I Spent a little time studying the 4-3 defenses and thought I would share my observations.
In general, the 4-3 formation is designed to control the run as well as short passing game. This is indicated by the positioning of the SS. He plays closer to the LOS than the FS in order to help out with the TE, and runs to the strong side. The FS stays back in order to help out with any deep passes. Because of this positioning of the SS and FS, the weak side can be exploited if the OLB lacks in the AWR or SPD category. On offense, you can utilize motion in order to force repositioning of the FS and SS in order to create mismatches of this sort. In my opinion, 4-3 plays do not fair well against 3,4 and 5 receiver sets, in passing situations. Nickel and Dime plays are more suited for defending that kind of fire power. Should you ever call a 4-3 play when the offense goes to 3 WRs ? The answer here depends on what you know about your opponent. Have they tried to run out of 3 receiver sets? Are they running ball with ease? These are some things to think about and should be tested with the personnel on your team.
The more I look at this play the more impressed I am with it. Before the snap, the LBs will show Blitz (even though they dont blitz). This play uses a standard 4 man rush. Both CBs will bump their WRs and then play Zone in the flats, picking up the FB and HB coming out of the back field. The SS and FS will Pick up the WRs as run into the deep secondary. Meanwhile the OLBs zone cover the soft spot between where the CBs release their man and the Safties pick them up. The MLB plays zone on anyone coming across the middle. As QB, this defense can be intimidating as it appears all receivers are covered, but patience in the pocket will pay off. The safest place to attack this defense is over the middle or Deep. Both safties are one on one with the receivers and pass rush is average.
***4-3 Under 2 Man***
Good pass and run defenseexcellent pressure on the QB and very confusing to read the flow of defenders. The Weak OLB and the MLB line up directly behind the defensive line. The strong OLB is close up to the LOS right over the TE. The 4 front will stunt giving good pressure on the QB. Both CBs Bump their receivers and play tight man coverage, and the SS and FS on each side of the field will give double coverage with the CBs. Heres where the play gets interesting! ***IF the RBs release*** into pass routes, the Strong OLB bumps the TE and then plays zone in the middle of the field. The weak OLB will pick up the FB in man coverage to the weak side, and the MLB will play zone in the flats on the strong side. This is extremely confusing to the QB trying to get a read on the safe place to throw. Now if the RBs stay in, BOTH OLB will blitz from the outside giving the QB only seconds to make a decision. The safest throw is a very quick pass to the FB before the OLB can pick him up (which doesnt take long).
***4-3 Double Zone***
This play is almost identical to the 4-3 pinch. The only difference is the OLBs zone is doubled with the CBs zone in flat as well as deep. It gives the appearance the LBs are in double coverage if theres receivers in the flat or deep. Use timing routes or hit the seams.
Good run defense, but can be exploited with a deep pass provided your QB gets time to set and throw. CBs in man coverage, SS and FS will pick up the HB and FB in man coverage, Both OLB play zone in the flats, and the MLB picks up the TE. My favorite target against this defense is the TE streaking deep against the MLB.
Let me point out, that on the last post as well as this one, that my study off these plays is aimed at pass defense much more so than run. Look for later versions of the breakdown for run orientation as well as more plays.
Four man rush, with the defensive Ends curling towards the outside (should provide good containment for outside runs), QBs be aware of dropping back too farstay close in the pocket. CBs play man behind coverage, meaning you can drill the ball to either WR as they are always in front of the CB. The Wk OLB will play a short zone picking up any backs flowing into the flats. The strong OLB will jam and cover the TE. I thought this play (by the way it looks in the diagram had the SS jamming the TE, but this is not the case.) He hovers over the TE until he breaks loose from the OLB and allows the TE to go right past him (OLB following.) He then appears to spy the strong side flat for the HB sneaking out. The FS drops back into a middle deep zone for extra help deep. Hit the WR's at will as the CBs are not in position to protect a low fast pass.
***4-3 Man Lock***
5 Man rush - 4 linemen and wk OLB. Great pressure on the QB and run stopper. CBs play B&R tight man coverage. SS drops back into a deep middle zone. FS locks onto RBs coming out of the backfield to the weak side. MLB picks up TE. Strong OLB picks up any RB to his side. A quick pass to the wk side will do the trick (FS has a long way to go to pick up the RB). A quick toss to the Wk side can also exploit the blitzing LB if you let him creep up to the line before the snap.
***4-3 Crash Left/Right***
4 linemen rush plus an OLB blitz. Which LB that will blitz, depends on whether you call Left or Right version of the play. These plays attack the gaps in the offensive line. Both CBs play tight man coverage, FS picks up RB headed for flat on wk side. If RB stays in, he will play a deep zone OR Blitz! Same thing happens on the opposite play with the SS. I have not been able to determine reason the safties decide whether to blitz or zone cover. Most likely has something to do with whether or not a WR is approaching their zone. MLB picks up the TE and the OLB thats not blitzing will cover a RB to his side. If RBs stay in he will also blitz! This is a stout defense for run or pass near the goaline where the offense doesnt have a lot of room. Safest pass is to a RB in the wk side flat.
This play is strictly zone coverage with a 4 man rush. I believe its purpose is to confuse the QBs reads. The safties flow to the deep wk side, and the LBs drop straight back with the exception of the Strong side LB. He flows back and over to the area vacated by the SS (kind of sneaky if your making quick reads). Strong side CB drops back deep (again sneaky, inviting the QB to throw to what appears to be open but remember, the LB is eyeing this area of the field). All in all its a fair zone play, but a patient QB with plenty of time should have no trouble finding the seams.
***4-3 Cover 3 Wk / Over 3 St.***
These are more straight up Zone defenses. Cover 3 Wk, has the Wk side CB, FS & SS all flowing to the weak side of the field, with the MLB and strong side LB flowing to the Strong side. Just the opposite with Over 3 St. Other than perhaps trying to confuse the QBs reads, the only real advantage I can see with these plays is placing your coverage to an opponents preference side. (i.e. they like going to the weak side a lot).
***4-3 Double TE***
The name of this play can be misleading as you will soon see. Check the notes that follow. The LBs all crowd the LOS. Both CBs are in B&R tight man coverage. The Wk OLB blitzes! The FS line up close to the LOS looking much like an OLB on the wk side. If a RB floats out he will pick him up in man coverage, otherwise he drops back in a deep zone.
NOTE-1 : The SS is always going to cover the TE. If the TE cuts towards the middle, then the MLB will be the double coverage on him. If the TE cuts towards the sideline, then the OLB will be the double coverage on him.
NOTE-2: Between the MLB and OLB, whichever one does not add double on the TE, will pick up the FB floating out.
NOTE-3: Between the FB and TE - which ever one goes deep, he will be the one to draw double coverage!
NOTE-4 If the FB stays in, the LB not in double coverage will commence with Blitz!
To attack this, Hot route either the FB or TE deep to draw the Double coverage and hit the other one inside or out (preferably outside to avoid the ball getting batted down) who will be one on one with the OLB.
Thats all for now. Hopefully some of you will find some help in these notes and better your game. If you have any defenses you want dissected, let me know. I love studying this stuff.