Most of you probably shoot your sports photos with your left eye closed. I try to capture action shots with my left eye open. With the camera held to my face and viewfinder against my right eye, I'm able to follow the sports action with my open left eye, then quickly focus on the shot I want to capture in the viewfinder with my right eye.
For this shot, I followed the action with my open left eye that led to seeing the ball in the air for a potential header. As it became clear there was a good possibility for a header type action shot, I refocused on the action in the viewfinder using my right eye.