Watch: NBA "Know Your Role" Moments

In order to play basketball, every player must have a position. Each has a role to play. Every player must know, understand, accept, embrace and perform their role to the best of their abilities. 

Other players know their role and play it well, but some role players are simply the poor versions of good players. When they come in, you squirm as they toss up bad shots, passing too far, dribble into double-team etc...And the wrong choice can lead to a turnover or worse—a loss.
  (courtesy: youtube/HoopsTube)