While deliberate practice is a large part of the story of success, it is unlikely to be the entire story. After all, what contributes to the motivation to practise in the first place? Why do some people seem to learn particular material faster than others? How come even when we take two people with the same amount of deliberate practice, there are still differences in their performance? In a recent study, David Z Hambrick and colleagues found that deliberate practice only explained 30% of the differences in performance ratings in chess and music, leaving most of the variation unexplained by other factors.