The World Cup field is down to its final 16 teams after one of the most entertaining, unpredictable group stages in the competition's history. A few pre-tournament favorites remain, with host Brazil, rival Argentina and European power Germany all reaching the knockout stage. Others, like defending champion Spain, 2006 winner Italy and Cristiano Ronaldo's Portugal, were not so fortunate.
MORE: World Cup knockout bracket | Schedule
What we're left with is a blend of underdog stories, knockout stage newcomers, clear favorites and deep-run hopefuls. Here's how we see the final 16 teams ranked by chances of winning it all, taking group performance, knockout opponents and potential road to the final into account:
Round of 16 Opponent: Switzerland
Lionel Messi has put the Albiceleste on his back, and their path to the final is considerably easier than their chief competitors. Argentina is the heavy favorite to reach the final from its side of the bracket.
Round of 16 Opponent: Algeria
The powerful Germans emerged atop a difficult Group G and drew a favorable first knockout opponent. That they can avoid a South American side until the semifinals is a huge bonus.
Round of 16 Opponent: Mexico
Few teams impressed more than the Netherlands in the group stage, and the Oranje's knockout draw is about as favorable as it gets, at least until the semifinals. With Robin van Persie and Arjen Robben in peak form, the Dutch look primed for another deep run. This comes with the caveat that the Netherlands have looked like world-beaters one day, underachievers the next on plenty of occasions.
Round of 16 Opponent: Chile
Neymar & Co. were supposed to coast through Group A, but it was no cakewalk. Neither is their knockout draw. Brazil might have a historical edge over Chile, but the two sides are comparable. Another tough all-South American matchup beckons in the quarterfinals. If Brazil is to win the World Cup on home soil, it will have earned it.
Round of 16 Opponent: Uruguay
Los Cafeteros dazzled in the group stage, and now they draw a Uruguay side reeling from Luis Suarez's suspension. James Rodriguez has been a Golden Ball contender, and a pair of South American foes in the first two knockout games won't strike fear into Jose Pekerman's side.
Round of 16 Opponent: Nigeria
The French impressed mightily in the group stage, but the knock is that they progressed out of a very favorable group. They also have a very favorable first matchup. A potential date with mighty Germany looms in the quarterfinals.
Round of 16 Opponent: Brazil
Jorge Sampaoli has his Roja playing at a high, intense level, and it's one that could fluster the hosts in their final 16 meeting. If Chile is able to topple Brazil, who's to say it can't run all the way to the Maracana?
Round of 16 Opponent: USA
The Red Devils didn't exactly live up to the world-beating expectations bestowed upon them in the group stage, but they still won Group H and face an opponent they've beaten twice in two meetings in the last three years.
Round of 16 Opponent: Colombia
Few are going to give La Celeste a chance with Luis Suarez done for the competition. Familiarity with Colombia and either Brazil or Chile certainly helps, though, and Oscar Tabarez already has experience playing without a suspended Suarez in the knockout stage from 2010.
Round of 16 Opponent: Belgium
The Americans got out of the Group of Death and are having visions of 2002. Getting to the quarterfinals again would mean beating Belgium, though, a very dynamic European foe that has yet to play its best game. Looking past that, it's likely to be Messi waiting in the wings. It's a tall task, but so was getting out of Group G.
Which teams have best chance of upsetting a big power in the knockout stage?
Grant Wahl discusses the four favorites to make the semifinals -- Brazil, Germany, the Netherlands and Argentina -- and talks about the other teams in the round of 16 with the best chance of knocking one of those big powers off.
Round of 16 Opponent: Netherlands
El Tri inspired by giving Brazil all it could handle and getting out of Group A. They won't fear the Dutch and can certainly win this matchup, but it's among the tougher last-16 draws in the field.
Round of 16 Opponent: Argentina
The Swiss have the misfortune of being paired with Messi's Argentina in the first knockout game, and they've shown little ability to defend at a level high enough to progress. They validated their World Cup draw seed by getting out of their group, but one more win would be a shock.
Round of 16 Opponent: Greece
Costa Rica is one of the stories of the World Cup, emerging atop a group with three former champions. Los Ticos drew a manageable last 16 foe, but can this dream run really go further than that?
Round of 16 Opponent: France
The Super Eagles gave Argentina all it could handle in a losing effort, and Stephen Keshi will have his side ready for Les Bleus, but with internal turmoil regarding unpaid performance bonuses and a tough foe in the offing, Nigeria's time could well be up.
Round of 16 Opponent: Costa Rica
It took a last-gasp, controversial penalty for Greece to get into the last 16, and the side hadn't scored a goal until its final group game. Euro 2004 will prevent anyone from underestimating the Greeks, but it's hard to see another deep run coming.
Round of 16 Opponent: Germany
There's plenty of historical motivation for Algeria, making its first knockout showing ever, to down the Germans and make up for 1982 (when West Germany and Austria purposefully played for a result so both advanced and Algeria did not). That alone isn't likely to make up for the biggest mismatch of the stage, though.
GALLERY: Memorable U.S. Moments in Brazil