John Randle likens a great pass rush to opening door after door after door until eventually a quarterback is there for the sacking.

“It might be the first door; it might be the last door of 1,000 doors,” Randle said. “The great pass rusher opens every single door just as hard as he did the first door.”

Randle was a great pass rusher, a Hall of Famer who had 114 of 137½ career sacks while playing for the Vikings from 1990 to 2000. It’s too early to suggest the Vikings have anyone who can rise to Randle’s level of success, but coach Mike Zimmer and his No. 2-ranked scoring defense head to Chicago on Sunday with an athletically gifted and schematically unpredictable pass rush that’s gaining a lot of attention and could be a key factor in helping the Vikings beat the Bears at Soldier Field for the first time since 2007.

The Vikings have 17 sacks and rank eighth in the league in sacks per pass play. They are also third in quarterback knockdowns with 42 and have 10 sacks off blitzes.

A week ago, Vikings defenders flung open door after door after door while sacking Matthew Stafford seven times in a victory at Detroit. Six times, the sacking defender was untouched or barely brushed. A day later, the Lions sacked their own offensive coordinator and two offensive line coaches.

Next up is Jay Cutler and a young, makeshift Bears offensive line. Chicago has given up 12 sacks, ranking 14th in sacks allowed per pass play in a more protective scheme under new coach John Fox and new offensive coordinator Adam Gase. To have a chance at punishing Cutler, the Vikings must first contain running back Matt Forte, who ranks fourth in the league in yards from scrimmage and sixth in rushing yards.

Film gives a fast feeling

Vikings defensive end Everson Griffen was asked how much film study he does beyond the two hours or so he said he gets during his typical workday at Winter Park.

“A lot,” said Griffen, who has 16½ sacks in 21 games since replacing Jared Allen as the starting right defensive end in 2014. “I got two kids, but I still watch a lot. At least an hour to an hour and a half on my own every day. My son might be climbing on my back, but I’m watching film.

“If I got to help around the house, I do that, too. God, family, football. You got to put it in that order. But there’s time to help this team win by doing what I have to do to make that happen.”

Ask Griffen to describe a typical film session and you get a better respect for the cerebral aspect of a game known more for its emotion and brute strength.

“I’ll watch the same play 10, nine, maybe 20 times,” Griffen said.

Pass rushers study the habits of the quarterback and every last twitch, tweak and tendency of the lineman they will be competing against. When asked to explain this part of the job, Griffen practically started speaking another language.

“I’m looking to see is he a 45-degree kicker, is he a double-hand puncher, is he a ‘Y’ clamper,” Griffen said. “If he jumps me, is he going to give me my hands? Is he going to give me his hands? If I speed around the corner, what does he do? Does he cross over? Does he open up? Does he leave the gate open for me?

“It’s like a million different things you look at, but my biggest thing is if you use speed on a guy you get him to move and now you’re on him.”

Fox has been around his share of great pass rushers at Carolina and Denver. He said each was physically gifted but they were great because of time spent watching film.

“That’s very critical,” Fox said. “Studying your opponent, knowing their weaknesses, their formational tendencies, their stances, it allows guys to play fast. If guys are fast and can play fast, they usually have great performances.”

Outthinking the opposition

To understand what preparation can do for a pass rush, study the seven sacks the Vikings had last week at Detroit.

Sack No. 1: Chad Greenway was an “add blitzer,” meaning his first responsibility was covering the tight end. When the Lions brought in a third tackle as the tight end for extra protection, it was a green light for Greenway to hit Stafford with a delayed front-side blitz he never saw coming.

Sack No. 2: Griffen had an untouched and inexplicable path to the quarterback when the left tackle blocked down on tackle Tom Johnson.

Sack No. 3: Safety Harrison Smith was one of four rushers sent to Stafford’s front side. Only one back-side defender rushed while Griffen dropped into coverage. With the front side so overloaded, Smith made the sack untouched.

Sack No. 4: Five defenders rushed at the snap of the ball. Middle linebacker Eric Kendricks made it six on a delayed rush that surprised Detroit. Stafford avoided Brian Robison but ran into the speedy Kendricks, who was untouched.

Sack No. 5: This time, the Vikings overloaded Stafford’s blind side with four rushers, including nickel cornerback Captain Munnerlyn and linebacker Anthony Barr rushing over Griffen’s outside corner. A fifth rusher was sent from the other side. Barr, who looped to the outside, and Griffen, who beat the tight end to the inside, met at the quarterback to share the sack.

Sack No. 6: The Vikings lined up in Zimmer’s favorite formation: the double A-gap with Barr over the right guard and Kendricks over the left guard. Both showed blitz. Barr dropped and Kendricks rushed and was untouched while making the sack before Stafford reached the top of his drop. It was the fourth sack in three games for the NFL defensive rookie of the month for October.

Sack No. 7: On third-and-9, the Vikings had seven men at the line of scrimmage: Four linemen, two linebackers in the A gaps and Smith lined up outside of Griffen. Right before the snap, Smith sprinted back into coverage while Munnerlyn moved into position to blitz from the opposite side. But after all of that, the Vikings rushed only three linemen and Munnerlyn. Johnson, the lone rusher from the blind side, got the sack. And, yes, he was untouched.

“The man has no chance,” Fox play-by-play man Chris Myers said of Stafford after that final sack.

Having ‘that will’

Fox said Zimmer’s “fingerprints are all over” what the Vikings are doing now compared to what Zimmer had success with as defensive coordinator with Cincinnati.

“They create good pressure by running what we call ‘mud’ looks,” said Fox, presumably a reference to how unclear the looks are for the quarterback and his pass protectors pre-snap. “They will bring four rushers weak or four strong off the things they do. It can cause us a lot of problems.”

According to Pro Football Focus, Cutler has been pressured on 39.2 percent of his 189 dropbacks, sixth-most in the league. He is completing 49.2 percent of his passes with three touchdowns and one interception while under pressure.

The Vikings’ 10 sacks off blitzes are third-most in the league. Cutler was asked how long it took him to get used to that kind of pressure at the NFL level.

“I played in the SEC at Vandy, so we were kind of outmanned and outgunned a lot of the time,” he said. “So I was kind of used to the speed and being back there under the gun.

“The Vikings show you a lot of different fronts. And they do a good job of mixing it up. Bringing four to a side, bringing the safety down. They can come from any edge. You’re not certain which five are going to come, which six are going to come or if there will only be four of them coming after you.”

At this point, the Vikings are relishing the opportunities to keep ripping open door after door after door looking for the next sack.

“Every pass rusher is different; none of us do the same things well,” Robison said. “Everybody has their own little niche. But at the end of the day, it’s about having a will to get to the quarterback. Right now, we all have that will.”