Because the spanker is in the position to easily spank the rear-end at the correct angle, it is much less likely that a blow will fall too high or too low. The spanker's position gives them the upper hand and allows them to easily control the spankee. They sit or stand higher than the spankee and are easily able to restrain and situate the spankee. Bending over and getting into position to get your bottom blistered signals the beginning of the spanking and builds anticipation. A properly positioned bottom will tend to be spanked harder and more completely on the sensitive 'sit spot'.
Humiliation Being put over the knee is a childish, humiliating posture.
Having to 'assume the position' is humiliating in its submission and rubs in the fact that they are being spanked. Exposure A properly positioned bottom is fully exposed. The cheeks are fully presented and split, their undersides turned up. In the case of men, the anus and back of scrotum show. Women are even more exposed, their rectums and vulvas fully visible.