How much do readers actually want whodunit — and how fast is that want moving right now? Tropesmith tracks individual reader requests across ~40 sources (BookTok, Reddit, Goodreads, StoryGraph, AO3) and classifies every one by trope, then separately mines negative reviews for what makes readers walk away. Here's both sides for whodunit.
Figures from Tropesmith's reader-demand engine, current as of 9 September 2026. The 14-day figure is the clearest read on momentum this dataset supports on a single trope — see the demand radar for a cross-trope momentum comparison.
Whodunit is the classic-form mystery promise: a closed set of suspects, a fair-play puzzle, and a solution the reader could theoretically have reached first if they'd paid close enough attention. It's the structural backbone the rest of mystery riffs on — cozy softens it, thriller speeds it up, noir darkens it — but the pure form still has its own dedicated audience.
Demand for it runs steady rather than spiky, which is typical of a structural trope versus a trend-driven one. Tropesmith classifies it "balanced": meaningful tagged supply already exists, so the opportunity here is less "nobody's writing this" and more finding the specific angle — setting, sleuth archetype, era — that isn't already crowded.
Supply and demand are both substantial for this trope; the opportunity is in a specific angle or pairing, not the trope's existence.
Demand tells you what readers want written. Rejection tells you how they'll punish it if you get the execution wrong. Tropesmith mines 1–2★ Goodreads reviews for the specific reason a reader gave up, then classifies it against a fixed list of dealbreaker patterns:
Read the three numbers above together, not separately. 27,522 requests tells you the trope is wanted at real scale; 100% underserved tells you how much of that want has no matching tagged supply yet; and the 13% recent-request share tells you whether that gap is closing or holding steady right now. A high request count with low underserved means the trope is proven but the shelf has largely caught up — the opportunity is in a specific unclaimed angle, not the trope's bare existence. A high underserved figure means more room, but pair it with the rejection data above: readers punish weak execution of a trope they want just as fast as they ignore one they don't. The full methodology page walks through all four core numbers Tropesmith surfaces and how they interact.
Tropesmith logs 27,522 individual reader requests for whodunit, 3,452 of them in the last 14 days alone — a 13% share, which is the closest thing to a velocity read the engine gives on a single trope.
Tropesmith flags 100% of tracked demand for whodunit as unmet by current tagged supply. Its market_state classification is "Balanced coverage": Supply and demand are both substantial for this trope; the opportunity is in a specific angle or pairing, not the trope's existence.
The most common dealbreaker Tropesmith mines from 1-2 star mystery reviews is "Poor Writing Quality", flagged in 100% of reviews naming a reason for Female Detectives & Sleuths.
A Tropesmith Map scores your exact trope stack on live demand versus supply — and names the gap you can own.
Build my Map → See a real sample Map first →Part of Tropesmith's romance market intelligence hub and free research tools. Demand and rejection figures are read-only snapshots of the live spine, refreshed on a weekly cadence.