One week after 68 teams were announced as NCAA Tournament participants on Selection Sunday, 52 of them have been eliminated in the chase for the national title.

It's been a bracket short on buzzer-beaters, but the upsets that didn't come in the first round revealed themselves in the second round, as one No. 1 seed (Villanova), two No. 2 seeds (Duke and Louisville) and one No. 3 seed (Florida State) have already been eliminated. There may be no mid-major Cinderellas, but the East Region in particular has been a surprise, as has the fact that only one of the ACC's nine tourney teams (North Carolina) is still left standing.

So with the tournament field down to only a Sweet 16 entering the regional semifinals on Thursday and Friday, how do the remaining teams' championship chances stack up? Let's re-rank them based on talent, Final Four path and championship ability.

16. Xavier (11, West). The preseason AP No. 7 Musketeers started the season 13-2, only to crumble to 21-13 by the time the NCAA Tournament started, barely allowing them to make it off the bubble. Shorthanded with Edmond Sumner (injury) out the second half of the season after Myles Davis left the team, Xavier lost six games in a row late in the year and looked like a March Madness afterthought. Suddenly, however, coach Chris Mack has turned the team around behind the hot shooting of star guard Trevon Bluiett, who scored 29 points in a 91-66 dismantling of No. 3 seed Florida State after hitting five 3-pointers against Maryland. Xavier is a No. 11 seed, but it's played much closer to its preseason national contender projection thus far. The remaining teams in the West -- Arizona, then Gonzaga or West Virginia -- are probably too much for Xavier to have much of a chance to get to Phoenix, but Mack continues to make a positive impression and Bluiett has an argument for first-weekend tourney MVP.

15. South Carolina (7, East). The Gamecocks didn't look like a team that would do much NCAA Tournament damage down the stretch, but now the same could be said about everyone left in the bracket-busting East Region. After losing six of their last nine games entering the Big Dance, the Gamecocks' struggling offense scored 93 points against Marquette, then inexplicably scored 65 points in the second half, after a horrendous first half, to beat Duke 88-81 in one of the most shocking results of the tournament. The Gamecocks have had shooting issues all season, but they do play some of the nation's best defense. Plus, senior guard Sindarius Thornwell is a star on both ends of the floor. This is already at least as successful as any South Carolina tournament appearance ever after the Gamecocks hadn't won an NCAA tourney game since 1973.

14. Butler (4, South). The ruthlessly competent Bulldogs easily took care of Winthrop in the first round, then shut down the Middle Tennessee Cinderella story, 74-65, in the second round. In a South Region that features the top four seeds advancing, Butler is naturally going to be the overlooked team, given that the other three teams are viewed as national title threats: North Carolina, Kentucky and UCLA. The Bulldogs have a ridiculously difficult path left just to get to the Final Four, let alone win a national title. Still, after watching North Carolina struggle with Arkansas, Butler's chances of winning at least one game in Memphis shouldn't be dismissed. After all, the Bulldogs play a mistake-free brand of basketball with an efficient offense, and two wins over Villanova show they can beat anybody.

13. Purdue (4, Midwest). Purdue nearly suffered a monumental collapse against Iowa State in the second round, but it survived a second-half onslaught to advance to the Sweet 16 for the first time since 2010. Not surprisingly, its frontcourt carried it against Iowa State's small-ball lineup, with All-American Caleb Swanigan and Vince Edwards both putting up double-doubles with 20-plus points. The game plan may be similar against Kansas, where Purdue will have a frontcourt advantage while also needing to defend Frank Mason, Devonte' Graham and Josh Jackson. The Boilermakers can have problems with turnovers, but Swanigan and their 3-point shooting are still capable of taking them a long way.

12. Oregon (3, Midwest). The Ducks lost center Chris Boucher to a torn ACL during the Pac-12 tournament, dealing a blow to their hopes of making a Final Four run. They have survived thus far, however, thanks to Pac-12 player of the year Dillon Brooks and absurd production from the red-hot Tyler Dorsey, who hit the game-tying and game-winning 3-pointers in a 9-for-10 shooting, 27-point second-round performance against Rhode Island. Dorsey and Brooks can be a lethal combination, and after putting an end to Rhode Island's winning streak, they'll turn their attention to attempting to slow down Michigan, which won the Big Ten tournament as the league's No. 8 seed and now is in the Sweet 16 as an NCAA No. 7 seed.

11. Florida (4, East). The Gators' two opponents thus far have shot a combined 35 percent from the field, a number especially dragged down by the horrific offensive effort from Virginia in the second round, in a game that Florida won 65-39. The Gators have played well despite the absence of center John Egbunu, who tore his ACL a month ago, although it won't be as easy against Wisconsin's Ethan Happ in the Sweet 16. Florida has especially gotten positive contributions from 6-foot-8 junior Devin Robinson, who had 24 points against East Tennessee State and a double-double against Virginia. The Gators are fantastic defensively, and that gives them a chance in an unpredictable East Region that's now wide-open after the exits of Villanova and Duke.

10. Wisconsin (8, East). Should we really be surprised? Certainly, beating No. 1 overall seed and defending national champion Villanova was shocking in some respects, especially given the way the Badgers played late in the season. They turned a 21-3 record into a No. 8 seed, losing five of their final seven regular-season games, then losing to Michigan by 15 in the Big Ten tournament final. Plus, while they had a great record for much of the year, their first three losses were all by double-digits, to Creighton, North Carolina and Purdue. Still, this Badgers squad is filled with familiar faces: sophomore Ethan Happ, surrounded by seniors Nigel Hayes, Bronson Koenig, Vitto Brown and Zak Showalter. Happ is a defensive force, Hayes made huge plays in the Villanova game (as he has throughout his career) and Koenig has played out of his mind, going 11-for-23 from 3-point range thus far in the tourney. This is a March-tested team capable of playing at a much higher level than it did in February, and we're seeing it now.

9. Baylor (3, East). Sharing a region with Villanova and Duke after an uninspiring finish to the regular season, Baylor wasn't a trendy bracket pick, appearing in just 2.1 percent of ESPN Tournament Challenge Final Fours despite being a No. 3 seed. But despite the rough February, this is a Baylor team that has proven as much as anyone against nonconference competition, racking up wins against Oregon, VCU, Michigan State, Louisville and Xavier, in addition to beating West Virginia on Feb. 27 to snap out of a funk. Now, Villanova and Duke are both gone, and suddenly the door is wide-open for Baylor to make a Final Four push behind star big man Johnathan Motley, who had 19 points and 10 rebounds in the 82-78 win over USC on Sunday. The Bears have size and rebounding ability, and they own a top-20 offense and defense in KenPom's efficiency ratings.

8. Michigan (7, Midwest). Nobody would have believed it a few weeks ago, but Michigan has won 10 of its past 12 games, with five of those wins coming against Wisconsin (twice), Purdue (twice) and Louisville. The Wolverines are ridiculously hot offensively, a trend that was initially led by Derrick Walton and Zak Irvin on the perimeter but transferred to sophomore forwards Moe Wagner and D.J. Wilson against Louisville. While Michigan is reliant on outside shooting and is capable of hitting 3-pointers at a high rate, it has displayed versatility, too, especially because of the emergence of Wagner. Will this remarkable streak extend all the way to a national championship? Probably not. But the team that started 4-6 in Big Ten play is ancient history, and the new Michigan looks like it can play with anybody.

7. West Virginia (4, West). Notre Dame stayed in the game the entire way, but West Virginia's aggressive defense flustered the Fighting Irish all game. That's what Press Virginia is designed to do. The Mountaineers are deep and play hard, relentlessly attacking opposing ball handlers to force a higher percentage of turnovers than any other team in the country. They also crash the opposing glass, and the combination of takeaways and offensive rebounds creates chances that can mitigate their occasional shooting problems. Of course, West Virginia shot 50 percent from the field and went 8-for-14 on 3-pointers against Notre Dame, and that version of West Virginia is nearly unstoppable. On any given day, the Mountaineers can knock anybody off their game, so a Final Four run is certainly on the table.

6. UCLA (3, South). It's one of the most difficult tasks in college basketball to slow down UCLA's offense for a full 40 minutes. Cincinnati's physical defense did it for a half, but Lonzo Ball and the Bruins still snapped out of it and scored 49 second-half points to beat the Bearcats by 79-67. Questions about defense are going to follow the Bruins until they're eliminated (if they're eliminated), but this remains a highly potent offense, led by the freshman phenom Ball, plus TJ Leaf and Bryce Alford. Ball had 18 points, nine assists and seven rebounds in a dazzling effort against Cincinnati. The defense could unravel, but this is a UCLA team that has lost only four games -- all to teams that made the Round of 32 -- and already beat Sweet 16 opponent Kentucky 97-92 in December. While Michigan's offense has been spectacular, nobody's offense has a higher ceiling than UCLA's.

5. Gonzaga (1, West). The Zags averted disaster twice, first shaking off a horrendous first half to beat 16 seed South Dakota State, then fending off a huge Northwestern rally to win in the second round. They're safely into the Sweet 16 for the eighth time in their 19th consecutive NCAA Tournament appearance, and their hopes of, at long last, being the first Gonzaga Final Four team are still intact. After two rounds, Gonzaga -- which has lost only one game all season -- remains atop the KenPom ratings, now owning the No. 1 defense in adjusted efficiency. The Zags have size, they have a great point guard in Nigel Williams-Goss and they've gotten strong tournament play from Jordan Mathews and Zach Collins. They're deep, balanced and efficient, and despite the uneven play in the first two rounds, they're still a legitimate championship threat.

4. Kentucky (2, South). The Wildcats survived their brutal second-round draw against Wichita State, getting big plays down the stretch from the players we've come to expect: freshmen Malik Monk, De'Aaron Fox and Bam Adebayo. Kentucky hasn't lost since getting crushed at Florida on Feb. 4, and while a lot of the attention goes to the scoring surges, especially from Monk, this team has been excellent defensively -- as shown by the game-winning blocks by Monk and Adebayo on Wichita State's final two possessions. The No. 10 seed that Kentucky edged on Sunday is actually a top-10 overall team, according to KenPom, and there's no shame in winning close against the Shockers. Now, the fight through a tough region continues with UCLA, a team that won in Rupp Arena in a high-scoring game back in December. Kentucky is a national title favorite, but it's position in the bracket gives it one of the most difficult paths.

3. Arizona (2, West). There were some similarities between the Arizona-Saint Mary's and Kentucky-Wichita State games, as both national power Wildcats teams were faced with strong teams from mid-major conferences that didn't have great resumes but were highly regarded by advanced statistics and played much better than their seed. Arizona, then, pulled off one of the best wins of the second round, pulling off a big second half to beat the Gaels by nine and safely advance to the Sweet 16 despite a tricky matchup. Now, they face an unexpected opponent in No. 11 seed Xavier. Arizona is still only 18th in the KenPom ratings, but it's a complete team with few weaknesses, especially with Allonzo Trier playing at a high level after being suspended for the first half of the season. If 7-footer Lauri Markkanen catches fire, this will be a hard team to eliminate.

2. North Carolina (1, South). Sunday's second-round win against Arkansas was uninspiring, with North Carolina shooting 38.1 percent from the field and turning the ball over 17 times but hanging on to win by seven. The Tar Heels can't afford similar lapses going forward, first against Butler, then against the winner of Kentucky-UCLA. The Tar Heels are beatable, but assuming he bounces back from a rough shooting game against the Razorbacks, they have a fantastic guard in Joel Berry, the ACC player of the year in Justin Jackson and terrific size in the post. They're the nation's best offensive rebounding team, helping to mitigate the shooting problems, and they're loaded with experience with a lineup dominated by upperclassmen that came so close to a national title a year ago. They've shown flaws recently, but so has everybody.

1. Kansas (1, Midwest). The final score of Kansas' second-round game against Michigan State certainly doesn't tell the story of what was a tight game for a while. But, yet again, the Jayhawks accelerated to the finish, owning the late stages of the game to beat Michigan State going away, 90-70, after the Spartans played their best game of the season in the first round against Miami. Kansas scored a total of 190 points in two games in Tulsa, and it moves on to the Sweet 16 in its home away from home in Kansas City. National player of the year frontrunner Frank Mason didn't shoot well from the field against Michigan State, and yet he still had 20 points (8-for-8 on free throws) and got help from Josh Jackson's 23 and Devonte' Graham's 18. Kansas' frontcourt depth could still be a problem -- particularly in the regional semifinal against Caleb Swanigan and Purdue -- but the trio of Mason, Jackson and Graham is so difficult to contain. If you had Kansas as your national title pick before the tournament, there would be no reason to think differently now.

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