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

The Standings → Claude Haiku 4.5 (thinking)

Live run data

Anthropic

Claude Haiku 4.5 (thinking)

extended thinking · via Claude CLI · judged by Claude Sonnet 5 · the setting shown on the standings; also run at no thinking38.8

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

Claude Haiku 4.5 (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 character, relatively weak on restraint and period detail. On the mechanical checks it kept to the brief’s word range on 7 of 10 items and leans on stock phrases more than most.

Headline 41.1 of 100 · compliance × craft
Compliance 90 of 100
Craft 46 of 100

The record: 10 items · 10 verdicts · 0 errors · 1,997 words on average · est. generation cost $0.54

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
48
Character
48
Scene
47
Integration
44
Momentum
48
Restraint
40
Specificity
44
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
The Secret Garden item 013 · after ch. 2 · Frances Hodgson Burnett 54.095572,043
Persuasion item 001 · after ch. 1 · Jane Austen 48.695511,888
The Moonstone item 011 · after ch. 8 · Wilkie Collins 47.985562,633
The Awakening item 016 · after ch. 7 · Kate Chopin 42.090471,788
The War of the Worlds item 006 · after ch. 1 · H. G. Wells 39.9100402,085
The Mysterious Affair at Styles item 017 · after ch. 3 · Agatha Christie 38.985462,795
Leave It to Psmith item 022 · after ch. 3 · P. G. Wodehouse 37.880472,583
Red Harvest item 023 · after ch. 2 · Dashiell Hammett 36.195381,763
Dracula item 015 · after ch. 5 · Bram Stoker 33.880421,639
The Sun Also Rises item 021 · after ch. 3 · Ernest Hemingway 31.99036753

§ 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
The Secret Garden
2,043
Persuasion
1,888
The Moonstone
2,633
The Awakening
1,788
The War of the Worlds
2,085
The Mysterious Affair at Styles
2,795
Leave It to Psmith
2,583
Red Harvest
1,763
Dracula
1,639
The Sun Also Rises
753
08001,6002,4003,200
words; the ink tick marks each brief’s maximum

Seven of ten items landed inside their brief’s word range.


§ IV

Worst Flaws, as Recorded

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

Franklin's own account of the letter contradicts itself on timing ('reached me in London yesterday' versus the letter itself saying it 'came to my lodgings in town three days ago,' dated the same day as the story's events), and the chapter tells us the stakes directly instead of letting a scene carry them.

on The Moonstone, item 011 · Claude Sonnet 5

The narrator keeps stopping to explain exactly what Edna is feeling and why ("a kind of triumph that was almost fierce in its intensity"), so nothing is left for the reader to notice themselves, and it makes the writing sound modern rather than like 1899.

on The Awakening, item 016 · Claude Sonnet 5

Psmith already greets Eve by name ('Miss Halliday?') hours before the ending scene where he is supposed to just be hearing her name for the first time from Tuppy, so the planned final beat doesn't actually make sense within the chapter's own timeline.

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

It keeps telling us characters' feelings outright (fear, racing hearts, chills) instead of letting their actions show it, and the final exchange between Poirot and Hastings is just confusing rather than intriguingly mysterious.

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

§ V

The Mechanical Docket

Automated screening results across the ten outputs.