The respective roles of the environment and innate talent have been a recurrent question for research into expertise. The authors investigated markers of talent, environment, and critical period for the acquisition of expert performance in chess. Argentinian chess players (N = 104), ranging from weak amateurs to grandmasters, completed a questionnaire measuring variables including individual and group practice, starting age, and handedness. The study reaffirms the importance of practice for reaching high levels of performance, but it also indicates a large variability: The slower player needed 8 times as much practice to reach master level than the faster player. Additional results show a correlation between skill and starting age and indicate that players are more likely to be mixed-handed than individuals in the general population; however, there was no correlation between handedness and skill within the sample of chess players. Together, these results suggest that practice is a necessary but not sufficient condition for the acquisition of expertise, that some additional factors may differentiate chessplayers and nonchessplayers, and that starting age of practice is important.

Why are some people more skilled in complex domains than other people? Here, we conducted a meta-analysis to evaluate the relationship between cognitive ability and skill in chess. Chess skill correlated positively and significantly with fluid reasoning (Gf) (r =0.24), comprehension-knowledge (Gc) (r =0.22), short-term memory (Gsm) (r =0.25), and processing speed (Gs) (r =0.24); the meta-analytic average of the correlations was (r = 0.24). Moreover, the correlation between Gf and chess skillwasmoderated by age (r=0.32 for youth samples vs. r =0.11 for adult samples), and skill level (r =0.32 for unranked samples vs. r =0.14 for ranked samples). Interestingly, chess skill correlated more strongly with numerical ability (r = 0.35) than with verbal ability (r = 0.19) or visuospatial ability (r =0.13). The results suggest that cognitive ability contributes meaningfully to individual differences in chess skill, particularly in young chess players and/or at lower levels of skill

Deliberate practice (DP) occurs when an individual intentionally repeats an activity in order to improve performance. The claim of the DP framework is that such behavior is necessary to achieve high levels of expert performance. The proponents of the framework reject evidence that suggests that other variables are also necessary to achieve high levels of expert performance, or they claim that the relationship between those variables and expert performance is mediated by DP. Therefore, the DP framework also implies that DP is sufficient to achieve high levels of expert performance. We test these claims by reviewing studies on chess expertise. We found strong evidence that abundant DP is necessary (but not sufficient) and estimated that the minimum requirement to achieve master level is 3,000 hours of DP. We also review evidence showing that other factors play a role in chess skill: general cognitive abilities, sensitive period, handedness, and season of birth.