Before moving on in the series, I wanted to take a moment to hit on the concept of leverage. It's a concept that's fundamentally very simple, but fully capable of eliciting a full-on Keaneau Reeves "Whoa!" when you reflect on how integral it is to more or less every schematic element of the game.
The first and best description of the concept of leverage relative to football that I heard was from a fresh-faced Scipio Tex back in the HornFans days. This was during the heyday of Greg's Dancing Bear Fandango on the offensive line, and young Scip was describing reach blocking with an awesome labrador/tennis ball analogy that he'll hopefully reprise in the comments. The upshot was that if you've got three things in a hallway - you, the ball and your dog - your starting position relative to the dog will either make it a lot easier or a lot harder for you to keep your dog from beating you to the ball.
In football, it's basically the same deal. All over the field on every down, you've these battles taking place. There's an offensive player and a defensive player, and they're both fighting for position relative to where the ball is (or, most of the time, where it's going or is most likely to go). And their leverage relative to that place they're trying to get to either makes life a lot easier or a lot harder.
And THAT, in a nutshell, is a very good way to think about the whole science and discipline of drawing up plays and schemes. Whether you're drawing up an offense or a defense, your job is to get as many of your guys in good leverage situations as you can.
Run Game Leverage
Leverage plays a role in every battle along the offensive line. Let's consider a very simple world for a moment - an offensive guard, the defensive tackle across from him who he needs to block, and where the running back will be carrying the ball (as always, click to embiggen):
It's a happy day for the guard! The ball is going outside him, and the defensive tackle is lined up inside him. The orange shading in the the guard's circle denotes that he's still "covered" by the DT - here, aligned over his inside shoulder, though he's been moved up and out a bit for the purposes of drawing in some blocking diagrams. Since many zone blocking rules in particular have to do with who's covered and who's uncovered, you'll often see shading like this on play diagrams to help denote the exact alignment of the DL. Most likely, our guard in this situation will be asked to perform a down block:
He'll hit the DT at an angle and try to drive him out and away from where the ball is headed, or at the very least stonewall the DT and keep him from closing on the ball. Down blocks aren't all cake and candy - if the guard lacks agility or engages at the wrong angle or height, a quick DT can slip under that block into the backfield and wreck the play. But on the whole, it's relatively easy for the guard to execute his assignment here thanks to his positioning advantage. Mason Walters used to be very good at this block on Harsin's signature Pin n' Pull run, and Chris Hall did a laughably bad job of executing it against Ndamukong Suh in the Big XII Championship Game.
But what if the DT is lined up head-up over the guard?
Now we've got a little bit more of a fight on our hands. Nobody's really got a position advantage here, and this kind of positioning from the DT means that he's likely got a two-gap responsibility which includes getting out to where the ball is trying to go. This is man-on-man, strength-on-strength time that typically calls for a standard base or drive block:
The guard is probably firing out on the snap, looking to win the "low man" battle and the battle of arm positioning in order to control the DT. He may be working to get his helmet and hips between the ball and the DT at that point, or he may just be looking for vertical displacement (a.k.a. driving the dude's ass backwards) and staying engaged so that the DT can't come off his block to molest the runner.
And now the fun really begins. What if the ball carrier is aiming at that B gap outside the guard...and that's right where the DT is aligned?
Now you're living in a whole different world. To execute his assignment and leave the runner free to run on his outside shoulder, the guard will need to to do a lot of things differently. Does this mean giving this assignment to the guard is wrong or bad or dumb? Not in the least. This assignment - reaching a three-technique DT - is usually exactly what's asked every time an Inside or Outside Zone run gets called to the weak side. And there's a whole lot of tape of a whole lot of dudes - Terrell Davis, Arian Foster and Alfred Morris in the NFL, Joseph Randle and pick-your-OSU-back among many others in college - making a whole lot of yards running right off this block. But because of the initial leverage situation, the guard's whole approach changes:
The guard is performing a reach block here, and the way it's drawn up denotes the different approach that a reach block in a zone scheme requires. That little jag at the bottom denotes what Joe Wickline calls the zone drop step. Taking that step will give the guard some depth to improve his angle (and thus his shot at getting in front of the DT) and get his hips aligned on the track that he's going to run. The angle of the main line denotes the zone track that he's running - we'll delve into all this a lot more deeply in the zone blocking installments, but you'll usually see a zone play diagrammed with all of the OL running parallel tracks.
The guard's step, track and approach when he hits the DT are all aimed at giving him a shot to establish that outside leverage before the ballcarrier arrives and the DT has a chance to eat him. But, of course, this is a hard thing to consistently accomplish. And THAT is why high-functioning zone attacks do a few very important things:
1) Vary your snap count so that the advantage of knowing when the ball will be snapped is a meaningful advantage for your OL,
2) Feature complementary plays that will punish a DT for sprinting outside at first movement, and by far most importantly,
3) CUT THE DAMN BALL BACK.
If this is a weakside Inside Zone run, that block on the first down D-lineman (here, the 3-tech DT) is the key read for the runner - if the DT is sealed inside, the ball is almost certainly going outside him. But winning outside leverage isn't a do-or-die proposition for our guard, because if that DT is flying fast to the outside the guard can simply transition to a drive block and take his ass all the way to the sideline. And if everyone else on the back side is doing their job, the runner can cut back into the A gap (or even all the way out the back door past the right tackle) and find plenty of daylight:
Leverage is vital, but it isn't immutable - it can change as quickly as a runner can plant his foot for a cutback. But it takes a whole offensive front (or defensive front) working together as an integrated whole to make sure that the leverage stays ever in your favor.
Passing Game Leverage
The concept of leverage is also primary to both sides in the passing game. Just about every offensive scheme and route combination can be thought of as a way to get somebody (or ideally several somebodies) a leverage advantage over the guy who'll end up trying to prevent a completion. The organization of the multifarious zone schemes and pattern-matching approaches on the defensive side can all be thought of as making sure that all the offense's receivers are running into a leverage situation that favors the defense - or, if it's unfavorable to the defense, it's shallow and in the flat.
Of course, leverage plays a role in something as fundamentally basic as Cover One. Let's take a look at our old Cover One diagram:
And zoom in our our friendly neighborhood left cornerback (left being the defense's left):
Pre-snap, the corner is aligned outside the receiver to give himself some off-the-bat outside leverage. Now, alignment (both depth and width-wise) for a corner can be informed by everything from specific assignments to the relative strengths (and pure physical strength) of the players involved. But let's see why an outside alignment would make sense based on both the defense that's been called and where the receiver himself is aligned.
With the receiver lined up inside the field numbers but well away from the formation, pretty much any route in the tree is on the table. But if he runs something in-breaking like a dig or post, he's running right to where the help should be:
On an out-breaking route, the corner can count on two kinds of help - Jack and shit, and Jack left town. So that outside leverage can be a much-needed help in denying an out or corner route:
Now if the same receiver lines up much further outside - say, at the bottom or outside of the field numbers:
The corner will probably go ahead and align inside/look for initial inside leverage, even in Cover One. By aligning that wide, the receiver has increased the distance from himself to the inside help and made it easier to complete in-breaking throws between an outside corner and an inside defender. But he's also taken some out-breaking routes off the table for himself simply based on how close he is to the best defender in the history of football - the sideline. That all adds up to the corner getting a bigger advantage for himself by choosing inside leverage.
Finally, let's take a look at how potential leverage problems can be addressed by defensive assignments. Here's a standard Cover 2 look against an offense that's presenting two receivers split out to the weak side:
And a favorite route combination that offensive coordinators like to use to attack Cover Two, the "smash" concept:
The smash concept can be run out of a variety of formations and can swap routes between the inside/outside guys, but the basic idea is that one receiver hitches up short in the flat area while the other runs a deep (breaking at 12 yards or deeper) corner route. The usual read for the QB is what the corner is doing - if he sinks deep then throw to the hitch route, but if he bites up on the hitch then go for your moneymaker (the corner route). That corner route tends to be open because a lot of Cover Two safeties are still a little ways inside the route as it's thrown, and the receiver capitalizes on that leverage advantage coming out of his break to give the QB a big throwing window.
But what if the safety is reacting more quickly and getting in better position relative to that #2 receiver? There's a coverage concept typically known as "2-Read" that can be a great equalizer for the safety against the smash. Good ol' LonghornScott did a detailed 2-Read breakdown for IT a while back - it's well worth your time for a full read, but for right now I'll summarize (read: steal) the relevant bit.
From the same two-deep alignment, a 2-Read call would change the jobs of the three relevant cover guys to that side (the corner, strong safety and Will linebacker) from the zone assignments pictured above to more man to man-style responsibilities based on what the receivers do after the snap (EDIT: #1 refers to the widemost receiver, #2 to the next widemost):
Basically everyone is reading the pattern of the #2 receiver. If he is still going vertical after X number of yards (usually 7-8) then everyone knows that the corner has the #1 wideout in man coverage and the safety has #2.
So how does that help our safety with his leverage problem? Well, as soon as the #2 receiver hits (let's say) seven hards, the safety knows unequivocally that #2 is his responsibility. He can start lessening that horizontal distance while getting ready to react to #2 and only #2. If he does his job well, hopefully the picture ends up something like this:
Which is a lot less inviting to throw at - and which could turn into a pick if the QB gets lazy, thinks he is looking at Cover 2 (since the Will backer and corner would have been doing Cover 2-like things post-snap) and makes an automatic throw when the corner bites up short.
So there you have it, folks - a quick(ish) look at how the idea of leverage drives schemes on both sides of the ball in the run and pass games. As I've been thinking about it, I'm leaning towards ordering the series by run and pass games on both sides of the ball and how they react to/attack each other (route trees and combos versus various cover schemes; man and zone blocking against defensive front assignments) but as always I'm open to ideas. Thanks for reading!