The first step in studying a player is identifying their orientation. This is begun by establishing which spinal associated side of the body– anterior or posterior– is more developed.
For reasons that are not fully understood, every modern human favors development on one side of their body over the other (front or back). In fact, this study seems to suggest that these developmental patterns begin within the embryo. Identical twins (in a small sample to date) show opposite orientations in every studied example, despite identical DNA, further supporting this theory.