The author is Dutch International Master Willy Hendriks (IM is the rank below Grandmaster; there are ~4000 IMs and ~2000 GMs). He takes aim at chess instructors like IM Jeremy Silman, whose popular books The Amateur’s Mind and How to Reassess Your Chess teach students a structure for thinking about chess positions:

Before you get carried away, let me remind you: DON'T look at individual moves! In fact, never calculate until you understand the basic components (imbalances) of the position.
The Amateur’s Mind

Imbalances include a space advantage on one side of the board, or two knights traded for two bishops, or an unsafe opposing king. Silman lists imbalances like these and tells you to use them to formulate plans which only then suggest individual moves.

Hendriks rejects this definitively: “No chess player thinks like this, no one has learned to play chess by thinking like this and even trainers and authors of chess books don’t think like this.” Instead, the verbal descriptions are mostly retroactive and follow the initial step of identifying good candidate moves from pattern recognition alone. He gives you some reasons to think this:

He gives some examples of positions where the best move is hard to find unless you’re familiar with the pattern. In the game below (Oleg Romanishin v Predrag Nikolic, Leningrad 1987) I marked the correct move for black with an arrow. It’s hard to find this move unless you’ve been exposed to similar maneuvers before but easy to fabricate yourself some position justifications (“Yes, I saw this bishop being a bit hampered by my pawns, and he has weakened his light squares … works nicely together with the rook’s semi-open file on f8”). It’s often difficult to get students to produce the move using verbal descriptions like these as a hint.
He cites Adrian de Groot’s research from Thought and choice in chess in which grandmasters and weaker players think out loud about positions. Hendriks argues against the top players displaying extreme verbal clarity. Instead, “de Groot saw no great differences regarding the process of decision-making: the grandmaster calculated not much more or deeper and didn’t seem to decide on his move in a fundamentally different way than the lesser player.”
He points out that common positional maxims are probably wrong and contradict each other in any case. An example is taken from Silman: “During my private lessons, I [often] … remind my students to follow one of the finest general rules in chess: The best reaction to an attack on the wing is a counterattack on the center.” He selects a sample of 110 games with a 17. g4 kingside attack and concludes that at most 10% call for a counterattack in the center.

The book isn’t worth actually reading. Several of the chapters are taken from Hendriks’s old magazine columns or something and so have basically no relation to the thesis. He repeats himself, rambles, and the text is awkward (translated from Dutch?)

A typical bizarre tangent:

With the attitude in his book, Silman reminds me a bit of the “Uncle Jan” figure in the famous parody by Donner. In the Netherlands there was a popular manual for beginners called Uncle Jan teaches his nephew how to play chess (first published in 1935). In Donner’s parody, there suddenly shows up another uncle, Uncle Hein. He seems to be the black sheep of the family (smoking, drinking, getting thrown out of the chess club for not paying his membership fee) but is, not surprisingly, the better player. Uncle Hein interrupts the solid and respectable teaching of Uncle Jan with some concrete lines that show Uncle Jan’s dogmatic approach to be incorrect. But then the lesson ends as the nephew’s mother throws Uncle Hein out of the house because of his disrespectful behaviour (and because of his “shameful cheating on my sister Truus”). “Uncle Hein said nothing, but I need not tell you that he was laughing uproariously as he slammed the door behind him”, the story ends.

Chapter 3 is called “My Most Beautiful Move,” has nothing to do with the book’s thesis, and opens with this paragraph:

Two things are slightly regrettable about the most beautiful move of my career: a) I didn’t think of it myself (Fritz [a chess engine] did) and b) I didn’t manage to play it (though I came close). But it is a very surprising and very beautiful move, so I like to present it as my best move ever …

Some sections barely relate to chess.

During my philosophy study I followed a popular series of lectures titled “The great unmaskers”. The object of this unmasking was the human being itself. More specifically: the classical image of the human being as a highly rational and moral being, the triumph of creation, the master of his own body and the centre of the universe. The great unmaskers presented in this course were Marx, Nietzsche, and Freud. They all contributed in their own way to the exposure of human self-satisfaction. Marx tried to show that our ideas were not independent, but dictated by our social (material) position. Nietzsche argued that our morality was driven by more down-to-earth motivates (the will to power). And Freud tried to demonstrate that we were not led by our rational consciousness alone, but at least as much by our unconscious motives or drives.
Other scientists and philosophers can be added to this list, like Copernicus, who showed that our earth is not the centre of the universe, and of course Darwin, who proved that we are relatives of the other animals, instead of creatures of a different and superior kind.

Another reason not to read the book is that for all its outward presentation—encouraged by the author—as iconoclastic, the audience has no enthusiasm in arguing. The book won the English Chess Federation book award in 2012 and boasts praise from former US, British, and world champions. Silman himself responds by basically conceding the major points:

When people ask me how good players got good, I say, “They acquire tens of thousands of chess patterns.” The fact is, the more patterns you absorb the stronger you will be. … So when Mr. Hendriks tells you that, armed with enough patterns, you can just reach out and play a move that at the very least makes some sense, he is completely correct. And that’s why so many good players have applauded the book

He defends his explicit pattern-descriptions as being more efficient and adds a layer of defense by saying his method is at least more pleasant and therefore easier to stick to (emphasis mine):

As for my idea of imbalances (which Mr. Hendriks evidently seems to think I created without any thought or reason), it was created as a shortcut to pattern recognition. Since most students were not willing to do it the old fashioned way, I decided that imbalances would give them a full diet of patterns. … Thus imbalances are, in effect, a digestible way to have chess hopefuls drink the “medicine” (patterns) they usually shy away from.

IM John Watson, another writer facing Hendriks’s fire, makes a stronger concession that descriptions merely the “medicine” easier to swallow:

Once again, I have to agree with Hendrik's specific objection. … But Silman's books are deservedly among the most popular and admired in the world, and very many players have stated that his works were directly responsible for their improvement. Why is that, if imbalances aren't at the heart of chess understanding? For one thing, I don't think you can underestimate how engaging Silman's writing is; while writing in a lively style, he finds typical and therefore instructive examples. … For most people, learning without joy or inspiration isn't very productive.

The references to liveliness bring to mind the psychological principle of desirable difficulty (warning: PDF link): methods like rereading material create a momentary feeling that learning is taking place but are actually much worse than testing, which induces more learning but creates immediate feelings of lower performance.

Also interesting is to look for other cases of this broader distinction between methodical/formal study and just gobbling down patterns as fast as you can. Sports stories often feature scrappy players who have ingrained thousands of patterns just kicking the ball around compared to their well-heeled competitors. The most obvious parallel is language learning: Stephen Krashen’s input hypothesis argues that explicit instruction doesn’t affect learning, which flows entirely from the quantity of “comprehensible input” (which is understandable while containing a marginal increase in language-knowledge). Anecdotally a lot of people attribute most of their English fluency to watching a hundred hours of Friends while most language students describe retaining very little.

On the other hand, while Silman and others recommend skimming hundreds of high-level chess games to quickly absorb patterns, I’ve never heard of anyone quickly skimming hundreds of mathematics problems or leetcode problems. People are instead strongly advised to try as hard as they can to solve problems before giving up.

I asked the nearest IMO medalist to explain. He said that unlike peeking at the best move in a chess position after briefly considering what move you’d play yourself in the situation, reading the solution to a hard math problem doesn’t give you much of what you need to solve similar problems. Individual moves are the final atomic unit of a chess game, but math solutions are divided into many smaller “moves” and there isn’t any resource to quickly skim many math problems at various stages of solution and peek at the best “next move.” In the extreme case, reading just the numerical solutions to math problems would obviously not help you at all. But specific steps could be trained via pattern-avalanche—e.g., for problems that ask you to “prove statement X or provide a counterexample” you might be able to absorb the patterns that give you the intuition for whether you should start searching for a proof or a counterexample.

Reading thousands of leetcode problems while briefly chunking the solution into parts still feels promising. My recent refreshing of some technical chops is what reminded me of Hendriks’s book again in the first place (I’d first skimmed it while in a book store set up at the US Junior Open in 2013). The book isn’t very good but lends some evidence to the general question above and confirms my biases about “spinning your wheels reading” vs “grinding out reps.”