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

The Standings → Claude Opus 5.5 (xhigh)

Live run data

Anthropic

3

Claude Opus 5.5 (xhigh)

xhigh reasoning effort · via Claude CLI · judged by Claude Sonnet 5 · the setting shown on the standings; also run at medium75.2 high74.9

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

Claude Opus 5.5 (xhigh) scores 77 on craft, 14 points above the field’s 63 and 16 points short of the authors themselves. Its shape differs from the field’s: relatively strong on restraint and folding the brief into the story, relatively weak on momentum. On the mechanical checks it kept to the brief’s word range on 8 of 10 items.

Headline 77.4 of 100 · compliance × craft
Compliance 100 of 100
Craft 77 of 100

The record: 10 items · 10 verdicts · 0 errors · 2,293 words on average · est. generation cost $5.12

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
78
Prose
78
Character
76
Scene
77
Integration
77
Momentum
76
Restraint
78
Specificity
79
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 77. 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 85.6100862,419
Persuasion item 001 · after ch. 1 · Jane Austen 81.8100822,297
The Mysterious Affair at Styles item 017 · after ch. 3 · Agatha Christie 80.6100812,484
The Moonstone item 011 · after ch. 8 · Wilkie Collins 79.9100802,668
Leave It to Psmith item 022 · after ch. 3 · P. G. Wodehouse 79.8100802,362
Dracula item 015 · after ch. 5 · Bram Stoker 77.5100782,361
The War of the Worlds item 006 · after ch. 1 · H. G. Wells 74.4100742,638
The Awakening item 016 · after ch. 7 · Kate Chopin 74.4100741,668
Red Harvest item 023 · after ch. 2 · Dashiell Hammett 74.1100742,042
The Sun Also Rises item 021 · after ch. 3 · Ernest Hemingway 66.4100661,987

§ 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
2,419
Persuasion
2,297
The Mysterious Affair at Styles
2,484
The Moonstone
2,668
Leave It to Psmith
2,362
Dracula
2,361
The War of the Worlds
2,638
The Awakening
1,668
Red Harvest
2,042
The Sun Also Rises
1,987
08001,6002,4003,200
words; the ink tick marks each brief’s maximum

Eight of ten items landed inside their brief’s word range. The Secret Garden and The War of the Worlds ran over by 19 and 38 words respectively.


§ IV

Worst Flaws, as Recorded

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

During Poirot's long room search the chapter switches into a quick list of actions ('He took measurements, and lay flat upon the floor... He examined the washstand') instead of staying in scene, so a couple of hours go by as summary rather than drama.

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

Splitting the letter into a separate short scene after the library meeting breaks the momentum built up by the tenant-word confrontation, so the chapter ends on a slightly quieter note than it could.

on Persuasion, item 001 · Claude Sonnet 5

The chapter jumps from 5 June straight to 10 July with nothing in between, so the middle goes slack and the reader loses a month of the Jonathan worry the chapter is supposed to be building.

on Dracula, item 015 · Claude Sonnet 5

The wife's line 'I do not like it. I cannot tell you why' is a stock foreboding cliche that tells us she's uneasy instead of showing it the way the rest of the chapter otherwise does.

on The War of the Worlds, item 006 · Claude Sonnet 5

§ V

The Mechanical Docket

Automated screening results across the ten outputs.