This phrase refers to a type of research model commonly conducted in mainstream sports studies, such as baseball and soccer. These studies examine the differences, mental or physical, between novices and experts of a sport.
As Makris & Urgesi find in their study, for example, the predictive abilities of professional soccer players surpass those of amateur soccer players, allowing them to better predict the trajectory and speed of a moving soccer ball.
Few studies of this type have been conducted in martial arts physics research, and for the few that are, there are only two groups: "experienced" and "inexperienced" martial artists.
However, many martial arts disciplines are organized by a belt system, a belt hierarchy in which specific colors are supposed to signify a certain level of proficiency corresponding to that color.
The picture to the right shows the Universal Taekwondo Federation's belt ranking system.