Welcome to the NFL playoffs?

If nothing else, the NFL is one big surprise party. Each season certain teams surprise in positive and negative ways. This one will be no different. History mandates it.

In each of the past 15 seasons, at least five teams made the playoffs that failed to make it the year before.

Here are five potential candidates:

San Diego: It's hard to do what San Diego did last season. The Chargers ranked first in the league in total offense, first in the league in total defense -- and still managed to miss out on the playoffs in large part because of special-teams failures. This season, the Chargers hired former Buccaneers special-teams coach Rich Bisaccia. Never has one special-teams coach been as celebrated and as anticipated as Bisaccia is in San Diego.

Houston: In their nine-year history, the Texans never have advanced to the postseason. But this offseason, the Texans made all the right moves. They hired Wade Phillips as their defensive coordinator. They signed defensive backs Johnathan Joseph and Danieal Manning. They drafted pass-rushers J.J. Watt and Brooks Reed. If ever a season were set up for the Texans to win the AFC South, this would be it.

Dallas: For the past five years, the Cowboys have alternated between good and bad seasons. Nine wins in 2006, 13 wins in 2007, nine wins in 2008, 11 wins in 2009, six wins last season. Which means the Cowboys are poised, once again, for double-digit wins. And for all the moves the Eagles made this summer, the single most significant move in the NFC East was the hiring of Rob Ryan as the Cowboys' defensive coordinator. He could be the difference.

St. Louis: Just as Rob Ryan will be a factor in the NFC East, new Rams offensive coordinator Josh McDaniels will be a factor in the NFC West. Think of how the Patriots' offense operated in 2007 under McDaniels. Now he will attempt to make Sam Bradford his version of Tom Brady and Danny Amendola his version of Wes Welker.

Detroit: The last time the Lions went 4-0 in a preseason like they did this summer was 2008, the year they became the first NFL team in history to finish 0-16. Not only will this team not go 0-16, but it has the chance to become one of those surprise turnaround teams if quarterback Matthew Stafford can stay healthy for the full season.

There could be an even bigger surprise. In each of the past eight seasons, without fail, at least one team has made the jump from worst to first. Last season's last-place teams were Denver, Tennessee, Cincinnati, Buffalo, Arizona, Carolina, Minnesota and Washington. As unlikely as it seems, the chances are one of these teams will win its division and become this season's biggest surprise.

On to this week's 10 Spot:

1. Could Manning move on? Hard to imagine Peyton Manning wearing a Miami Dolphins uniform.

Or Peyton Manning playing for the Seattle Seahawks.

But it's not as farfetched today as it was at other times.

There's a lot that still can happen and it makes no sense to predict how it will evolve. But it's worth pointing out that the Colts can get out of Manning's contract after one year and $26 million without any other money being guaranteed, according to a league source.

Manning has a $28 million option bonus/non-exercise bonus in Year 2 that is due on the fifth day before the end of the 2011 league year, according to the source. But if the Colts cut Manning after Year 1, they pay neither.

It sounds crazy because it's Manning we're talking about. But he will be 36 years old next season, and if he can't play this year because of his neck and back injuries, then the Colts could be staring straight at one of the most significant financial decisions they will ever have to make.

They could be deciding whether to pay Manning the balance on his contract or to stick their necks on the line and decline the option bonus.

2. Schaub has stability on his side: Suddenly, Texans quarterback Matt Schaub is the most tenured starting quarterback in a very unstable AFC South, having served as Houston's quarterback since 2007.

In Indianapolis, Manning is out for who knows how long, and the Colts must lean on former Titans quarterback Kerry Collins to keep the team competitive until No. 18 can return.

In Jacksonville, the Jaguars jettisoned David Garrard for Luke McCown on Tuesday, much the way the Jaguars once jettisoned Byron Leftwich on Sept. 1, 2007, for Garrard.

In Tennessee, the Titans have turned over their team to Matt Hasselbeck for now and Jake Locker in the future.

Houston has done its own fine job of building up its roster and positioning itself to win the AFC South.

3. Throw out the preseason: As challenged as the Falcons, Chiefs and Raiders looked this summer in failing to win a preseason game, they should hardly be discouraged. Preseason records mean less than the weekly injury reports.

In each of the past two seasons, a team that went winless in the preseason managed to advance to the postseason. The Cardinals did it in 2009, and the Colts did it last season. On the flip side, this summer's unbeaten teams -- the Lions and Rams -- should not assume that their summer success ensures any postseason possibilities. The 49ers were the only team to go unbeaten last summer; they finished the regular season 6-10.

4. Former Wolverines strike it rich: Take pride, Lloyd Carr: No draft class in college history has produced the type of contracts that Michigan's Class of 2007 has.

This summer alone, former first-round pick Leon Hall signed a four-year, $39 million extension with the Bengals; former second-round pick LaMarr Woodley signed a six-year, $61.5 million extension with the Steelers; former second-round pick David Harris signed a four-year, $36 million extension with the Jets; former second-round pick Alan Branch signed a two-year, $9 million deal with the Seahawks; and former fifth-round pick Steve Breaston signed a five-year, $20 million deal with the Chiefs.

All together, Michigan's draft class of 2007 earned $165.5 million worth of contracts this summer.

5. Eagles spending wisely: When Philadelphia began accumulating the talent that led Vince Young to proclaim the Eagles the Dream Team, many around football wondered how president Joe Banner and general manager Howie Roseman were squeezing so much talent under a confining salary cap. What many failed to realize is that the Eagles were paying so little to so many, making some of their high-priced expenditures possible. Eleven rookies -- making rookie salaries -- are on Philadelphia's roster this season, along with 10 players who were rookies last season. Thus, players who are in their first or second NFL seasons make up 40 percent of Philadelphia's 53-man roster. Cheap labor, NFL style, fills out the back end of the Eagles' roster.

The Eagles will start rookie Jason Kelce at center and rookie Casey Matthews at middle linebacker, plus their kicker (Alex Henery) and punter (Chas Henry) are rookies. The Eagles are loaded with big names. But they're also loaded with young players, which could impact Philadelphia early this season.

6. Newton fighting history: As if there weren't enough pressure on Carolina's Cam Newton, he will try to do something that no other quarterback drafted No. 1 overall ever has. None of the 19 quarterbacks drafted first overall during the Super Bowl era -- from John Elway to Troy Aikman to Peyton Manning -- has had a winning record as a starter during his rookie season.

In fact, those 19 quarterbacks drafted No. 1 overall have accumulated a 49-122 record as rookies. And usually, the quarterbacks don't get off to quick starts, either. Only three of the past 11 quarterbacks drafted No. 1 overall have led their teams to a win in their regular-season openers. The last one to do it was David Carr in 2002.

Now, after a summer in which he had an NFL preseason-low completion percentage of 42, Newton is set to try Sunday against Arizona. But the numbers of the men who came before him are a reminder of how difficult Newton's job will be.

7. Variety reigns in the NFC: Whereas the AFC has sent only an elite fraternity of teams to the Super Bowl, the NFC doesn't discriminate. Last season, for the 10th straight year, the NFC sent a different team to the Super Bowl. Since 2001, not one NFC team has gone to the Super Bowl more than once. But during the same time, the AFC has sent only four franchises to the Super Bowl -- New England four times, Pittsburgh three times, Indianapolis twice and Oakland once.

If the trend continues, it would be welcome news for the Cowboys, Redskins, Vikings, Lions, Falcons or 49ers. One would be on its way to an NFC championship and the Super Bowl.

8. You have to win early: It's just one game, true. Teams can bounce back from a loss, absolutely. But there's no denying that teams that win on opening weekend increase their chances of making the playoffs.

Since 1978, when the NFL went to the 16-game schedule -- and excluding the abbreviated season of 1982 -- teams that are victorious on opening weekend are more than twice as likely to reach the playoffs as losers of an opening game are.

Just look at the numbers. Of the 474 teams that won openers, 251 went to the playoffs and 147 won division titles. Of the 474 teams that lost openers, 106 went to the playoffs and 63 won division titles. Just last season, it held up again. Eight of the 12 playoff teams -- Baltimore, Chicago, Green Bay, Kansas City, New England, New Orleans, Pittsburgh and Seattle -- won their first game.

9. Watch your head: Concussion awareness has risen to unprecedented levels in the NFL. It could help to explain why, within the past two weeks Patriots quarterback Tom Brady and Eagles quarterback Michael Vick both have changed helmets, shifting to the Schutt AiR XP from the Riddell VSR-4, according to Schutt's marketing communications manager, Glenn Beckmann. Other players who have changed helmets for this season include Falcons quarterback Matt Ryan, Browns quarterback Colt McCoy and Titans quarterback Jake Locker.

It is the same change that Packers quarterback Aaron Rodgers and Eagles wide receiver DeSean Jackson made last season after they suffered concussions.

Their new Schutt helmets feature thermoplastic urethane (TPU) cushioning rather than the foam padding that was introduced in the Riddell helmets 20 years ago. TPU cushioning supposedly offers better impact absorption.

"We have clinical proof that our helmets absorb more impact than any other helmets across a wider range of temperatures -- temperatures that are more consistent with game-like conditions," Beckmann said.

If it works for Brady, Vick and others, more players could be changing helmets as the league tries to change the culture surrounding concussions.

10. Best day of the year: There aren't many days better than Sunday, the first day of the NFL season. Any football fan can feel the meaning of it. The offseason officially is over. Football and surprises await. Every Sunday from now through February will be filled with football. There are other great American days: Halloween, Thanksgiving, Christmas, Super Bowl Sunday, Draft Day, Mother's Day, Memorial Day, Father's Day, July 4, Labor Day. But there aren't any days that are packed with the anticipation the way the first day of the NFL season is. Enjoy.

The Schef's specialties

Game of the week: Detroit at Tampa Bay. It would be easy to pick Pittsburgh versus Baltimore, but let's go with the matchup that pits two of the league's top young teams.

Player of the week: Cardinals QB Kevin Kolb. For Kolb's first game as a Cardinal, he gets an ideal matchup to shine.

Upset of the week: Redskins over Giants. No NFL team had a rougher summer than New York, and the bumps could continue Sunday.

Adam Schefter is an ESPN NFL Insider.