Humans organize themselves in 2 ways with regard to gravity & this plays a vital role in movement and technique. 

The pelvis determines it in the hip joint that tilts forward or backwards around the horizontal axis.

If COG passes ⊥ through the hip joint, it would be difficult to move. 

We always need balance consolation, some prefer to do this by bringing COG to the front & others by bringing it back!

That’s why AM pitchers need to ‘corkscrew’ and PM pitchers, can’t do that because that would negatively influence their delivery and is a possible injury creator. They need to generate power from bounce by having the shoulders initiate the movement.