San Francisco 49ers: Breaking Down the Most Dominant Unit in the NFL

Ever since Jim Harbaugh and his staff arrived in San Francisco, the 49ers have grabbed greatness by the horns. While Harbaugh has turned Alex Smith into a game managing extraordinaire, it's apparent that Vic Fangio's defense drives this team. 

Week in and week out his unit harasses opposing offensive players. Fangio's group is led by their stout play at linebacker, where Ahmad Brooks, Patrick Willis, NaVorro Bowman and Aldon Smith make up the strongest core unit in the NFL.

Brooks plays the run as well as any other 3-4 outside linebacker in the league, Smith is a pass rushing phenomenon from the ROLB spot and we all know what Willis and Bowman do well—everything. I have no problem ranking Willis and Bowman as the top two linebackers in the game.  

Even before Coach Harbaugh, Willis was a solid player, yet it's hard to believe that he has gotten even better under his tutelage. Bowman didn't see the field under coach Singletary, so I credit a lot of his development to the current coaching staff and their hands on approach. 

However, in fairness to the other seven starters on defense, the linebacking corp couldn't thrive without their help. Players like Carlos Rogers and Justin Smith are studs at their respected positions as well. 

With yesterday's domination of Green Bay being a total team effort, I decided to take a look at what makes the 49ers defense the most dominant unit in all of football.

Run Stuffing Ability

Stopping the run was San Francisco's calling card in 2011 as they managed to hold opponents to a measly 77.2 yards per game. In fact, they only allowed three rushing touchdowns and one 100-yard rusher all season long. 

Yesterday against Green Bay proved to be the same old song and dance as the Packers managed only 45 yards rushing on 14 attempts. It's getting to the point where teams don't even attempt to run the ball, or try for a few plays and find it to be frustrating, and so abandon it.

On this second-quarter run play Green Bay's offense is in an obvious run grouping with two tight ends, two wide receivers and one running back. This is one area that was not well disguised yesterday—the Packers often tipped off their running plays by using similar personnel groupings. 

I would say 90 percent of teams play the 49ers defense this way because they have to. Most teams know they can't block San Francisco's defensive front with five guys, so what do they do? They bring in two extra blockers for help. 

The screenshot above is a perfect example. I numbered and circled five Packers offensive linemen who are trying to block the 49ers front four. The tight end No. 83 is taking on Brooks one on one, the center and right guard double down on Ray McDonald, the left guard tries to block Justin Smith but fails miserably and Finley attempts to throw a block on Aldon Smith.

The right and left tackles, by design, are supposed to get to the second level and put blocks on No. 52 Willis and No. 53 Bowman, two guys who rarely lose one-on-one situations.

Ideally, good offensive lines shouldn't have to use double team blocks, but that's the beauty of the 49ers: Every team has to double team at least one of their defenders. 

They dominate the run game by destroying one-on-one match ups, just like Willis does on this play. In turn, this allows them to never have to put eight defenders in the box, making for solid coverage on the back end.

Pass Rushing Ability

According to Pro Football Focus, the 49ers were the second-best pressure team in the NFL last year. Only the Philadelphia Eagles were above them in terms of pure pass rushing from every level. 

A lot of that success is attributed to three players who stood out when rushing the passer—Justin Smith, Aldon Smith and Ray McDonald accounted for a majority of the teams' sacks, quarterback hits and hurries. 

Yesterday proved no different as No. 12 was sacked three times and hit numerous others. Brooks' fourth quarter sack was the most impressive of the three takedowns.

San Fran is rushing four on this play and as you can see, No. 55 is lined up over the left guard in a stand up position. As soon as the ball is snapped he is going to try and split the center and left guard, which will give him a path straight to Rodgers.

As he successfully splits the defense, the play calls for Ray McDonald to come around on a backside stunt. The backside stunt confuses the center for a split second—that moment of confusion is what allows Brooks to easily split the double team.

The sack ended up playing a big role down the stretch as the Packers failed to convert a fourth-and-10, which sealed their fate for good.

Coverage

To me the 49ers pass coverage is an extension of the way they rush the passer. Without a doubt San Francisco has one of the top secondaries in the league, but would they be one of the top coverage units without a dominant pass rush? 

That's a hard question to answer, but what I can say is that they have done a great job of schematically bringing in the right players. Carlos Rogers has become an absolute knockout since coming over from the Washington Redskins.

Last year he picked off six balls, deflected 13 passes and only allowed a quarterback rating of 65.1 when thrown at, easily a career season for the eight-year vet. Tarell Brown is the corner opposite of Rogers and to the surprise of no one he had a career year in 2011 as well. 

The coaching and development of players is what stands out to me the most. They know how to squeeze every drop of talent out of every player on the roster.

The video clip above is a perfect representation of how the pass rush and coverage work hand in hand. As Rodgers winds up to throw Perrish Cox comes off the edge free on a cornerback blitz from the slot. 

The pressure forces Rodgers to get rid of the ball early, and when getting rid of the ball early play development works against you. Given more time, Jordy Nelson could have possibly beaten Chris Culliver down the sideline or have had more time to scan the field for another option.

However, the 49ers bared down on him all game long, which pushed him out of his comfort—something Rodgers isn't used to considering he never faced a top-10 defense in 2011. 

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