Principles of the 3-4 defense

[PATRIOTS-80]

per request from ShirtsLeeve I decided to post another thread dealing with football defense.

I found the following article fascinating. Click the diagram to go to the link.

the reason that I personally like the 3-4 defense is that it allows you to involve eight players against the run without having to play man-to-man in the secondary. This helps us to stop the run with our guys up front and limits the offense’s potential of the big play. We can be aggressive with our front seven without taking risks in the secondary.

In this play, the secondary goes into a cover-3 shell. The SS is the force/flat defender (sky coverage). The ROLB (defense perspective) covers the other flat.

Notice that the play allows a

"Mike” or “Will” blitz and our cover 3 behind it. Notice how we are able to actually get eight men involved against the run and still be a zone team in the secondary. We can bring two and sometimes three linebackers depending on the offensive personnel group that is in the game and still play some type of zone coverage behind it.

 

[PATRIOTS-80]

ok, here's another one. Feel free to comment. And remember, its all for fun!!!

The coverage is a standard cover-2 shell. The underneath coverages are divided into 4 sections, the CB takes 1/4, the RILB takes 1/4, the LILB takes a 1/4 and the other CB takes a 1/4. Both OLBs blitz along the 3 defensive lineman.

 

[PATRIOTS-80]

here's a link of one I'm still digesting. If unoriginal or Triple Option or anyone else with some background want to discuss it, feel free.

http://www.americanfootballmonthly.com/Subaccess/Magazine/2004/sep/landmarks.html

 

[PATRIOTS-80]

what I don't get is cover-2 squat and cover-2 read.

 

[shirtsleeve]

Thanks, 80. Gotta check it out, but wont have time till later tonight!

 

[TripleOption]

what I don't get is cover-2 squat and cover-2 read.

2 Squat is also known as 2 Hard. The CB's are pure flat players. 2 Read has the CB's playing flat, unless #2 goes vertical. Then they must play deep as the Safety would get 2 deep in his area.

 

[shirtsleeve]

Here's a pretty good diagram of the two gap 3-4:


http://football.calsci.com/DefensiveLine3.html

 

[PATRIOTS-80]

2 Squat is also known as 2 Hard. The CB's are pure flat players. 2 Read has the CB's playing flat, unless #2 goes vertical. Then they must play deep as the Safety would get 2 deep in his area.

Based off of pattern pressure, we could have four deep defenders. The safeties will “stay inside of the #2 receivers” leveraging the seams, and the corners will read their way deep or read their way up to the out zones or flats.

When they say "stay inside of the #2 receivers," is that referring to the slot receivers?

The aforementioned threat of pattern pressure creating four deep defenders dictates that we define this as a true 1/4, 1/4, 1/4, 1/4 zone coverage. We are now taking that same 26.67 yards worth of width and dividing it in half again. There are four deep zones each width being 13.34 yards.

ok, whats the difference between cover 4 and a cover2 read?

 

[unoriginal]

When they say "stay inside of the #2 receivers," is that referring to the slot receivers?

Yes, them or the tight end or motioned tailbacks (technically a slot receiver). Actually the real answer to this premise is not so much "the #2 receiver pre-snap" its "the 2nd receiver on that half of the field running deep." The DC here is asking his safeties to stay inside of the inside-most deep receiver on his half, when the default technique for the safety would be to split the two receivers and play the ball once thrown. The safety can jump the inside guy if the corner is responsible for the deep out and fade.

ok, whats the difference between cover 4 and a cover2 read?

Cover 2 "Read" or "Soft" is a hybrid of Cover 4 and Cover 2 "Squat," "Hard" or "Tough." Not to be insulting by noting the obvious, but the pattern to understand for coverages is the number tells you how many men are deep/without force responsibility. In Man 1 one person (generally the Free Safety) is deep, in Man 0 no one is deep, and in Cover 4 four men are deep.

Cover 2 Read is called like it is because it is more a Cover 2 than a Cover 4. It becomes a Cover 4 when the deep zone is stressed, but pre-snap coverage and force assumptions are made consistent with a standard Cover 2 (Cloud Force is the standard Cover 2). If the offense were to run a sweep the corners would have outside contain, which is not true out of a Cover 4 (outside linebacker has to get over the top). Also the Cover 4 usually has the outside backers dropping out to the flats, while the Cover 2 puts them in the hook/curl area on the seam.

 

[PATRIOTS-80]

Yes, them or the tight end or motioned tailbacks (technically a slot receiver). Actually the real answer to this premise is not so much "the #2 receiver pre-snap" its "the 2nd receiver on that half of the field running deep." The DC here is asking his safeties to stay inside of the inside-most deep receiver on his half, when the default technique for the safety would be to split the two receivers and play the ball once thrown. The safety can jump the inside guy if the corner is responsible for the deep out and fade.



Cover 2 "Read" or "Soft" is a hybrid of Cover 4 and Cover 2 "Squat," "Hard" or "Tough." Not to be insulting by noting the obvious, but the pattern to understand for coverages is the number tells you how many men are deep/without force responsibility. In Man 1 one person (generally the Free Safety) is deep, in Man 0 no one is deep, and in Cover 4 four men are deep.

Cover 2 Read is called like it is because it is more a Cover 2 than a Cover 4. It becomes a Cover 4 when the deep zone is stressed, but pre-snap coverage and force assumptions are made consistent with a standard Cover 2 (Cloud Force is the standard Cover 2). If the offense were to run a sweep the corners would have outside contain, which is not true out of a Cover 4 (outside linebacker has to get over the top). Also the Cover 4 usually has the outside backers dropping out to the flats, while the Cover 2 puts them in the hook/curl area on the seam.

thanks unoriginal. So, if the inside slot receivers run deep routes, the safeties have to read into a cover 4 look, and so do the CBs. Don't the underneath coverages have to change then ... if the CBs are vacating the flats?

 

[unoriginal]

thanks unoriginal. So, if the inside slot receivers run deep routes, the safeties have to read into a cover 4 look, and so do the CBs. Don't the underneath coverages have to change then ... if the CBs are vacating the flats?

You're close, but you're still not getting the finer points.

Let's say you've got a slot receiver and split end weak side, with the free safety, Will, and corner in a Cover 2 Cloud Read. A common route combination is out/seam. Even though your inside receiver is running deep (seam), the corner does not bail. He jumps the inside shoulder of the flanker. The Will drops the tight end at about 15 yards to the safety then looks for ins and crosses.

Another combination is slant/chute. The corner directs the slanting split end to the Will and peels off onto the chute route, passing it off at 15 yards to the safety.

In both of these cases the inside receiver went deep, but in neither of these cases should the corner leave his zone, unless the ball is in the air. Only if two or more receivers go deep against Cover 2 Read does the corner provide deep help to the safety.

The underneath coverages, aside from the corner leaving the flats, do not and can not change. The linebackers can not see what the split ends and flankers are doing, and consequently cannot tell until late in the play if the corners have bailed the flats or not. If the inside receiver has left the hook/curl zone and no crosses or ins are coming, the linebacker can and will jump up on routes run by the backs, but that's their prerogative in most cover 2 schemes. What the linebackers cannot do is cover the flats. The flats are vacated in Cover 2 Read against multiple deep routes.

 

[PATRIOTS-80]

Another combination is slant/chute. The corner directs the slanting split end to the Will and peels off onto the chute route, passing it off at 15 yards to the safety.

In both of these cases the inside receiver went deep, but in neither of these cases should the corner leave his zone, unless the ball is in the air. Only if two or more receivers go deep against Cover 2 Read does the corner provide deep help to the safety.

And just to be sure we're on the same page, this is a chute route, right?

And when you say, "passing it off at 15 yards to the safety," which player is the "it," the player running the slant route, or the player running the chute route?

 

[TripleOption]

And just to be sure we're on the same page, this is a chute route, right?

And when you say, "passing it off at 15 yards to the safety," which player is the "it," the player running the slant route, or the player running the chute route?

A Shoot route is also known as an Arrow. It's a 5 yard out.

The CB would peel off the Slant and jump the Arrow.

 

[PATRIOTS-80]

A Shoot route is also known as an Arrow. It's a 5 yard out.

The CB would peel off the Slant and jump the Arrow.

is the shoot route #7 on this passing tree?

http://www.football.com/playbook/passtre.shtml

 

[TripleOption]

is the shoot route #7 on this passing tree?

http://www.football.com/playbook/passtre.shtml

No, that is a "Chair" route or and Out and Up.

A Shoot is a shallow out at 5 yards. Usually #2 or #3 runs it...or a Back out of the Backfield.

I see on the website they are calling that a Shoot. Terminology may differ. We call it an Arrow. The Chair Route shown we call a Wheel. Usually a Wheel is run by a BOB but we call any out and up a "Wheel".

 

[PATRIOTS-80]

No, that is a "Chair" route or and Out and Up.

A Shoot is a shallow out at 5 yards. Usually #2 or #3 runs it...or a Back out of the Backfield.

I see on the website they are calling that a Shoot. Terminology may differ. We call it an Arrow. The Chair Route shown we call a Wheel. Usually a Wheel is run by a BOB but we call any out and up a "Wheel".

oh, okay, so in unoriginal's slant/arrow combination .... the arrow route is a 4 or 5 yard route run at full speed by the #2, while the SE runs a slant. If the defense was in man-coverage, wouldn't that be a "rub"?

 

[TripleOption]

oh, okay, so in unoriginal's slant/arrow combination .... the arrow route is a 4 or 5 yard route run at full speed by the #2, while the SE runs a slant. If the defense was in man-coverage, wouldn't that be a "rub"?

Sure. It's a staple combo of most teams. In Cover 3, the Arrow is always open.

Also, on the Goalline, the Arrow is cash in the bank. Run it shallow enough to just get across the goalline...

 

[PATRIOTS-80]

okay, so on a cover-2-read, if the slot runs a seam, and the SE runs a chair route, the CB would have to play deep because the safety will have the slot passed on to him by the LB. Right?

 

[TripleOption]

okay, so on a cover-2-read, if the slot runs a seam, and the SE runs a chair route, the CB would have to play deep because the safety will have the slot passed on to him by the LB. Right?

2 vertical means that the CB better get deep.

 

[unoriginal]

And just to be sure we're on the same page, this is a chute route, right?

And when you say, "passing it off at 15 yards to the safety," which player is the "it," the player running the slant route, or the player running the chute route?

My apologies for using confusing terminology (again ). A "chute" route meets an iin-cut route (in this case a slant, some other routes would be post, curl, dig) right at the cut point and proceeds up the sidelines, almost like a fade. It is different from a chair route because there are no hard cuts. Oftentimes it is run by a skill player motioning into twins formation, to give that player a speed advantage getting wide and deep.

The corner plays it exactly like he does TripleOption's arrow route, except for the chute eventually passes out of the flats, and the corner hands it off to the safety.

EDIT: I realize now that the common term for this route is likely "wheel." It's a wheel being run out the slot, however, so there's not as much parallel motion and the receiver gets up the field faster.