„Regrettably, concluding and/or seeking to demonstrate that “part-to-whole training progressions” are a preferred instructional paradigm simply because such progressions appear to “make sense”, … This ignores nearly a century of scientific evidence and volumes of published research that have conclusively demonstrated that part progressions have minimal transfer to the whole skill and in a number of scientific studies part training methods have actually demonstrated negative transfer.“

Motor Learning Principles and the Superiority of Whole Training in Volleyball by Steven Bain, Ph.D, and Carl McGown, Ph.D.