JournalBehavior Research Methods 2006, ??38 (?),(4), ???-???698-703 A complete database of international chess players and chess performance ratings for varied longitudinal studies ROBERT W. HOWARD University of New South Wales, Sydney, New South Wales, Australia Chess is an oft-used study domain in psychology and artificial intelligence because it is well defined, its performance rating systems allow easy identification of experts and their development, and chess playing is a complex intellectual task. However, usable computerized chess data have been very lim- ited. The present article has two aims. The first is to highlight the methodological value of chess data and how researchers can use them to address questions in quite different areas. The second is to pres- ent a computerized database of all international chess players and official performance ratings begin- ning from the inaugural 1970 international rating list. The database has millions of records and gives complete longitudinal official performance data for over 60,000 players from 1970 to the present. Like a time series of population censuses, these data can be used for many different research and teaching purposes. Three quite different studies, conducted by the author using the database, are described. Chess has been an oft-used research domain in psy- 1982; Saariluoma, 1991), and concurrent visuospatial chology and artificial intelligence (Charness, 1992) for tasks interfere strongly with intake of chess information several reasons. The domain is well defined; its quantita- (Saariluoma, 1992). Waters, Gobet, and Leyden (2002) tive performance rating systems allow easy identification reported little relation between chess skill and a measure of experts and their development; real-world longitudinal of visual memory, the Shape Memory Test, but they also data are available; and chess playing is a complex intel- noted that the ability to manipulate visual images (which lectual task. PsycINFO lists about 200 papers with chess unfortunately was not gauged in their study) may be much in the title, by psychologists who have used chess data for more important. various research purposes. Some have aimed to under- Chess has been particularly useful for the study of stand chess performance itself, others have generalized expertise. Researchers have examined the development findings from one obviously intellectual task to others and possible decline of high performers, with findings (see, e.g., van der Maas & Wagenmakers, 2005). Indeed, often generalizing to many other domains. Perhaps the Newell (1973) dubbed chess a “drosophila” for cognitive best-known research thread has focused on what chess psychology. experts know that allows them to outperform novices. De Groot (1965) reported that experts “chunk” chess pieces Some Illustrative Examples of Research Studies on the board into familiar patterns, a finding later repli- Using Chess Data cated by Chase and Simon (1973). These well-organized A variety of findings in psychological studies have “chunks” of domain-specific knowledge aid recall and been based on chess data. Atherton, Zhuang, Bart, Hu, analysis of chess positions and suggest courses of ac- and He (2003) examined patterns of brain activation tion (see, e.g., Holding, 1985). This general finding has during chess playing. Burns (2004) looked at speed and been replicated in many other domains, such as go, dance chess performance. Some researchers have examined the steps, and computer programming (Howard, 1995; Reit- psychometric abilities involved in chess (see, e.g., Gobet, man, 1976). Charness, Krampe, and Mayr (1996) studied de Voogt, & Retschitzki, 2004). Some research suggests, the effects on chess performance of age, coaching (which for instance, that visuospatial ability, particularly the abil- apparently had little effect), and amount of practice. Char- ity to manipulate visual representations, is important for ness, Tuffiash, Krampe, Reingold, and Vasyukova (2005) chess performance (Frydman & Lynn, 1992). Chess im- also looked at the link between amount of practice and agery seems to differ according to skill level (Milojkovic, expertise. Charness and Gerchak (1996) aimed to relate some well-known differences in proportions of top chess performers by sex and nationality to differing national participation rates. The author thanks Herman Lukito for his valuable help in starting this Chess also has been useful for studying other phenom- database project, as well as the many individuals and chess federations who contributed data. Send reprint requests to R. W. Howard, School of ena in varied areas. For instance, Howard (1999, 2001) Education, University of New South Wales, Sydney, NSW 2052 Austra- used chess data to examine interpretations of the Flynn lia (e-mail: [email protected]). effect, essentially comparing the performance of younger Copyright 2006 Psychonomic Society, Inc. 698 CHESS PERFORMANCE DATABASE 699 and older players over several decades. Schwarz, Schach- ies of high performance in many other domains, such as inger, Adler, and Goetz (2003) used chess play to look at science, can be difficult to interpret because, for example, the link between heart rate and various mental states. Elo talent, amount of practice, and motivation often are con- (1965), using a very small sample of grandmasters, looked founded with variations in opportunity. In chess, though, at intellectual aging. He found that the peak chess perfor- talent can readily rise, however unpopular or unconnected mance age is about 35 years old; performance may decline a player may be. Expertise development and other phe- thereafter because overall chess skill is a race between nomena can therefore be studied in an environment with a player’s decreasing fluid intelligence after age 20 and little influence of gatekeepers and no glass ceiling. Fourth, increasing domain-specific knowledge with experience. the data already have been collected, so the most expen- Howard (2005b), with a much larger sample, confirmed sive and difficult part of most research projects can be Elo’s (1965) estimate of the peak performance age. avoided completely. A Major Difficulty With Using Chess Data Aims of the Present Article for Research The present article has two major aims. The first is to As the studies above show, chess is a domain with highlight the methodological value of the domain of chess many potential uses for psychologists. However, research- to researchers and to encourage greater use of chess data ers wishing to use chess data often have faced a grave to study a wide variety of research problems. The second problem that has limited their research possibilities: Us- aim is to describe the FIDE database and its limitations, able, computerized, longitudinal chess data are relatively how to access and use it, and how to combine its use with scarce. Various national chess federations run perfor- other sources of chess data. mance rating systems, but the data often are computer- ized only for recent years. For instance, the United States ORGANIZED CHESS Chess Federation (USCF) rating system began in 1950, but the data only are computerized from 1977. Because Chess is one of the world’s most popular games, and of hardware and software changes, the computerized data some nations class it as a sport. FIDE was founded in are also usable only from much later, according to a USCF 1924, and currently it has about 160 member national spokesperson (personal communication). Official ratings chess federations. In 1999, the International Olympic data of the international chess federation (FIDE) are com- Committee recognized FIDE as an international sports puterized only from 1990, and these computerized files federation, and FIDE hopes eventually to insert chess have problems, as described below. Howard (1999) used into the Olympics. Chess is very well organized. Many FIDE data from 1970 but could only access pre-1990 of- nations have national and provincial chess associations, ficial FIDE data from printed volumes of the periodical and many run national rating systems—for instance, the Sahovski Informator (“Chess Informant”). Because of re- United States, the United Kingdom, Australia, New Zea- source constraints, top-10 and top-50 player data could land, and Canada. Chess also has a very large literature only be sampled every 3 years, and many other issues (Graham, 1984). could not be tackled at all. Male and female players once competed in largely separate tournaments, as in tennis. Today, however, most A New FIDE Database to Solve This Problem chess competitions are mixed. However, this problem is now partially solved. The au- thor has computerized all official FIDE ratings data since The FIDE Rating System the inaugural 1970 list, creating a consistent database for Chess performance rating systems date back to the the entire time span from that date to the present, and has 1920s, when they were used by U.S. correspondence play- tested this database by using it for three major studies in ers playing by mail. An early national rating list was de- different domains. vised by Kenneth Harkness for the USCF and appeared in The database has potential uses for research in many the December 1950 issue of the popular magazine Chess areas, as well as for the teaching of research methodology. Life. This list was based on all USCF games in the previous In general, computations with a large database can yield 30 years and listed about 2,000 players. In it, all players many useful inferences. Consider, for example, a database were given numerical ratings on a scale that could go up to containing the name and address of everyone in a town. about 3000. A player lost or gained rating points after each On the basis of these data, one can derive much more use- game, according to the result and the opponent’s rating. ful information, including who lives with whom, average After a number of games, the rating was a rough measure of household size, typical household types, and so on. a player’s current playing strength (Elo, 1986). In 1959, the The chess database has many advantages for researchers.