The first weekend of the NCAA tournament is in the rearview mirror, and it featured no shortage of surprises — as always — while 68 teams were rapidly trimmed to 16.

Some of the Sweet 16 teams’ pathways to their respective Regional were anticipated, like top seeds Kansas, North Carolina and Gonzaga. Others busted brackets and dropped jaws along the way (ahem, Wisconsin and South Carolina). Regardless of their story lines, they are now four wins away from winning a national championship.

Which teams have the best odds to cut down the nets in Phoenix? As we look ahead to the second weekend, here’s a glimpse at those most ready to win it all.

BRACKET: Track the tourney

ACC FLOP: Just one of nine in second weekend

BIG TEN:  Silencing critics in March

1.) Kentucky Wildcats

Of all the top seeds, Kentucky (31-5) had the toughest second-round opponent in No. 10 seed — or No. 4 seed according to John Calipari — Wichita State. The Shockers used their gritty defensive style to infiltrate the game’s tempo and keep the game close.  “We do little things, too,” Calipari said of his team in comparison to Wichita State, emphasizing that his team plays with its own dive-on-the-floor tenacity. Perhaps what’s most impressive about the Wildcats’ victory: Not that they beat a tough team, but how they won, particularly down the stretch when their freshmen looked like seniors.

Whether it was De’Aaron Fox making blow-by moves that ended in highlight-reel windmill slams or the game-winning defensive stops of Malik Monk and Bam Adebayo, Kentucky looked like a title contender more on Sunday night than it had all season, including a dominant SEC tournament run and huge wins against Florida. It shouldn’t necessarily be a surprise that Calipari’s teenagers are thriving, but it’s always impressive to see them mature over the course of the season and into March.

? X-Factor player: Adebayo. Monk and Fox get more the the spotlight, but Adebayo was the main reason UK beat Wichita because he dominates in ways that stretch beyond the stat sheet with his motor and presence around the rim.

2.) Wisconsin Badgers

Ignore the No. 8 in front of Wisconsin’s name on the bracket. The Badgers just knocked off the tournament’s top seed, Villanova, which means they should be respected in the same wavelength as the top seed. Veterans Bronson Koenig and Nigel Hayes have been here  — in the Sweet 16 — before. Three times, in fact, two of which led to Final Fours and one to a national runner-up finish. That alone is reason why to not count out this Wisconsin team. Koenig’s 28 points in the first round and Hayes’ game-winning lay-up against Villanova provide snapshots as to why Wisconsin is on the top-five of this list.

? X-Factor player: Ethan Happ. Now that all that praise about Koenig and Hayes is out of the way, it’s important to note that Happ, a 6-10 sophomore big man who truly blossomed this season, might be the team’s best player. He averages close to a double-double and will be key to advancement, starting with a Florida team lacking a serious interior presence.

3.) UCLA Bruins

The Bruins (31-4) had gotten to two Sweet 16s before this, but were never this well positioned to win the whole thing. UCLA’s offense is just astoundingly good behind do-everything point guard Lonzo Ball, who deservingly gets most of the credit. But that also overshadows just how good the supporting pieces are. Bryce Alford is one of the best shooters in the country, fellow freshman T.J. Leaf is athletic and smooth in the paint, and mainstays Isaac Hamilton and Thomas Welsh add scary-good depth.

An argument could be made that the Pac-12’s top-heaviness took away from just how unstoppable the offense can be against any team. UCLA scored 79 points on 63 possessions against a Cincinnati defense rated as one of the best in the country. Also, UCLA committed less than 10 turnovers in wins against the Bearcats and Kent State. Whether in potency and efficiency, the Bruins are a well-oiled machine on offense. If it can get in the same stratosphere on the defensive end, it’s tough to foresee anything short of a title.

? X-Factor player: Aaron Holiday. The sophomore guard might be the fourth or fifth best option on this team, but his production will be a difference-maker if the key guys are off.

4.) Kansas Jayhawks

Kansas (30-4) hit another gear in its 20-point second-round win against Michigan State when freshman guard Josh Jackson did Josh Jackson things. While national player of the year Frank Mason III is undoubtedly the face and backbone of this team, Jackson is Jayhawks’ electricity on both ends of the floor. Kansas’ early exit in the Big 12 tournament to TCU maybe made it seem like it wasn’t playing its best basketball in March. Sunday’s Sweet 16-clinching victory erased any of those thoughts.

? X-Factor player: Landen Lucas. The 6-10 senior big man is quietly a force for this Kansas team that’s fueled by a high-octane backcourt. Against Michigan State, for instance, he had 10 points and 11 rebounds.

5.) Michigan Wolverines

The Wolverines (26-11) are living up to being the hottest team in the tournament, getting past a similarly hot Oklahoma State team in the first round and then a Final Four-contending Louisville No. 2 seed in the second. Derrick Walton Jr. is a fierce guard who can make big-time shots and he’s complemented nicely by Zak Irvin and D.J. Wilson.

? X-Factor player: Moritz Wagner. His career-high 26 points against Louisville did two things: Won the game for Michigan and elevated the 6-11 sophomore’s confidence for more breakout performances going forward.

6.) Arizona Wildcats

Arizona (32-4) beat a really good Saint Mary’s team in the second round and continues to look impressive here in March after winning the Pac-12 tournament — including wins against UCLA and Oregon. Freshman big man Lauri Markkanen and explosive sophomore guard Allonzo Trier both are tough to stop, especially if they’re on at the same time.

? X-Factor player: Kadeem Allen. Having a senior guard who can calm the team down — or pump it up — is an awesome luxury for Sean Miller with a roster loaded with underclassmen.

7.) Gonzaga Bulldogs

Either Mark Few or Sean Miller seem poised to get to their first Final Four out of the West Region. As great as Arizona has been playing, same goes for this one-loss Gonzaga team that fended off a determined Northwestern squad in the second round. The concern is that the Bulldogs haven’t been challenged by a great team since December. That being said, all the weaponry is as good as it’s ever been for Few, who has had some flat-out awesome teams over the years. The big difference is how sound this team is on the defensive end. Point guard Nigel Williams-Goss and 7-footer Przemek Karnowski make the ‘Zags a force to be reckoned with.

? X-Factor player: Zach Collins. The freshman 7-footer had 14 points and four huge blocks in the win against Northwestern, while appearing ripe for an even bigger breakout performance in late March.

8.) North Carolina Tar Heels

Yes, “survive and advance” applies to mighty North Carolina, which eventually dispatched Arkansas in the second round in a game that looked like the Tar Heels were bound for the same fate as archrival Duke, which got stunned. Remember, UNC got a No. 1 seed because of its overall body of work, which it did most of in the ACC, a conference that saw its other eight tournament teams bounced before the second weekend. All-in-all, there’s no way to not look at UNC as a title contender given the names on the roster. That’s not to mention the Tar Heels’ motivating factor that’s been with them all season: Avenging last year’s last-second national title loss. Most of the players are back from that, including offensive juggernauts Justin Jackson and Joel Berry II.

? X-Factor player: Kennedy Meeks. The junior big man saved the day for UNC against Arkansas with a crucial tip-in that turned the tide of the game. His 16 points and 11 rebounds are the type of numbers Roy Williams needs for the rest of the tournament.

9.) Baylor Bears

Scott Drew’s team looked somewhat vulnerable down the stretch of the regular season after losing four of seven heading into the tournament. But the moxie this team played with in mid-February and in two down-to-the-wire losses to top-seeded Kansas has seemed to resurface. In a narrow win against USC in the second round, the Bears got a huge lift from guard Manu Lecomte, who went scoreless in the first half but had 12 game-deciding points in the second.

? X-Factor player: King McClure. The sophomore was a lightning rod for Baylor in the win against USC, scoring 17 points off five three-pointers. His outside shooting will be pivotal for the Bears’ title hopes.

10.) Purdue Boilermakers

Purdue is boring. There’s no way around it. Coach Matt Painter has a team that grinds it out and wins with tough-nosed blue-collar play. And that’s a good reason to view Purdue as a dark-horse to win the whole thing. Remember, the Boilermakers won the now-sailing Big Ten Conference regular season title for a reason. Caleb Swanigan, or “Biggie” as fans call him, is a wrecking ball-force in the lane. He often requires double teams and the sophomore big man is a solid passer. Once he establishes himself on the block, it’s either two points or a trip to the foul line. His 20 points, 12 boards and seven assists carried Purdue past Iowa State and into the Sweet 16.

? X-Factor player: P.J. Thompson. The 5-10 point guard came up clutch down the stretch in Purdue’s win against Iowa State, drilling a go-ahead three-pointer and making two key free throws in crunch time.

11.) West Virginia Mountaineers

Bob Huggins full-court pressuring defense never fails to offset seemingly potent offenses and dictate the game’s tempo. Case and point: Notre Dame in the second round. If WVU wins, it’ll be because of an epic defense. The Mountaineers need to hit shots to advance. Against the Irish, they made 6-of-6 uncontested three-pointers. That effort was fueled by Jevon Carter, who had 24 points in the win.

? X-Factor player: Daxter Miles Jr. The 6-3 guard has been less productive than last season, but when he plays well — as he did Saturday against Notre Dame with 18 points — WVU has a strong chance of advancing.

12.) Florida Gators

There’s no hiding the fact that Michael White’s team plays stellar defense, which it showed in limiting a similarly defensive-oriented Virginia team to 39 points in a second-round beatdown. But the offense will need to match that form for a title run. Devin Robinson came to life against the Cavaliers with a big 14-point, 11-rebound performance.

? X-Factor player: KeVaughn Allen. The Gators’ leading scorer has struggled big time in this tournament, shooting 1-for-11 in an opening round win against East Tennessee State and then shooting 2-for-10 in the win against UVa. If Florida is to advance, he has to play way better.

13.) Oregon Ducks

The Ducks were able to escape a deceptively good Rhode Island team thanks to Tyler Dorsey’s 27 points, but it’d take more performances like that from Dorsey or All-American Dillon Brooks for Oregon to win the whole thing. This team has a different identity without elite shot blocker Chris Boucher, who was lost for the season with an ACL tear in the Pac-12 tournament.

? X-Factor player: Jordan Bell. With Boucher out, Bell’s play becomes all the more vital. He had 17 points and 12 rebounds against Iona, but was relatively ineffective against Rhode Island in the second round.

14.) Butler Bulldogs 

Butler has beaten two mid-majors who didn’t play their A-game in Wintrhop and Middle Tennessee State to get here. That being said, coach Chris Holtmann has a team that’s driven to prove doubters wrong and play with a chip on their shoulder. Kelan Martin fuels the team with his energy, while Andrew Chrabascz is a steady and deceptively quick big man to run the offense through.

? X-Factor player: Avery Woodson. The guard had 18 points off six three-pointers in Butler’s opening round win against Wintrhop.

15.) South Carolina Gamecocks

Yes, the Gamecocks beat a top title contender in Duke and are playing absolutely awesome basketball right now behind Sindarius Thornwell, who is having as good of a tournament as any player with 53 points in two games. But unlike Wisconsin, South Carolina doesn’t have the chops to win the national title. It just doesn’t. That doesn’t take away from an epic season and March Madness run,but the title potential is not there.

? X-Factor player: Chris Silva. The 6-9 forward had 17 points and 10 rebounds against Duke. Most of those buckets were rim-rattling and momentum-defining, too.

16.) Xavier Musketeers 

Another player that’s put his team on his back is Trevon Bluiett, who had 29 points in the Musketeers’ demolition of Florida State in the second round. Xavier, as a No. 11 seed that fell onto the bubble while trying to reestablish itself without starting point guard Edmond Sumner, got two favorable matchups in the opening rounds — the other against No. 6 seed Maryland in the first round — but much of why this team is here is elevated sense of urgency and playing with a swagger that was missing before the tournament began.

? X-Factor player: J.P.  Macura. With Sumner out for the season, Macura has upped his unselfish playmaking and it’s been a big difference-maker.

MEET THE SWEET 16 TEAMS OF THE NCAAS