Chess has one of the richest legacies of any game or sport. Praised for its intellectual depth, chess has well-documented cognitive and educational benefits for players. And psychological scholarship has increasingly turned to the game to reveal how expertise in chess relates to common abilities and tasks in life.

Chess is the primary arena for studying expertise, psychologist Christopher Chabris says. The advantages of chess include a wide range of abilities and tasks for analysis, ecological validity (the extent to which research reflects real life), historical expert performances, the ability to compare human performance to computer models and artificial intelligence research programs, and a statistical rating system (Elo) for comparing skill levels among players.

Few domains are as effective as chess in highlighting how topics like mental imagery and prior knowledge relate to problem-solving. By looking at how strong chess players approach situations, researchers can better understand cognitive processes like perception, memory and visualization as well as their implications.

Developing and Expanding the Chunking Theory

Seminal Works

World-class grandmasters and strong amateurs search equally deep, visit the same number of positions and propose the same number of candidate moves, Adriaan D. de Groot concluded in his 1965 book, Thought and Choice in Chess. The main finding from the study was that the best players almost immediately determined the real problem in the position. They were able to reconstruct a chess position almost perfectly after viewing it for just 5 seconds.

William Chase and Herbert Simon built on de Groot’s findings and produced the other landmark work in chess thinking, a 1973 study in Cognitive Psychology. Their theory, known as the chunking theory, proposed that expertise in chess partly rests on the ability to recognize important features in a position quickly. These features are stored in chunks, or patterns of pieces, and act as access points to semantic long-term memory.

The theory says that perception mechanisms allow players to recognize chunks on the board. For instance, in one part of the study, 60 of 77 chunks in middlegame and puzzle positions could be classified as either pawn chains, castled king positions or clusters of pieces of the same color, all common in a game of chess. Recognized patterns suggest moves, and the internal representation of the board, or the “mind’s eye,” is updated. Then, pattern recognition mechanisms are applied in the mind’s eye until search is terminated in a branch. Termination occurs when certain goals are above or below a threshold determined by the player’s expectation level of the position.

Later Research

Decades after the chunking theory was proposed, the template theory was developed to address weaknesses in chunking theory related to data from memory research. Thinking & Reasoning notes that contrary to chunking theory’s predictions, chess players’ memory is resistant to retroactive interference, and chess players can accurately recall several briefly presented positions.

Template theory expanded on chunking theory, proposing that chunks are accessed by traversing a discrimination net. Chunks are linked to other information, such as moves, plans, tactical motives and other elements in long-term memory. More common chunks in a player’s experience can evolve into more complex data structures, known as templates, which have slots allowing variables to be encoded. Templates can store about 10 pieces, including information such as the square occupied by a piece. The theory also proposes that information stored in the mind’s eye can decay rapidly and needs to be updated by inputs from the external world or from memory structures.

Cognitive Science Society hypothesized that links are formed between visuospatial chunks and more abstract knowledge, such as positional advantages and, for the topic of the study, whether the chunk contains a check or not. Researchers used CHREST (Chunk Hierarchy and Retrieval Structures), a cognitive architecture that simulates certain aspects of the human mind, to present 60 chess positions of a king and one other piece to players of different skill levels.

As expected, stronger chess players took less time to make a check perception decision. In the first experiment of standard perceptual strategies, amateurs or fourth-class players (Elo from 1200 to 1400) took 1,705 milliseconds to make a decision compared to 1,068 milliseconds for grandmasters (Elo typically from 2500 to 2700). For the second experiment of simplified perceptual strategy, grandmasters took less than half the time of fourth-class players. Researchers believed that weaker players spent additional time double-checking their decisions, whereas stronger players didn’t feel the need to do this based on their confidence in their ability.

Size of largest chunks correlates with chess skill, according to a study from PLOS. Higher-rated chess players recalled bigger largest chunks than lower-rated players.

Insights from Blindfold Chess

Blindfold chess is a form of chess where the players are not allowed to see the board. Research in blindfold chess has added to the psychological field of skill-based mental images or skilled imagery.

Hundreds of world-class grandmaster games were analyzed for blunders, in a study from Cognitive Science. The games were taken from the Amber chess tournament in Monaco, where the same 23 players competed in slow time controls as well as rapid time controls with and without sight of the board. The Fritz 5 chess program analyzed an equal number of games under the three playing conditions for blunders, using the threshold of 1.5 pawns to constitute a blunder.

Grandmasters made fewer and smaller mistakes with the additional time given in sighted games. However, during rapid games, there were no consistent differences between blindfold and sighted groups. The blindfold condition actually produced fewer mistakes than the rapid condition, highlighting the importance of visualization.

Patterns or chunks help the mind’s eye construct images through visual working memory and long-term memory in blindfold chess, Acta Psychologica found. Strong players in the study followed games presented to them one move at a time, guided by important features and neglecting insignificant features of games.

Applications in Psychology

Findings from chess research can illuminate and apply to processes in other domains. For instance, interactions between knowledge and search are also apparent in medical diagnosis, physics and text comprehension, Thinking & Reasoning says. The template theory can integrate these domains of expertise into a single framework.

Mental imagery in standard and blindfold chess has been linked to the “mental cartoons” hypothesis, which says that expertise in visual-spatial domains such as chess is based on the development of cartoon-like representations of important properties, in contrast to photograph-like representations of elements. Chabris compares visualization in chess to how experts in physics solve problems. Research on physics reveals that problems are solved by thinking in abstract concepts, such as point masses and friction, instead of options like blocks and inclined planes present in the display. Both can use cartoon-like imagery to highlight important information and obscure unimportant information.

Southeastern University’s online Bachelor in Psychology allows students to explore fields such as cognitive and experimental psychology. Graduates will gain a strong foundation in psychological methods needed to pursue graduate study in psychology or counseling. Graduates are also equipped to enter a number of service settings.