EAGAN, Minn. -- Mike Zimmer was hunkered down in front of the computer in his office, steadily grinding away tape of draft-eligible three-technique defensive tackles, when Sheldon Richardson not-so-magically appeared in his doorway.

On March 15, the day the Vikings signed quarterback Kirk Cousins, they were also catering to another prized free agent. After deciding to let Tom Johnson walk in free agency (he would later re-sign with the Vikings in Week 3), Minnesota placed high importance on upgrading the three-technique position. Once Richardson hit the free-agent market after one year in Seattle, it was among Zimmer and general manager Rick Spielman’s top priorities to land the 27-year-old to solidify their star-studded defensive line.

Richardson had everything Zimmer was looking for at the position: athleticism, strength, first-step quickness and lateral speed.

“But the thing that kind of surprised me a little bit is the power that he has with it,” Zimmer said. “The good three-techniques I have been around have all kind of had those qualities.”

The Vikings' defense is tied for third in the NFL with 36 sacks through 12 weeks. Ahead of the Vikings’ 24-17 win over the Green Bay Packers, Richardson led the team in quarterback hurries but only had three shared sacks. Zimmer has repeatedly said that sack numbers don’t tell the complete story of how effective a defensive lineman is. After all, Richardson had just one sack in 2017, which didn’t come remotely close to painting the picture of how disruptive he was at getting the quarterback off his spot.

Richardson signed a one-year deal worth $8 million this offseason to prove he can provide the push needed to generate a stout pass rush from the interior. What that translated to against Aaron Rodgers was a two-sack performance from the defensive tackle.

Given the capabilities of the Vikings' front four, Zimmer hasn’t had to blitz as much as he expected. The Vikings have generated pressure on 27 percent of dropbacks when sending four or fewer pass-rushers this season, which is the seventh-best rate in the NFL. That’s led to getting a sack on 8.2 percent of dropbacks with a standard pass rush, which is the fourth-best rate in the league, according to ESPN Stats & Information.

While Danielle Hunter and Everson Griffen’s pass-rushing skills make them one of the most lethal defensive-end duos in the league along with Linval Joseph’s force at nose tackle, it can be argued that the three-technique position is what sparks the entire unit. It’s why it’s such a critical piece of what allows Zimmer to do what he wants defensively.

“Most of the time the three-technique gets a lot of one-on-one situations with the guards,” Zimmer said. “A lot of times the center is going away, the tackles -- the way we play our ends have a tendency to sit on the inside just a little bit more, and they get chipped a lot more. The three-technique is the one that if he can be a pass-rusher it really helps with the two ends, especially because the tackles can’t sit in on him quite so long, because they got to get to the ends or vice versa.”

Richardson has proven to be an ideal fit in Zimmer’s scheme. His athletic edge allows him to get off blocks and chase down opposing quarterbacks, while his presence next to Joseph makes it difficult for teams to run up the gut. Every time a team tries to execute that playcall on a third-and-1 or fourth-and-inches, Richardson said he and Joseph find themselves in awe.

“We laugh. Seriously, we laugh,” Richardson said. “Like are you really going to run the ball up here? OK. And then we get mad when they run outside. Beggars can't be choosers.”

Minnesota’s Week 13 opponent is familiar with Richardson’s level of dominance. Having gone against him twice a year when he was with the Jets from 2013 to '16, where he started as a defensive end before moving inside to tackle and even playing some outside linebacker in New York’s 3-4 defense, the Patriots know all too well how Richardson’s athleticism can break a game open.

“He’s a great player and he was certainly a problem when he was in this division,” Patriots coach Bill Belichick said. “I think it’s just a testament to how athletic he was to be able to play out there. I think he’s playing at a more natural position now at 3-technique. He’s strong, he’s hard to knock off the ball, he’s smart, he reads blocking schemes well, and he’s athletic and quick and explosive on the pass rush. He can run through guys and he can run around them. He does a good job of recognizing schemes and play action, blocking angles and so forth to be able to make the right reaction and put himself in good position. He’s a hard guy to handle inside, they have a great edge rush. Joseph does a great job inside. The whole front’s a problem.”

Richardson’s fit in the Vikings' defense has not only helped this unit reach the heights it has on third down (league-best 27.64 percent conversions allowed) and pull out stop after stop in the red zone, but it’s the fit culturally and from a mentality standpoint that Richardson believes helps him achieve what he came to Minnesota for: to get back to playing like the Pro Bowl version of himself.

“Coach Zimmer and Rick Spielman and Coach (Andre Patterson) Dre, it's a blue-collar organization,” Richardson said. “Definitely blue-collar organization. They're just asking me to work. ... That's the whole purpose of us being here. To be good and be great and stay in the league, you've got to do it every day. That's one of the main reasons why I like the organization ... no politics.”