middle of the field (or near the seam) for the QB. Many offenses that see a “kicking” safety attack the vacated zone behind him.

Using a Two-High Shell to Gain a 7-Man Box

Trips formations force a box player out of the box. This can lead to a lack of numbers when defending the run. Especially if a DC does not understand how a Trips formation changes who is deemed a “box” player from a two-high scheme. Many DCs when defending the Spread want to stay in a two-high shell. This allows them to protect the backside CB and gain run fitters from the safety position. Even staying two-high, some DCs will still “kick” the backside safety to account for the vertical of #3. See below:

The issue with both of these coverages is that the offense can easily use a false read by the #3 WR to get the DS to kick frontside. This creates issues to the boundary because the Will is technically the new Mike and there is no one outside the DE. Essentially, by kicking, the defense has lost its plus-one. The point of staying even and using a two-high shell is to always have a plus-one in the run fits and pass distribution. One way to do this is to use Stress or Special as a base coverage. Most offenses do not utilize the #1 WR to the three WR side (plus, it is a hard throw to make from the boundary). By using the law of averages and challenging the offense to complete low percentage throws, a defense can stay plus-one and protect the boundary CB by keeping a two-high shell.

01 3x1 Run Fits

In the image above, the defense is utilizing Stress as its base and an Under Front to gain a cover down for the Mike. This setup allows the defense to gain a seven-man box. Most OCs do not see the DS as a “box” player because he is aligned at 10 yards. This is an advantage to the defense because he is a box fitter. To the OC, he may see a 4-1 box because the DS is deep and the Mike is “hipped” on the DE (not in his open gap). Offenses choose to attack this defense by putting the RB to the three WR side and run the ball to the weak side. In an OC’s eyes, there is a numbers advantage weak.

In actuality, the numbers are there for the defense to gain a plus-one. As the Sam covers down to his responsibility in the #2 WR, he has removed himself from the box and is no longer responsible for a run fit. This defensive alignment shifts the defense to the three WR side. The responsibilities in the box shift as well. Using Stress as a base coverage and leaving the backside safety (DS) to help with the run, the defense now must adjust the fits. The Will becomes the new Mike and the Mike and DS take the roles as the OLBs. By doing this the defense still has four down linemen and three “LBs.” The fits should stay the same as though the formation was a simple 2×2. As stated earlier, the offense will see this as an advantage because they will believe they have a 4-1 box and now fit support defender to the boundary.

By adjusting (and sliding) the LBs to the three WR side, the defense has created a numbers advantage against the run and the pass. To the front side, there is a four-over-three pass distribution advantage, and in the box, there are seven defenders six potential blockers (QB run). If the offense does not utilize the QB in the run game, the advantage is even greater for the defense.

Run Fits vs. Popular Spread Plays


Zone Read

Versus the Zone Read, natural gap exchanges to the front side allow the Mike and play side DE to keep option responsibilities (Mike = QB/DE = Dive). Using single-gap principles, the Will can take his “A” gap and the DS acts as a plus-one to the backside of the play. Even if the offensive tackle sifts (holds the DE from crashing by duck walking vertically), the DE will still have time to take the cut back and the Mike does not have to move (negating the sift). The ability to “hang” in his position allowed by natural gap exchanges also helps if the QB decides to throw a WR screen. The Nose pays a key role in collapsing the play from the backside. If the offense “bangs” the Nose to allow the Guard to overtake, once the Center climbs to the Will, the Nose must cut off his backside. This movement can allow the Will to “belly key” to the opposite “A” gap for the cutback. The DS acts as the adjuster to the Will. If the Will gets walled by the Center, the DS can scrape to the opposite side for the cutback. If the Will belly keys and gets caught outside, the DS will fit into the vacated “A.” Either way, the defense is granted a plus-one.

Power Read

Power Read (and all its variations) might be the toughest play in football to defend. The issue with the Power Read is that it is in fact Power. The major difference is the path of the RB. In traditional Power, the RB is downhill and the play side DE is asked to spill any puller or “J”/out block. Versus a 3×1 formation, the DE is responsible for the Dive. This creates a problem.

Power Read flips the read traditional rules for option. The Dive is no longer going to the RB, it is going to the QB. The path of the back is flat like stretch. If the DE climbs to get the RB, the QB pulls to a spilling Will. The Mike, who is outside the box, should climb to the RB working outside. Now the defense finds itself with two players outside and no one for the QB. If the DE plays it like Power and attempts to spills the puller, the Guard can log the DE and still work vertically. This is why as a DC, it is important to teach the DE to read the RB’s path. If it is downhill, the DE should play it like Power. If the RB’s path is flat and fast (Stretch), the DE should climb to the QB.

With any gap play, a defense wants a man on either side of the puller. Versus Power Read, if the DE reads the path of the RB (flat and fast) and climbs to the outside shoulder of the QB, he technically is the “boxer” on the pulling Guard. If the QB escapes the DE he will have to cut it back to the Will who is fitting inside. This fit should create a “give” look and the Mike should tackle the RB as he exits the box. Here are the base fits versus strong and weak Power Read:

If the play is run to the weak side, the DE will climb to the RB (he has first outside threat) and the QB should pull. Using Power fit rules, the Will spills the play to the DS. Mike works into the box as the cut back player (to the front side that would be the DS). Fitting Power Read as though it is Power allows an easy transition and simple rules to follow when defending the Spread’s most dangerous play.

Counter GT (Read)

The Counter GT from a 3×1 formation can be a tough play to defend. With two pullers, the defense must account for two created gaps. When ran to the weak side, there are two options a DC can have: 1) Spill the pull or box the pull. If the DC decides to have the DE spill, it conflicts with his Power Read responsibilities. The objective of the spilling DE would be to force the Tackle to log or stop him from wrapping. The DE could box the kick out block, but that would allow the pulling Guard to easily work upfield. Either way, the play is elongated and it frees up the LBs. The Will fits the puller the same way he would Power (spill). The DS should fit on the outside of the puller and work the alley if the play spills.

The easiest way to keep things consistent, and to ensure the DE does not have to “read” is to keep this simple rule: DE with the Nose = Spill, while the DE to the 3 tech. = Box. This would keep the DE’s action the same. If reading the play by the DEs, the trick is to read the QB. In first-level read schemes, the QB will look directly at the DE he is reading. In Power Read, the QB will stare down the front side DE. In Trips, this would make the DE climb to the QB as the OT down blocks. If the offense is running Counter to the weak, the DE would close off the OT’s down block, see the QB’s back and spill the first puller. Obviously, this is to the DC’s discretion. See the two fits below:

The backside of the play is just as important as the front. With the running back working flat and fast away, the DE can close off the pulling Tackle’s back (Dive). The objective here is to muddy the QB read. If the DE stays at home and keeps his shoulders square (or climbs), the QB will give the ball (if reading the DE). The Mike LB only works into the box for the cutback when the QB hands the ball off. Otherwise, he stays at home taking the QB (Option rules). Another way to play the DE would be to read the RB path like he would verse Power Read. Flat and fast means take the QB, downhill means take the Dive. The only problem with this is the offense can play with the way the DE reads the RB. Leaving two players on the QB can also open a hole for the cutback, especially if the Nose cannot cross face.


The main issue with defending Trips from a two-high shell alignment is the DS must be aggressive to any run weak. This makes him susceptible to play-action. By using a Sky technique and setting the front away from the three WR side, the backside safety (DS) is allowed the luxury to step-off from his alignment. By placing the front away from the offensive strength, the defense has created a natural barrier to the boundary. The DE to the 3 technique’s side will hold the edge versus any stretch or outside run. This allows the safety time to run the alley or work into the box.

Keeping fits consistent throughout a defense is a key component to getting players to play fast to the ball. Understanding how a two-shell can adapt to work as a 4-3 front seven can help a DC in much more than run fits. Utilizing the DS in a Sky scheme to the backside of Trips can help with the run and pass. When the offense shifts to a Trips formation, the defense must adjust accordingly, taking the Sam out of the box. This shift makes the DS the new Will and the “box” LBs shift to cover down on the #3 WR (“pull the rope”).


Looking for Part 1 and Part 2? Click the links below.

Part 1: Why You Should Run an Under Front to 3×1 Sets

Part 2: Top Trips Coverages Explained


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11 thoughts on ““How Do You Play Trips?” Pt. 3 – Defending the Run”

  1. Could you teach it as the RB on a stretch path on Pwr Read is the same as the kickout on a regular QB Pwr? Then boxing the wrapping guard and going for the QB would be the same as spilling the guard on Counter since the DE is boxing the wrapping tackle. The problem would be to recognize when the pulling guard coming towards you is kicking out or wrapping

    1. We teach our DE to read the RB’s path. Fast & flat = Read & climb to outside shoulder of the QB. If RB is downhill = attack the pull.

  2. Okay, defending the read side on power read and the kickout/wrap side on counter GT is taught two different ways here? Vs Power Read, the end being read plays QB. But vs a pulling guard, he spills? You mentioned reading the backs path, but what if both plays are run with the back coming to the end? If that’s the case, he has two different reads for nearly the same concept. How does the DE, in a split second, know to kick or spill?

    I’m not trying to be difficult, it’s one of the hardest things to teach and I’d love some coaching points if you have some on it.

    1. To simplify it you read the QB. Face to you = Read/Back to = traditional blocking. Vs Pwr Read QB will be starring at him, in Ctr he will be looking away. Close down off the OT & read the QB. The 1st initial steps are the same. Eyes to me, climb. Eyes away spill. You have to rep it like anything. If you don’t think the DE can do it simplify: Nose side spill, 3t side box.

      **Added this to the article.**

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