From the smooth, almost laid-back approaches of Lovie Smith and Jim Caldwell to the fiery passion of Mike Zimmer, new NFL coaches are reshaping the environments of their teams.
Some have much bigger chores than others.
Bringing in a new coaching staff usually means the previous one did too much losing. That's true times seven this year as Smith takes over at Tampa Bay, Caldwell in Detroit, Zimmer in Minnesota, Ken Whisenhunt in Tennessee, Bill O'Brien in Houston, Jay Gruden in Washington and Mike Pettine in Cleveland.
PETTINE: BEING BLUNT
Pettine might have the biggest challenge because he takes over a perennial loser: Cleveland last made the playoffs in 2002. There's been discord surrounding the franchise ever since Jimmy Haslam bought it in 2012, and he's already on his third head coach.
The son of a highly successful high school coach, Pettine is bright, self-confident and media savvy, seemingly lacking the suspicious nature of so many NFL head coaches.
He doesn't pull punches, which is critical in engineering a cultural change.
''I would say no nonsense,'' Pettine says. ''I have been nicknamed BFT: Blunt Force Trauma. The days are too short to dance around subjects and I think guys appreciate that.''
SMITH: STAYING LOW-KEY
Another necessary skill is communication. Smith, who was 84-66 in nine seasons in Chicago, yet was canned after 2012, is a master at that. After the roughness of Greg Schiano's reign in Tampa, Smith's low-key style easily won over the players.
Not that Smith doesn't know how and when to be stern; he learned under Tony Dungy, a master communicator.
''It's been a while, I can honestly say, since you've seen guys smile this much and have this much fun,'' says DT Gerald McCoy, among the Bucs' best players. ''It's just a completely different feel around the building.''
CALDWELL: STAYING CALM
Caldwell also comes from the Dungy coaching tree, and he might still be the man in Indianapolis had Peyton Manning not missed 2011 after neck surgery. The Lions needed a steadying influence as head coach after the often unpredictable Jim Schwartz regime.
To some, Caldwell was a surprise choice. To others, he is the anti-Schwartz and will bring a calm steadiness to Detroit - along with more discipline for a team that sometimes stepped beyond the bounds of NFL protocol in its on-field behavior.
Caldwell has joked about his reputation for remaining even-keeled.
''There's no need for a whole lot of cussing, screaming, yelling and all that kind of stuff,'' Caldwell says. ''It's a mini-quiz out here. I never had any of my professors yelling in my ear when I was sitting at the desk filling out those multiple-choice questions.''
ZIMMER: THE TEACHER
Zimmer might be doing some yelling in Minnesota, but it will be in a constructive way. An outstanding defensive coach in Cincinnati since 2008, he was in the running for several jobs before landing the Vikings gig.
His forthright manner, confidence in his defensive schemes and tough love approach make him stand out from predecessor Leslie Frazier.
Most of all, Zimmer sees himself as an educator.
''I think one of the things of being a coach, you're a teacher,'' he says. ''You're trying to teach them about techniques, you're trying to teach them about all the different aspects of the game of football, not just offense or defense, but what the other side of the ball is thinking.''
GRUDEN: FOLLOWING HIS OWN LEAD
Gruden, the younger brother of ESPN analyst and 2003 Super Bowl-winning coach Jon Gruden, was Zimmer's alter ego in Cincinnati. Gruden ran the Bengals' offense, and when Washington decided to replace Mike Shanahan, it sought someone who could design an attack around Robert Griffin III, while also protecting the 2012 Offensive Rookie of the Year.
Nearly everything had fallen apart in the nation's capital last year, one season removed from an NFC East title. Perhaps most damaging was the fractured relationship between veteran coach and dynamic quarterback.
So Gruden is charged with fixing things on the field and off it.
''I'm not going to try to do something that Shanahan didn't, or not do something that he did, or do something that my brother did or Joe Gibbs did,'' Gruden says. ''I'm just going to try to coach the way I know how, and the way I've done it in the past, and hopefully it'll be good enough.''
WHISENHUNT: PICKING UP THE PACE
Like Gruden, Whisenhunt is considered an offensive guru. With Kurt Warner as his quarterback, he took usually downtrodden Arizona to a Super Bowl. What he likes best is a quick pace - everywhere.
His practices in Tennessee are run at a faster tempo than in previous years. Players and coaches jog from drill to drill. Whisenhunt says he hopes that's noticeable because the intent is to better mimic game speed and conditions.
''I think you have to create an intensity in practice because the game is so fast,'' he explains.
Veteran receiver Nate Washington, who was with Pittsburgh when Whisenhunt was an assistant there, says the change is impossible to miss.
''Before, things have happened in the past and we can't really sit here and try to compare the two or what's been happening before,'' he says. ''But as of right now, I have seen a lot more intensity on this team, period.''
O'BRIEN: TEAM FIRST
The excitement in Houston disappeared with a 14-game losing string that sank the Texans from AFC South champs to worst in the league. O'Brien, who could have written his own ticket at Penn State for years, instead chose to return to the NFL and take on a reclamation project.
Not as massive a challenge as the one he faced with the Nittany Lions, perhaps. But certainly a hefty one for the former offensive assistant at New England.
O'Brien delivered some not-so-subtle messages early on. Veterans don't have their names on their lockers anymore, only their numbers. A note on the inside of each locker says: ''Always put the team first.''
Rookies have a temporary cubicle set up in the middle of the locker room and won't get real ones until they make the team. That goes for everyone, even top choice Jadeveon Clowney.
''Being a head coach is about making sure the team understands the philosophy of what you want to get done: hard work, being a good teammate, team first and all of those things that we talk about every day,'' O'Brien says.
AP Pro Football Writer Dave Campbell and Sports Writers Noah Trister, Tom Withers, Kristie Rieken, Teresa M. Walker, Fred Goodall and Joseph White contributed to this story.
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