Breaking Down What Makes the San Francisco 49ers Defense so Dominant

Jesse Reed@@JesseReed78Correspondent ISeptember 18, 2012

SAN FRANCISCO, CA - NOVEMBER 13:  Ahmad Brooks #55 and Patrick Willis #52 of the San Francisco 49ers celebrate after Willis tackled Eli Manning #10 of the New York Giants at Candlestick Park on November 13, 2011 in San Francisco, California.  (Photo by Ezra Shaw/Getty Images)
Ezra Shaw/Getty Images

The San Francisco 49ers have the most dominant defense in the NFL. This unit has effectively shut down the Green Bay Packers and Detroit Lions two weeks in a row—two of the most high-powered offenses in the league—and made it look easy. 

So how do these guys do it?

That's what we're going to delve into today, so let's get down to business. 


Stuff the Run

The best way to attack any offense is to make it one-dimensional. The 49ers are the best team in the NFL at shutting down opponents' running games, and as a result, teams typically start abandoning that part of their offense early on in games. 

The play of the outside linebackers is a big reason why this team has so much success against the run. Aldon Smith and Ahmad Brooks are both athletic and strong enough to hold the edge, and they force runners back inside on runs to the outside. 

NaVorro Bowman and Patrick Willis eagerly wait for the runners to come back their way, and the defensive linemen are rock-solid and devout in their gap assignments. This is a recipe for success, and whenever a runner finds himself somehow getting to the second level, hard-hitting safeties Donte Whitner and Dashon Goldson are waiting to knock them silly. 

The Lions admirably didn't abandon the run in their Week 2 loss, running the ball 26 times. Unfortunately, it didn't do them any good, and the 49ers held them to just 3.2 yards per carry.

Here is an example from Sunday's game of how the 49ers stuff the inside runs so easily. The 49ers lined up in their base 3-4 defense with both safeties deep, while the Lions line up with one tight end and two backs.

Isaac Sopoaga—the nose tackle—gets an excellent push right off the bat while the rest of the front seven fire at their gaps. Kevin Smith has nowhere to run, and Sopoaga makes the stop for a one-yard gain. 

This isn't the exception to the rule; rather, it is the rule. 

Now, let's take a look at an outside run—the plays where A. Smith and Brooks dominate the edge.

The Lions line up in a three-wide set with one tight end and one running back, Joique Bell. Aldon Smith is lined up across from tight end Brandon Pettigrew—an unfair matchup 10 times out of 10. 

Smith easily dispatches Pettigrew's would-be block on the outside of the play, forcing Bell back into the inside where Smith's mates are waiting. In the end, Smith gobbles him up for a mere one-yard gain, getting some help from Justin Smith and Bowman.

Smith's quickness, strength and agility is too much for most offensive tackles (let alone tight ends) and it's a rare occasion when a running back gets outside of him or Brooks on the other side. 


Pressure on Opposing Quarterbacks With Only Four Pass-Rushers

The 49ers were the second-best team in the NFL in 2011 at getting pressure on opposing quarterbacks, according to Pro Football Focus, and they did it without blitzing more often than not (82 percent of the time), according to

Whether the team is lined up in the 3-4 or with four down linemen, the men up front get the job done. A. Smith and J. Smith are two of the best pass-rushers at their position, and Brooks and Ray McDonald are two of the most underrated defenders in the NFL. 

Check out this example from Sunday's game against the Lions. 

Detroit lines up with three wide receivers, one tight end and a running back, and the 49ers rush four, leaving seven defenders back in coverage. 

Brooks and McDonald immediately push their defenders off the ball a handful of yards, while J. Smith and A. Smith hang around on the other side, waiting for the pocket to collapse on the left side. 

Sure enough, Stafford is forced to the left and A. Smith is waiting for him for the easy sack. 

The 49ers make this look easy on a regular basis, but they are one of only a handful of teams that can afford to rush only four passers with success. 


Secondary Play is Solid

You've heard how important it is for the front line and the back end of defenses to work together, right? Well, the 49ers have a nice balance in this regard, as their cornerbacks and safeties work well together and in concert with the pass rush up front. 

Chris Culliver—the team's No. 3 cornerback—is good enough to start for many teams. He's stuck behind Tarell Brown and Carlos Rogers, though, and that's a good problem to have for the Niners.

Whitner and Goldson are intimidating enforcers in the middle, and both are capable of defending passes and making plays while the ball is in the air. The biggest key for this unit is discipline, and from what we've seen thus far in 2012, the players are sticking to their responsibilities. 


Middle Linebackers Athletic Enough To Cover Wide Receivers and Tight Ends

One of the ways teams are succeeding the most these days on offense is by utilizing three-wide-receiver sets. Another way teams are succeeding these days is because of the growing number of tall, fast, athletic tight ends who can beat most linebackers.

The 49ers have two middle linebackers—Bowman and Willis—who are fast enough, athletic enough and smart enough to cover wide receivers and tight ends. 

What this does for the 49ers can't be overstated. Defensive coordinator Vic Fangio can leave his two stud linebackers in on most downs, knowing that they have the ability to stuff the run and defend the pass. It also allows Fangio to keep his defensive backs in coverage, meaning that the 49ers have seven men in coverage on most passing plays.

We saw it on Sunday night, when Willis and Bowman were the ones tackling Calvin Johnson on quite a few of his eight catches, and it's something we're going to continue to see throughout the season. The effect of these two linebackers being able to do what they do can't be lauded enough. 

It makes everyone else's job easier, including Fangio's. 


Vic Fangio

Who in their right mind would consider taking Willis off the field when he's healthy and raring to go? Fangio did just that in the team's first game against the Packers, and his strategy paid off to great effect. 

Fangio seems to have a knack for coming up with just the right game plan to stymie opposing offenses, no matter what strengths they may bring to the table. 

Whether it's Willis covering Jimmy Graham all by his lonesome or whether it's having the guts to keep Willis out of the game, Fangio isn't afraid to do what he believes is the key to stopping an offense. 

He's the mad genius behind the top defense in the NFL, and it's about time he gets more credit for what he's done since joining the team at the beginning of last season. 


Note: Screenshots courtesy of NFL Rewind.

Follow me on Twitter @JesseReed78


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