[pterhx]

In Peak: Secrets from the New Science of Expertise, Ericsson had chess grandmasters look chess boards of real games, and they could recreate the board in a pretty short fashion.

But when they took chess boards of randomly placed pieces, they could not remember the placement of pieces any better than a random group of people.

The idea is that through practice, you develop the ability pattern match and chunk together the data into more cohesive blocks, and memory fewer of these blocks.

The rough analogy in software is to take a quick look at some code and recognize the design patterns, and remember the design patterns used rather each individual character.

In fact, words are a form of chunking -- we don't remember hundreds of character sequences, but we remember the words instead.

[maxxxxx]

It's probably like boxing a beginner. They do all kinds of weird stuff you never have seen and don't know how to categorize.

[cepth]

If you want to see what pterhx was referring to in action, National Geographic did a documentary featuring Susan Polgar a few years back. The relevant clip and timestamp are here: https://youtu.be/LdKHrxcpxrY?t=238.

The difficulty in recalling nonsensical positions is not that it's like "boxing a beginner", it's that the pieces are literally placed in a way that the positions could not have been reached with legal moves.

Analogously, remembering famous quotes or memorable phrases in a certain language is quite easy. If instead, you had to memorize a string of randomly placed words that did not follow established rules of grammar or sentence structure, it'd be a much harder task.

Chunking is context and experience dependent.