Breakdown of NCAA Tournament regionals

The beauty of the NCAA Sweet 16 is how it captures the diversity of college basketball from the brand-name programs in the East Regional to the individual brilliance of Kemba Walker in the West and Jimmer Fredette in the Southeast to the mystery guests in the Southwest, where three double-digit seeds are alive. Here a breakdown:

EAST REGIONAL

Best story line: Kentucky had five players, including four freshmen, leave as first-round NBA draft picks, but coach John Calipari has reloaded with three freshmen scorers in Brandon Knight, Terrence Jones and Doron Lamb and has another great recruiting class in the pipeline.

Key player: Ohio State guard Jon Diebler has hit 50 percent of his three-point shots this season to lead an outstanding perimeter attack that helps relieve the pressure inside on center Jared Sullinger, who was named national freshman of the year.

Favorite: Ohio State is ranked No. 1 in the tournament field and seems to have the best inside-outside combination of any team in the country.

Dark horse: North Carolina has flown under the radar but topped Duke to win the ACC regular-season title, has gone 21-3 after a 7-4 start and gets 11th-seeded Marquette in regional semis.

Prediction: Ohio State has the best freshman in the field and far more experience than Kentucky and Carolina.

WEST REGIONAL

Best story line: Connecticut became the first college team to win five games in five days to win its conference tournament, but instead of running out of gas, Kemba Walker is picking up momentum with time to rest in the NCAAs.

Key player: Duke freshman point guard Kyrie Irving was sensational in his first eight games before injuring his toe. How well Duke adjusts to his return will determine its ability to defend the national title.

Favorite: Duke returns senior leaders Nolan Smith and Kyle Singler and has a towering frontcourt that will bother Arizona's Derrick Williams in semis.

Dark horse: UConn was only 9-9 in Big East play, but it has been rolling behind Walker against far tougher opposition than second-seeded San Diego State.

Prediction: Connecticut coach Jim Calhoun has beaten Duke's Mike Krzyzewski in some memorable showdowns and is positioned for the upset.

SOUTHWEST

Best story line: This regional is Kansas and the three numerically challenged seeds: No. 10 Florida State, No. 11 Virginia Commonwealth and No. 12 Richmond, and the last two come from the same city.

Key player: In this case, its key co-players for Kansas, who will rely on the leadership of twin forwards Marcus and Markieff Morris to get the Jayhawks past their history of tournament inconsistency.

Favorite: Kansas has tremendous depth with freshman guard Josh Selby and sophomore forward Thomas Robinson, who would be starters on most teams.

Dark horse: VCU was criticized as undeserving of an NCAA bid but has won three games, starting in the First Four, by an average of 16.7 points.

Prediction: Kansas was knocked out last season by Northern Iowa, and the prospect of another underachieving embarrassment should keep the Jayhawks focused.

SOUTHEAST

Best story line: There are a couple, but the growing cult status of national scoring leader Jimmer Fredette of BYU trumps the return of last year's runner-up Butler because Fredette's uncanny shotmaking has to be seen to be believed.

Key player: Wisconsin point guard Jordan Taylor might be the best player you never heard of in the field. He averaged 18.0 points for the season, topped the Big Ten with a 20.1 conference average and leads the nation with a 4.18 assist/turnover ratio.

Dark horse: The fourth-seeded Badgers scored only 33 points in a loss to Penn State in the Big Ten Tournament, but their defense is fourth in the nation and their free-throw shooting is first.

Prediction: BYU faces a rematch of last year's first-round double-OT win over Florida, but Fredette is reviving Louisiana memories of Pistol Pete Maravich.