Robert Saleh officially has been named the new defensive coordinator for the 49ers, and he’s expected to bring some changes with him.
For many seasons, the 49ers essentially have run a 3-4 base scheme, with three defensive linemen and four linebackers. Saleh, however, is expected to run a 4-3 base scheme, much like the one used in Jacksonville and Seattle, his two previous coaching stops.
However, Saleh’s system will be fluid. New 49ers head coach Kyle Shanahan said in a recent interview on KNBR that Saleh intends to run a defense very much like the one in Seattle under Pete Carroll. That system has been described by Carroll as a “4-3 front with 3-4 personel.”
Often, it features four defensive linemen plus a linebacker on the line of scrimmage, like a 3-4 scheme.
The scheme – which favors quick, active linebackers – promotes an aggressive, attacking style, say Shanhan and general manager John Lynch. It gives an offense a lot of shifting, multiple looks.
“Here’s what we know on defense: We want to be aggressive,” Lynch said recently. “We want to be multiple. Kyle talked a lot about what gives him problems as an offensive coordinator, so I think those are things that we’re looking for.”
Shanahan said in a recent interview on KNBR that Saleh is “as smart as anyone I’ve been around,” and will alter the defense into a unit that operates in the mold of the Seattle-Jacksonville systems.
One of the big questins will be, how does the 49ers’ talent fit into the new scheme? As Matt Barrows of the Sacramento Bee noted, over the past two drafts, the 49ers’ have taken a pair of Oregon defensive linemen, Arik Armstead and DeForest Buckner, who fit the prototype of a 3-4 defensive end. Shanahan, for one, believes they’ll both fit nicely into the new system. It’s adaptable, he said.
“I think all that is semantics, to tell you the truth,” he said. “Seattle has a linebacker on the ball every single play. So does Atlanta. And that’s five guys on the line of scrimmage. So whether you call it a 4-3 or a 3-4 … for the most part, we call it a 4-3.”