How did teams running Jeff Hafley's defense choose to build in the NFL?

The Packers won't tell us exactly how they plan to build this new defensive structure, but it's not hard to find crucial trends among coaches who have done it before.

Jeff Hafley wasn’t going to give us the recipe before he and Brian Gutekunst cooked the meal. We will have to wait until September at the earliest to get a taste, but at least we’ll get some insight into how they want to build this Packers defense this offseason. On the other hand, it’s a new scheme, new coaching staff, new working relationship with the head coach and general manager. We don’t know what it’s going to look like. Hell, they don’t know either. To try and tell the Green Bay Packers’ defensive fortune, we can look at how other teams running the same style of defense chose to build, and several obvious trends emerge including the most crucial one: build the trenches.

This defense only works with the front winning its matchups.

In Kyle Shanahan’s first year in San Francisco with Robert Saleh at the helm, a flailing 49ers team built its offensive infrastructure with familiar names at the skill positions, while beefing up their front seven. Shanahan and Saleh kept the previous defensive backs coach on that staff, an ex-Browns coach Shanahan knew from Cleveland named Jeff Hafley.

The starting cornerbacks for the 2017 49ers were Rashard Robinson and Dontae Johnson, each playing in their final year by the Bay. It was, predictably, a disaster with the Niners ending the year 26th in DVOA, but it set a clear standard of priorities: they were building from the front.