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

The Standings → Claude Sonnet 5 (high)

Live run data

Anthropic

Claude Sonnet 5 (high)

high reasoning effort · via Claude CLI · judged by Claude Sonnet 5 · the setting shown on the standings; also run at xhigh60.4 medium60.0 low55.9

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

Claude Sonnet 5 (high) scores 65 on craft, 2 points above the field’s 63 and 28 points short of the authors themselves. Its shape differs from the field’s: relatively strong on the author’s voice and restraint, relatively weak on building scenes. On the mechanical checks it kept to the brief’s word range on 7 of 10 items, reproduced a 29-word run of the real book verbatim and leans on stock phrases more than most.

Headline 60.8 of 100 · compliance × craft
Compliance 94 of 100
Craft 65 of 100

The record: 10 items · 10 verdicts · 0 errors · 2,097 words on average · est. generation cost $0.37

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
68
Prose
66
Character
64
Scene
63
Integration
62
Momentum
64
Restraint
64
Specificity
65
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 65. 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 77.0100772,125
The Sun Also Rises item 021 · after ch. 3 · Ernest Hemingway 71.195751,769
Leave It to Psmith item 022 · after ch. 3 · P. G. Wodehouse 70.395742,938
Dracula item 015 · after ch. 5 · Bram Stoker 62.785741,506
The Moonstone item 011 · after ch. 8 · Wilkie Collins 59.495622,793
The Awakening item 016 · after ch. 7 · Kate Chopin 59.195621,420
Persuasion item 001 · after ch. 1 · Jane Austen 55.8100562,288
Red Harvest item 023 · after ch. 2 · Dashiell Hammett 52.690581,858
The Mysterious Affair at Styles item 017 · after ch. 3 · Agatha Christie 52.595552,163
The War of the Worlds item 006 · after ch. 1 · H. G. Wells 47.490532,109

§ 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
2,125
The Sun Also Rises
1,769
Leave It to Psmith
2,938
Dracula
1,506
The Moonstone
2,793
The Awakening
1,420
Persuasion
2,288
Red Harvest
1,858
The Mysterious Affair at Styles
2,163
The War of the Worlds
2,109
08001,6002,4003,200
words; the ink tick marks each brief’s maximum

Seven of ten items landed inside their brief’s word range. Leave It to Psmith ran over by 138 words.


§ IV

Worst Flaws, as Recorded

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

One sentence in the swimming scene ('A quick vision of death smote her soul') is lifted almost word for word from the real novel's later chapter instead of being the writer's own prose, and right after it the timeline gets muddled — a swim that starts around five o'clock somehow ends with the children already 'long asleep' by the time she gets home.

on The Awakening, item 016 · Claude Sonnet 5

It reads like a checklist of the required plot points ticked off in order, with little of the sly humor or verbal tics that make Poirot and Hastings feel alive, and the person who tips off Poirot is only a vague 'little page-boy' rather than someone the reader actually knows.

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

Jake's narration keeps explicitly spelling out his feelings ("it left me feeling exactly as though I had been hit, though nobody had touched me at all"), which tells the reader what to feel instead of trusting the scene the way this author does.

on The Sun Also Rises, item 021 · Claude Sonnet 5

Betteredge decides not to tell Franklin about the Indian jugglers, which undoes the setup's promise that he would tell him that same day and that Franklin would name the Moonstone, so a thread the reader was told to expect just gets dropped.

on The Moonstone, item 011 · Claude Sonnet 5

§ V

The Mechanical Docket

Automated screening results across the ten outputs.