They say the best NFL teams are home grown. That you build the team and cultivate it over time. There are few instances that better fit that description than the Vikings defense.

“Well, I’m amazed by the continuity they have on defense,” Gruden said of the Vikings. “It’s kind of like a 1975 or 1980 team. They’ve been together, playing together at every level in the same system, which is uncommon.”

How much continuity are we talking? The average time with the team for their 11 starters is six years. The newest starter has been on the team three years. That’s either Ben Gedeon or Eric Wilson. depending on which of them starts t linebacker Sunday. The longest tenured is Everson Griffen with ten years on the team. Every other starter has been with the team between 5 and 8 years. That’s insane.

That is incredible continuity. And it’s the reason why Mike Zimmer’s defense in Minnesota has been in the top ten in points allowed for five straight years.

“They don’t make mistakes, they don’t screw around on defense,” Gruden continued. “They’re really good, man. Really good. And it’s amazing that they’ve had that continuity, I don’t know how they’ve done that but they are challenging.”

That isn’t just about players knowing the system from running it for so long. It’s also about knowing how to scout talent. Ten of the team’s eleven starters are original Vikings. The only guy who isn’t is veteran defensive tackle Linval Joseph who started his career with the Giants and who is in his sixth season with the team.

“They have had a number of players that they have drafted that they have been able to keep on their team and are in their second contracts. That’s very rare,” said Raiders offensive coordinator Greg Olson. “They’ve been able to maintain continuity in terms of personnel and he’s maintained continuity in terms of scheme being there, so certainly a challenge for us.”

All told, there are only five defensive starters who weren’t on the team from the moment head coach Mike Zimmer took over. And four of them came in his second season as head coach. I guess when you find players who fit your scheme, you keep them.

It’s the reason Paul Guenther — a Zimmer protege — makes sure he has veterans on his defense every season who know his scheme. Last year it was Reggie Nelson and Leon Hall. This year it’s middle linebacker Vontaze Burfict.

Guenther needs all the help he can get from players who know his scheme. Though with as bad as the defense was last season, upgrades were needed. He has four newcomers starting for the team from last season as he heads to Minnesota to face his mentor.