UNC plays a more structured, defensive, build-from-the-back method of play. This is the type of team that can really give BYU a hard time. BYU thrives on multiple chances to move forward and let their stars make plays. UNC obviously slows the game down and likes to hold possession. If they are able to successfully limit BYU's opportunities to score by not pushing forward, BYU will start to get frustrated and UNC will be able to exploit BYU's defensive holes.
All this being said, BYU has some very special players right now and I think this is going to be an awesome game. BYU can definitely win, but the defense is going to have to stay focused and not let players roam unchecked in the scoring area.