Open a commercial thriller and the chapters are frequently two or three pages long. That is a deliberate construction, and it works on the reader's decision-making rather than on the story.
The decision to stop happens at a break
Readers rarely abandon a book mid-sentence. They stop at the end of a chapter, where the text offers a natural place to close the cover.
A thriller's job is to make that moment arrive when the reader is least willing to take it, which means ending each chapter before the tension has resolved.
Short chapters create many such moments, and each one is an opportunity to pull the reader forward rather than to release them.
The reader also sees how short the next chapter is before committing to it, which makes continuing feel like a small decision rather than a large one.
Progress feels faster than it is
Turning pages that carry chapter numbers produces a sense of movement, because completed chapters are the units a reader uses to measure progress.
Twenty short chapters in an evening feels like more accomplishment than four long ones covering the same number of words.
That feeling of speed is inseparable from what readers mean when they describe a thriller as gripping, and it is largely a formatting effect.
The structure supports parallel plotting
Thrillers commonly run several strands at once: the investigator, the antagonist, the victim, the wider institutional response.
Short chapters let the narrative cut between them frequently, leaving each strand at a point of unresolved pressure before switching.
The reader is then carrying several open questions simultaneously, which makes stopping harder because nothing has been closed off.
White space changes how the page reads
Frequent chapter breaks mean more blank space, larger openings and shorter blocks of text, so a page contains fewer words than it appears to.
A book of a given page count reads faster as a result, and the physical object still looks substantial on a shelf.
That combination suits a category whose readers value both momentum and the sense of having consumed something substantial in a weekend.
The technique has limits
Constant cutting makes sustained description or interior reflection difficult, since neither survives being interrupted every few pages.
Thrillers that want psychological depth generally lengthen their chapters and accept slower momentum, which is one of the clearest structural differences between the commercial end of the genre and its literary neighbours.