Half-Slide Protection: Review and how to Incorporate it in Any Offense

Introduction

Half-slide pass protection has a lot of content out there for any fan to read.  For this article, I want to pose a question around the practicality of half-slide protection: If you had to run an offense that used only one pass protection, what would it be?  To me, that answer is half-slide.  I will be honest, I am not a half-slide expert, nor have I ever had the opportunity to coach it or play under it, but it is quickly becoming my favorite pass protection, and in my opinion, is one of the most fun ones to learn.  The vast majority of my knowledge on half-slide protection comes from J.T. O’Sullivan’s phenomenal video that walks viewers through the ins and outs of calling pass protection.  If you have not watched this video yet, I recommend you doing so. 

The QB School: “How do Quarterbacks Understand Pass Protection?”

What is Half-Slide Protection

Half-slide is just called “slide” by many other teams, so pay attention as you learn about various pass protections.  For this site, I’m going to call it “half-slide.”  Half-slide protection is primarily a six-man protection that features a combination of BOB (big on big) or man blocking along with slide blocking (could even argue there are some zone concepts in there).  This protection was a favorite of the classic West Coast teams in the 80’s and 90’s, and is still very popular in the NFL today, along with many college and high school programs.  It is a flexible protection that can easily fit into a lot of different systems, and has the ability to protect against almost any front or blitz a defense can throw at an offense. 

In order to use half-slide protection, you have to declare a call side.  This can be either the direction your play is going, the strong-side of the formation, or some other selected criteria.  In the end, the protection is going to have to be set to the right or the left.  To your call side, or play side, your offensive line and the lone back will execute BOB or man protection.  Offensive linemen will block the nearest defensive player on the line, and the back will be responsible for the declared “Mike” or middle linebacker through the play side or outside linebacker.  Linemen on the BOB side will often step towards that lineman on their first step.  This is a protection where calling a “Mike” or middle linebacker-type is necessary in most situations.       

The back reads the inside or Mike backer through the outside linebacker (always protect the inside first).  If the Mike blitzes, the back picks them up.  If the Mike doesn’t blitz, but the play side OLB does (we’ll call them the “Sam”), the back picks them up.  If both blitz, the back picks up the Mike, and the Sam goes free.  When this happens, the QB needs to know to throw “hot” or throw to the hot read receiver.  Some teams may also teach the back that if both blitz, to quickly get past them or to the outside and have the QB throw hot to them instead.  If none of the back’s reads blitz, the back releases into a route. 

To the backside of your call, the line will slide protect.  There are a couple different ways you can describe the slide rules.  You can treat it as BOB protection, but then have the line also be responsible for the first linebacker (or linebacker-type) to the backside of the “Mike.”  You can also treat it like zone, where each lineman is responsible for their backside gap, and they need to maintain a solid wall that has all those gaps covered.  You can also use covered/uncovered principles like in zone blocking, where the covered linemen block the defender over them, and the uncovered lineman has that backside linebacker.  For linemen in the slide, their first step is often with the foot to that side.  An easy way to watch on film and determine which is the BOB or slide side is to watch the center.  If you can see a six-man protection, with the center stepping to their left on the first step, it usually means the slide is set to the left, and the BOB side is to the right. 

Basic diagram of half-slide protection.  Note the blackened linemen are those in the slide, while the blockers in white are on the man/BOB side.  The grey bar indicates the 1st open gap play side of the center. 

Setting up the Pocket

How do you know who is sliding and who is BOB protecting?  This rule is pretty simple, but you have to pay attention to this little detail in order to really grasp the concept.  To determine who is in the slide, you need to find the first open gap (or bubble) to the play side working from the center to tackle.  Whoever is inside of that first open gap is in the slide.  Whoever is outside of that first open gap is BOB protecting.  If Half-slide is called to the right, and the center has no defender in the play side gap, that is the first open gap or bubble to the play side, so the center and anyone backside of them will slide (3-man slide).  If the first open gap is the B-gap (between the guard and tackle), the guard to the play side will join the slide (4-man slide).  As mentioned, anyone in the slide will step with their backside foot off the snap to primarily protect that backside gap, while the BOB side will primarily step towards wherever the nearest defensive lineman is. 

To set up the pocket for the QB, you’re going to want your interior linemen (guards and center) to be more aggressive on their blocks, and to take a flatter trajectory off the snap (more parallel to the line, then back).  If a center or guard that is sliding, or is BOB blocking to a defensive lineman that is in an adjacent gap, while they’ll retreat off the snap, it will not be deep, and you’ll notice they quickly stand their ground and try to keep that defender in front of them.  With the tackles, you’ll often see them taking a more liberal retreat in an attempt to wall off outside pass rushers.  If you watch film carefully, you’ll notice an almost deliberate set up of a semi-circular pocket based on the steps; guards will often step right at where the tackle’s inside foot was, while the tackles back up off that point, facing out, forming an almost seamless wall as the pocket opens up. 

The back needs to aggressively step forward to get in front of the QB, and aim for the Mike backer first.  As they read and progress, their feet must be always on the move so that they can quickly turn out to take on the Sam if they blitz. 

Adjusting Half-Slide Protection

A secondary rule or aspect of the protection is when a defense has another LB-type threatening the protection to the outside of the backside or “Will” linebacker.  When this happens, a few things can be done. 

• As J.T. O’Sullivan explains, the QB can make a “Tom” call, which tells the back to block that defender, but that leaves the Mike and Sam unopposed if they blitz.  This should only be called if the QB is confident the Mike and Sam are not going to blitz. 

“Tom” call adjustment, as explained in “The QB School.”

• The second option is for whoever is declaring the Mike to call that would-be-Will as the Mike instead, therefore making that extra defender the Will (the line has that extra defender now).  The new Mike is now backside, and the Sam is the would-be-Mike had that adjustment not been made. 

• Like changing the Mike to a defense’s weak side linebacker to account for a backside overload, the Mike can also be the defense’s strong side linebacker as well (so a would-be Mike and Sam become the Will and Mike).  Changing who the Mike is can be as easy as simply saying “Number X is the Mike!” 

Half-slide with the BSLB declared as the Mike.

• A third option, if you don’t want to change the back’s assignments, or are worried about the play side rush too, is to utilize “sight adjustments,” and use sight adjust reads off that extra defender.  This can be done on the play side too if there’s another DB/LB-type blitz threat outside of the Sam. 

Half-slide with backside sight-adjustment using a detached receiver.

Sight adjustments are when a receiver is called on to assist with blitz beaters.  When a sight adjust is declared it’s because there is simply one too many defenders to a side for the protection to pick up.  The declared receiver (based on the rules of the pass concept, or formation) will eye that defender off their first couple steps post-snap.  If that defender blitzes, the receiver will immediately break their route and run a slant, or some other route that immediately replaces that defender, and they get ready for the quick pass from the QB.  When a sight adjust is being executed, the QB will “sneak a peak” at that defender, right off the snap.  If the defender blitzes, the QB immediately throws to that receiver.  If the defender doesn’t blitz, the receiver runs their normal route, and the QB goes into the play’s progression. 

Another adjustment is when the defense has only a five-man box, or the offense wants to put an offensive lineman on a Mike linebacker.  J.T. O’Sullivan calls this a “base” call, but you can call it whatever you want.  All that changes here is that the line now “slides to” the Mike, and they are responsible for that defender.  That of course leaves the Will and Sam unblocked, so that responsibility falls to the back.  The back will read Will to Sam, instead of Mike to Sam. 

Half-slide with a “Base” call (from “The QB School”).

You can also run an empty version of half-slide, which is pretty simple.  The line uses the same rules as normal.  The QB now has to throw hot off the Mike, then Sam.  If the Mike comes, throw hot.  If the Mike stays, but the Sam comes, throw hot.  If neither come, go into the play’s progression.  The “base” call can also be utilized so that the Mike is covered, who against an empty formation, will be the most likely linebacker to blitz. 

Half-slide “empty.” 

Incorporating Two-back and Tight-end Sets in Half-Slide Protection

Say you’re an offense that still wants to run only one protection which is half-slide, and you’d rather have more than six protecting.  You can easily add more backs and tight-ends into the protection.  Nothing really has to change for the offensive line.  Below are some different ways to incorporate these skill players:

• From a 2-back formation, have both backs take the Mike and Sam.  The rules you use can determine which one has which.  By doing this, you can now protect seven defenders, and only have to throw hot if eight rush.  The hot defender would then be the first defender outside of the Sam.

Half-slide with two backs and play action.  Note there is no “hot” defender, because the extra LB for the normal 1-back is picked up by the second back.  The “hot” defender would be an eighth defender coming down into the box.

• From a 2-back formation, make the “base” call, putting the line on the Mike, and have each back take the OLB to the side they are closer to.  The next defender outside of the Sam is the hot defender, and the next defender outside of the Will is the sight adjust defender.

Half-slide with two backs and a “Base” call.  Note there is no “hot,” because the extra LB is picked up.  The “hot” defender would be an eighth defender coming into the box.

• If you incorporate a tight-end and one back, it’s the same as the 2-back set, but now the TE takes the Sam, and the back takes the Mike. 

• If you use two backs and a TE (8-man protection), and your TE is on the play side, the TE can take the Sam, one back can take the Mike, and the second back can take the sight adjust or first defender outside of the Will.

Half-slide set to the right with TE in place of 2nd back (left), and half-slide set to the left with max protection (right).

Using Play Action

If you are a team that loves play action passing using half-slide is a great way to marry your play action and drop-back pass protection.  If you operate from a 2-back formation, you use the same rules as the 2-back adjustment.  If you’re faking an inside run, like inside zone, power, or ISO, the faking back should take the Mike, and the blocking back takes the Sam.  If one of them doesn’t blitz, the back blocking them can release into a route.  If you want to fake an outside run, like a toss sweep, or an outside zone with the back coming across the face of the QB in shotgun, you can allow this fake to happen by switching the blocking assignments: The back faking takes the Sam, and the blocking back takes the Mike.   

One thing you might want to consider changing up however is the aggressiveness of your offensive line.  When you’re running play action, you want to keep that defensive line at the line of scrimmage, and sell the run to get the defense to bite.  Rather than having your line retreat into the pocket off the snap, consider having the tackles fire-out at the defensive ends, almost as if they’re going to kick them out to the sidelines.  With your center and guards, rather than taking a kick or drop step, simply to a post or replacement step (pick the foot up and put it back down), then hold their blocks at the line.  Note that if this is the route you take though, you won’t be as able to pick up delayed blitzes and wacky twists and stunts.   

Incorporating Half-Slide Protection in Different Systems

This section will show various diagrams and ways you can incorporate half-slide protection into some different offensive styles and series.

• Wing-T: Buck Play Action

• Wing-T: Belly/Down Play Action

• Flexbone Option and Split-back Veer

Half-slide from option oriented offenses.  Flexbone option (left), and split-back veer (right). The pitch-back in the triple option could be used in route, and the dive back blocks (regular 6-man half-slide), or you can have the pitch back block the Sam (half-slide with 2-backs). 

• Spread (Air Raid, Run ‘n’ Shoot, Zone Read, RPO…any gun + spread oriented offense…

Not shown: If you are in a 3x1 (trips) formation, and your protection is called to the trips side, your single receiver to the other side is your sight-adjust receiver, unless you have your back be the sight-adjust receiver (right diagram).

Summary

Half-slide protection is one of the most versatile pass protections out there.  It can be used against just about any defense, and with careful planning, can be the foundational pass protection in any type of offense (I was even diagramming this protection from the unbalanced Single-Wing, but I felt that was a bit too much for this article).  What makes it so useful is that it can easily be used in your play action game as well.

I hope you all enjoyed the read! Stay safe and keep learning!