The rulebook has this specific language, The NCAA softball rule on obstruction states that a defensive player is obstructed if they: "Block the runner from advancing or returning to a base" "The rule change clarifies the language and removes any gray area for plays of that nature. For example, the defender could previously block the plate or base while in the act of catching the ball. Under the revised rule, the runner will be called safe if the defender blocks the plate or base before gaining possession. If the runner contacts the defensive player without making a legitimate attempt to slide, the runner will be called out."