The question, What is, or ought to be, the relationship between motor learning research and the teaching of motor skills in sport and physical education? has been the subject of three decades of inconclusive discussion. After setting aside a number of topics as related, but not immediately relevant, the boundaries for the present effort were drawn at Why is there no evidence that teachers or teacher educators use knowledge based on motor learning research? A series of hypotheses are then entertained and rejected. Inadequacies in the theoretical base, research designs, undergraduate courses, teacher intellect, teacher educator effort, and workplace conditions do not adequately account for the neglect of motor learning. A more likely explanation is that knowledge based on motor learning research is ignored by teachers because it is irrelevant to their work. If motor learning scholars will accept that this conclusion does not diminish the legitimacy of their discipline, they will coexist more comfortably with their professional colleagues. Motor learning research is not a waste of time, but it does not happen to have a substantial part to play in the design and conduct of instruction for school settings.