During the course of an offensive possession there may be guard penetration to the paint. When this happens it is important that the post player spaces off of the block to create a passing angle and space for the guard. If they do not space, the post defender will be able to help on the drive, and also recover in time on the dump off pass.
This specific drill is going to work on taking a crab dribble after the pull through move, and then finishing on the other side of the basket. The reason that the post player is going to finish on the other side of the basket, is to protect the basketball from the defensive post player. By using the rim, you eliminate the defenders ability to become a shot blocker. This is a great post move drill that can be done in small groups or in practice.