Location coding in chess

Whether the chunks used in memorizing chess positions are general and relatively encoded schemata or very precisely coded instances is a problem that has raised some controversy within the psychology of chess skill. As chess research has had a strong impact on expertise research, this problem is important in many areas of skills research other than chess. To resolve it, four experiments were set up. In the experiments it was shown that subjects were better at recalling correctly located non-transposed chunks than transposed chunks, which were similar in structure but incorrectly located on the chessboard. The results imply that the representation of chess-specific patterns in the memory of a chess player contains not only information about the forms of chess-specific patterns, but also about their absolute locations on the chessboard. This provides an explanation for the well-known interaction between skill and type of position and its disappearance in recent experiments by Lories and Saariluoma. It can be argued that the difficulty of recalling random positions is not chiefly caused by the total absence of chunks but by their dislocation.     

Recall or evaluation of chess positions revisited: the relationship between memory and evaluation in chess skill

We extend work by Holding and Reynolds (1982) on recall and problem solving with quasirandom chess positions. We tested 17 chess players on both quasirandom and structured chess positions. Consistent with the earlier study, initial recall of quasirandom chess positions is unrelated to chess skill level, and quality of the move selected in subsequent problem solving is related to skill level. However, recall following problem solving is related to chess skill level. These results support the view that pattern recognition processes underlie superior performance by skilled chess players, contrary to the conclusions of Holding and Reynolds (1982). Mechanisms such as long-term working memory retrieval structures (Ericsson & Kintsch, 1995) or templates (Gobet & Simon, 1996a) could explain the effective encoding of quasirandom positions during problem solving.     

Recall memory for visually presented chess positions

A series of three experiments replicated and extended earlier research reported by Chase and Simon (1973), de Groot (1965), and Charness (Note 1). The first experiment demonstrated that the relationship between memory for chess positions and chess skill varies directly with the amount of chess-specific information in the stimulus display. The second experiment employed tachistoscopic displays to incrementally "build" tournament chess positions by meaningful or nonmeaningful chunks and demonstrated that meaningful piece groupings during presentation markedly enhance subsequent recall performance. The third experiment tested memory for one of two positions presented in immediate sequence and demonstrated that explanations based on a limited-capacity short-term memory (Chase & Simon, 1973) are not adequate for explaining performance on this memory task.     

Chess players' recall of auditorily presented chess positions

Abstract

Chess players' recall of auditorily presented chess positions were studied in three experiments. The results of the first two experiments showed that the skilled chess players are better at recalling game and random positions. This contradicts the standard finding that they perform better only in game positions. In the third experiment, the memory load was increased by increasing the number of positions to be recalled simultaneously from one to four positions. Skilled subjects are still far better at recalling game positions, but they score no more than moderately skilled subjects in recalling four random positions.

The results are in contradiction with the direct chunking hypothesis. Skilled chess players do not fail to recall random positions because there are no chunks in them, but because they are not, under some special conditions, able to encode them properly. It is necessary to postulate more complicated encoding mechanisms than a simple recognition-based activation of a chunk in long-term memory.     

Recall of rapidly presented random chess positions is a function of skill

A widely cited result asserts that experts’ superiority over novices in recalling meaningful material from their domain of expertise vanishes when they are confronted with random material. A review of recent chess experiments in which random positions served as control material (presentation time between 3 and 10 sec) shows, however, that strong players generally maintain some superiority over weak players even with random positions, although the relative difference between skill levels is much smaller than with game positions. The implications of this finding for expertise in chess are discussed and the question of the recall of random material in other domains is raised.     

Working memory in chess

Three experiments investigated the role of working memory in various aspects of thinking in chess. Experiment 1 examined the immediate memory for briefly presented chess positions from master games in players from a wide range of abilities, following the imposition of various secondary tasks designed to block separate components of working memory. Suppression of the articulatory loop (by preventing subvocal rehearsal) had no effect on measures of recall, whereas blocking the visuospatial sketchpad (by manipulation of a keypad) and blocking the central executive (by random letter generation) had equivalent disruptive effects, in comparison with a control condition. Experiment 2 investigated the effects of similar secondary tasks on the solution (i.e., move selection) of tactical chess positions, and a similar pattern was found, except that blocking the central executive was much more disruptive than in Experiment 1. Experiment 3 compared performance on two types of primary task, one concerned with solving chess positions as in Experiment 2, and the other a sentence-rearrangement task. The secondary tasks in each case were both designed to block the central executive, but one was verbal (vocal generation of random numbers), while the other was spatial in nature (random generation of keypresses). Performance of the spatial secondary task was affected to a greater extent by the chess primary task than by the verbal primary task, whereas there were no differential effects on these secondary tasks by the verbal primary task. In none of the three experiments were there any differential effects between weak and strong players. These results are interpreted in the context of the workingmemory model and previous theories of the nature of cognition in chess.     

Planning abilities and chess: A comparison of chess and non‐chess players on the Tower of London task

Playing chess requires problem‐solving capacities in order to search through the chess problem space in an effective manner. Chess should thus require planning abilities for calculating many moves ahead. Therefore, we asked whether chess players are better problem solvers than non‐chess players in a complex planning task. We compared planning performance between chess (N=25) and non‐chess players (N=25) using a standard psychometric planning task, the Tower of London (ToL) test. We also assessed fluid intelligence (Raven Test), as well as verbal and visuospatial working memory. As expected, chess players showed better planning performance than non‐chess players, an effect most strongly expressed in difficult problems. On the other hand, they showed longer planning and movement execution times, especially for incorrectly solved trials. No differences in fluid intelligence and verbal/visuospatial working memory were found between both groups. These findings indicate that better performance in chess players is associated with disproportionally longer solution times, although it remains to be investigated whether motivational or strategic differences account for this result.     

The effects of speed on skilled chess performance

Two types of mechanisms may underlie chess skill: fast mechanisms, such as recognition, and slow mechanisms, such as search through the space of possible moves and responses. Speed distinguishes these mechanisms, so I examined archival data on blitz chess (5 min for the whole game), in which the opportunities for search are greatly reduced. If variation in fast processes accounts for substantial variation in chess skill, performance in blitz chess should correlate highly with a player's overall skill. In addition, restricting search processes should tend to equalize skill difference between players, but this effect should decrease as overall skill level increases. Analyses of three samples of blitz chess tournaments supported both hypotheses. Search is undoubtedly important, but up to 81% of variance in chess skill (measured by rating) was accounted for by how players performed with less than 5% of the normal time available.     

Visualization,pattern recognition,and forward search: effects of playing speed and sight of the position on grandmaster chess errors

A new approach examined two aspects of chess skill, long a popular topic in cognitive science. A powerful computer‐chess program calculated the number and magnitude of blunders made by the same 23 grandmasters in hundreds of serious games of slow (“classical”) chess, regular “rapid” chess, and rapid “blindfold” chess, in which opponents transmit moves without ever seeing the actual position. Rapid chess led to substantially more and larger blunders than classical chess. Perhaps more surprisingly, the frequency and magnitude of blunders did not differ in rapid versus blindfold play, despite the additional memory and visualization load imposed by the latter. We discuss the involvement of various cognitive processes in human problem‐solving and expertise, especially with respect to chess. Prior opposing views about the basis of general chess skill have emphasized the dominance of either (a) swift pattern recognition or (b) analyzing ahead, but both seem important and the controversy appears currently unresolvable and perhaps fruitless.     

Chess knowledge predicts chess memory even after controlling for chess experience: Evidence for the role of high-level processes

The expertise effect in memory for chess positions is one of the most robust effects in cognitive psychology. One explanation of this effect is that chess recall is based on the recognition of familiar patterns and that experts have learned more and larger patterns. Template theory and its instantiation as a computational model are based on this explanation. An alternative explanation is that the expertise effect is due, in part, to stronger players having better and more conceptual knowledge, with this knowledge facilitating memory performance. Our literature review supports the latter view. In our experiment, a sample of 79 chess players were given a test of memory for chess positions, a test of declarative chess knowledge, a test of fluid intelligence, and a questionnaire concerning the amount of time they had played nontournament chess and the amount of time they had studied chess. We determined the numbers of tournament games the players had played from chess databases. Chess knowledge correlated .67 with chess memory and accounted for 16% of the variance after controlling for chess experience. Fluid intelligence accounted for an additional 13% of the variance. These results support the conclusion that both high-level conceptual processing and low-level recognition of familiar patterns play important roles in memory for chess positions.     

Expertise and age effects on knowledge activation in chess

Novice, intermediate, and expert chess players of various ages, playing with two chess pieces on a quarter-section of a chessboard, performed a simple task to detect that the king is in check or is threatened with being in check. Age slowed response for both tasks. An interaction of task and skill revealed differences in diminishing response time between check and threat tasks as skill increased; experts were equally fast on both tasks. Measures of speed and working memory were negatively related to age but unrelated to skill. Skill did not mitigate age-related effects on speed of detection. These results suggest that knowledge-activation processes necessary to assess basic chess relationships slow with age, even in experts.     

Theories of chess skill

Summary The paper reviews the evidence for and against the recognition-association theory and a forward-search (SEEK) theory of chess skill. The recognition-association theory appears to be founded on indirect evidence concerning visual short-term memory, together with supplementary assumptions that may be questioned, and provides no role for verbal processes. There is no direct support for the theory, which omits forward search for reasons that are reexamined. In contrast, the SEEK theory maintains that move choice is based on search and evaluation processes supplemented (or else supplanted) by a knowledge base. These processes are directly evidenced by experimental findings. The objection that search theories cannot account for speed chess is met by a review of the available evidence. It is concluded that chess skill relies on thinking ahead rather than on pattern recognition.     

Visual span in expert chess players: evidence from eye movements

The reported research extends classic findings that after briefly viewing structured, but not random, chess positions, chess masters reproduce these positions much more accurately than less-skilled players. Using a combination of the gaze-contingent window paradigm and the change blindness flicker paradigm, we documented dramatically larger visual spans for experts while processing structured, but not random, chess positions. In addition, in a check-detection task, a minimized 3 × 3 chessboard containing a King and potentially checking pieces was displayed. In this task, experts made fewer fixations per trial than less-skilled players, and had a greater proportion of fixations between individual pieces, rather than on pieces. Our results provide strong evidence for a perceptual encoding advantage for experts attributable to chess experience, rather than to a general perceptual or memory superiority.     

Identification and conceptualization of procedural chunks in chess

When it comes to cognitive architecture and human information processing, chunks are one of the best known and most recognized constructs. Nevertheless, the nature of chunks is still very elusive, especially when it comes to chunks in procedural knowledge. This study deals with basic features of procedural information processing and examines the manifestation of chunks in procedural knowledge. The participants' task was to reconstruct sequences of chess moves. Chess was chosen as an experimental domain, because of its complexity, well-defined rules and standardized measure of chess player strength. From the results we conclude that short-term memory capacity is determined by the combination of the size and amount of procedural chunks recalled to the short-term memory. We have shown that on average, participants with more specialized knowledge operated faster and with larger chunks of procedural information than participants with less specialized knowledge. We have shown that in procedural information processing, the level of expertise and the sorting order of the retrieved information are important factors that influence the amount of procedural chunks retained in the short-term memory. Therefore, the capacity of short-term memory in complex situations cannot be expressed as a simple concept.     

Novice construction of chess memory

Novice acquisition of skilled recall of chess positions was studied in an experiment in which two novices studied a series of five hundred chess positions during a period of several months. They spent fifteen minutes to half an hour a day teaching themselves these positions. As a result their skill in recalling chess positions rose from sixteen percent to somewhere between forty to fifty percent. The learning curve proved to have a shape which indicates that in the beginning learning is very fast but after some 100-150 studied positions the speed of learning decreases substantially. A computer simulation was used to model the results and analyse alternative explanations. Two alternative ways of thinking were tested. In the first, chunk construction was assumed to be based on the neighbourhood of associated pieces. The second model assumed a frequency-based correlative association process. Although the learning curves of the two models are very similar in shape to those of the subjects, the frequency-based associative model gave a better explanation for the data. This is why it is natural to suggest that common co-occurrence in addition to easily recognizable chess-specific characteristics, like colour and type of pieces, guide associative processes during chess players' learning of chess-specific chunks.     

Five Seconds or Sixty? Presentation Time in Expert Memory

For many years, the game of chess has provided an invaluable task environment for research on cognition, in particular on the differences between novices and experts and the learning that removes these differences, and upon the structure of human memory and its paramaters. The template theory presented by Gobet and Simon based on the EPAM theory offers precise predictions on cognitive processes during the presentation and recall of chess positions. This article describes the behavior of CHREST, a computer implementation of the template theory, in a memory task when the presentation time is varied from one second to sixty, on the recall of game and random positions, and compares the model to human data. Strong players are better than weak players in both types of positions, especially with long presentation times, but even after brief presentations. CHREST predicts the data, both qualitatively and quantitatively. Strong players' superiority with random positions is explained by the large number of chunks they hold in LTM. Their excellent recall with short presentation times is explained by templates, a special class of chunks. CHREST is compared to other theories of chess skill, which either cannot account for the superiority of Masters in random positions or predict too strong a performance of Masters in such positions.     

Recall of random and distorted chess positions: Implications for the theory of expertise

This paper explores the question, important to the theory of expert performance, of the nature and number of chunks that chess experts hold in memory. It examines how memory contents determine players’ abilities to reconstruct (1) positions from games, (2) positions distorted in various ways, and (3) random positions. Comparison of a computer simulation with a human experiment supports the usual estimate that chess Masters store some 50,000 chunks in memory. The observed impairment of recall when positions are modified by mirror image reflection implies that each chunk represents a specific pattern of pieces in a specific location. A good account of the results of the experiments is given by the template theory proposed by Gobet and Simon (in press) as an extension of Chase and Simon’s (1973b) initial chunking proposal, and in agreement with other recent proposals for modification of the chunking theory (Richman, Staszewski, & Simon, 1995) as applied to various recall tasks.     

Visuospatial representations used by chess experts: A preliminary study

Blindfold chess is played without the players seeing either the pieces or the board. It is a skill‐related activity, and only very skilled players can construct the mental images required. This is why blindfold chess provides a good task with which to investigate the spatial memory and skilled mental images of expert players. In a PET investigation, we compared memory performance and problem solving in very experienced chess players with their performance in an attention task, in which the subjects classified the names of chess pieces. The memory task predominantly activated the temporal areas, whereas problem solving activated several frontal areas. The relevance of these findings to concepts such as general imagery, skilled imagery, apperception, and long‐term working memory are discussed.     

Perception in chess

This paper develops a technique for isolating and studying the perceptual structures that chess players perceive. Three chess players of varying strength — from master to novice — were confronted with two tasks: (1) A perception task, where the player reproduces a chess position in plain view, and (2) de Groot's (1965) short-term recall task, where the player reproduces a chess position after viewing it for 5 sec. The successive glances at the position in the perceptual task and long pauses in the memory task were used to segment the structures in the reconstruction protocol. The size and nature of these structures were then analyzed as a function of chess skill.     

Meta-analysis of age and skill effects on recalling chess positions and selecting the best move

A meta-analysis was conducted of studies that measured the effects of both age and skill in chess on the tasks of selecting the best move for chess positions (the best move task) as well as recalling chess game positions (the recall task). Despite a small sample of studies, we demonstrated that there are age and skill effects on both tasks: age being negatively associated with performance on both tasks and skill being positively associated with performance on both tasks. On the best move task, we found that skill was the dominant effect, while on the recall task, skill and age were approximately equally strong effects. We also found that skill was best measured by the best move task. In the case of the best move task, this result is consistent with the argument that it accurately replicates expert performance (Ericsson & Smith, 1991). Results for the recall task argue that this task captures effects related to skill, but also effects likely due to a general aging process. Implications for our understanding of aging in skilled domains are also discussed.