When playing beer pong and you are down to three cups, you use the one re-rack to form the shocker. The formation makes it slightly easier to sink a cup as the cups are closer together.
The formation is simple: two cups in the front one in the back or an upside down triangle, just like the real life shocker when pleasuring a woman.
Playing beer pong, guy 1 has three cups left.
Guy1 does the shocker with his fingers and shouts out Shocker Formation.
Guy2 instantly arranges two cups in the front and one in the back and the game resumes.