It Takes More Than Practice and Experience to Become a Chess Master: Evidence from a Child Prodigy and Adult Chess Players

Ericsson’s theory of deliberate practice and Chase and Simon’s recognition-action theory both hold that the key to reaching master level performances in chess is to engage in at least 10 years or 10,000 hours of deliberate practice. Moreover, Ericsson claims that the primary source of individual differences in chess skill is deliberate practice time. Two studies were conducted to investigate whether deliberate practice or other chess-related experience is sufficient to explain individual differences in chess expertise and to investigate other factors that may contribute to chess expertise. Study 1 investigated the amount of time a young and exceptional chess player, CS, had studied alone and engaged in other chess-related experiences. CS spent little time studying alone and little time engaging in other chess-related experiences. Nonetheless, she achieved an exceptional chess level. CS’s achievement is difficult to reconcile with the 10 years or 10,000 hours rule. Finally, CS performed exceptionally well on a test of visual short-term memory. Study 2 investigated factors contributing to the chess ratings of 77 adult chess players. Time spent studying alone and time spent engaging in other chess-related activities were strongly related to chess skill. However, contrary to the theory of deliberate practice, other factors including domain-general fluid intelligence, domain-specific fluid intelligence, and domain-specific crystallized intelligence all contributed substantially to the prediction of chess ratings even after controlling for practice and other chessrelated activities. These findings support the view that spending time studying alone and playing chess is necessary but not sufficient for achieving a very high level of chess performance.