Great post SystemicAnomaly
Thanks for the info but I wonder if the study of the Advanced vs Novice tennis coaches was to have them observe servers for the purpose of i) how best to return a serve or ii) how best to detect serve flaws. The reason is the following excerpt from the study: "The main areas of interest for both
groups of coaches were similar in both situations, and there was not clear the effect of the dimensionality of the display on the visual behaviour of the coaches during the mistakes detection process." So I will still try to focus on the hitting shoulder.....