Updated

By Simon Evans

MIAMI (Reuters) - One of the most unpredictable NFL seasons in years suddenly gets serious this weekend when eight of the 12 surviving teams lock horns in the first round of sudden-death playoffs.

Fittingly, after a regular season dominated by wildly fluctuating results, the opening round is known as the "Wild Card Weekend", featuring all but the top two teams from each conference, New England, Pittsburgh, Atlanta and Chicago, who advanced automatically to the divisional playoffs.

The odds are stacked against the sides playing the first round going on to win the Super Bowl, with only six teams in the past 30 years landing the sport's ultimate prize, but few tipsters are discounting any of the teams this time with both of last season's Super Bowl finalists in action on Saturday.

Later that night, the Indianapolis Colts will host the New York Jets in a repeat of last season's AFC Conference final won by the Colts.

On Sunday, the Baltimore Ravens take their bruising defense to Kansas City in the AFC playoffs while the Green Bay Packers travel to Philadelphia to tackle the Michael Vick-led Eagles.

The Saints (11-5) were underdogs throughout last season's playoffs but are the overwhelming favorite to win in Seattle after thumping the Seahawks 34-19 at the Louisiana Superdome in November.

But Seattle have improved greatly since then, registering five of their seven regular season victories at home and sealing their spot in the playoffs by beating their NFC West rivals St. Louis in a winner-take-all clash last weekend.

REVENGE

Last year, the Colts (10-6) piled on 17 unanswered points to down the Jets 30-17 and book their place in the Super Bowl, but haven't looked as strong this year.

They struggled with injuries throughout the regular season campaign, but with quarterback Peyton Manning calling the shots, they remain a potent threat against a Jets (11-5) team unashamedly hellbent on revenge.

The Ravens (12-4) are also brimming with confidence after entering the playoffs having won their past four games.

"We have exactly what it takes to win a championship," said wide receiver Anquan Boldin.

The Packers (10-6) have had a lengthy injury list to deal with throughout the season but have found form at the right time.

Quarterback Aaron Rodgers looks to be back to his best and Green Bay's win over the Chicago Bears last weekend, which clinched their playoff spot, was further evidence the Packers could live up to their tag as pre-season Super Bowl favorites.

Vick, back in the NFL after serving a prison term for his part in a dog fighting ring, made a blistering start to the season but has struggled in recent weeks against the blitz being sacked 16 times in his last five games.

(Editing by Julian Linden)