"In evaluating the way in which ball possessions are gained during the course of a game, we find that 60 to 80 percent of the possessions are gained by rebounding and after an opponent's score. Twenty percent come from opponents's error, and only 5 percent of the possessions come from steals and interceptions. A study of the way ball possessions are gained makes it seem highly impractical to base pressure defense on interceptions and steals."