A basketball phrase describing the defensive technique of
changing one's position from between the offensive player and the
basket to between the ball and the offensive player.
It is also used to refer to the type of defense played on inbounds plays. When denying the ball on an inbounds play, the offensive team is passing the ball in from out of bounds, and the defense, rather than putting two defenders on one of the offensive players, defends the inbounds pass.
The first definition of this phrase is the most common. This technique is an effective move when the offensive player is bigger than the defensive player. By putting his body in front of the offensive player, the defender significantly reduces the number of passing lanes the opposition has to get the offensive player the ball. This move can also be used effectively by a bigger player on a smaller player; however, since the offensive player is smaller in this example, he would have an advantage on passes lower to the ground.