Ball reversal in basketball refers to the ball being passed from one side of the court to the other by the team in possession of the ball. When executed properly, ball reversal can cause the defense to scramble, opening up easy shots for the offense as a result. Ball reversal is performed when the team that controls the ball is in a half-court situation, meaning they have crossed the midline of the court and are trying to run a play to beat the defense.
Each player on the defense has what is known as an assignment. Whether this is a specific player to guard or area of the court to protect, each player has a defined role in trying to stop the team on offense. When the ball is quickly changing direction, the defense is forced to alter its plans, with each player simply trying to follow the ball rather than sticking to their assigned player/area. Once the defensive players are in disarray, it becomes easy for offensive players to either dribble towards the basket for a layup or pass the ball out to teammate that has been left alone for a wide open shot.