Baltimore Ravens coach John Harbaugh recently told me that, in his estimation, it takes five years for a head coach to effectively build his program in the NFL. Setting the culture, installing offensive and defensive systems, drafting the proper players and molding them to his liking, it all takes time. And patience. And resolve.

Five years is an eternity in the NFL. But five years, Harbaugh said, is what it takes.

Of the 32 head coaches, only 11 have been with their current team for at least five full seasons. Only two, Bill Belichick and Andy Reid, have coached more than 10 seasons with their current team. There are seven new head coaches, counting Romeo Crennel, who took over the Chiefs late last season. Turnover is a part of the life.

So too is being listed on the hot seat, or as I like to call it, the Coughlin chair. No man has been on the proverbial hot seat more often than Tom Coughlin, who was squarely on it late last season before the New York Giants got hot themselves and won Coughlin his second Super Bowl in five seasons. Suffice it to say, Coughlin probably should never be on the hot seat in New York again, but New York being New York, he probably will get back there.

But not this season. Who is on the Coughlin chair? Take a look:

Norv Turner

's Chargers were a disappointing 17-15 over the past two seasons. Donald Miralle/Getty Images

• Norv Turner, San Diego. The Chargers coach almost lost his job after finishing 8-8 last season, but team president Dean Spanos opted to give it one more try with Turner and general manager A.J. Smith. San Diego is 52-34 since Turner took over in 2007 but has gone 17-15 in the past two seasons and has only three playoff wins despite having had one of the better rosters in the NFL.

The players went to bat for Turner after last season, and it worked. They'll have to do it again this season by making the playoffs, a decidedly tougher task now that Peyton Manning is in the division and Kansas City has loaded up. Another 8-8 season and Turner -- and probably Smith -- will be gone.

• Lovie Smith, Chicago. New Bears general manager Phil Emery could not have been more effusive with his praise of Smith earlier this week, telling Sean Jensen of the Chicago Sun-Times: "He's [an] extremely earnest person. He loves people. He loves players, and they love him. He has a scheme, and a system and a plan. I mean, what's not to like?"

Smith also has a contract that runs through 2013 and has missed the playoffs four of the past five years (although the Bears reached the NFC title game two seasons ago). Emery provided Smith with a reliable backup quarterback in Jason Campbell, and in Brandon Marshall the Bears have something they haven't had recently: a true No. 1 wide receiver. This team is built for a Super Bowl run. Missing the playoffs isn't an option.

• Ken Whisenhunt, Arizona. It was just two years ago that Whisenhunt was awarded a contract extension. With Kurt Warner at quarterback, the Cardinals had won two NFC West titles and during the 2008 season made a Super Bowl run. But since Whisenhunt signed the extension, Arizona has gone 13-19 and has not been able to adequately replace Warner, despite trading for Kevin Kolb and signing him to a lengthy and expensive contract.

It is still unclear who will begin the season as Arizona's starter, Kolb or John Skelton. Whoever wins the job, the Cardinals will need to avoid last season's slow start, when the team lost six of its first seven games.

• Pat Shurmur, Cleveland. With the Browns' impending change in ownership, no one currently employed by the team should feel like his job is safe, including Shurmur, president Mike Holmgren and general manager Tom Heckert. New owner Jimmy Haslam could clean house, or he could wait to see what Shurmur and Co. are able to do with a new quarterback, new running back and old expectations.

Shurmur is entering his second season in Cleveland. The Browns were 4-12 last season.

It's going to be difficult for Vikings coach Leslie Frazier to turn things around quickly in the tough NFC North. AP Photo/Rich Addicks

• Leslie Frazier, Minnesota. The 53-year-old Frazier is in a tough spot. He took over for the fired Brad Childress late in the 2010 season and inherited a young roster with plenty of holes. He has managed a 6-16 record. Minnesota has a young quarterback, Christian Ponder, in place, but he will need time to develop. And with this team playing in arguably the toughest division in football, it is going to be difficult for Frazier's Vikings to do any better than 7-9, and even that seems awfully optimistic.

A potentially ugly record aside, also working against Frazier is the fact that Rick Spielman became general manager in January, and Frazier's contract isn't guaranteed after this season. Spielman didn't hire Frazier. Frazier isn't his guy. That is never good. But Frazier is a good man who is liked and respected inside the organization.

• Andy Reid, Philadelphia. Eagles owner Jeffrey Lurie wants to see this talented team prove it on the field this season. He expects the team to perform to its capabilities and to be better than last season, when the Eagles started 4-8 and finished 8-8.

What does that mean exactly? Lurie hasn't specifically defined his expectations. Reid is entering his 14th season in Philadelphia. He has taken the Eagles to the playoffs nine times and the NFC Championship Game five times, and he has won six division titles. He has been very, very successful. But there is that gaping hole on his résumé. Fans want a Lombardi Trophy. For Lurie, he'd probably like to see at least a nice playoff run.

• The wild cards. Probably not going to happen. Probably shouldn't happen. But you never say never in this business, so there could be others.

What if Dallas doesn't make the playoffs? Jerry Jones has conceded that the Cowboys' window could be closing. Does that mean the impatient owner would change course -- again -- if Jason Garrett's team falters in his third season? Unlikely, but not out of the realm of possibility.

Rex Ryan went to the AFC title game in each of his first two seasons with the Jets and has a 32-22 record (including the postseason), but the team was a disaster in 2011. It underperformed. There was friction in the locker room. And now, as a salve, the Jets have brought in Tim Tebow to run the Wildcat and be Mark Sanchez's backup. It's probably unlikely, but Ryan could be in trouble if the team disintegrates.

Atlanta's Mike Smith, like Harbaugh, is entering his fifth season with the Falcons. He has compiled a 43-21 regular-season record, the fifth-best mark since 2008. Smith has led Atlanta to four consecutive winning seasons and three playoff appearances. The problem: zero playoff wins. A fourth playoff loss without a win would be crushing. Again, probably not going to happen, but Smith needs to get a postseason win.

And Coughlin oh, forget it.