It's slow so a quick review from an old chalk talk :
What is the 3-4 Defense?
Put simply, it's three down defensive linemen and four linebackers. Unfortunately, most folks' understanding starts and ends there. The 3-4 is really just a base set, no different than the I-Formation, Empty Set, One-Back, whatever. How the weapons are aligned and how the weapons are deployed are two entirely different discussions. Saban's version of the 3-4 vastly differs from Wade Phillips' 3-4 whose is vastly different from Dom Capers 3-4, and you get the idea.
The primary difference will be the technique played by the three down linemen up front. Saban's scheme more classically relies on "two-gap" technique up front, with big-bodied defenders responsible for engaging the OL, or, "eating up blockers." The NT and both DEs line up directly over the OC and both OTs, respectively.
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It's called a "two gap" because the defenders are, quite literally, responsible for two gaps. Ends are responsible for both the "B" (inside the tackle) and "C" (outside the tackle) gaps. The nose tackle is responsible for both "A" gaps (between center and guard). Their responsibilities are less to penetrate and more to clog. Even behind them LB responsibilities can vary. Some inside linebackers will fill gaps, while the outside 'backers play contain. Other times, the insiders flow to the action of the play and accrue tackles.
The other primary variation is a "one-gap" system, which Wade Phillips commonly utilized. Here, a single player is responsible for only one gap, thus relying much more on penetration and disruption, rather than swallowing an offense whole.
/cdn0.vox-cdn.com/uploads/chorus_asset/file/3320042/1_gap_34.0.0.jpg)
This system doesn't quite require the mammoths that Nick Saban utilizes in his front. Phillips utilized a 305-pound nose, successfully, in Dallas, in Jay Ratliff. He oft-utilized DeMarcus Ware as a fourth d-lineman, despite his designation as a LB, frequently asked to pin back his ears and rush. The end effect of said attack is essentially no different than an aggressive 4-3 attack. In fact, Phillips pretty regularly ventures into standard 4-3 looks on passing downs.
To throw an additional wrinkle on top of all this, how about a look at a standard 4-3 Under front? The 4-3 under is the alignment most commonly associated with the likes of Monte Kiffin and Pete Carroll. It's also what Kevin Steele defaulted to at Clemson. Here's the basic 4-3 Under look:
/cdn0.vox-cdn.com/uploads/chorus_asset/file/3320088/289417f79622d7a2cd53c56f88f123a5_original.0.0.png)
Look familiar? Remember all the hype surrounding Clancy Pendergast and his "genius" scheme for stopping the spread? USC coaches and media took to calling it a 5-2. Here's a good breakdown of the system. That look he implemented was essentially a 3-4 under defense, looking something like this:
/cdn0.vox-cdn.com/uploads/chorus_asset/file/3320202/3-4-under-gaps.0.png)
If you are curious about the differences in "over" and "under" alignments, the basic difference is that the interior defensive line shift the the weak side in the Under, and the strong side in the Over. The strong side, of course, is the side to which the tight end lines up. The other end and the strongside ("Sam") LB will also adjust how they line up. In the Over the end will wind up in a 9-technique, on the outside shoulder of the tight end. In the Under, he remains in a 5-tech, outside shoulder of the tackle, while the Sam steps into the 9-tech.
The point here is that alignment and deployment are very different things. Think of a one gap system as trying to get a peanut stuck in a person's throat, while a two-gap is more hoping a person with a mouth full of food eventually chokes. The end result is both the same, the methodology is different. Or, as Chris Brown says, "In short, while a 1-gap player attacks gaps, a 2-gap player attacks people."
Coverage ?
Really, this will depend on the play caller, anything from cover 3 to cover 1 and robber coverage is common on the backside.
Hope you enjoyed that little chalk talk. Will try to find a few more.
What is the 3-4 Defense?
Put simply, it's three down defensive linemen and four linebackers. Unfortunately, most folks' understanding starts and ends there. The 3-4 is really just a base set, no different than the I-Formation, Empty Set, One-Back, whatever. How the weapons are aligned and how the weapons are deployed are two entirely different discussions. Saban's version of the 3-4 vastly differs from Wade Phillips' 3-4 whose is vastly different from Dom Capers 3-4, and you get the idea.
The primary difference will be the technique played by the three down linemen up front. Saban's scheme more classically relies on "two-gap" technique up front, with big-bodied defenders responsible for engaging the OL, or, "eating up blockers." The NT and both DEs line up directly over the OC and both OTs, respectively.
It's called a "two gap" because the defenders are, quite literally, responsible for two gaps. Ends are responsible for both the "B" (inside the tackle) and "C" (outside the tackle) gaps. The nose tackle is responsible for both "A" gaps (between center and guard). Their responsibilities are less to penetrate and more to clog. Even behind them LB responsibilities can vary. Some inside linebackers will fill gaps, while the outside 'backers play contain. Other times, the insiders flow to the action of the play and accrue tackles.
The other primary variation is a "one-gap" system, which Wade Phillips commonly utilized. Here, a single player is responsible for only one gap, thus relying much more on penetration and disruption, rather than swallowing an offense whole.
This system doesn't quite require the mammoths that Nick Saban utilizes in his front. Phillips utilized a 305-pound nose, successfully, in Dallas, in Jay Ratliff. He oft-utilized DeMarcus Ware as a fourth d-lineman, despite his designation as a LB, frequently asked to pin back his ears and rush. The end effect of said attack is essentially no different than an aggressive 4-3 attack. In fact, Phillips pretty regularly ventures into standard 4-3 looks on passing downs.
To throw an additional wrinkle on top of all this, how about a look at a standard 4-3 Under front? The 4-3 under is the alignment most commonly associated with the likes of Monte Kiffin and Pete Carroll. It's also what Kevin Steele defaulted to at Clemson. Here's the basic 4-3 Under look:
Look familiar? Remember all the hype surrounding Clancy Pendergast and his "genius" scheme for stopping the spread? USC coaches and media took to calling it a 5-2. Here's a good breakdown of the system. That look he implemented was essentially a 3-4 under defense, looking something like this:
If you are curious about the differences in "over" and "under" alignments, the basic difference is that the interior defensive line shift the the weak side in the Under, and the strong side in the Over. The strong side, of course, is the side to which the tight end lines up. The other end and the strongside ("Sam") LB will also adjust how they line up. In the Over the end will wind up in a 9-technique, on the outside shoulder of the tight end. In the Under, he remains in a 5-tech, outside shoulder of the tackle, while the Sam steps into the 9-tech.
The point here is that alignment and deployment are very different things. Think of a one gap system as trying to get a peanut stuck in a person's throat, while a two-gap is more hoping a person with a mouth full of food eventually chokes. The end result is both the same, the methodology is different. Or, as Chris Brown says, "In short, while a 1-gap player attacks gaps, a 2-gap player attacks people."
Coverage ?
Really, this will depend on the play caller, anything from cover 3 to cover 1 and robber coverage is common on the backside.
Hope you enjoyed that little chalk talk. Will try to find a few more.
