There are many reasons why the North Carolina Tar Heels are the overwhelming favorite to cut down the nets come the first Monday in April.
With their top six players from last year's team returning, Carolina's impressive offense remains intact. Bobby Frasor is again healthy after suffering a torn ACL last December and will provide steady backup for Ty Lawson.
Finally, three McDonald's All-Americans have been added to the roster—Ed Davis, Tyler Zeller, and Larry Drew.
However, one lingering flaw from last season could prevent Carolina from winning their second title in five years.
The team still hasn't learned how to play defense consistently.
Ken Pomeroy rated Carolina's defense last season No. 19 in the country. By comparison, last season's champion, Kansas, was No. 1 in Pomeroy's defense efficiency ratings.
Defense wins national titles.
Carolina's lineup has a handful of defensive liabilities. Carolina's star, Tyler Hansbrough, is only average on defense, with athletic forwards such as Darrell Arthur able to outplay him under the rim. Deon Thompson, Hansbrough's frontcourt partner, is also an average defensive player.
The team still lacks an effective shot blocker, with the entire team only blocking 174 shots last season. UConn's Hasheem Thabeet had 147.
Backcourt defense wasn't much better, with Marcus Ginyard being Carolina's only proven returning defender.
Carolina's weak defense allowed opponents an effective field goal percentage of 48.2 percent, No. 90 in the nation. North Carolina cannot allow their opponents too many unchallenged shot attempts if they expect to win it all.
Last season, it was Carolina's offense that powered the team to 36 victories and a trip to the school's 17th Final Four. If Carolina hopes to win a national title this season, a repeat of last year's high-powered offense will not be enough.
Roy's boys will have to learn how to play defense in order to win come March.