CHAPEL HILL - Looking back to March, it's easy to blame North Carolina's lack of offense for its collapse against Georgetown and failure to reach the Final Four.

But looking ahead to this season, the Tar Heels blame something else: a lack of defense.

And it's something they know they must improve if they want another chance to advance to the national semifinals, and beyond.

"The other day in practice, Coach [Roy] Williams told us we were 73rd in the nation in [defensive] field-goal percentage last year," junior guard Marcus Ginyard said. "... That's pretty far down there, and that's something that's more motivation. Nothing that Carolina does should be near 73."

Williams, a newly-enshrined Hall of Famer, has preached stick-to-itiveness since he returned to his alma mater in 2003. But at times last year, the deep, youth-laden Tar Heels leaned on their firepower more than their stopping ability.

They were 7-6 in games decided by 10 or fewer points even before the NCAA regional final meltdown against Georgetown, when the Hoyas shot 71.4 percent from the field over the final 10:34, 57.6 percent for the game, and won 96-84 in overtime.

"We've got to play better defense from Day 1. ... That has to be our focus," Williams said.

Especially considering it could be the final piece to putting together a Final Four team.

North Carolina, ranked the preseason No. 1 in both The Associated Press media and ESPN/USA Today coaches polls, returns six of its top eight scorers, including two-time All America forward Tyler Hansbrough, who averaged 18.4 points and 7.9 rebounds last season.

It needs to replace starting forward Brandan Wright -- an agile shot-blocker and rebounding force down low -- and starting small forward Reyshawn Terry, whom Williams called one of the most improved defenders he's ever coached.

But with sophomores Deon Thompson and Alex Stepheson, plus juniors Danny Green and Ginyard competing for increased minutes, the Heels believe they can contend.

"If we defend like we're capable of," Ginyard said, "anything is possible."