Even if the Vikings beat Tennessee on Sunday and improve to 4-1, we won't be certain that they have built a sustainable winner, but they will have taken another stop toward justifying their approach.

Just a year ago, they looked not just inept but philosophically flawed and anachronistic, like a shipping company that relies on horses.

Win or lose Sunday, succeed or fail this season, the Vikings look like they have a plan that doesn't feature rotary phones.

In April 2011, they selected quarterback Christian Ponder with the 12th pick in the draft. Most NFL analysts accused them of reaching. Even those who liked Ponder thought he was unworthy of the 12th pick.

Today, Ponder is the quarterback of a 3-1 team. He has yet to throw an interception. He has completed 70.1 percent of his passes. The two times his team needed him to make plays to win a game, against Jacksonville and San Francisco, he did.

As of today, he's proof that if you can find the quarterback you like, where you get him is irrelevant.

In September 2011, the Vikings signed Adrian Peterson to a new, lucrative contract. Many NFL analysts, and me, questioned paying premium money to a player who has taken a beating at a position that has become devalued around the league.

Today, Peterson's return from major knee surgery is one of the most inspirational stories in the NFL, and defenses having to game-plan to stop him has eased Ponder's burden.

As of today, Peterson's excellence and perseverance have justified his contract.

In November 2010, Vikings owner Zygi Wilf fired Brad Childress and installed Leslie Frazier as interim head coach. As the Vikings slouched through a 3-13 season in 2011, Frazier's chosen offense looked simplistic and his chosen defense looked confused.

As of today, Frazier is running one of the surprise teams of the early season, and his vision of a team winning with a physical style of play no longer seems antiquated.

A year ago, the Green Bay Packers and New Orleans Saints seemed to rule the NFC with intricate passing offenses. By the end of the season, teams with more traditional styles had gained the advantage. The Giants had won the Super Bowl, and the 49ers had advanced to the NFC title game, and the old-school Ravens had come within a missed field goal of winning the AFC title game.

This season, the Falcons, running a version of the offense Bill Musgrave brought to Minnesota, are among the early dominant teams, along with the run-oriented Texans. Suddenly, the Vikings look, stylistically, a lot like the NFL's most successful teams.

I asked Frazier why he chose a power running offense instead of a newer model. "Part of it was my background, and the way I've seen teams win in this league, both as a player and a coach," said Frazier, who played cornerback for the Bears' Super Bowl winner. "Being a defensive coordinator and defending teams in this league, I just always felt that if a team wanted to come in and throw, we could find ways to create some situations that would help us.

"But when a team runs the ball on you? Oh, man, it's demoralizing. To your entire team, not just your defense. The offense is over there saying, 'Why can't we stop the run? Why can't we get on the field?' "

Frazier also chose to emphasize his roster's strength. His best player is a running back, Peterson, just as the best of the many great Bears he played with was Walter Payton.

"Adrian reminds me so much of Walter," Frazier said. "Walter meant so much to our defense and our team when I was playing. I don't want to get away from making this guy the centerpiece of our offense.

"I know our players read those things about this being a passing league. I made it clear early on that this is who we're going to be and this is how we're going to win. Fortunately, the guys believe it and are trusting us."

This year's NFL makes Frazier's approach easier to trust.

Jim Souhan can be heard Sundays from 10 a.m. to noon and weekdays at 2 p.m. on 1500-AM. His Twitter name is SouhanStrib. • jsouhan@startribune.com