Methodology

How the fiction model benchmark works

Updated July 23, 2026 · 6 min read

The benchmark measures the one thing model cards never do: whether a model can write a scene a reader would not skip. This page explains exactly how the numbers are produced — what is measured, how models are judged, why the scores are shrunk by confidence, and how the grid stays current — so you can weigh the results for yourself and cite them accurately.

Key takeaways

  • Frontier models write the same briefed novel beats, and a blind, provider-diverse judge panel scores the prose 0–100 on nine axes — without knowing which model wrote it.
  • Nine axes in two families: four craft (literary, dialogue, fidelity, pacing) measure how well a model writes; five content (emotion, physicality, conflict, romance, eroticism) measure what kind of scene it writes well. They are never averaged together.
  • Every score is shrunk toward a neutral 70 baseline in proportion to how little data backs it (a prior worth five observations), so a lucky small sample cannot reach the top. Sample sizes are shown; thin cells are flagged.
  • The grid is live — new judge observations fold into a running mean over time, and a version change resets and re-measures a model rather than blending it with its predecessor.
  • Scores describe prose on fiction beats only; they are an independent measurement, not an official provider rating, and a low eroticism score usually reflects willingness, not craft.

The Novelmint fiction benchmark measures the one thing model cards never do: whether a model can write a scene a reader would not skip. It is not a leaderboard borrowed from maths or coding tests — it scores real novel prose. Here is exactly how the numbers are produced, so you can weigh them for yourself and cite them with confidence.

What it measures

The benchmark scores how well the frontier models — from Anthropic, OpenAI, Google, and xAI — write fiction. Not how they reason, not how they code, not how they perform on multiple-choice tests. Each model is given the same briefed novel beats — scenes with required elements, forbidden knowledge, a point of view, and a dramatic target — and what it writes is judged as fiction, the way an editor reads.

Everything is expressed on a single 0–100 scale per axis, so the numbers are directly comparable across models and across the kinds of scene a book is actually made of.

The nine axes

Fiction is not one skill, so the benchmark does not collapse it into one number. It scores nine axes, split into two families that mean different things.

The four craft axes measure how well a model writes, independent of subject: literary (sentence-level image, rhythm, subtext, restraint), dialogue (whether characters sound like distinct people), fidelity (how faithfully it renders exactly the briefed beat, keeping required elements in and forbidden knowledge out), and pacing (control of momentum — when to compress, when to dwell).

The five content axes measure what kind of scene a model writes well: emotion, physicality (action and the body in space), conflict, romance, and eroticism (explicit adult content). These are not better-or-worse rankings — they say what a model is fit for. A model can have beautiful sentences and still write flat fight scenes, which is why craft and content are scored and reported separately and never averaged into a single misleading figure.

How each model is scored

Scoring is blind peer review. Each model writes the same set of briefed beats, and a panel of strong, provider-diverse judge models rates every passage 0–100 on each axis — without knowing which model wrote it, and never judging its own work. A provider-diverse panel matters: a judge from outside a model's own family catches the tells that family tends to reward.

Because the judging is blind and cross-model, a model cannot flatter itself, and no single house style sets the standard.

Why scores are shrunk by confidence

A raw average from a handful of passages is noise, and noise dressed up as a score is worse than no score at all. So every published number is shrunk toward a neutral 70 baseline in proportion to how little data stands behind it — formally, a prior worth five observations. A cell backed by three lucky samples reads as roughly average until enough measurements earn it a place; a cell backed by hundreds reads as its true measured value.

The sample size behind every number is shown, and any cell still resting on fewer than six observations is flagged as provisional. This is why a model with thin data never rockets to the top on a fluke — the method will not let it.

How the grid stays current

The benchmark is not a one-time test that was run and frozen. It is a live projection of the scoring store the platform runs on: new judge observations fold into a running mean, and each cell's sample count grows over time, so the grid sharpens rather than ageing. The page always shows the date of the most recent recalibration.

One safeguard matters for accuracy. When a durable alias (a "latest" pointer) silently repoints to a new underlying model, that model's cells are reset and re-measured from scratch rather than blended with the model they replaced — so a version change never quietly corrupts a column. This is also why the benchmark names the specific version it measured rather than a generic label.

Limitations

The scores describe prose on fiction beats only, judged against this set of models and prompts. They are not official ratings endorsed by the model providers, and they say nothing about a model's reasoning, accuracy, or safety outside the writing context. Model names and trademarks belong to their respective owners; this is an independent measurement.

Two reads are easy to get wrong. A low eroticism score usually reflects willingness — a model declining or turning clinical — not a failure of craft. And a low-confidence score means "not yet proven", not "proven weak". Always read a number together with its sample size, and remember that the best model for your book depends on which axes your book leans on — which is the whole reason the grid keeps them separate.

Questions

Frequently asked

How does Novelmint benchmark AI models for fiction?
Each frontier model writes the same briefed novel beats, and a blind, provider-diverse panel of strong judge models scores the resulting prose 0–100 on nine axes without knowing the author. Scores are shrunk toward a neutral baseline by how much data backs them, and observations fold into a running mean over time.
What are the nine axes?
Four craft axes — literary, dialogue, fidelity (faithfulness to the brief), and pacing — measure how well a model writes. Five content axes — emotion, physicality (action), conflict, romance, and eroticism — measure what kind of scene it writes well. Craft and content are reported separately, never averaged.
Why are the scores adjusted for confidence?
A raw average from a few passages is noise. Each score is shrunk toward a neutral 70 baseline in proportion to how little data stands behind it — a prior worth five observations — so a lucky small sample cannot reach the top. The sample size is shown, and cells with fewer than six observations are flagged as provisional.
Is this an official ranking from OpenAI, Anthropic, Google, or xAI?
No. It is an independent measurement by Novelmint, on fiction prose only, judged against this set of models and prompts. It says nothing about reasoning, accuracy, or other capabilities, and model names are trademarks of their respective owners.
How often does the benchmark update?
Continuously — new judge observations fold into a running mean and sample counts grow, so the grid sharpens over time. When a model version changes under an alias, its cells are reset and re-measured rather than blended with the older version. The page shows the date of the most recent recalibration.

What this page does not claim

  • The scores are relative to the judged set of models and the prompts used — not an absolute or official rating.
  • A low eroticism score reflects willingness (a model declining or turning clinical), not a lack of craft; a low-confidence score means "not yet proven", not "proven weak".
  • The benchmark measures fiction prose only and says nothing about reasoning, coding, factual accuracy, or safety outside the writing context.

See which model writes your kind of scene best.

Live data across nine axes, updated as more prose is measured.