Can it really be this simple?

Can it really work this fast?

For most of the past five seasons, the Vikings have been the cold-weather edition of the Tennessee Titans, relentlessly mediocre save for the occasional distracting month.

For the Vikings, that four-week optical illusion arrived in December 2012, when they won four straight games to finish with 10 victories and a playoff berth, delaying the firing of Leslie Frazier by a year.

That monthlong and unexpected burst of competence is all that stands between the Vikings and five straight losing seasons. In 2010, 2011, 2013 and 2014, they averaged a little more than five victories.

So they did what bad teams do. They fired their head coach, invested their hope in high draft picks and set out to re-prove that in the NFL, a couple of key changes can immediately alter the personality and outlook of a franchise in what is otherwise the most complex and bureaucratic of sports.

Mike Zimmer made quite the impression during his first season as the Vikings coach.

As they prepare to report to training camp, the Vikings appear promising not only to those who were still paying attention when Teddy Bridgewater began improving exponentially toward the end of last season, but they also are becoming the fashionable pick to improve exponentially as a team this season.

Is that all it takes — the right head coach and a savvy young quarterback?

Well, yes and no.

Yes, a head coach in football makes more of a difference than a head coach in any other major professional sport.

Baseball managers can create an atmosphere conducive to winning but can't control the most important aspect of the game — the quality of a starting rotation. Basketball coaches need talent to win. Hockey coaches can create defensive systems conducive to winning but can't create goals without talented players.

Football coaches have so much control over their product that they can alter a franchise. They choose the offense, the defense and the coaches who run them. They influence the draft, morale, personnel decisions, game plans, strategic in-game decisions and the very personality of the team.

When Mike Zimmer took the job, some veteran players were worried he would be nothing more than the wild-eyed, prolifically cursing defensive coach they saw in "Hard Knocks" when he was with the Bengals.

Those concerns didn't dissipate until the middle of last season, when Zimmer revealed himself to be a humane coach open to modern ideas and critical of himself as often as his players.

Vikings linebacker Chad Greenway was one of those worried about Zimmer. Recently, Greenway offered a long dissertation on the promise of this season and the franchise's future, and ended, almost as an afterthought, with this:

"And of course we think we've got the coach in place to run it."

A few former Vikings have said this summer that Zimmer is the best coach the Vikings have had in a long time.

Zimmer didn't land a head coaching job until he was approaching 60. He immediately aligned himself with Bridgewater. Zimmer knows he'll get one shot to win or be recast as a lifelong coordinator, and he has placed his trust in a kid who hasn't even physically developed yet.

Whether via the eye test or statistical analysis, Bridgewater performed as one of the best quarterbacks in the NFL over the last five weeks of the season. With a struggling offensive line, no proven starting-caliber receivers, no Grade A tight ends and a backfield filled with mediocre or inexperienced runners, Bridgewater became more precise and polished as the season progressed.

This season Zimmer will benefit from the return of Adrian Peterson and Kyle Rudolph, the additions of Mike Wallace and Trae Waynes, the expected development of Anthony Barr and Bridgewater.

All the losing has helped the Vikings build a young, talented roster.

Can it really be this simple?

Can it really work this fast?

The last time the Vikings had a roster this talented and added a quarterback who knew what he was doing, they almost went to the Super Bowl.

Bridgewater isn't Brett Favre, but he could be something more valuable for the Vikings: a franchise quarterback with staying power.

As training camp begins, the Vikings' key figures remain unproven but remarkably promising. After five mostly awful seasons, fans can lace their dreams with realism.

Jim Souhan's podcast can be heard at MalePatternPodcasts.com. On

Twitter: @SouhanStrib. • jsouhan@startribune.com