Since Jim Harbaugh took over the reigns of the San Francisco 49ers franchise, this team has taken a dramatic leap into the ranks of the top-five defenses in the league. With the top two inside linebackers in the league in Willis and Bowman and the Smith Brothers terrorizing offensive lines off the edges, the Niners have established themselves as a true defensive powerhouse; however, they have come up second in points allowed per game two years in a row. This year, several changes in schemes and personnel will finally put them on top.
The key to the 49ers’ defensive lift will be the upgraded pass rush. In the past couple of years, Vic Fangio has implemented a base 3-4 defense, in which the three defensive linemen – the nose guard and the two tackles – compress the middle of the offensive line, allowing stud outside linebackers Aldon Smith, Ahmad Brooks, and Parys Haralson to come off the edge to get to the quarterback.
However, as the Niners did not have sufficient depth along the defensive line and outside linebacker positions and the inadequate pass rushing skills of former nose tackle Isaac Sopoaga, Fangio was forced to use more 5-2 sub packages than he would have liked. Because Willis and Bowman are so adept in coverage and the Smiths and Ahmad Brooks were so dominant off the edges, the defense was able to get away with it.
However, in the playoffs, when the Smith Bros. were hurt and the front seven began to show signs of fatigue, not enough pressure was placed on the opposing quarterbacks, and the elite ones such as Aaron Rodgers, Matt Ryan, and Joe Flacco were able to exploit the holes in coverage over the middle of the field and deep along the sidelines.
This year, however, the front office has made it a priority to beef up the depth among the front seven. After letting go of nose tackles Sopoaga and Ricky Jean-Francois, the Niners signed former first-round pick Glenn Dorsey and allowed young Ian Williams to seize the starting nose tackle job. During the preseason, Williams showed that despite his 305-pound frame, he has the athleticism to make plays in space and stop running backs through the A-gaps, the gaps between the center and the guard on either side.
He also demonstrated a much greater ability to press the pocket than Sopoaga did, allowing plays to be made on the edges. Williams will be relied upon this year to be a two-gapping nose tackle, responsible for clogging up both A-gaps and pushing the pocket to allow the playmakers on the outside to get to the quarterback. Dorsey, due to his size and versatility, will be expected to provide valuable depth across the line, at the nose and defensive tackle positions, and maybe even play some defensive tackle in 5-2 sub packages.
The front office also made it a point to infuse some youth into the front seven. They traded up to draft Corey Lemonier out of Auburn, one of the premier pass rushers in college. While his game may be raw, Lemonier is quick, powerful, and ferocious off the edge, giving the Niners a valuable backup to Aldon and Brooks. During the preseason, Lemonier opened some eyes with a lightning quick first step, allowing him to blow by slower footed offensive tackles. Though he may have done all of this against inferior competition and his weaknesses in run defense, I believe the Niners have found something special in Lemonier.
They also drafted Tank Carradine and Quinton Dial, although they will not be playing until Week 7 due to injury. Carradine was one of the top defensive end prospects in college before suffering a torn ACL. When he returns from the injury, Carradine will likely be the main backup at defensive end, and assuming he does well enough, he will likely take over the right defensive end position permanently when Justin Smith decides to retire.
While they may seem minor, these additions will greatly improve the 49er pass rush, allowing them to put consistent pressure on elite quarterbacks and harass running backs in the backfield. The only uncertainty in the defense is the secondary, with rookie safety Eric Reid and the aging Carlos Rogers at cornerback.
However, with such a menacing front seven, the 49ers will be able to put enough pressure on the quarterback to cover up their weaknesses in the secondary, allowing Eric Reid to develop into the top-flight safety I believe he can become. With these improvements, expect the Niners to finally be the one and only top defense in the National Football League.