Chess Grandmasters Don't Have a Better Memory Than You

Give a chess grandmaster an ordinary memory test, with no pieces or boards involved, and they perform about as well as anyone else. And yet they can rebuild an entire board position after looking at it for a few seconds.

They don’t have a photographic memory or some general gift for retention that other people lack. They have something else, far more specific and, according to the research, far more trainable than it seems.

Amateurs, excellent players and grandmasters: three different ways of playing

In The g Factor (1998), psychologist Arthur Jensen reviews the research on how chess experts think, and he starts by dismantling the most obvious explanation.

• A weak player (a duffer, in English slang) usually thinks one move ahead, at most.
• An excellent player thinks several moves ahead.
• A grandmaster works in a way that is qualitatively different from both.

The difference isn’t how many moves they calculate in advance. It’s something faster and more automatic: the ability to perceive a whole pattern on the board at a glance.

That idea didn’t start with Jensen. It goes back to the thesis of Dutch psychologist and chess master Adriaan de Groot, published in 1946 and translated into English as Thought and Choice in Chess (1965). De Groot asked players of different levels to think aloud while facing a position and noticed that grandmasters didn’t explore more moves than good amateurs. What they did was land on the good moves sooner.

The random board experiment

The decisive test came in 1973. William Chase and Herbert Simon (the latter won the Nobel Prize in Economics in 1978) showed chess positions for five seconds to three players: a master, a Class A player and a beginner. Then they asked them to rebuild the positions on an empty board.

• With positions taken from real games, the master placed far more pieces correctly than the other two, and did it in groups: pieces defending each other, a castled king with its pawns, a typical pawn chain.
• With the same pieces placed at random, the master’s advantage practically disappeared: all three remembered only a handful of pieces.

Chase and Simon concluded that the master doesn’t have more working memory than anyone else. They perceive the board in larger chunks: each familiar configuration takes up as much room in their memory as a single piece does in a beginner’s. Simon estimated that a master stores on the order of 50,000 chunks of this kind, a figure Gobet and Simon supported again in 1996 with computer simulations.

The nuance came later. Pooling thirteen studies, Fernand Gobet and Herbert Simon (1996) found that a small advantage for experts remains with random positions. That doesn’t contradict the chunking idea: even a scrambled board happens to contain a few patterns an expert recognizes.

Exceptional memory, but only within their specialty

This is the finding that breaks the intuition of the “genius with a prodigious memory”:

• Grandmasters memorize entire positions at a glance, the way you remember a sentence you just read without attending to each letter.
• On general memory tests, unrelated to chess, Jensen reports that they show no appreciable advantage over other people.
• What they do have is a long-term memory richly stocked with positions, plans and combinations, which come to mind on their own as soon as a familiar configuration appears.

Jensen compares it to reading in your own language: nobody decodes a familiar word letter by letter, the brain recognizes it whole. A grandmaster does the same with the board after thousands of hours of exposure to that particular language.

Lots of practice, and a particular kind

If the advantage isn’t a superior general memory, where does it come from?

According to the research Jensen reviews on exceptional performance in any field, the critical difference between an expert and an average person isn’t so much raw g as the degree of automatization of the knowledge specific to that field. That automatization is marked by the simultaneity of processes and by a kind of “thinking in patterns” that doesn’t exist in someone who still processes information step by step.

The road there is practice, lots of it, with a conscious effort to improve. Psychologist K. Anders Ericsson called it deliberate practice and argued for decades that it was the main factor behind expertise.

Later data qualify that claim. David Hambrick and colleagues (2014) reanalyzed six studies covering more than a thousand chess players and concluded that deliberate practice explains, on average, around 34% of the differences in skill. That’s a huge share for a single factor, but it leaves most of the variation unexplained. In one of those studies, grandmasters had accumulated anywhere from about 800 to more than 24,000 hours of practice: some get there much sooner than others.

What about intelligence? What the 2016 meta-analysis says

If general memory doesn’t set the master apart, it’s fair to ask whether intelligence does. The most comprehensive study to date is the meta-analysis by Alexander Burgoyne and colleagues (2016), which pooled dozens of samples of chess players.

• Chess skill is positively but modestly associated with cognitive ability: around r = 0.24 with fluid reasoning, and similar values with short-term memory.
• The relationship is stronger in young and unrated players (r ≈ 0.32) than in adults and rated players (between 0.11 and 0.14).
• A correction published in 2018 slightly lowered the overall average (0.22) and left some associations non-significant, but kept the one with fluid reasoning.

The authors’ reading fits Jensen’s: intelligence helps most at the start, when almost everything still has to be calculated. As a player accumulates patterns, that specific knowledge comes to weigh more than general ability.

The isolated talent that rarely takes off

Jensen links this idea to an almost uncomfortable fact: savant syndrome (what older literature called idiots savants), people with an astonishing talent in a very specific area (calculation, music, drawing) alongside a general IQ well below average.

According to the book, almost none of these cases go on to become recognized first-rank mathematicians, musicians or artists, and very few manage to earn a living from that talent. Jensen’s conclusion is that an average or above-average level of g seems to be an almost necessary condition for a special talent to reach its most influential form within its field.

It’s an interpretation based on cases, not on an experiment, but it matches what Burgoyne’s meta-analysis shows: general ability doesn’t replace the learned pattern, and the learned pattern doesn’t fully flourish without it.

What this finding changes about the idea of “talent”

Putting the pieces together, the picture is more nuanced than the myth of the born genius:

• Expert performance depends largely on a repertoire of patterns built through a great deal of practice, not on a general gift for memory.
• Practice explains a lot, but not everything: cognitive ability and other factors also count, especially in the early stages.
• An isolated talent, without a general foundation to support it, rarely reaches the top level of its discipline.

What a grandmaster shows isn’t that some people are born seeing the board differently. It’s that seeing a board “differently” is built, move by move, over thousands of hours, on a foundation that was already there.

The idea of a “necessary foundation” also shows up in the history of how intelligence came to be studied: the 2,000-year-old advice psychology took a century to take seriously explains why something so obvious took so long to become an object of scientific study.

Sources

• Burgoyne, A. P., Sala, G., Gobet, F., Macnamara, B. N., Campitelli, G., & Hambrick, D. Z. (2016). The relationship between cognitive ability and chess skill: A comprehensive meta-analysis. Intelligence, 59, 72-83. doi:10.1016/j.intell.2016.08.002
• Chase, W. G., & Simon, H. A. (1973). Perception in chess. Cognitive Psychology, 4(1), 55-81.
• De Groot, A. D. (1965). Thought and Choice in Chess. Mouton. (Dutch original, 1946.)
• Gobet, F., & Simon, H. A. (1996). Recall of rapidly presented random chess positions is a function of skill. Psychonomic Bulletin & Review, 3(2), 159-163.
• Gobet, F., & Simon, H. A. (1996). Recall of random and distorted chess positions: Implications for the theory of expertise. Memory & Cognition, 24(4), 493-503.
• Hambrick, D. Z., Oswald, F. L., Altmann, E. M., Meinz, E. J., Gobet, F., & Campitelli, G. (2014). Deliberate practice: Is that all it takes to become an expert? Intelligence, 45, 34-45.
• Jensen, A. R. (1998). The g Factor: The Science of Mental Ability. Praeger.