Vol. I · No. 1 · MMXXVI
NextChapterBench A Benchmark of Literary Continuation
23 models · 10 items · 1 judge

The Standings → Claude Haiku 4.5 (no thinking)

Live run data

Anthropic

Claude Haiku 4.5 (no thinking)

no extended thinking · via Claude CLI · judged by Claude Sonnet 5 · not the setting shown on the standings; also run at thinking41.1

Results from run ‘first’: ten items, ten verdicts.

Claude Haiku 4.5 (no thinking) scores 46 on craft, 17 points below the field’s 63 and 47 points short of the authors themselves. Its shape differs from the field’s: relatively strong on momentum and sentence-level prose, relatively weak on restraint and folding the brief into the story. On the mechanical checks it kept to the brief’s word range on 4 of 10 items and leans on stock phrases more than most.

Headline 38.8 of 100 · compliance × craft
Compliance 84 of 100
Craft 46 of 100

The record: 10 items · 10 verdicts · 0 errors · 1,874 words on average · est. generation cost $0.13

Read the chapters in full

§ I

Craft by Dimension

Eight dimensions, each 0–100, averaged over ten items; the author’s real chapter was in the room every time.

Craft by dimension, 0–100 · judged by Sonnet 5 beside the author’s real chapter

Voice
48
Prose
49
Character
48
Scene
48
Integration
42
Momentum
50
Restraint
38
Specificity
46
0255075100
reader’s score, 0–100 · hollow tick: field average · filled tick: the authors themselves

The authors themselves average 93 on the five writing dimensions, the field 63, this model 46. Hover or focus a bar for the field and the authors on that dimension.

In plain words, item by item

The judge’s one-sentence best quality and worst flaw for each chapter, written for a general reader.


§ II

Per-Item Results

Headline, compliance and craft for each chapter, 0–100.

The same ten items in figures, with word counts.
Item Headline Compliance Craft Words
Red Harvest item 023 · after ch. 2 · Dashiell Hammett 44.395471,651
The Moonstone item 011 · after ch. 8 · Wilkie Collins 42.285502,407
The Secret Garden item 013 · after ch. 2 · Frances Hodgson Burnett 40.875541,393
The War of the Worlds item 006 · after ch. 1 · H. G. Wells 39.880501,884
Persuasion item 001 · after ch. 1 · Jane Austen 39.490442,068
The Mysterious Affair at Styles item 017 · after ch. 3 · Agatha Christie 39.280491,815
The Awakening item 016 · after ch. 7 · Kate Chopin 38.790431,493
Leave It to Psmith item 022 · after ch. 3 · P. G. Wodehouse 37.990422,873
The Sun Also Rises item 021 · after ch. 3 · Ernest Hemingway 36.285431,531
Dracula item 015 · after ch. 5 · Bram Stoker 30.070431,622

§ III

Length Against the Brief

Words written per item, against each brief’s maximum.

Word count per item vs. brief maximum · run ‘first’

words written brief maximum
Red Harvest
1,651
The Moonstone
2,407
The Secret Garden
1,393
The War of the Worlds
1,884
Persuasion
2,068
The Mysterious Affair at Styles
1,815
The Awakening
1,493
Leave It to Psmith
2,873
The Sun Also Rises
1,531
Dracula
1,622
08001,6002,4003,200
words; the ink tick marks each brief’s maximum

Four of ten items landed inside their brief’s word range. Leave It to Psmith ran over by 73 words.


§ IV

Worst Flaws, as Recorded

Each verdict names the chapter’s single worst flaw, with evidence. Quoted verbatim from run ‘first’.

The umbrella's whereabouts contradict themselves (Eve hands it to a porter in a taxi, then later is said to collect it from a cafe), and the interview is held by an invented stand-in named Waterbury instead of Lord Emsworth, who the story has already said would do the interviewing.

on Leave It to Psmith, item 022 · Claude Sonnet 5

Near the end, Poirot explains his whole theory about motive and a suspicious detail out loud in plain language, which makes him sound like he's narrating the plot rather than being the careful, tight-lipped detective from the books.

on The Mysterious Affair at Styles, item 017 · Claude Sonnet 5

The writing keeps stopping to spell out what things mean (what the note 'meant', what the ending 'thought about') instead of trusting the reader, which flattens the hard-boiled tone into something closer to a paraphrase of it.

on Red Harvest, item 023 · Claude Sonnet 5

The anonymous warning letter is overwrought and vague in a way that doesn't match the calm, everyday tone of the original, and a random mention of 'trouble at the jeweller's in York' is dropped in and never explained.

on The Moonstone, item 011 · Claude Sonnet 5

§ V

The Mechanical Docket

Automated screening results across the ten outputs.