Sprint Freestyle – Deep vs Deeper Pull

In this velocity meter study coach Gary Hall Sr. analyzes Olympian Brad Tandy's sprint freestyle technique.  Brad typically uses a deep pull and we wanted to find out what happened to his velocity when he used a slightly less deep pull.  While using a deeper pull creates more frontal drag, the sprint freestyle allows the athlete to make this compromise for a limited duration of time.  Since no one (world class) is swimming sprint freestyle with a high elbow pull the question is, how deep should the pull be?