Showing posts with label defensive front. Show all posts
Showing posts with label defensive front. Show all posts

Wednesday, September 2, 2009

Inside the Steele Curtain: Defending the spread with the Nickel defense

The first topic to address is the misconception that the spread offense is a system on its own, it isnt. The spread is a set of formations with 3 or more wide receivers, thats all. Steele comments in his press conference that he expects multiple formations from Tony Franklin's offense: wishbone, zone read, and read options. The 4-3 front is capable of defending the spread, and can handle anything another team throws at you, but there are a few things to go through each week to decide whether to take out that LB and put in another DB.

Vic Koenning ran a 4-2-5 here last year, as does TCU. But their schemes are very different. VK's we've covered, and its a more spot drop read-and-react zone scheme where the SAM LB was actually more like a SS. This week, you will see Clemson doing things on defense that you will likely see from TCU's in a couple weeks.

Why go to a Nickel look?
1. You are putting more speed on the field. Usually you recruit another safety and bulk him up to playing a hybrid SS/SLB role, like DeAndre McDaniel.

2. Its a one-gap defense. LBs only really watch one gap, and their alignment doesn't hardly change from formation to formation. However, should they miss their gap on a running play, you are toast. Depending on the reduction of the front, sometimes one or two LBs may have two gaps to cover in a 4-3.

A 4-4 scheme like VT is not all that dissimilar to teach. Their LBs are more like SS's, its just that they do different things with the front. It can be equally good against the spread.

3. Speaking of which, you can do different things with your free safety. A true FS is a deep player who is a sure tackler, but can cover alot of the field. Nickel is suited to more Cover 3, and he's more of a safety valve. In a 4-3, he has to be more of an attacking player, and a better tackler, and I would say more of a field general. In a 5DB look, you can take a smaller faster FS and put him deep, and recruit two SS's and put them in the game. As a result, the SS position becomes easier to play because his checks are simpler, and can be a real hitter or run-stopper (Hamlin) like a Linebacker. This would also mean the FS gets less exposure in run-support, something which makes them famous and gets headlines as a heavy hitter (Ronnie Lott).

4. Ask yourself 'Are they using the Spread formation to create problems in the running game?' Rich Rodriguez does this, as does Urban Meyer. His spread is not about the pass, its about spreading you out and creating running lanes. If you run a 4-3, it makes sense to play the spread with your base, if that is the case.

5. Particular formations are easier to cover, as in Twins, or Doubles.


This week, going to the Nickel, Sadat Chambers will be in the game more as the FS, with Gilchrist as the nickel corner. His position is not just like that of a true corner on the edge, but teaching him the things he needs to use as the FS in the base 4-3 will work at nickel.

The major problem to watch for is whether they decide to run 4 verticals, e.g. from doubles above, and you're stuck in Cover 3. The underneath zone defender is playing a matchup zone (tight man within his zone) and once two players release into the deep 3rd, a CB or S has to play two guys by himself. How do we deal with that?

The first adjustment, particularly if they play Twins or Trips, is to bring your FS over to the wide side (VK did this quite a bit) and play a 1/4, 1/4, half coverage. Its still cover 3 matchup, and the CB is playing one half the field with the boundary as his help. He must force his reciever outside or he could be toast.



This corner is not quite playing a deep Cover 3, as he has no underneath help, and its more of a matchup zone/man coverage now. The FS is rolled over onto a weaker receiver in the slot (since he usually has not-as-good man coverage skills), likely Gilchrist but perhaps McDaniel. A weak safety (probably Chambers this week for MTSU) will be playing deep middle.

Against an empty backfield, you simply have to matchup one-on-one. You can still play cover 3, and you can disguise who is actually going deep, but its likely to still be the safeties as their alignment will already be deeper pre-snap. Its more likely that this is when you'll see straight-man coverage and blitzing the LBs.

To take the problem of a CB/S having to play two guys in his deep 3rd, you can switch to Quarters coverage. This brings us back to boundary/field adjustments, which we ran last year under Koenning. The passing strength is set to the Field (wide) side, or the side with the most WRs. Usually the left side, since a RH QB throws to his right, which is the left from our perspective. I will mention more about Cover 4/Quarters and "Bronco" against Trips at some later time.

Pressuring the QB.
There are many things you can do from the Nickel, but I don't believe its as versatile as the 3-5-3 or even the 4-3 when it comes to crazy blitz angles. You will see some CB/S blitzing, and DL pressure is created through the use of stunts. Here is one particular blitz from Saban's playbook: a cover 1 CB blitz (star "*" is the nickel back, "$" is either a Sam or Will (now called Money), but sometimes another big safety). From Steele's comments this will be Scotty Cooper.

The dotted lines indicate who matches up on who in man coverage. If the TE blocks down, or the Back stays in to block, one of the two LBs becomes a Robber. The term "even" refers to the front reduction and the placement of the DL and LBs.

The DTs, in this front, each have 2-gap responsibilities. Everyone else has one. The
LBs, Mac and Money, key the OG and nearest RB. The Ends key the TE/NB/OT in that order.

Finally, a Cover 3 zone blitz. First you declare your front, in this case "Okie"


Notice the Nickel and SS switch responsibilities again, with the SS picking up the slot WR off the line and rolling down into his underneath zone opposite Money. There is a gap in the middle of the field to the TE side that Mac may not be able to cover from his hook zone. His responsibility will be more the RB than that TE.

In a Trey formation (3 WRs to one side, 1 RB, 1 TE) the adjustment is straightforward, with the CB shifting over top of the TE bracketed with the FS. Nickelback gets matched up on the inside slot man, with the SS rolling over the 2nd slot man. This generally can be given a double call and they'd check into a 1/4, 1/4, 1/2 setup with that CB ruling one whole side of the field. For Trips, shifted to the opposite side, the FS becomes the blitzer, with the nickel taking the flat and the SS dropping back in the middle.

I will save more on Nickel pressures for TCU game-week.

Just as an aside, I noticed Chris at Smartfootball wrote a blog on the scrape and defending the zone-read play using a 4-2-5, and since we'll see this play from our own offense many times, I think you should check it out. It'll also give a hint about TCU's philosophy.

Wednesday, August 19, 2009

More on the 4-3: Stunting

Defenses today have to be multiple; there is no true 4-3 or 3-4 set anymore that is played on every down. Last year's Alabama team played a 3-4 base, but essentially only played a 3-4 40% of the time. Saban at LSU ran primarily a 4-3, but he does so many things that you can never pigeonhole his defenses. Why would you run one over the other when you'd run a 4-3 and won a Title? The answer is simply that you have the personnel to do it. If youre hired as a head coach and have 6 LBs who can all play, and only 6 Linemen, what would you do?

This is what bothered me when Clemson fans stated Steele would run a 3-4 here when he ran one at 'Bammer. We dont have LBs here to run it, but you will still see a few 3-4 sets against certain opponents.

What is the 3-4? Its just a front. Its a 'look' you want to give the offense to confuse them, because you want to hide what you are doing on defense as long and as well as possible. So dont be surprised when you see a guy who normally plays DE stand up like a OLB. Virginia Tech, for example, might tell you they are running a 4-3 in the pregame introductions, but it is really a 4-4 (or Gap 8) system....thats why they always seem to have one great tackler in the secondary. They are reducing their fronts in passing situations with a player like DeAndre McDaniel playing a LB position that is really more like a SS, which makes them better versus the pass than you would think a 4-4 team would be normally.

In order to help run support in the 4-3, the most common adjustment is to bring the SS down to LB depth and create an overshifted front, which we've already covered. This lets you shift the LBs over to the weak side, with the SS being (usually) the cover man for the TE or slot WR.



But in preparation to explain other defenses we'll see this year, we think its necessary to look into the other defensive fronts besides the simple over/under reductions. Specifically, the defensive line play.

The first thing to remember is that when coaches use the term 'technique' they don't always mean how to do something, they also mean the player's alignment, this is explained in the article above.


There are various other techniques to teach in combinations on one side of the line or the other, or inside DTs vs what the DEs are doing. For example, there may be a call where you want both DTs to run to the inside hip of the OG opposing them, towards the center. You would call that a "Tim". If its outside, towards the outside hip and to the OT, a "Tom". This is called a stunt, and it just means that you are having someone attack a gap they are not normally responsible for covering. You want to do this to upset the rhythm and blocking schemes of the offense, to create penetration on run and pass plays. One point to remember is that you will only want to stunt when youre penetrating, otherwise your defense is giving up ground. The stunts you use also change based on the type of blocking you're up against: man or zone. (you'll have to click the pic, sorry)


(obviously there is more info on the stunt in the images, but i'm leaving that out for now)

If the DE is told to run a '6' technique, lined up directly across from the OT, he's usually taught to charge inside. So if I called a defensive front "26 Tim" from the sideline, I'm telling my DTs to line up in a 2, my DE to line up in a 6, and the DTs to charge to the inside. If I play a 2 or 4 technique often with my DTs, then they are usually the bigger guys like William Perry or Terrance Cody, who can muscle through blocks. In that case you usually end up using them as a Nose.

Thats just a name, and other coaches may use other stunts with the same name. Against a stunting defense an offense may widen their splits to force the defense to change their gap responsibilties and adjust the front (this is partly why Texas Tech's offense has such success, they have very wide splits).

A 3-technique tackle, like Jamie Cumbie or Jarvis Jenkins, will be more likely to be the 290-300lb guy who can immediately shoot the gap, and more likely to stunt.

A common stunt is to slant your weakside DT into the A gap on his side, and then loop the Strong DT around behind him and into the weak OG's face. More explicitly, one DT charges into the A-gap, the other DT runs around his backside and into the Guard, effectlvely double-teaming that Guard. You could expect that to happen to Thomas Austin this year. The only difference in the figure below and what I'm explaining is that the figure depicts the DT attacking the inside of the opposing guard, instead of his outside.

Usually a FB has to pick up the stunting DT, and coaches dont like their FB picking up tackles. A similar stunt is the Spike:

Opposing teams would then be smart to run an isolation play to the strong side, by doubling the DT, singling out the DE, and isolating the MIKE on a Fullback blocker. MIKE has to take him on with a shoulder, not head-up, and force the RB to run towards the DE. That seems to me to be the easiest way to handle such a situation.

A "3-game" or Pirate stunt is with both Tackles and the weakside End ("3" comes from "30" or weakside/oddside, not that 3 guys are involved). Its the same as the above stunt, except that the DT runs outside around the weakside End instead of the weakside tackle. Both the End and the weak DT are taught to charge inside on the hip of their opposing blocker. The only problem here, as with any penetration, is the Trap.

To eliminate that problem, along with cutbacks and isolation, you can run a "4-game" stunt, which is essentially the opposite except that the Weakside DT isnt stunting upfield to the QB, he's waiting to read the blocks and play the Trap.

The next variation on the 4-game is the Storm, which adds the SAM on a run blitz and the DT runs around his backside towards the TE. Obviously, you need athletic DTs to make such a play worthwhile, and you would preferably want to do this to the short side of the field.

An "open" or Jam stunt involves the Strongside End and the tackle. The End charges inside towards the Guard, while the tackle loops around him into the OT-TE C gap.

Against triple-option teams like Georgia Tech, the stunts are used to change the rhythm of the offense and break their timing. The option has to be finely tuned and practiced to be effective and stunts are best used to break their patterns. Usually, the best point to attack is the QB decision area: the space behind the OT/TE where the QB must decide to pitch or keep it. The only problem for a coach here is that a player CANNOT miss on his responsibilities; a huge play will result. This is why many teams refuse to stunt against the option.

A common stunt against the option is the End Slant, where your Strongside DE charges into the OGs outside hip, or a pinching stunt where the End charges in with the OLB cheating up to do the same towards the TE's outside hip.


So there is a few of the stunts you'll see by essentially every team that runs a 4-3 defense, all of which will be useful in explaining defenses later on. Tomahawk Nation did a similar post including more on stunts here.

Friday, March 13, 2009

Inside the Steele Curtain: 4-3 Over/Under fronts

It occured to me that you can't really explain any blitz packages without giving an explanation of the different defensive fronts you see in a 4-3. When you think of a 4-3 defense, most of you will just think of 4 linemen playing in a 3pt stance, with 3 LBs just sitting behind them; there is more to it than that and there are several variations of 4-3 defense.

Defensive line alignments
Bear Bryant's 1960 book published the defensive numbering system used by everyone today who coaches defense, though he says he did not invent the system. The numbering starts from 0, which means a DT lines across from the Center head-up, and proceeds from there. All the even numbers are shaded alignments, also called gap alignments. The odd numbers mean that the lineman lines up directly opposite an OL. In between the OLmen, you have gaps: A (C-G), B (G-T), C (T-TE/WR), and D (anything outside the TE or WR, if hes lined up close to the Line).

From Bryant's book:


So, if you look at the illustration, you'll see that if I tell my DT to play a 1-Technique, it doesn't mean that he's doing something different with his hands or footwork to get past somebody, it means that he just lines up on the shoulder of the Center. But which side, left or right? Thats where another set of terms comes in:

Slide-outside shoulder, weak side
Shade-outside shoulder, strong side

The DEs have more to learn, because they have run and pass responsibilities, and depending on whether they play strongside or weakside. I'm only going to cover a few as needed, so I won't list all of them.

LB Alignment
LB alignment techniques are the same, you just add a 0 so as not to confuse them. For example, a SAM playing 70-technique means you line up in a 7 (inside shoulder of the TE), 3-5 yards off the line. A LBs primary job is gap control, meaning that he has to control the gap where the DL isn't lined up. If the DT in front of him is lined up in a 3 (outside shoulder of his Guard), the LB lines up in a 50 (outside shoulder of his Tackle).

So you see, you can tinker with the alignment of the front seven players to make the defense look different to the QB, or give your team better chances at getting past a particular offensive lineman on any play.

Overshifted fronts
There are two main shifts to the 4-3, Over and Under, but there are different styles and ways of doing those shifts as well. This stuff is endless, but you may see one and wonder why they are doing it.

If the DC calls an "Over" front, then he is telling the MIKE to call the shift based on the passing strength of the formation, once MIKE sees the formation pre-snap. The passing strength side is nearly always the one with the most receivers, or if they are equal (like 4 wides with a RB) then the side with the WR the DC told him to watch most during the week of film study. In Saban's scheme, he declares which side he is going to play his 30-technique on, called The Bubble side, and all the linemen and other LBs adjust.


2-gap in the figure means that the NG and the Weakside DE both have to watch the two gaps on either side of themselves. 1-gap means that the strongside DT covers the B-gap that he is supposed to run into, and the strong DE runs into his C-gap.

The LBs are watching the linemen on the snap, preparing for a run play, and once they seen run towards their side (Flow-To) or away (Flow-Away) they are supposed to charge into different gaps. If they read pass, they just drop back into their coverage, otherwise this is what they do:

WILL is playing a 9, so this defense can look like a 5-2, except that he is standing up. Usually he's standing right behind the DE's back foot, but he can come up on the line. He is looking at the OT and the nearest RB and charges around him (or his FB blocker) if the flow is in that direction. If the play goes away from him, he has to be careful and watch for a reverse or a trap of some kind back to his side, or slide across the line towards the play. This is the toughest part of his job, called slow fold.

MIKE is watching the OG in front of him, and the nearest RB. In the I-formation example above, he's supposed to be watching for an isolation play (meaning the FB blocks him 1-on-1 and he has no help) up the B-gap if the flow is towards him. If the run goes away from him, he covers up the A-gap on his side and tries to pull the RB down from behind. Usually if flow is away, the OG in front of him might be pulling, and thats why he's watching him first and runs up the A.

SAM is also watching the OG and RB closest to him, and on Flow-To he stacks, sitting behind his DE up the C-gap. The DT is supposed to control the B-gap remember. If the ball goes away from him, he covers up the A-gap on his side.

So thats the basics, but why would you shift the front this way?
Lets say you have a big fat guy up front who can take two or 3 blockers. You want him at NG, or the DT playing 0. He also has to be really good and busting into either of his A-gaps. Think Warren Sapp. Both of your DEs are great pass rushers, and they get put on the outside shoulder of whomever is lined up: the Strong DE on the outside of the TE, the weak DE on the outside of the OT. The LBs just line up behind them this way, and since you want one OLB to "force" plays (like option plays) you move WILL over to one side on their best blocking OT (usually the LT). Note that if you just stand up your Strongside DE, this will look like a 3-4 system. There is no rule that says he has to be in a 3-point stance. Vice versa for the WILL playing on the other side.

If you are a Dallas Cowboys fan, or recall Jimmy Johnson's defenses, or the current Dave Wannstedt Pitt defense, this is the type of shift you saw/see alot of.

Of course, you usually shift this defense based on the formation shift of the offense. Lets say for example that the opponent uses a split-I formation, which Clemson does use alot. The Tailback stays where he is, and the FB moves over a couple yards behind the OG (as opposed to being right behind the QB). In that case, the WILL would initially line up to whichever side the FB is shifted, the offense sets and the defense lines up...and then the FB motions over behind the other side. In that case the DL won't have time to readjust, so the LBs just move over to the side the FB moved towards.

Similar occurs if the TE shifts from one side to the other, the Over LB has to move, so WILL backs up and plays like SAM did above, MIKE shifts over, and SAM moves to the 9-technique.

Another variant of the 4-3 Over front (there are many) is "Okie", in which the NG plays a Tilted stance and doesnt line up square on the Center; he lines up at a Shade angle to him, with the WILL now being matched across from the TE, but still playing his 9-technique.

Undershifted front
This is the primary shift that the Tampa Bay Bucs use under Monte Kiffin (now Tennessee), as well as the USC Trojans (Carroll worked under Kiffin at one point in his career). In this scheme, the MIKE calls the side of the strength after the DC calls "Under" from the sidelines, and the SAM is assigned directly onto the TE.

Usually in a pass situation, when this is called the SAM plays man coverage on the TE. Its essentially a flip from the Overshift above, but the gaps that are attacked change. This doesnt mean that your whole defense is playing man, this front is primarily used with Cover 2 and 3 in Saban's schemes.

In the Saban scheme, this is what they do:
SAM plays the TE man/man, in a "loose" 9 technique. Basically this means he is moved off the line of scrimmage 3 yards. If the TE motions, the SAM moves with him. On a run play, he has to control the D gap.

MIKE runs into the B-gap in flow-to, or the strongside A-gap in flow-away. WILL stacks behind the DL in front of him in flow-to, or the weakside A if away. They are both playing 30 techniques.

The NG plays 0 in this scheme. He has to control 2 gaps, as does the Strong DE. That means these guys must be run stoppers. The other DT stays in his 3 and controls his B-gap.

The weakside DE stunts, or "Crashes" out of a 6-alignment. That means he just runs as fast and as hard as he can, across the face of the Tackle. His goal is to get into the offensive backfield as quickly as possible, find the ball carrier, and knock him flat.

Now, thats the basic Under. Notice that I said that SAM usually plays man, which means this scheme lends itself to a total man/man coverage defense. In that case, you would play what is called Cover 1 Man Under (or Man Free), meaning that either the FS or SS drops straight back in coverage and is "free" to help anyone deep who needs it. This is the particular version that USC uses, and they shift over the NG so that he is responsible for only one gap, giving him less to think about during the play. Saban does it as well. Generally, because the SAM is matched man/man on the TE, the SS is the one who plays "free" and the FS picks up a RB or slot receiver to the weak side.

So those are the two main overshifted fronts in the 4-3.