Here is a concrete example. Bill Self has always coached that the way to defend an on the ball screen is to "jam the dribbler."
http://www.usatoday.com/story/sport...fficiating-hand-checking-rule-change/3422293/ A defender could mug a dribbler so long as the defender was "fighting" over the screen. The offender couldn't create any space.
Another Bill Self classic was for the defender to close off space by extending his arm into the offenders belly button. This made the crossover almost nonexistent. In Blake Griffin's first year our game at KU (which Blake didn't play in), our guards got shoved into the scores table with no call when the KU defenders used this method. It look like the offender is backing up, but in truth the defender is pushing him back every time the offender tries to drive.