EDEN PRAIRIE, Minn. -- If you dig to the core of the Minnesota Vikings' offensive turnaround, what you'll find is a conventional, practical method cultivated by offensive coordinator Pat Shurmur.

Shurmur took an offense ranked at the bottom of the NFL in 2016 -- 32nd in rushing (75.3 yards per game), 28th in yards per game (315.1), 24th in scoring (20.4 points per game) and 18th in passing (239.8 YPG) -- and manifested immense success for a playoff-bound team eyeing a first-round bye with a win this weekend.

The Vikings enter Week 16 ranked eighth in total offense, ninth in rushing and ninth in passing. In the midst of the best season of his five-year NFL career, Case Keenum has a passer rating of 98.9 and the third-highest Total QBR among eligible quarterbacks. He's coming off a near-flawless performance against Cincinnati, in which he posted an 87.0 completion percentage, which is the highest by a quarterback with a minimum of 20 attempts in a game this season, according to ESPN Stats & Information.

Of the 12 teams that would be in the playoffs if the season ended today, Minnesota is the only one that has a different starting quarterback (a QB who also has more than one start in the regular season -- sorry, Nick Foles) than the one it entered 2017 with.

The Vikings' offensive uptick began months ago but continues to draw the national spotlight, with Shurmur's name being linked to head-coaching gigs for teams desperate to spark their own offensive surges.

After all, given everything he has done this season with less-than-desirable circumstances, it isn't unlikely to think Shurmur's success will take him away from the Vikings in 2018.

To recap, everything started at ground zero with the offensive line. Minnesota spent money in free agency at both tackle spots with Riley Reiff and Mike Remmers, nabbed center Pat Elflein in the draft (and reserve guard Danny Isidora), moved Joe Berger from center to right guard and slotted Nick Easton at left guard. These five athletic linemen were the right fit as the Vikings shifted to a zone-running scheme.

With their O-line in a much better place than a season ago, the injury bug struck elsewhere. One by one, the Vikings lost quarterback Sam Bradford and lead running back Dalvin Cook.

Shurmur was thrown into emergency adjust mode to save the Vikings' season before it really had a chance to take off. Looking back, it was Bradford who eerily foreshadowed what Shurmur would be facing this season -- and why he would succeed.

Perhaps Bradford should know best. Prior to their time together with the Vikings, Shurmur and Bradford previously worked together in St. Louis (2010) and Philadelphia (2015).

"If I look back at what we were doing in St. Louis, what we were doing in Philly, what we were doing now, I think there's bits and pieces of all of those offenses," Bradford said ahead of the Vikings' opener against the Saints. "I think we're multiple, I think we throw a lot of different looks at defenses, and Pat's not afraid to change, which is really why I like working with him."

Shurmur's aforementioned process of getting the most out of his players? Keep it simple.

It isn't about trying to create something so complex to throw off a defense that in doing so, you confuse your own personnel.

No one understands this better than third-string quarterback Kyle Sloter, who missed all of OTAs and training camp before being signed to the practice squad at the beginning of September and called up to the 53-man roster two weeks later.

Naturally, it took Sloter a little longer to learn the playbook, and the fact that Shurmur was putting him in a position to simplify passing concepts not only was a surprise but also helped him not over-complicate things.

"As a player, I'm always wondering where the really tricky things are," Sloter said. "I'll give him credit. A lot of times I'll sit there, and I'll be like, 'Man, I don't know if this is going to work in this situation.' But every time I'm sitting there thinking that, we bust a 40-yard run or 20-yard pass. He keeps it simple, and it's worked out for our team."

In a league in which teams might throw the ball upward of 50 times per game, Shurmur’s offense is rooted in concepts that have been around for years. Often seen are slant-flat combinations that let Keenum easily depict where his safeties are on pre-snap reads before efficiently delivering the ball or curl-flat designs utilized by college and pro teams that make it difficult for a defender playing underneath to undercut the route.

In a stark contrast from last season, the Vikings are one of the more well-balanced attacks in the NFL, and it hasn't come at the expense of losing the explosive plays coach Mike Zimmer wanted to implement elsewhere after Cook went down.

Minnesota has 14 run plays that picked up 20 yards or more, which ranks fourth in the NFL. Since Cook's injury, both Jerick McKinnon and Latavius Murray are averaging 154 yards per game from scrimmage, combining for 1,652 yards this season.

In the post-Adrian Peterson era, Shurmur has utilized his two running backs as effective pass-catchers out of the backfield. Against the Bengals, McKinnon had receptions of 41 and 29 yards, while Murray caught a screen pass that went for 28 yards on the opening drive.

"I think we've done a nice job of keeping teams off-balance with some of the play-actions and some of the running game," Zimmer said Monday after the Bengals game. "We've had the opportunity to hit some shots when we've been able to. I think it's the combination of keeping people off-balance a little bit."

As Zimmer noted, the Vikings have attempted an NFL-high 136 play-action passes this season. Seven of Minnesota's 23 passing touchdowns have come off a play-action call.

Another area highlighted by vast improvement this season is red zone scoring, in which the Vikings finished 28th in 2016.

Shurmur has found an effective role for Kyle Rudolph inside the 20-yard line. The tight end has caught 14 passes on 17 targets and scored seven of his eight touchdowns inside the red zone, including a 1-yarder against Cincinnati.

Remember how Bradford led the league in completion percentage a year ago by quickly dumping off the ball near the line of scrimmage? The first game of the season, in which Bradford had one of the best performances of his career, showed signs that those days were in the past.

When Keenum took over the reins of the offense, it was certain that the Vikings would be utilizing him in different ways than they did Bradford.

Shurmur has been able to do more and get more out of Keenum's mobility. We've seen the quarterback extend drives with his legs, several of which have come in key third-down situations.

"I think that is an important quality for a quarterback," Shurmur said of Keenum's scrambling in October. "If you're going to take the ball and go 70 or 80 yards and score, somewhere in that drive the quarterback is going to have to do something with his feet. So move in the pocket to make the throw. If he has to escape the pocket, either make a run or make a good decision and throw the ball away, which is using your feet the right way. He's been able to do that, and I think that’s helped us."

Since taking over in Week 2, Keenum is completing a career-high 67.9 percent of his passes with an average of 7.5 yards per attempt, which ranks ninth in the league. Adam Thielen has reached new heights with Keenum as his quarterback, totaling 83 catches for 1,191 yards.

While those two have sparked the surge in the passing game, Shurmur has made sure that everyone has gotten involved, as seen when five different Vikings scored in Washington. A total of 10 have reached the end zone this season.

"He's done a good job of bringing everybody along and kind of molding everybody to the system as opposed to molding [the system to the players]," Sloter said. "It's a system that fits everybody. It's something I give him credit for. You could get Michael Vick who is a rusher, scrambler kind of guy, and he could fit into the offense.

"It works well with everybody's skill set. Sam was more of a pocket passer, where Case is a guy that can get out and move around and use his legs a little bit more. It really wasn't something that we changed. It fit everybody's style."

As the season has worn on, Shurmur has gotten more out of Keenum each game. The relationship has stretched over time because the offensive coordinator hasn't tried to make his quarterback something he isn't.

"It's a lot better than it was, and I think we still have some room to grow," Keenum said. "The more time we spend in meeting rooms watching film, talking through defenses. We're getting more and more on the same page and seeing things through the same set of eyes. I think that's important for a coordinator and a quarterback."