The stack formation in the spread offense is a great way to force defenders to play outside the box. It’s a difficult formation to defend because the receivers are balanced and can attack in, out, vertical, or in the flat without tipping their hand by their alignment. This is a great formation for the pass game, run game, and even RPO’s to ensure that the offense has a number advantage at all times.
How to Use Stack Formation in the Pass Game
Quick

This is a quick pass from the QB who will pre-snap read where he will throw the football. Depth of corners and width of $ and S will tell the QB which side of the field to throw to. Most of the time, the corner that is giving the most cushion before the snap is the side the QB should throw to.
The WR’s on the line (X and Z) are going to come off the line and block the most dangerous guy. That will either be the corner or the safety if their presence is felt. The goal of the receiver catching the football is to get up the field as quickly as possible. The receiver only gets one move to get downhill. Anything more than one move will allow the defense time to rally to the football. The receiver is taught that he must get 5 yards on this play, and anything more than that is a bonus. This play, although short and easy to throw, has a chance to be a big play if the WR’s on the line are excellent perimeter blockers.
Fade-Out

This Fade-Out concept is a high-low concept for the corner. The receivers on the line of scrimmage will run a go route, trying to get over the top of the corner. The receivers stacked behind will run a five yard out.
Pre-snap read from the QB will be to first check the depth of the corner. If the corner is rolled up at, or under 7 yards, then the QB can anticipate throwing it over the top on the fade route. The width of the $ and S will also tell the QB where he has leverage on the out routes from the #2 receivers stacked behind.
Post-snap read from the QB will be to read the hips and the peddle of the Corner. If the corner is playing zone technique where his hips are open and inside while peddling out, then the QB will throw the ball on the out route underneath the bailing corner. If the corner’s hips are square and he’s squatting in position, then the ball will go over the top to the fade route.
Most likely in this single high look, the corners are responsible for everything in their deep third, and will back pedal to stay on top of the go route.
Hitch Switch

Here’s another high low concept for the corners in this single high safety look. X and Z will run a five yard hitch route with an inside release. The #2 receivers stacked behind will run a go route trying to get over the top of the corner. The hitch route is at five yards, but receivers will hear coaches say “Don’t run to coverage!” meaning, do not hitch up next to a defender. We want our receivers to hitch up in space. If the $ and S get width and try to get underneath the hitch route, then X and Z may have to slide inside or out, depending on where they have leverage.
The same rules apply to this high low concept as in the previous play. If the corner is bailing to his deep third, then the QB will come down and throw the hitch route. If the corner jumps or sits on the hitch, then the QB will throw it over the top on the Go route.
Choice Switch

This is a great route concept in the stack formation and it also plays well off of “Go-Switch” where A and Y will continue running a Go Route to complete the four verticals. In this “Choice Switch” concept, the Choice route is a deep comeback to the outside from A and Y. This comeback is usually ran at 14 yards back to 12 yards. It’s important that receivers hit their break point at 14 yards and come back down the stem to the outside. This route is open 9 times out of 10 because the corners are influenced inside when X and Z get their inside release on their go routes down the hash marks. When the corner gets caught inside, the A and Y instantly gain leverage to the outside on their deep comeback.
Post snap read for the QB is to read the single high safety in the middle. It’s the QB’s job to look off the middle safety and influence him to one side. The QB can do this by showing his shoulder and hip to either X or Z. If the safety bites to one side, then the QB immediately throws the ball to the vertical on the backside.
However, a disciplined middle safety will peddle into the deep middle third without being influenced to one side or the other. If the safety cannot be influenced, then the QB will hitch up and throw the ball to the choice route on the outside.
X Dig

This stack formation is aligned just a little bit tighter than normal because of the layers over the middle of the field. This play is tagged for X to run the dig route. The compliment to the X running a dig is the Z running a post over the top. This is a high low concept for the middle safety. The depth of the dig route is 10-12 yards, and the post is trying to cut the top off the middle of the field.
The A and Y in this stack formation will mesh underneath the dig-post. The mesh will be ran at no more than five yards to allow spacing for the dig behind it. Since X has been tagged for the Dig, the A on the same side will run underneath the Y in the mesh. These two receivers need to run their route hard to the other side of the field to get attention of the linebackers. This will open up the intermediate dig route that’s layered behind the mesh.
Post snap read for the QB is to work front-to-back. This is because the mesh routes develop earlier than the intermediate dig route and the deep post over the top. The QB’s eyes will stay down the middle of the field seeing the triangle of the two middle linebackers and middle safety. If the linebackers drop in coverage, then the QB will dump it to one of his receivers running the mesh. If linebackers sit on the mesh, or widen with their routes, then the it opens up a window for the dig. Lastly, if the middle safety bites on the dig route, then the QB can hitch up and throw the post over the top.
Y Dig

This is the same concept as the X dig in the previous play, but now the route responsibilities are switched. The Y is now tagged for the dig route, and the compliment to Y running the dig is the A running the post over the top. The X and Z on the line of scrimmage will now run the mesh. X will be underneath Z and the mesh will be ran at no more than 5 yards.
The way the mesh routes are ran will depend on what coverage the defense is in. If you find the defense in man coverage, then the receivers must be coached to keep running their routes to the other side of field. If the defense is playing zone, then the receivers must settle in the open grass rather than running to coverage and passing up windows.
Snag Concept

This snag concept is best in a 3×1 formation, which is why A will come in motion. At the snap of the ball, the A will run a bubble route and get to width.
The A’s responsibility is to stretch the field horizontally and get the attention of the $ and make him widen with the bubble.
The Y will run a Go route and get an outside release. The responsibility of the Go route is to attack the deep third and force the corner to stay over the top of him.
The Z will run the Snag route. This is a 2 stem route concept where the Z will get an inside release and get vertical for 6 yards. The Z will break on his outside foot at 6 yards and then gain ground to the inside where he will sit at 8 yards. The receiver running the snag route must understand where $ and the play side LB are on the field so that he doesn’t run to coverage, or sit next to coverage. Most of the time, the bubble route pulls the $ out wide which opens up the Z spotting up in the snag route.
Lastly, the X has the backside post. The post route is great for big plays and can come open if the free safety moves with motion and cheats to the three receiver side.
The backside post is a pre snap read for the QB. If the middle safety cheats to the three receiver side, then the QB will keep the safety on that side of the field by looking him off before coming to the backside post. If the safety doesn’t cheat, then the post is dead and the QB will go through his progression with the snag concept.
At the snap of the ball, the QB will get his eyes on the corner and determine if he’s bailing to the deep third or if he bites on the snag route in front of him. If the corner bites on the snag route, then the QB will go over the top to the Go route. If the corner bails, then the Go route is dead and the QB will move on to his next progression.
The second read in this progression is the snag route. The QB will read $ and play side LB. He is looking for the Z to sit in the window between $ and LB. The QB must also understand where the $ and play side LB are on the field so he can anticipate where the Z will spot up on the snag route.
Finally, the 3rd progression is to check the ball down to the bubble route. The bubble route will be open if the $ sits underneath the snag route instead of playing to width.
Evolve the Stack Formation in the Spread Offense
As you can see, there are a lot of different pass concepts that you can run from the stack formation. Coaches can evolve on this formation by implementing RPO’s. This can be done by simply adding Inside Zone Read to the Quick (figure 1).
The idea behind this RPO is to put the offense in a position where they cannot be wrong. If the defense wants to cheat numbers to the box to defend the run, then throw the ball to the quick routes on the perimeter. Conversely, if the defense spreads out to defend the stack, then run the ball inside with zone read.
What are some of your favorite plays out of stack formation? Drop them in the comments below!