Nnamdi Asomugha to San Francisco 49ers: Which Asomugha Are The 49ers Getting?

The San Francisco 49ers acquiring Nnamdi Asomugha is one of the more interesting moves of this NFL offseason. The question is are the 49ers getting the same cornerback who dominated for the Oakland Raiders? Or will Asomugha be a bust in San Francisco, like he was with the Philadelphia Eagles?

The answer lies in how the 49ers can use Asomugha and how much his struggles in Philadelphia were due to diminishing skills and not other factors.

The 49ers play a lot of 2-deep zone concepts. On the surface, that won't suit Asomugha, who struggled in zone defenses with the Eagles.

However, there are key differences in the coverage schemes used in San Francisco.

Defensive coordinator Vic Fangio has tweaked things to give his corners more freedom to matchup one-on-one underneath.

So Fangio's scheme resembles man under with both safeties covering the deep zones behind it. The underneath man coverage part of that dynamic should appeal to Asomugha.

He came to prominence with the Raiders, thanks to his aggressive, man coverage. The phrase "press" was most often used to describe Asomugha's technique.

He became the last true practitioner of bump and run techniques in the modern game. It worked for wonders for Asomugha.

In 2008 he allowed only 16 passes to be completed against him. Given the pass-heavy nature of 21st century football and that Asomugha was usually isolated in single coverage, that's a phenomenal stat.

Can the 49ers help him reclaim that kind of form? If they can it will mean molding Asomugha to fit their Cover-2 schemes.

The key will be to let him use his physical, press techniques at the line. Fortunately, that's exactly what a true Cover-2 allows for.

The gap in the coverage is on the inside, between the cornerback and the safety. To prevent the receiver running freely to the inside, the cornerback must execute a firm bump at the line.

That's why a classic Cover-2 corner like Chicago Bears ace Charles Tillman, is usually up at the line, close enough to get that bump.

A cover-2 cornerback only goes with his receiver on out patterns to the sideline or flats, or intermediate routes across the middle.

If the receiver goes vertical, the cornerback simply lets him, knowing a safety has the deep coverage. Asomugha didn't exactly receive much help from a poor collection of safeties during his two years with the Eagles.

The Niners meanwhile play a disciplined two-deep shell. Safeties like Donte Whitner know their roles and don't desert their zones.

However, as much as the 49ers' version of the Cover-2 might appear to suit Asomugha, it's still a zone system and that's what he struggled with in Philadelphia.

The 49ers are mindful of Asomugha's recent struggles. That's why they only gave him a one-year deal, with no guaranteed money, according to ESPN's Adam Schefter.

However, things were never really right for Asomugha to succeed in Philadelphia.

His critics have become fond of saying Asomugha has lost a few steps. While vertical speed has never been the 31-year-old's strong suit, the Eagles zone concepts certainly didn't help.

With the Raiders Asomugha became a master of pinning his receiver to the sideline. This kept him in front and denied his receiver the space to run him deep.

Zone schemes don't allow for this ploy. Zone coverage is all about keeping any potential receiver in front of the defender.

That certainly didn't suit Asomugha in Philadelphia. Neither did too much flip-flopping between schemes.

He played most of his first season with the Eagles as an ill-suited zone defender. Then the team wisely reverted to more press coverage to start the 2012 season.

When defensive coordinator Juan Castillo was fired after six games, Todd Bowles replaced him and brought back more zone coverage.

It would be difficult for any cornerback to produce consistent, positive form amid so much change. There was also in-fighting among the Eagles defensive staff, notably between Castillo and line coach Jim Washburn.

Asomugha played on a defense that was a collection of individuals pulling in different directions, rather than a coherent unit, equipped with one clear plan.

The 49ers defense is the polar opposite. Fangio's group plays together in a coherent framework.

For all their defensive might, the 49ers don't do a lot schematically. They simply rely on their two-deep shell and powerful pressure up front.

Yet it is that simplicity that can get Asomugha back to his best. The system he played in for the Raiders was limited and very specific, but it helped him thrive.

Fangio's man-under, two-deep scheme lets Asomugha play to his strengths at the line and covers for his failing speed with disciplined safety help.

If it works the 49ers won't be stuck with the cornerback who couldn't cover anybody in Philadelphia. They'll have the corner who dominated receivers in Oakland.