Duke leads the ACC in 3-point field goal percentage (40.9) and ranks sixth nationally. All three Blue Devil starters on the perimeter – Seth Curry, Quinn Cook and Rasheed Sulaimon – are shooting better than 40 percent from beyond the arc.
Roy Williams is not one to often change his defensive strategy from game-to-game, but he acknowledged on his live radio show on Monday night that he's less inclined to help on dribble penetration to protect against Duke's preferred 3-point shot.
"I think you have to and that's the way we've always tried to play them," The 10th-year UNC head coach said. "Sometimes they've made a bunch of them, sometimes they haven't."
Since UNC's senior class enrolled in 2009-10, the Tar Heels have had varying degrees of success in limiting Duke's outside shooting. The Blue Devils have converted 35.5 percent of their 3-pointers (60-of-169) in those seven games.
Duke has averaged 8.6 3-point makes on 24.1 attempts during that stretch.
"Our pattern has always been to try to help less against them and be able to get to the 3-point shooter and that usually makes it more difficult for your guy inside because you don't give the guy inside very much help," Williams continued.
Therein lies the problem for North Carolina on Wednesday night.
While UNC ranks ninth in the ACC and 249th nationally in defending the 3-ball (35.2), Williams and his staff will have to stay true to their primary philosophical belief – defending the high percentage shot.
Plumlee, reigning USBWA National Player of the Week, demands that sort of attention. The senior forward is averaging 18.2 points on 61.0 percent shooting and 10.7 rebounds per game.
"When Ryan Kelly got hurt, it's almost like he took on a little bit more," Williams said. "Just a dominating rebounder and defender who's had two 30-point games. He controls the inside area for them… They have the 3-point shooters and he scores inside."
N.C. State elected to not double-team Plumlee and instead focus on defending the perimeter with disastrous results. Plumlee scored a game-high 30 points on 9-of-11 shooting and single-handedly put C.J. Leslie and Richard Howell in foul trouble.
North Carolina has struggled defending the post this season due to its lack of size, and the one player with serious heft – freshman Joel James – will miss Wednesday's rivalry matchup after suffering a concussion against Wake Forest last week.
"I think [James's absence] affects us a little bit, but we have the players to back it up," senior guard Dexter Strickland told reporters on Tuesday. "Plumlee's a great player, he's nice and strong - a great size for them – but I think we've got players on our bench that are ready to step up and take that position."
Sophomore forward Desmond Hubert will likely earn the first assignment in guarding Plumlee, while James Michael McAdoo will guard Amile Jefferson. If Williams elects to go small, however, McAdoo could draw the defensive duties against Plumlee.
McAdoo picked up two fouls in the opening two minutes while guarding N.C. State's C.J. Leslie two weeks ago and told reporters that he's learned from the experience. He added that having one less post player available will make managing fouls an even bigger focus for UNC's frontcourt.
Williams acknowledged on Tuesday that Duke's ability to score inside and out prevents defensive schemes intent on shutting down one or the other.
"We need to do a little bit of both," Williams said. "We need to try to see if we can put a crowd around Mason, but you can't over-help because I'm real good at math and threes add up faster than twos."
Add in North Carolina's 3-5 road record and recent trend of falling behind early in games with Duke's scoring prowess inside and out, and you may discover UNC's toughest challenge of the season.