No. 1 Ohio State (34-2) vs.No. 4 Kentucky (27-8)
Things to know: Both teams rely on a six-man rotation. Kentucky's Doron Lamb is nursing a sore ankle. Ohio State point guard Aaron Craft comes off the bench for center Dallas Lauderdale and is coming off a school-record 15-assist performance in the victory over George Mason.
Players to watch: Freshmen are the stars. Ohio State forward Jared Sullinger, Big Ten freshman of the year, averages 17.1 points and 10 rebounds. Kentucky point guard Brandon Knight averages 17.4 points and 4.2 assists.
Things to know: Both young teams fought through some rough regular-season stretches. The Tar Heels have put together a string of comebacks, including charging from 11 down to beat Washington in the third round. Marquette rallied from 10 down to topple No. 3 Syracuse.
Players to watch: Marquette senior Jimmy Butler has the ability to guard a point guard or a power forward, while also producing offensively with 15.8 ppg and 6.1 rpg. North Carolina freshman Harrison Barnes is a clutch shooter, averaging 15.5 points and 5.7 rebounds.
No. 1 Duke (32-4) vs.No. 5 Arizona (29-7)
Things to know: The Blue Devils added another weapon to the backcourt when freshman Kyrie Irving returned from a three-month absence with a toe injury. Arizona advanced after a controversial call against Texas and could be playing to prove it belongs.
Players to watch: Arizona's Derrick Williams, a 6-8 forward, is a beast in the lane, getting to the free-throw line frequently and averaging 19.1 points and 8.2 rebounds. Duke is led by senior guard Nolan Smith, who averages 21.3 points and scored 24 against Michigan.
No. 2 San Diego State (34-2) vs.No. 3 Connecticut (28-9)
Things to know: The Huskies have won seven games in 11 days, and many fans are wondering how long their legs will hold up. San Diego State, one of the tournament's most athletic teams, will enjoy five days off after it needed two overtimes to beat Temple.
Players to watch: UConn guard Kemba Walker might be the tournament's most electric player. He puts up 23.6 ppg and dropped 33 on Cincinnati. Athletic forward Kawhi Leonard averages 15.6 points and 10.6 rebounds for the Aztecs.
Things to know: Richmond gave Morehead State rebounding machine Kenneth Faried trouble with double teams in a matchup zone. The Spiders have another looming task against the Jayhawks' Morris twins, Marcus and Markieff, who combine for about 15 rpg.
Players to watch: Richmond point guard Kevin Anderson has averaged 19.4 points during the Spiders' nine-game winning streak. Kansas point guard Tyshawn Taylor hit his stride in the Big 12 tournament, and it has transferred to the NCAA tournament with two double-digit scoring performances.
No. 10 Florida State (23-10) vs. No. 11 Virginia Commonwealth (26-11)
Things to know: VCU emerged from the First Four, beating USC and Georgetown before blowing out Purdue. Florida State is known for outstanding defense, holding opponents to 62 ppg, but it also shot the lights out against No. 2 seed Notre Dame.
Players to watch: Florida State forward Chris Singleton was the ACC defensive player of the year, averaging 6.7 rebounds and 1.5 blocks. VCU guard Joey Rodriguez was outstanding against Purdue with 10 assists and 10 points, his third double-double of the season.
No. 4 Wisconsin (25-8) vs.No. 8 Butler (25-9)
Things to know: Both teams pride themselves on efficiency and defense. The Badgers ranked third nationally in holding opponents to 58.3 ppg. Before giving up 70 to Pittsburgh in another down-to-the-wire tournament victory, the Bulldogs had held 10 of their last 11 opponents to 65 or fewer.
Players to watch: Wisconsin point guard Jordan Taylor leads the nation with a 4.03-to-1 assist-to-turnover ratio. Butler guard Shelvin Mack is coming off a 30-point performance against Pittsburgh.
No. 2 Florida (28-7) vs.No. 3 Brigham Young (32-4)
Things to know: Guard Kenny Boynton, Florida's No. 2 scorer with 14.1 ppg, sprained his left ankle against UCLA but is expected to play. The Cougars are deeper than they have been in the tournament since Danny Ainge beat Notre Dame in 1981.
Players to watch: Who else but "The Jimmer"? Jimmer Fredette leads the nation with 28.6 ppg, including 32 and 34 in BYU's tournament wins. Erving Walker, a 5-foot-5 point guard, has provided the Gators late heroics, scoring 10 of their last 12 points against UCLA.