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On Chess: 'Chunking' Is The Memory Trick You Don’t Know You’re Using

An officer practices 'chunking' during a C.H.E.S.S. Cops match at Gateway Middle School.
Crystal Fuller | St. Louis Chess Club
An officer practices 'chunking' during a C.H.E.S.S. Cops match at Gateway Middle School.

The field of cognitive psychology is filled with tips, tricks and strategies to improve memory; however, you don’t need to be a cognitive psychologist to be familiar with these strategies. Chess players have long since mastered one of cognitive psychology’s most useful tricks: chunking.

The idea of chunking first appeared in an article published in the Psychological Review titled “The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information."

Written by George Miller (1956), the paper discusses the concept that the human brain can maintain five to nine pieces of information at any given time. Take note that it says pieces. The term “chunking” refers to the process of forming multiple pieces of information into a single piece — a chunk — that is easier to encode in our limited memory. A common example is phone numbers.

Experience it yourself. Try to memorize this list:

Apple, pen, eye, pear, hand, orange, paper, marker, leg.

Recalling all nine items is by no means an impossible task. It might take some time, but eventually you could recall each item individually. However, what if we tried chunking? All we have to do is change the way we look at that list — transforming it from individual pieces of information to larger groups, or chunks. 

With the change of perspective, we quickly realize that the list consists of items from familiar categories: fruits, office supplies and body parts. Cognitive psychology suggests that if we can remember the items on the list as distinctive and cohesive groups, then the information will be learned quicker and easier.

Now, try to memorize these three lists:

  • Peach, mango, banana
  • Stapler, paper clip, binder
  • Mouth, shoulder, elbow

You may have noticed it took much less time than before. The chess player does this when he or she looks at the board, regardless of whether they are consciously aware of the process. Better players utilize better, faster chunking skills.
Chess is a game of chunks. There are pawns, minor pieces and major pieces — three categories covering 16 individual pieces. Even aside from the pieces, there are seemingly limitless positional chunks of data. 

For example, instead of memorizing that there are three pawns each on their own square (b2, c3, d4), a chess player notes the chunk of data: There is a pawn chain starting on b2. Three pieces become one easily remembered block of information.

In the picture above, the officer has built a defensive structure (King’s Indian defense or Fianchetto’s Castle) around his King with his rook, bishop and three pawns (Kg1, Rf1, Bg2, and pawns on f2, g3, and h2). Instead of remembering each of the six pieces and their individual positions, he can recall the entire formation as one chunk of information.

There is one more component of the 1956 study: memory capacity. Both the study and chess are concerned with working memory or short-term memory — the memory that usually spans seconds. How many individual pieces of information can a person hold in their memory and use?

While Miller suggests that five to nine pieces of information will max out our processing capacity, newer studies suggest it is even lower — around three to five. Regardless of the precise number, a chess player can only work with a finite number of information pieces, chunked or otherwise. The better the player is at chunking — that is, the more information they can tuck away into each chunk — the larger the advantage.

It is easy to see the advantages of chunking. A chess player who can better consolidate information leaves more of his or her attention available for strategic endeavors.

Consider this last thought: one player formulates half the board into four chunks, while their opponent uses four chunks to capture the whole board. Next time you look at a board, consider how you are chunking, and perhaps you can push your capacity a little further.

Brent Allmon is a writer, chess instructor and lover of science. He is also a member of the St. Louis Chess Club, a partner of St. Louis Public Radio.

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