He's been sneaky impressive over the last few weeks. It's not like he's out there blowing by guys with impressive athleticism or flashy plays. He's been a cold, calculated assassin making the right plays, shooting really well, and playing good defense. I would argue that the starting PG spot is Mack's to lose if he continues to play like this. Exum should have his hands full getting up to speed, and continuing to grow and learn the offense. Hopefully we have this "problem".