The Pittsburgh Steelers made the most impressive coaching hire in the NFL over the past 20 years.

Not merely because the coach they hired, Mike Tomlin, won a Super Bowl in his second season and has a record of 154-85-2, but because the Steelers avoided so many of the cliched processes and obvious pitfalls that lead to bad hires around the league.

In 2006, the Vikings went 6-10 in Brad Childress' first year as their head coach, and Tomlin, 34, in his first year as an NFL defensive coordinator. The Vikings ranked 14th in total defense.

The Steelers were thought to be leaning toward promoting Russ Grimm from assistant to head coach, or promoting offensive coordinator Ken Whisenhunt. Grimm had coached the Steelers' offensive line for six seasons and was a popular figure in Pittsburgh. Whisenhunt would become the head coach of the Arizona Cardinals.

Because Tomlin was brought in late in the hiring process for an interview, and because he was inexperienced and the only Black candidate, it was thought that the Steelers were talking to him to conform to the Rooney Rule.

The Rooney Rule was named after former Steelers owner Dan Rooney, and it requires NFL teams to interview minority candidates for key management positions.

The Steelers could have justified hiring Grimm or Whisenhunt, and either choice would have been popular in Pittsburgh. Tomlin so impressed them during the interview process that they hired him instead.

Grimm would never become an NFL head coach. Whisenhunt's Cardinals would lose to Tomlin's Steelers in XLIII. Whisenhunt's final NFL coaching record: 48-71.

The Steelers made what at the time felt like a surprising and unconventional hire — and they were proven right. Their patient, insightful approach should be a model for the Vikings as they replace fired head coach Mike Zimmer.

The Vikings are first working on selecting a general manager, and during and after they will grow and prune their head coaches list. What they need to realize is that conventional wisdom on coaching hires is likely to lead to a terrible hire.

Here are seven examples of popular notions that could cost the Vikings a great coach, followed by reasons why these notions are wrong:

1. "You need to hire someone different from the coach you just fired." The Vikings just fired Mike Zimmer, an older, gruff defensive coach. Bill Belichick is an older, gruff defensive coach. Does this mean that if Belichick were available, the Vikings shouldn't hire him? Or the next Tony Dungy?

2. "Don't hire anyone from Bill Belichick's coaching tree." Mike Vrabel played linebacker for Belichick and won the No. 1 seed in the AFC this year with a castoff quarterback and while missing his best player, running back Derrick Henry. Recently fired Dolphins head coach Brian Flores worked for Belichick and went 19-14 the past two years without a sure-thing quarterback.

3. "Don't hire a retread." Belichick went 36-44 in Cleveland. He won six Super Bowls in his second job. Andy Reid had a winning percentage of .583 and failed to win a Super Bowl in Philadelphia. In his second job, with Kansas City, he has a winning percentage of .710 and has won a Super Bowl. In his first two head coaching jobs, Pete Carroll went 33-31-0. In his third head coaching job, in Seattle, he is 152-104-1 and came within one play of winning consecutive Super Bowls.

4. "You can't hire a college coach." Correction: You can't hire a college coach named Urban Meyer. Jimmy Johnson was ridiculed by Buddy Ryan and other members of the NFL establishment when he moved from the University of Miami to the Dallas Cowboys. He took over a 3-13 team, went 1-15 in his first season, then built a team that won three Super Bowls.

5. "You have to hire a young offensive mind who can be innovative and develop quarterbacks." Of the past 21 Super Bowls, 10 have been won by coaches with offensive backgrounds, 10 by coaches with defensive backgrounds, and one by a former special teams coach.

6. "You have to hire someone from an established coaching tree." See: Mike Tomlin.

7. "You must hire someone from a winning organization." The Vikings went 6-10 in Tomlin's only year as a coordinator.

The Wilfs should remain patient and open-minded as they interview candidates. The best coach may not have the best résumé. The best coach might be someone you interviewed on a whim.