Practice other than playing games apparently has only a modest role in the development of chess expertise

Mapping the outer reaches of the learning curve: Complex intellectual skill performance after decades of extensive practice

Little is known about the outer reaches of learning curves for very complex cognitive skills exercised over decades. Can skill performance improve as long as practice lasts or do all learners ultimately plateau? Furthermore, does natural talent set widely varying performance limits or do all learning curves eventually converge? Chess skill learning curves were examined for 333 players, mostly grandmasters, who, over a median 20 years, played at least 1500 internationally-rated games. Curves of nine of the 333 participants who played more than 3050 games, and one of the 333 and two others who played more than 4250 games over more than 30 years, also were examined. Players on average reached an approximate plateau by around 1200 games. This asymptotic value has changed little from the 1990s despite massive changes in the chess environment. Out to more than 3050 or 4250 games, players stayed at an approximate plateau for many games and years and then performance eventually declined. Chess skill learning curves do not rise forever. Over extensive practice lasting decades, they typically plateau for a long time and eventually decline. The more talented tend to plateau later and curves of the greater and lesser talented do not converge.

The Impact of Domain-Specific Experience on Chess Skill: Reanalysis of a Key Study

How important are training and other forms of domain-relevant experience in predicting individual differences in expertise? To answer this question, we used structural equation modeling to reanalyze data from a study of chess by Charness, Tuffiash, Krampe, Reingold, and Vasyukova (2005). Latent variables reflecting serious chess activity and formal instruction, along with a manifest variable indexing serious starting age, accounted for 63% of the variance in peak rating. Serious starting age had a significant negative effect on peak rating (β = –.15), even after we controlled for domain-specific experience, indicating an advantage for starting earlier. We also tested the prediction that formal instruction increases the effectiveness of serious study (Ericsson & Charness, 1994) using moderated regression. This claim was not supported. Overall, the results affirm that serious study and other forms of domain-specific experience are important pieces of the expertise puzzle, but other factors must matter too.

Supplemental materials are available at https://www.press.uillinois.edu/journals/ajp/media/chess_skill

Learning curves in highly skilled chess players: a test of the generality of the power law of practice

The power law of practice holds that a power function best interrelates skill performance and amount of practice. However, the law's validity and generality are moot. Some researchers argue that it is an artifact of averaging individual exponential curves while others question whether the law generalizes to complex skills and to performance measures other than response time. The present study tested the power law's generality to development over many years of a very complex cognitive skill, chess playing, with 387 skilled participants, most of whom were grandmasters. A power or logarithmic function best fit grouped data but individuals showed much variability. An exponential function usually was the worst fit to individual data. Groups differing in chess talent were compared and a power function best fit the group curve for the more talented players while a quadratic function best fit that for the less talented. After extreme amounts of practice, a logarithmic function best fit grouped data but a quadratic function best fit most individual curves. Individual variability is great and the power law or an exponential law are not the best descriptions of individual chess skill development.

Gender differences in intellectual performance persist at the limits of individual capabilities

Males predominate at the top in chess, and chess is a useful domain to investigate possible causes of gender differences in high achievement. Opportunity, interest and extent of practice can be controlled for. Organized chess has objective performance measures, extensive longitudinal population-level data and little gatekeeper influence. Previous studies of gender differences in chess performance have not controlled adequately for females on average playing fewer rated games and dropping out at higher rates. The present study did so by examining performance of international chess players at asymptote and over equal numbers of rated games. Males still were very disproportionately represented at the top. Top female players showed signs of having less natural talent for chess than top males, such as taking more rated games to gain the grandmaster title. The hypothesis that males predominate because many more males play chess was tested by comparing gender performance differences in nations with varying percentages of female players. In well-practised participants, gender performance differences stayed constant even when the average national percentage of female international players increased from 4.2% to 32.3%. In Georgia, where women are encouraged strongly to play chess and females constitute nearly 32% of international players, gender performance differences are still sizeable. Males on average may have some innate advantages in developing and exercising chess skill.