We know what Flagg can do but with Brown, UNC found out first hand on Saturday. When Brown entered the game in the second half with UNC up seven, Duke went on a big run. He essentially took RJ Davis out of the game with his length and he's an issue on switches for guards.

Fierce rivals clash in the ACC Tournament Semifinals as the Duke Blue Devils take on the North Carolina Tar Heels in this highly anticipated matchup.

The Tar Heels might need to win the conference tournament this year to earn a spot in the NCAA tournament and keep playing in March. A look at how UNC could do that.