That part of the ball that is drilled. There are different tolerances that are allowed. A three-ounce difference is allowed between the top and bottom of the ball. Not more than one- ounce difference is allowed between the sides to the right and left of the finger holes or between the sides in front and back of the finger holes. If a ball has Negative Weight then there is less top weight than bottom weight and this will result in the ball's hook to be delayed until the very last second. Generally, top weight, finger weight, and right side weight, produce more hook and bottom weight, thumb weight and left side weight, reduce hook and hold back the action of the ball.