The Inside Zone

And I promise I wont complain about Eli Manning this time.

Before we look at the inside zone you need to have read the article on the outside zone, as references will be made back to it. The reason for this is because the plays are so similar.

Really the big difference between the two is the intention of where to send the running back. In the outside zone play, the running back uses the position of the tight end as his aiming mark. He makes a mental note of the spot where the tight end is lined up, and at the snap of the ball is running towards that spot. The goal of the offensive line is then to get outside of the defense and pin them in, allowing the back to get around the end of the line and upfield. Really, if the back has to cut inside then it's sort of a "plan B" situation, often as a reaction to the end tackle having been beaten to the outside.

The inside zone does kind of the opposite. Now the goal is to attack the gap between the offensive guard and the offensive tackle. At no point really should the back find himself running outside of the tackle. He has to get inside and get penetration through the middle of the defense. This play compliments the outside zone for precisely that reason; when the defense starts to cheat and overplay the outside zone, it makes it easier to block them with the inside zone.

The inside zone also shares many of the benefits that the outside zone does in terms of being 'Front Ambiguous', that is to say that it can be used against a wide variety of defensive fronts without the need for any major changes in the way the play is blocked. This helps to reduce the number of plays in the offense, which in turn permits greater repetition of the remaining plays in practice, honing the skills of the players to a finer edge.

To start with then we need to look at the rules that the offensive linemen use. The good thing about this is that they use precisely the same rules as they do with the outside zone. If you have a down lineman covering any part of your body then you are "covered". If not, you are "uncovered". And just like in the outside zone the linemen will decide whether to work together or whether to work alone based on these rules.

The uncovered linemen must work to their playside, helping their covered team mate if necessary. The covered linemen must check their team mate to the backside (or non-playside, if that makes it easier for you). If that man is also covered, you're on your own. If he's uncovered, he'll help you out.

And this is where the main difference comes in. In the outside zone, the preference was to get covered linemen who had help to come out of their stance, hit the defensive linemen over them, and then work up to the linebacker level, letting their backside team mate take over the block on the defensive linemen. The covered linemen with help only really stayed on his original man if that defender made a hard move to the playside.

Now we want our offensive linemen to focus a little more on blocking the defensive linemen. There is no major rush to get up to get wide or to get up onto the linebackers. The uncovered linemen in the outside zone would take a very much horizontal first step, looking to get across and cut off the D-line. Now all our linemen can afford to take a slightly shorter, more controlled first step that goes up towards the D-line, as opposed to laterally across their face.

At this point we'll do a diagram  review, just so we can get a better idea of what we're looking at;

Hopefully now you have a better idea of what the offensive linemen are doing and what they're looking for.

The key to this play is double teams on the defensive linemen, then working up to the linebackers. If the D-lineman goes inside then the backside linemen will take over the block and the playside linemen will work up to the next level and get the linebacker. If the D-lineman goes outside, then the playside linemen stays on him and the backside guy will go up to the linebacker. And if he tries to stay head up on the playside linemen, then the two will work together to drive him back, until one of them can come off and get the linebacker, depending on how things pan out.

The next thing to look at is the running back. In the outside zone, the running back was using the tight end as his original land mark and then he made the decision to cut based on a read of the second defensive lineman to the playside of the center. If that guy went hard outside then he switched his read to the first down defensive lineman and read that guy.

Now with the inside zone we want the running back to start off by aiming at the "B" gap between the playside guard and the playside tackle, using that as his landmark. Some teams like the running back to make a more specific read of the defensive front and then aim at either the inside hip of the tackle or the outside hip of the guard, but I personally find that cumbersome and largely irrelevant for this discussion.

The decision as to where the running back will end up cutting is based on the first down defensive linemen to the playside of the center (remember in the outside zone he read the second man). If this defender works his way to the outside (playside) then the back cuts inside of him. If he tries to drive inside then the back works to get outside of him.

Here's what it looks like;

So in this case the running back reads the block of the defensive tackle and cuts off of him. If that man presses to the playside then the back cuts up inside. If the man presses inside then he cuts around him and up through the resulting wide gap between the guard and the tight end. The block on the "Mike" middle linebacker is determined by the actions of the Nose Tackle. If he drives hard laterally and blocks off the center then that will leave the backside guard with the opportunity to go up and get the backer. If the guard and center can pin him and stop him moving, that will allow the guard to take over the block and the center can go up for the Mike.

There are also two more things we need to be aware of here. First, if the Nose tackle does press hard across the face of the center then that would give him the opportunity to tackle the running back if the back tries to cut inside. For this reason, the back has the option to read the nose tackle after making his first read and to then cut behind him.

This is doable, but risky, as it presents the opportunity for the back to end up dancing about behind the line of scrimmage when really one of the mantras of zone running is "one cut and get up field!", the idea being to remove the chance of negative plays. How much freedom the back has to cut behind the nose really depends on the coaches and their judgement, which will likely be influenced by the quality of the back.

A bigger, slower running back is unlikely to be given too much leeway, especially if he's young and/or inexperienced in this system. A smaller back, with much better cutting ability and/or more experience in the system is likely to be given the green light to cut back as far as he sees fit.

The second thing of note is that some teams have tried to completely avoid the situation above where the back has to potentially read the Nose Tackle by devising methods for making checks at the line of scrimmage to change the play a little.

The first of these methods is to ask the playside guard and tackle to execute a "fold" block. This is where the offensive tackle blocks down on the defensive tackle who is covering the "B" gap, and the offensive guard pulls back off the line and goes around the block of the tackle and up to get the Sam linebacker. The second solution is to simply run away from that defensive tackle, flipping the play as it were, by the quarterback making a check at the line.

The best method I've seen of doing this is to use a "Red/White" call. Obviously you can use any two names you like, but the Red/White concept seems to have gained some traction with many coaches at all three levels. The basic explanation of this is that when a "B" gap is covered (even if just partially) with a defensive tackle, that's referred to as Red. When a "B" gap is uncovered (there will still be a linebacker lurking about 5 or so yards back), then that is referred to as White. Ideally you want to run to the white side and away from the red side. Here's how it looks when you run away from that covered "B" gap;

As you can see we now get the full back going up to get the Will linebacker and we now have two double teams right up the middle of the defense. Now the running back would read the Nose tackle as his first read. If he has to cut back inside of him he'll have a much easier time of it, thanks to the double team on the other defensive tackle.

So there you go, the inside zone. Coupled with the outside zone and a few other runs you can actually put together quite a formidable rushing attack without having to have a hundred different ways to run the ball. The play action possibilities are also pretty good, especially when you substitute the Fullback for a second tight end and start messing around with things like lining him up on the playside and having him run all the way across the formation to block the back side of the play.

Maybe next week we'll take a look at just that?

Tomorrow I'll be back to look at Tom Brady and hopefully I can dig out some video clips to show you what I was talking about with his vision. Till then, enjoy your day.

49ers vs Lions; Gore's big runs

Today I promised to take a look at Frank Gore's two big runs of 47 and 55 yards from Sunday's game against the Lions, mainly because both runs came using roughly the same play call. Now I've since discovered this play was actually covered by Chris Smart on his site, smartfootball.com. Or more specifically, he covered it for Grantland.com and obviously left a link on his own site.

On this note I was about to abandon my plans on the principle of redundancy, until I noticed something about the write up that caught my eye, that being that the blocking scheme was actually drawn up wrong from the right guard leftwards. I should point out that this is very much unlike Mr. Smart, whose blog is normally one of the true gems of football blogging. But I wont complain, mainly because it gives me something to do by drawing it up.

We'll look at the 47 yard run to start with. The video clip of the play is here on NFL.com. First things first, lets look at the starting positions, pre-snap;

Before we get down to the detail, we need to point out some issues. The first thing an astute observer will notice is that the wide receiver on the left side is missing, as is the corner covering him. That's basically because they're not of great importance to this play. The other thing we have to be wary of is that there were no decent camera angles (all the more reason to switch to Skycam during games) so the position of the linebackers and and safeties may not be perfect. I did the best I could using the hash marks as a guide.

You'll also notice that the defensive end on the right hand side (from our perspective) is quite wide. This is because the tight end was split out a little and the end lined up on his outside shoulder. This is a good example of the fabled "wide nine" that the Eagles have been using and ironically enough - given the reason that I'm doing this - was covered by Chris Smart in his most recent post.

So now we've laid the ground work, just what is all the fuss about this run? Well as Mr. Smart pointed out, there are two tight ends on the field. One is Vernon Davis, who is split out to the right and has the defensive end lined up on his shoulder.The second is Delanie Walker, who is probably the most under rated asset on the 49ers offense. He's lined up behind Davis and is going to go in motion slightly towards the formation and then do something incredible. Kind of.

The 6 foot tall, 242 pound Walker is going to be asked to block the 6 foot 4 inch, 307 pound Ndamukong Suh.... Believe it.

So how does a tight end, known more for his receiving, manage to block a defensive tackle with a reputation for tough, physical play, and who out weighs him by 65 pounds? The answer is to use a bit of finesse and a bit of trickery; by giving Suh a sniff of an easy tackle for loss, and by putting the tight end in a position where he can block down on Suh from an angle, giving him an advantage in leverage while not asking him to knock Suh clean off the ball, just pin him inside for a moment.

(I should clarify at this point that the "N" in the diagram above means "Nose" not "Ndamukong". Suh is actually the "T" defensive tackle. I only just realised that this might cause confusion and, well, frankly it's easier to type this explanation than it is to go back and change the diagram!)

This is known as trap. You're giving the defensive linemen the impression that he has a free shot into the backfield, only to blindside him with another blocker. Not only is this an effective block on the play being run, but it also serves up a minor side effect of interest. In the future if that defensive linemen finds himself running free into the backfield (perhaps due to an assignment error by the offensive line) there's a chance he will hesitate for a moment and take a quick peek to the side, worried about getting trapped again. We sometimes see this same effect in defensive linemen when they play against a team that runs a lot of screen passes to backs.

Now, up to this point Chris Smart had the scheme down pat. But what he missed was what was happening from the right guard onwards. He wrote that the interior linemen went up to get the linebackers but that's actually not what happens. In fact both the right guard and the left guard are going to perform trap blocks themselves. The left guard, first rounder Mike Iupati (rookie watchlist from last year) is going to pull off the line and go left to get the wide defensive end on his side. The right guard, Adam Snyder, is going to pull off the line and go left to trap the other defensive tackle.

This does three things, all of which are important. Number one, it frees up the center and left tackle to go and get two of the linebackers. Number two, it draws the linebackers to move left (from our perspective), because they think they're seeing a power run to that side. This makes them easier to block for the offensive line. Number three, it draws the weak safety down and to the left for the same reason as the linebackers (he thinks he sees "power"), and this draws him away from the true path of the running back. Remember reasons two and three, we'll touch on them again later.

At this point I think it would be helpful to put up a visualisation to ease our understanding of what is taking place;

There we go. Now you can see all the blocking assignments for the offense, with the exception of the wide receiver off to the left, who would ignore the corner on his side in favour of coming inside and cracking down on the weak safety. The dotted line coming from Delanie Walker indicates his pre-snap motion, triggered by a small foot movement by quarterback Alex Smith. Walker shuffles across to get behind the right tackle, then after the snap he turns inward and slams into the side of Suh, trying to pin him inwards.

The only person left unblocked (and who has a realistic chance of actually making the play) is the strong safety Amari Spievey, who you can see lurking in the top right corner of the diagram. The play is run pretty much right at him and he comes flying downhill to fill the resulting gap and attempt the tackle. The trouble is he's counting on everyone else to fill the other gaps and unfortunately the "Sam" linebacker Bobby Carpenter (whose being blocked by 49ers right tackle Anthony Davis) ends up out of position. The ironic thing about that is that Carpenter actually does a great job of beating the block by Davis, chucking him to the side, but goes the wrong way. He goes into the gap already being filled by Spievey, leaving Gore with the opportunity to cut back to the inside and use Anthony Davis as a barrier.

Here I've drawn the play out with the approximate positions that everyone ends up in, also showing the path that Gore takes;

As you can see, Gore knifes right through the heart of the Lions D and will eventually be brought down near the Lions goal line for a 47 yard gain. Chris Houston, the corner on the right side (from our perspective) is the one who chases Gore down and makes the tackle, after 49ers receiver Ted Ginn jr. fails to make any contact with him at all, merely herding him away from the main effort of the play.

The second time the 49ers ran it, they got an even bigger gain of 55 yards. Video here for the interested. The blocking scheme works out slightly differently this time around, mainly due to the reaction of the defense. In this second run, the defensive end to the playside identifies the play and comes inside the tight end. The wide receiver to the playside cracks down on the "Sam" linebacker (who has in fact been replaced by Lions Nickel corner Eric Wright). The right tackle goes up and finds himself blocking the same man as the center. Luckily the tackle realises his mistake and comes off in time to block the strong safety.

In the end Gore cuts outside around the rushing end, then back inside of the wide receivers block on Wright, then back to the outside to get past the safety. Corner Chris Houston is on the field again, but he comes down far too wide and Gore is able to get inside of him and up the field. Houston ends up chasing the play down from behind and again making the tackle, which probably highlights the main flaw that Frank Gore has; his lack of speed in the open field.

Now before we wrap this up, do you remember earlier that I mentioned the pulling action of the guards drawing the linebackers and the weak safety across to the backside of the play? No? Well go back and read it again, because I did.

The reason why this happens is because the pulling action of the guards in that manner looks a lot like the action that happens when both guards pull for a "Power" play. The difference is that on the Power play the Guards would be lead blocking for the running back, whereas here the guards are going away from the running back. That adds another dimension to this play for the offense, as not only is it a good play in isolation, but it also serves as a compliment to the Power play, showing the defense one action but giving them two very different plays.

Which leads us nicely back to where we began, with Chris Smart, and an article he wrote in 2008 about the constraint theory of offense.

So that's your lot for today. Thanks for stopping bye and hopefully you'll spread the word about the blog. Tomorrow I'll follow up my post from last week about the "Outside Zone" running play by going over its sibling; the Inside Zone.

Till then, enjoy your day.

Run-down

Inevitably when I bring up the subject of statistical analysis in football and how I think many false conclusions are drawn through the misuse of statistics, two things happen; the first is that most readers switch off mentally, preferring to eat out there own intestines rather than be forced to sit through what amounts to a lecture in applied mathematics. The second is that I wake up with an e-mail inbox overflowing with literally a couple of e-mails telling me that I'm a simpleton and that I should spend more time studying at Football Outsiders or AdvancedNFLstats. (I'm sure some of you are already preparing to send your pre-written hate mail, so for those that cant wait the address is here). Anyway, stopping by the aforementioned Advanced NFL stats I came across an article that includes a run down of an article from their seemingly hated rivals at Football Outsiders. Let the graph wars begin!! But there is a serious point to be brought up. Football number crunchers, for want of a better title, have a serious thing against the run in football. It's like the hatred NFL coaches had for the pass in the '60s... but in reverse. It would appear that most football number crunchers also seem to share a trait with the vast majority of high school coaches who frequent various Internet message boards, (no names mentioned), in that they all seem to assume that anything said by any analyst on TV must be inherently wrong in some way; doubly so if that analyst works for ESPN. The classic central point and counter-point between number crunchers and TV analysts (an argument held on the analysts behalf in absentia) surrounds the issue of whether running the ball and stopping the run is important in winning football games. The analysts believe that it is. The Number crunchers do not. I'm with the analysts on this point (hold the hate mail for a minute!) and I'd like to try and explain why. I'd like to draw on a combination of my own coaching experience, the experiences shared with me by others, what I've absorbed over the years from the idiot box, and what I've absorbed from various coaching materials (books, coaches forums, etc). First we have to highlight a point that the number crunchers/analysts/everyone seems to be at a consensus on; the greater the distance to go on third down, the harder it is to make the yards and get a first down. This is important because I believe that when analysts (even those on ESPN) talk about running the football and stopping the run, they're referring to three very specific circumstances; first and second downs (that counts as one), goal line & short yardage. I do not believe that they are suggesting for a second that a dominant run defense and a chronic pass defense will breed success (or ditto for a dominant rush/poor pass offense). So why is stopping the run such an issue on first and second down? Well again we have to throw in a caveat. When I hear "you've got to stop the run!" I understand that to mean "... with your front 7, without the need to drop a safety into the box". And it comes back to that first and second down argument. If you can stuff the run on first or second down, you improve the chances of forcing the defense into long yardage third down situations. Which means one thing; Le Passe! (I'm not entirely sure that's actual French). The defense sits back a little. Substitutions can be made, bringing in third down linebackers and linemen who specialise in either pass coverage or pass rushing. You can remove that clunky, run stopping DT (Terrence Cody anyone?) and insert a more lithe and agile individual, or at least as lithe and agile as defensive linemen get. You can tell your corners to sit back a little. Let them have the short stuff. If the offense dumps it off with a short pass then you come racing down and nail them short of the first down marker. This is what I've always understood as the primary advantage to being strong against the run. It's not about the fear of an 80 yard dash, it's the fear of the 5 or 6 yard scamper. That run that allows the offense to obtain a fresh set of downs. It's the knowledge that a stuffed run plus an incomplete or short pass puts the offense in a tricky and somewhat predictable situation. This is why we call third down the defenses down. It's the one down where they have the best possible chance of predicting what the offense will do, while having the best chance to make a play. Obviously stopping short yardage runs and goal line runs is important as well. Forcing the offense into third and 3 is of no use if they then run it straight over you. Similarly in and around the goal line it is necessary to keep the RB out and force the defense to throw in the much restricted area of the end zone. I'm not expecting this to start some kind of revolution. My only hope is that the number crunchers among you will see that sometimes there is more to football than the numbers. The underlying strategy and the many inter-weaving factors that go into football sometimes bring up unexpected goals and challenges. Things that go beyond just the statistics and the analysis. Tomorrow I'm going to do the stupid and attempt to predict the play off teams for this season. I can hear the sound of crashing and burning already.... Have a great day everyone.