The one thing we know for certain is that nothing is certain in the NCAA tournament.

With two No. 1 seeds and two No. 2's failing to get out of the first weekend, this tourney has reinforced the notion that there is almost no such thing as an upset anymore. Even those first-round games the favorite pulled out -- think Pitt over Central Florida, or Maryland's squeaker over UTEP -- demonstrated how deep the parity is in the college game. Isn't it only a matter of time before a 16 seed defeats a No. 1?

So as we look ahead to these next two rounds, understand that rankings, reputations and pedigrees mean nothing. There are no "better" teams anymore. But by Sunday night, only four will remain. Here's how I see things breaking down:

ATLANTA

Duke vs. Illinois

Duke's Shelden Williams is averaging 14.5 points and 10 rebound per game. Ezra Shaw/Getty

The fact that the Blue Devils were able to pummel Seton Hall from the get-go last weekend is very impressive, especially with Chris Duhon still in obvious pain from his bruised ribs. If you think about it, there are really two Dukes: The team that gets poor shooting from J.J. Redick, which is very, very tough to beat; and the one that gets great shooting from Redick, which is virtually impossible to beat. Redick was lights out against the Hall, and the Devils also got some promising inside play from Shavlik Randolph. They'll need Randolph to be a more consistent complement to Shelden Williams to make it past this weekend.

In many ways, Illinois is a bad matchup for Duke. The Illini have several players, most notably Luther Head, who can lock down Redick one-on-one. Redick still will have his opportunities, but he'll have to make the most of them. Illinois, unlike most teams, also can play a quick, up-and-down game with Duke, and though the Illini's guards are not as consistent as the Devils', they do have the ability to take their game to a level Duke has trouble matching. Up front, Illinois has not one but two big men -- in James Augustine and Nick Smith -- who can give Williams trouble. They also have a do-everything Glue Guy -- in Roger Powell -- who provides for his team what Nate James did for the Blue Devils when they won the 2001 title. The bottom line: Illinois is talented, surging and in this game, they have nothing to lose. That's a perfect formula for pulling off the upset.

Texas vs. Xavier

This is a hard game to figure out because Xavier is a hard team to read. Yes, the Musketeers have been dominant the past month and completely manhandled Mississippi State. But when will this team come back to earth? The good news for Xavier is that Texas is a good matchup for them. The Longhorns have everything a team could want -- except a point guard. That has enabled them to play well for long stretches but still not pull away from teams, and they often have a hard time scoring when they really need a bucket. With Lionel Chalmers and Romain Sato both able to shoot, dribble and pass, Xavier has no such problems.

Though Chalmers was sensational against the Bulldogs, Anthony Myles and Brandon Cole did an excellent job defending Lawrence Roberts -- certainly nobody in the SEC was that successful against Roberts during the regular season. But I think Texas' bigs will pose a tougher matchup. Texas doesn't have anyone as good as Roberts, but it does have more players of Roberts' size, and the Horns' bigs are better at stretching defenses than Mississippi State's. Texas also has a not-so-secret weapon in Royal Ivey, who can lock down any guard in the country one-on-one. Whether it's Sato or Chalmers (or both), one of Xavier's key guys will be a non-factor, and that will enable Texas to win.

Regional final

Texas will have a much bigger problem with Illinois' guards than it will with Duke's because of the Longhorns' shortcomings in the backcourt. But the Horns have played with those shortcomings all season, yet they still continue to win. The Illini have managed to win even when Dee Brown and Deron Williams go cold because they are so good at getting to the offensive glass, but they won't be able to do that as much against Texas. Besides, UT has its own go-to guard in Brandon Mouton, and something tells me Mouton is going to play like a star this weekend. Texas heads for a home game in San Antonio.

ST. LOUIS

UAB vs. Kansas

Keith Langford and the Jayhawks haven't won more than five games in a row all season. Elsa/Getty

I guess I was less surprised than most to see UAB beat Kentucky. The Blazers had demonstrated during the regular season that they don't just play a frenetic style, they play it well. That's an important distinction. UAB's system produces lots of open looks in transition, and because the Blazers know they'll all be taking lots of shots, they feel less pressure when they do shoot. Also, UAB was able to expose Kentucky's inside duo of Chuck Hayes and Erik Daniels in a way that other SEC teams could not. Hayes and Daniels are marvelous players who had great seasons, but they are so not very big and were held in check by UAB's Gabe Kennedy and Demario Eddins.

Kansas' frontline players, however, present a much tougher problem for UAB.  Within the past month, the Jayhawks somehow have forged a new identity, one built around defense and toughness. Those were staples of Bill Self's teams at Tulsa and Illinois, but it took until late February for the principles to take hold at KU. Heck, even Jeff Graves, who had his own suite in Self's doghouse for most of the year, has moved into the starting lineup. KU also has a gritty leader at the point, Aaron Miles, who I think will handle UAB's pressure better than Cliff Hawkins did. Kansas will win, and it will be easier than you think.

Georgia Tech vs. Nevada

The most impressive thing about Wolf Pack guard Kirk Snyder is the way he manages a game. He rarely forces plays, and he places an emphasis at the beginning of games to get his teammates involved. Then, when his team really needs a bucket, he takes over. At 6-foot-6, 225 pounds with excellent shooting range (he made 35 percent from 3 this season), Snyder is a difficult matchup, but were it not for the significant contributions from Todd Okeson, Nick Fazekas and Co., Nevada would be back home in Reno this weekend instead of in St. Louis.

In most situations, Nevada would be pose a real good matchup with Georgia Tech. The most interesting duel will be between the 6-11 Fazekas and 7-1 Tech center Luke Schenscher, who has made great strides this season, but rarely is called on to play defense 18 feet from the basket. Tech also has the ideal counter to Snyder in 6-5 Isma'il Muhammad. In the end, the difference here will be at point guard, where Okeson is simply overmatched by the Yellow Jackets' Jarrett Jack. Also, I see Nevada being befelled by the same happy-to-be-here psyche that will also clip Vanderbilt and UAB.

Regional final

I left this pick for last because it's such a tough call, and I've changed my mind twice since starting this column. I'm going with Kansas because I see the Jayhawks as a better version of Boston College, which gave Tech all it could handle last weekend. Kansas can win both in a full-court footrace and a half-court grinder, whereas Tech really needs to run to be effective. I expect Miles will be able to control the tempo of this game, and with nobody out there to keep Wayne Simien, Graves and David Padgett in check, the Jayhawks will thump their way back to the Final Four.

EAST RUTHERFORD

Saint Joseph's vs. Wake Forest

CBS' Billy Packer beat the Hawks as a Demon Deacons guard in the 1962 NCAA tournament. AP

This will be the most entertaining game of the Sweet 16, and not just because of the Billy Packer sideshow. Both of these teams love to run and shoot, and they obviously get first-rate leadership from their respective point guards: St. Joe's senior Jameer Nelson and Wake freshman Chris Paul. I've been saying for a while that Saint Joseph's frontline players, Dwayne Jones and John Bryant, are due to be discovered, and both guys made important plays down the stretch of the Hawks' win over Texas Tech. Wake might have a slight advantage up front with Eric Williams, Jamal Levy and Vytas Danelius, but Saint Joseph's has faced bigger disadvantages this season and still only lost one game.

Saint Joseph's, however, is also used to having a huge advantage on the perimeter, but that will not be the case here. I'm not saying Paul is as good as Nelson -- nobody is -- but he's closer than most. Justin Gray and Taron Downey can also run and shoot with their Hawks' counterparts, Delonte West and Pat Carroll. Games like this usually are won by the team that does more things well, and in this instance that team is Wake. The Deacs will run with the Hawks, and in the end they'll move on by dominating the glass.

Pittsburgh vs. Oklahoma State

It's hard to imagine a team winning more games and looking worse doing it than Pitt has. That may sound like a back-handed compliment, but it is definitely a compliment. The Panthers are not a good offensive team, but they still put away opponents with toughness, teamwork and, above all, smarts. That's a pretty good formula for success in the NCAA tournament, because while other teams (such as Saint Joe's) are vulnerable when they hit the inevitable cold shooting night, every night is a cold-shooting night for Pitt. If the shots start falling, that's just gravy.

Eventually, though, the NCAA tourney will expose a team's flaws, and that's what will happen when Pitt faces Oklahoma State. The Cowboys are one of the few teams in the field that can match the Panthers' toughness (though certainly not their size in the frontcourt), but the Pokes are also remarkably efficient on offense. (They are No. 2 in the nation in field-goal percentage.) Oklahoma State's backcourt duo of John Lucas III and Tony Allen reminds me a lot of the Scoonie Penn-Michael Redd tandem that took Ohio State to the Final Four in 1999 -- and Lucas and Allen have a far better supporting cast. Pitt has perfected the art of winning ugly, but in this case I like the prettier team to win.

Regional final

Once again, we have two great perimeter groups squaring off. The difference here will be Oklahoma State's defense. Wake Forest has not reponded well to physical teams this season. Instead of meeting force with force, the Deacs tend to settle for quick jump shots and fail to get their inside players the necessary touches. Oklahoma State has been the best team in the Big 12 all year and easily could have been awarded a No. 1 seed. Wake Forest, which has no scholarship seniors on the roster, will use its appearance in the regional final as a springboard into a top-five ranking next season. Oklahoma State will use it to leap to San Antonio.

PHOENIX

Alabama vs. Syracuse

Will Syracuse win another 'ugly' battle on the court? AP

As I watched 'Bama's upset of Stanford on Saturday, I was struck by how the long, athletic Tide players aggressively challenged the Cardinal on both ends of the floor. That attacking mode enabled them to repeatedly go to the foul line, shooting 44 attempts to Stanford's 11. They made a high enough percentage from the stripe to barely put them over the top. Alabama has been a pretty good shooting team all year, but over the past month it has found a toughness on defense that is admirable. The Tide certainly will need that to get to the Final Four.

Many of the things that worked for Alabama against Stanford won't help against Syracuse, however. The Orangemen are much quicker than the Cardinal, especially on the wing. Second, Syracuse plays that maddening 2-3 zone that negates dribble drives and limits opponents' free-throw attempts. The Tide will need to have a great shooting night -- which could very well happen when Earnest Shelton and Kennedy Winston get their groove on -- but the 'Cuse is simply operating on a larger margin for error. Like Pitt, Syracuse has perfected the art of winning ugly, and it says here the Orange have one more ugly win in them.

Connecticut vs. Vanderbilt

On paper, this looks like it could be a rout, but remember things rarely play out as they should in this tournament. The Commodores are benefiting from some excellent guard play right now from Mario Moore, and they have two big men with great shooting range in Matt Freije and Dawid Przybyszewski. If Moore and his perimeter sidekicks can withstand UConn's pressure and keep this game in the halfcourt, Vandy will have a distinct advantage.

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That, suffice it to say, is a big if. UConn can look pretty ugly itself at times, but when the Huskies are rolling, there's nobody better. Their ability to score points quickly does more than just pad their margin; it breaks opponents' spirit. Vandy coach Kevin Stallings can talk all he wants about how his team isn't just happy to be in the Sweet 16, but the Commodores are a lot happier just to be there than the Huskies are. That's why they won't be staying long.

Regional final

In one sense, UConn will be catching a bad break in going up against a fellow Big East team, especially one that beat the Huskies just two weeks ago in Syracuse (even though Emeka Okafor was severely limited by back problems at the time). On the flip side, Syracuse is also playing a team that won't be so riddled by that zone. And with Okafor looking strong again and the teams facing off on a neutral floor, the Huskies should be able to seize the upper hand right away and keep it.

Sports Illustrated staff writer Seth Davis covers college basketball for the magazine and is a regular contributor to SI.com. Davis' first book, Equinunk, Tell Your Story: My Return to Summer Camp, is available through Chandler House Press.