There's always a stable of rising assistant coaches and coordinators who are advertised as being in line for a head coaching position. It looks like heading toward 2018, some of those guys actually have already been in charge somewhere.

Last year, five teams — the 49ers, Rams, Bills, Broncos and Chargers — hired new coaches. All of them were assistants from a variety of organizations who moved up.

A sixth change came in Jacksonville, where interim Doug Marrone got the full-time gig. He previously was a head coach in Buffalo, though.

The five novice head coaches are a collective 21-30, from Sean McVay's terrific 7-3 with the Rams, to Kyle Shanahan's unsightly 1-9 in San Francisco. Marrone is 7-3 with the Jaguars.

It appears there are more assistants and coordinators with previous top man experience who are in line for possible openings than potential rookie head coaches. Such names as Pat Shurmur in Minnesota, Jim Schwartz in Philadelphia and Josh McDaniels in New England are bandied about. None had particular success in those previous stints, but their work with the Vikings' and Patriots' offense and Eagles' defense has lifted them loudly into the conversation if the No. 1 jobs come open in Cleveland or Cincinnati or Indianapolis or Chicago or Tampa Bay or with the Giants in New York.

That doesn't surprise Bill Polian, who didn't get into the Pro Football Hall of Fame as a contributor because he couldn't find strong coaches. Among his guys are Marv Levy and Tony Dungy, both of whom are also enshrined in Canton.

"It helps," Polian says of prior head coaching experience, regardless of the level, but particularly in the pros. "All things being equal, having had that experience before may well be the determining factor in if you choose him or not. There is no substitute for having the experience.

"The ideal situation — Bobby Ross was a prime example — would be a guy who has had assistant coaching experience in the NFL, has gone back to college and had success at the college level as the head coach. He then becomes a very viable candidate in the NFL.

"That experience as a head coach, even though not at the same level, is really important."

Not that the next Jimmy Johnson is on the horizon for pro teams. In recent years, few college coaches have done well in the NFL, with Chip Kelly perhaps the most obvious example.

While there have been several experienced head coaches recently landing another spot in charge of a pro team — John Fox in Chicago, Jim Caldwell in Detroit, Jack Del Rio in Oakland — more teams are enamored of the "hot" assistant.

Mike Zimmer has turned out just fine in Minnesota, as have Doug Pederson in Philadelphia and Dan Quinn in Atlanta. They got their positions in part because of their years serving under a proven head coach such as Marvin Lewis, Andy Reid or Pete Carroll.

They also were hired because they recognized what owners today are seeking.

"I think the most important thing is vision," Polian says. "Does he see the big picture as a head coach as opposed to being a coordinator or position coach? Does he understand what his responsibility is in terms of the entire team, the organization, how to manage the salary cap, interact with personnel people?

"Most importantly, can he see and understand the present personnel and then determine and enunciate how he wants the team to look and wants the team to play."

Those are major challenges. And there's more.

"Communication comes next," Polian adds. "If you have vision, it doesn't do any good if you can't communicate. That is a very important part of the interview process. You must communicate your vision, ideas, orders, be able to communicate and handle a large group, to, as they say, command the room."

So who might be in line to get that chance to command the room for the first time?

Jacksonville's turnaround season could get offensive coordinator Nathaniel Hackett or defensive coordinator Todd Wash some looks. Carolina DC Steve Wilks has caught many eyes. So has Texans DC Mike Vrabel.

Should they get the opportunity, Polian has some advice for them.

"What players want and respond to is authenticity, consistency, truth, dignity and the ability to provide them with a chance to be a better player and a better team," he says. "They will respond to that no matter how the message is delivered."

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