Asked earlier this month about the working relationship between coach Mike Zimmer and John DeFilippo, the team’s first-year offensive coordinator, General Manager Rick Spielman answered with something of a summary of Zimmer’s mission statement on offense.

“I know ‘Zim’ is very tied up on the defensive game-planning, but I know he gets together with ‘Flip’ once a week,” Spielman said. “I know Zim knows what kind of football team he wants. We’re always going to want to pride ourselves on playing good defense. We want to be a balanced attack on offense and, you know, try to win games like we always have around here.”

If the Vikings remain built on those principles, it will come at a time when the league is racing rapidly in the other direction.

NFL teams are running the ball less frequently in 2018 than at any point in the league’s history, averaging only 25.7 rushing attempts per game. The eight seasons with the fewest carries in NFL history have all come since 2010, and while the average number of runs could increase with the arrival of cold weather, 2018 is on pace to break the previous record for fewest number of carries, set in 2016, at 26.0.

Of the NFL’s top 10 offenses, only two — the Saints and Patriots — even run the ball 40 percent of the time, with the Saints topping out at 47.2 percent.

But while teams are running the ball less than ever, they’re also running it more efficiently than ever. In fact, the NFL’s 4.37-yards-per-carry average this season is on pace to shatter the previous record set in 2012, when former Viking Adrian Peterson’s MVP season and the arrival of read-option attacks in Washington and San Francisco powered the NFL to a 4.26-yard average.

This season, it seems again, that innovation has played a prominent role in driving greater efficiency. While the Broncos’ relatively conventional ground game leads the league with a 5.2-yard average, teams such as the Rams and Chiefs — who combined for 105 points on Monday night — are among the league leaders in rushing average, making the most of their limited rushing attempts out of spread sets and creative play designs.

“I think maybe schematically, teams are doing some different things,” Vikings running back Latavius Murray said. “You talk about RPOs [run-pass options], the ability to have a lot more chunk running plays — sweeps, RPOs. It’s getting trendy, and teams are finding ways to run the ball and get outside, not so much inside. When you get outside, that’s where those yards are going to come.

“A lot of times, when you spread people out, you get guys out of the box, but another part of it is, when you have personnel — let’s say it’s nickel or dime — those are usually littler guys. Our linemen will mostly likely have more success blocking nickel [corner]s, compared to inside and strong linebackers, things like that.”

Passing options

Not only are teams finding more creative ways to run the ball, they’re doing away with the idea they have to run to set up play action. The three quarterbacks who throw the largest percentage of play-action passes — the Rams’ Jared Goff, the Chiefs’ Patrick Mahomes and the Eagles’ Carson Wentz, according to Pro Football Focus — play in offenses that run the ball 39, 44, and 36 percent of the time, respectively.

“I haven’t felt a total dependence on that,” Vikings quarterback Kirk Cousins said. “I also believe that, at times, you can use the play action to set up the run. You can use the screen game to slow down the pass rush, and you can use all elements of offensive football to help the complementary action. The key is to be multiple; the key is to have plays that are the same but look different and have plays that are different but look the same.”

So where does that leave the Vikings?

They ran the ball 47.4 percent of the time last season under offensive coordinator Pat Shurmur, and said they wanted to retain much of Shurmur’s offensive philosophy before hiring the 40-year-old DeFilippo, who came from an Eagles offense that was hailed as one of the NFL’s boldest last year. The Eagles ran 44 percent of the time last season, albeit while implementing many of the run-pass option concepts that Wentz liked at North Dakota State.

Line woes

Zimmer called for both more balance and less volume in the Vikings offense on Monday, saying the team needed to stick with the run game and simplify some of its offensive concepts. On Wednesday, he elaborated further on his philosophy, pointing out the Vikings had been better in third-down situations a year ago, which enabled them to incorporate a few more runs.

“You know what’s kind of interesting? I’ve been taking 10-game stats from a year ago to 10-game stats this year,” he said. “Actually our run average a year ago at this stage [last year] was 4.04 [yards] per carry. This year we’re at 4.01 per carry, so it’s really, at the end of the day, number of carries. You can look at our offense a year ago and we were 380 yards per game. This year we’re 378. There’s so many statistics that are like, ‘Oh my gosh.’ It’s the same thing. There’s a few that are different that we have to improve on.”

The Vikings’ offensive line instability this season — exacerbated by the retirement of Joe Berger and season-ending hernia surgery for Nick Easton — might also contribute to a reluctance to run the ball more. It’s worth noting that Shurmur opted to throw it 62.3 percent of the time in 2016, when the Vikings had an injury-ravaged offensive line and an established pocket quarterback in Sam Bradford. DeFilippo, in much the same situation this year, has opted to throw it 63.3 percent of the time.

Ready for change?

DeFilippo praised Zimmer in May for the role he could play as something of a foil in their meetings, bringing a defensive coach’s appreciation for time of possession, field position and the cumulative effect of a bruising running game on an opponent.

“Defensive coaches and offensive coaches sometimes see the game a little bit different,” DeFilippo said. “They see the big picture a little bit more than offensive coaches.”

As the Vikings try to find the right balance on offense this season, with a new quarterback, new coordinator and a shifting offensive front, they’re also faced with a league that’s running with ever-greater efficiency, even as teams flock to pass-heavy offenses while incentivized by rules changes designed to encourage more scoring.

How the NFL views offensive balance, it seems, has changed inexorably. It remains to be seen, in a year where the league is on pace to set records for total yards and points, whether the Vikings try to win by standing firm on their foundational principles or following the trend toward ground games as a counterpunch.

“If teams have become more pass-first, then, as a defense, you’re going to prepare for that,” Murray said. “You’re going to honor that. You’re going to back up. You’re going to double guys, like sometimes guys do [to] Adam [Thielen] and [Stefon] Diggs. When you’re doing that, the run maybe is a little less of a worry.”

Ben Goessling covers the Vikings for the Star Tribune. E-mail: ben.goessling@startribune.com