NBA Power Rankings: Pistons, Cavaliers, Rockets among league's top overachievers

As we approach the midpoint of the season, some teams have surprised and others have disappointed. And then there are the Lakers.

NBA Power Rankings: Pistons, Cavaliers, Rockets among league's top overachievers
As we approach the midpoint of the season, some teams have surprised and others have disappointed. And then there are the Lakers.