NC Bench
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Run: 2026-02-17-01KHMQE6PAXCCHBY27NS2TA7ME
Run Details
Model:
Claude Opus 4.5
Test:
Bad Writing Habits
Scenario:
Thriller: chase through city streets
Duration:
57.2s
Cost:
$0.063210
Provider:
Anthropic
Model input
System
You are an expert novelist with a gift for vivid, immersive prose. You write in tight third-person limited point of view with a strong narrative voice. Your prose is clean, precise, and engaging — you favor strong verbs, concrete details, and natural-sounding dialogue. You will be given a story bible (codex) containing canonical details about characters, locations, items, and lore. Use these details to ground your writing in the established world. Stay consistent with the codex. Write only the prose of the scene. Do not include titles, chapter headings, markdown formatting, or any commentary before or after the scene.
User/Human
<codex> <character id="4416" name="Detective Harlow Quinn" aliases="Quinn, Detective Quinn, Harlow" pronouns="she/her" species="Human" storyRole="Antagonist"> <eyeColor>brown</eyeColor> <hair>closely cropped salt-and-pepper</hair> <height>5'9"</height> <age>41</age> <jawline>sharp jaw</jawline> <watch>worn leather watch on her left wrist</watch> <bearing>military precision</bearing> <description>A Metropolitan Police detective with 18 years of decorated service who suspects the clique is involved in criminal activity.</description> <backstory>She lost her partner, DS Morris, during a case three years ago under unexplained circumstances that had supernatural origins she doesn't yet understand.</backstory> </character> <character id="4417" name="Tomás Herrera" aliases="Tommy, Tomás, Herrera" pronouns="he/him" species="Human" storyRole="Support"> <eyeColor>warm brown</eyeColor> <hair>short curly dark brown</hair> <height>5'10"</height> <age>29</age> <skinTone>olive skin</skinTone> <scar>scar running along his left forearm from a knife attack</scar> <medallion>Saint Christopher medallion around his neck</medallion> <birthplace>Seville, Spain</birthplace> <description>A former paramedic who provides off-the-books medical care for the clique.</description> <backstory>Born in Seville, Spain. He moved to London to work for the NHS but lost his license after administering unauthorized treatments to supernatural patients.</backstory> </character> <location id="854" name="The Raven's Nest" aliases="the Nest, Raven, Silas' bar" realm="Earth"> <signColor>distinctive green neon sign above the entrance</signColor> <secretRoom>hidden back room accessible through a bookshelf, used for clandestine meetings</secretRoom> <description>A dimly lit bar in Soho, London. The walls are covered with old maps and black-and-white photographs.</description> </location> <location id="856" name="The Veil Market" aliases="Veil Market, the Market, underground market" realm="Earth"> <currentLocation>abandoned Tube station beneath Camden</currentLocation> <entryRequirement>bone token</entryRequirement> <schedule>moves locations every full moon</schedule> <description>A hidden supernatural black market that sells enchanted goods, banned alchemical substances, and information.</description> </location> </codex> Write a fully fleshed out scene of at least 1000 words in the thriller genre. A detective is pursuing a suspect through rain-soaked city streets at night. The chase takes them from the street level down into an underground market. The detective must decide whether to follow the suspect into unfamiliar and potentially dangerous territory. Use the codex entries above as your world reference for characters and setting. Only include the prose of the scene without any markdown or commentary.
Model response
Messages
Meta
AI
The rain came down in sheets, turning Soho's narrow streets into rivers of reflected neon. Detective Harlow Quinn's boots slapped against the wet pavement as she rounded the corner onto Frith Street, her eyes locked on the figure thirty meters ahead. Tomás Herrera. The man moved like someone who knew these streets intimately, ducking through alleys and cutting across traffic with the fluid ease of a local. Quinn's breath came in sharp bursts, her lungs burning against the cold November air. Eighteen years on the force had kept her fit, but Herrera was younger, faster, and apparently desperate enough to run despite the weather. The green neon glow of The Raven's Nest
flickered
past on her left—she'd been
watch
ing that bar for weeks now, certain it served as a meeting point for whatever network Herrera had gotten himself tangled up in. But she couldn't stop, couldn't pause to consider the implications of what she
was doing
out here alone, off the clock, chasing a man who technically wasn't wanted for anything concrete. She'd spotted him by accident. Or maybe not by accident at all. Quinn didn't believe in coincidences anymore, not since Morris. Herrera glanced back over his shoulder, his dark curly hair plastered to his forehead. In the strobing light of a passing taxi, she caught the panic in his warm brown eyes—the look of a man running from something far more frightening than a lone detective. That should have given her pause. It didn't. "Metropolitan Police!" she shouted, though the words
were swallowed
by the rain and the rumble of traffic. "Stop!" He didn't stop. If anything, he accelerated, his olive skin
gleaming
under the streetlights as he vaulted a row of rubbish bins and disappeared into a narrow passage between buildings. Quinn followed, her worn leather
watch
catching on the rough brick as she squeezed through the gap. The passage opened onto a small courtyard she'd never seen before, despite knowing this area like the back of her hand. A dead end, she thought—until Herrera dropped to his knees and wrenched open what looked like a storm drain cover. Quinn drew her weapon. "Herrera! Don't—" He dropped into the darkness without hesitation. The cover clanged shut behind him. She stood there for a moment, rain streaming down her face, staring at the rusted metal disc set into the concrete. Her training screamed at her to call for backup. To report her position, request support, follow procedure. But procedure had gotten Morris killed. Procedure had left a dozen questions unanswered and a case file stamped UNEXPLAINED that still haunted her dreams three years later. Quinn holstered her weapon and crouched beside the cover. Her fingers found the edge, slick with rain, and she pulled. It opened with a grinding shriek that set her teeth on edge. Below, a ladder descended into absolute darkness—no, not absolute. Somewhere far below, she could see a faint amber glow, like candlelight filtered through fog. The smart thing would be to walk away. To add this location to her notes, to come back with a team, to do this properly. But Herrera
was connected
to the same network she'd been investigating since Morris's death. The same whispered names, the same impossible evidence, the same trail that always
seemed to
vanish just when she got close. She descended. The ladder was old, its rungs rough with rust that bit into her palms. The shaft was narrow enough that her shoulders brushed the walls on either side, and the air grew warmer as she climbed down—warmer and thicker, carrying scents she couldn't quite identify. Something herbal. Something metallic. Something that reminded her, absurdly, of the incense her grandmother used to burn in the small shrine she kept in her bedroom closet. The ladder ended on a platform of corroded metal, overlooking a space that shouldn't exist. Quinn's breath caught in her throat. She stood at the edge of what had clearly once been a Tube station—she could see the curved walls, the tiled alcoves, the ghost of old advertisements still clinging to the ceramic surfaces. But the platform below had
been transformed
into something out of a fever dream. Stalls crowded every available space, their canopies a patchwork of moth-eaten
velvet
and oilcloth, their tables laden with objects that caught the firelight in ways that defied logic. The amber glow came from hundreds of lanterns suspended from the vaulted ceiling, their flames burning in colors she'd never seen fire produce—deep purple, vivid green, a blue so bright it hurt to look at directly. And the people. Dozens of them, moving between the stalls with an ease that suggested familiarity. Some looked ordinary enough—men and women in coats and scarves, haggling over prices, exchanging small packages. Others were... different. A woman with skin that
seemed to
shift between shades of grey and blue, like a living oil slick. A man whose shadow moved independently of his body, reaching out to touch merchandise he hadn't approached. A child—or something child-sized—with eyes that reflected the lantern light like a cat's. The Veil Market. She'd heard the name whispered in interrogation rooms, seen it scrawled in the margins of confiscated notebooks. A myth. A story criminals told each other. A place that supposedly moved every full moon, accessible only to those who knew the right people, carried the right tokens. It was real. Quinn pressed herself against the wall, her hand instinctively moving to her weapon. The platform she stood on
seemed to
be a kind of observation point, separated from the market floor by a rusted railing and a series of old service stairs. Below and to her left, she could see Herrera pushing through the crowd, his pace urgent but not panicked anymore. He
was heading
for a stall near the far end of the platform, where a hunched figure sat surrounded by glass jars filled with liquids that glowed with their own inner light. She could follow him. The stairs were right there, and the crowd was dense enough that she might be able to blend in if she moved
carefully
. But everything about this place screamed danger—not the familiar danger of armed suspects and dark alleys, but something deeper, something her body recognized even if her mind couldn't name it. The same feeling she'd had three years ago, standing in that warehouse in Whitechapel, looking at the symbol drawn in Morris's blood on the concrete floor. The same feeling she'd been chasing ever since. Quinn checked her weapon. Fifteen rounds in the magazine, one in the chamber. Her phone had no signal this far underground. No backup. No procedure. Just her and whatever truth lay waiting at the bottom of those stairs. She thought of Morris. Of the way he'd laughed when she told him she didn't believe in the supernatural. Of the way his body had looked when they'd finally found it, three days after he'd gone in alone. Of the coroner's report that made no sense, the wounds that matched no known weapon, the expression frozen on his face that suggested he'd seen something in his final moments that defied comprehension. Quinn took a breath. Then another. Then she started down the stairs. The crowd didn't part for her so much as flow around her, conversations pausing mid-sentence as she passed, eyes tracking her progress with expressions ranging from curiosity to alarm. She kept her hand near her hip, her bearing straight, channeling the military precision her father had drilled into her during childhood. Look like you belong, and people will believe you do. It had worked in interrogation rooms and crime scenes. She had to hope it would work here. A hand caught her elbow. Quinn spun, her other hand closing around her weapon—but the figure who'd grabbed her raised both palms in a gesture of peace. An old woman, barely five feet tall, her face a map of wrinkles beneath a shawl that
seemed to
be woven from actual feathers. Around her neck hung a pendant that pulsed with a faint inner light, and her eyes—Quinn forced herself not to look away from those eyes, which held no whites, only a deep and swirling silver. "Bone token," the woman said. Her voice was dry as autumn leaves. "Show me your bone token, or leave." Quinn's mind raced. "I'm pursuing a suspect. A man who just—" "I don't care if you're pursuing the Devil himself." The old woman's grip tightened with surprising strength. "The Market has rules. Bone token, or you don't pass." Over the woman's shoulder, Quinn could see Herrera completing his transaction at the distant stall. He accepted a small package from the hunched figure, tucking it inside his jacket—his jacket, where she knew he kept the Saint Christopher medallion he never removed. Whatever he'd come for, he had it now. In moments, he'd be gone. "I don't have a token," Quinn said. The admission tasted like ash. "But that man—" "Then you don't belong here." The old woman's expression softened
slightly
, though her grip didn't loosen. "Go back, surface-dweller. Go back to your world of paperwork and procedure. What hunts in the dark is not for you to chase." "What hunts in the dark?" But the woman was already releasing her, already turning away, already disappearing into the crowd with a speed that belied her apparent age. Quinn stood frozen at the base of the stairs,
watch
ing as Herrera slipped through a gap in the far wall—another exit, another passage into the London underground, another trail going cold. She could push forward. Force her way through the crowd, damn the consequences. But the old woman's words
echoed
in her mind, mingling with the memory of Morris's final voicemail, the one she'd listened to a thousand times since his death. *Quinn, I found something. Something big. But listen—don't follow me, alright? Whatever happens, don't follow me down. Some doors aren't meant to be opened.* She'd followed anyway, three days too late. Now, standing in this impossible market beneath the streets of Camden, surrounded by things that couldn't exist, Quinn made her choice. Not the choice Morris would have wanted. Not the choice her training demanded. Not even the choice that might keep her safe. She stepped forward into the crowd. The hunt wasn't over. It was only beginning.
created_at
"2026-02-17T02:39:57.163537+00:00"
2/17/2026, 2:39:57 AM
model
"anthropic/claude-4.5-opus-20251124"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1206
moderation_latency
(null)
generation_time
56701
tokens_prompt
914
tokens_completion
2641
native_tokens_prompt
917
native_tokens_completion
2345
native_tokens_completion_images
(null)
native_tokens_reasoning
0
native_tokens_cached
0
num_media_prompt
(null)
num_input_audio_prompt
(null)
num_media_completion
0
num_search_results
(null)
origin
"https://ncbench.com/"
is_byok
false
finish_reason
"stop"
native_finish_reason
"stop"
usage
0.06321
router
(null)
provider_responses
0
id
"msg_016HW8MVRv83Ud5MtD3WGVkK"
status
200
is_byok
false
latency
1206
endpoint_id
"be883404-eb42-4b2d-b6e4-c7daa3aa8d62"
provider_name
"Anthropic"
model_permaslug
"anthropic/claude-4.5-opus-20251124"
api_type
"completions"
id
"gen-1771295939-yoKSzNUbeFzkfF1IrlUX"
upstream_id
"msg_016HW8MVRv83Ud5MtD3WGVkK"
total_cost
0.06321
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Anthropic"
Evaluation details
Result
Evaluator
Details
Meta Data
100.0000%
Adverbs in dialogue tags
Target: ≤10% dialogue tags with adverbs
totalTags
3
adverbTagCount
0
adverbTags
(empty)
88.4925%
AI-ism adverb frequency
Target: <1% AI-ism adverbs (57 tracked)
wordCount
1738
totalAiIsmAdverbs
2
found
0
adverb
"carefully"
count
1
1
adverb
"slightly"
count
1
highlights
0
"carefully"
1
"slightly"
100.0000%
AI-ism character names
Target: 0 AI-default names (17 tracked, −20% each)
codexExemptions
(empty)
found
(empty)
100.0000%
AI-ism location names
Target: 0 AI-default location names (33 tracked, −20% each)
codexExemptions
(empty)
found
(empty)
76.9850%
AI-ism word frequency
Target: <1% AI-ism words (140 tracked)
wordCount
1738
totalAiIsms
4
found
0
word
"flickered"
count
1
1
word
"gleaming"
count
1
2
word
"velvet"
count
1
3
word
"echoed"
count
1
highlights
0
"flickered"
1
"gleaming"
2
"velvet"
3
"echoed"
100.0000%
Cliche density
Target: ≤1 cliche(s) per 800-word window
totalCliches
0
maxInWindow
0
found
(empty)
highlights
(empty)
100.0000%
Emotion telling (show vs. tell)
Target: ≤3% sentences with emotion telling
emotionTells
0
narrationSentences
124
matches
(empty)
100.0000%
Filter word density
Target: ≤12% sentences with filter/hedge words
filterCount
1
hedgeCount
4
narrationSentences
124
filterMatches
0
"watch"
hedgeMatches
0
"seemed to"
100.0000%
Overuse of "that" (subordinate clause padding)
Target: ≤10% sentences with "that" clauses
thatCount
1
totalSentences
132
matches
0
"watching that bar"
100.0000%
Paragraph length variance
Target: CV ≥0.5 for paragraph word counts
totalParagraphs
43
mean
39.95
std
32.27
cv
0.808
sampleLengths
0
67
1
105
2
21
3
53
4
18
5
88
6
6
7
13
8
65
9
56
10
60
11
2
12
72
13
15
14
6
15
111
16
84
17
49
18
3
19
94
20
83
21
8
22
38
23
71
24
6
25
6
26
78
27
5
28
81
29
19
30
11
31
27
32
55
33
15
34
39
35
5
36
54
37
41
38
24
39
7
40
43
41
6
42
8
100.0000%
Passive voice overuse
Target: ≤5% passive sentences
passiveCount
3
totalSentences
124
matches
0
"were swallowed"
1
"was connected"
2
"been transformed"
100.0000%
Past progressive (was/were + -ing) overuse
Target: ≤10% past progressive verbs
pastProgressiveCount
2
totalVerbs
276
matches
0
"was doing"
1
"was heading"
100.0000%
Purple prose (modifier overload)
Target: <4% adverbs, <2% -ly adverbs, no adj stacking
wordCount
1655
adjectiveStacks
0
stackExamples
(empty)
adverbCount
52
adverbRatio
0.03141993957703928
lyAdverbCount
18
lyAdverbRatio
0.010876132930513595
100.0000%
Repeated phrase echo
Target: ≤20% sentences with echoes (window: 2)
totalSentences
132
echoCount
0
echoWords
(empty)
100.0000%
Sentence length variance
Target: CV ≥0.4 for sentence word counts
totalSentences
132
mean
13.02
std
9.61
cv
0.739
sampleLengths
0
15
1
26
2
2
3
24
4
14
5
23
6
37
7
31
8
5
9
7
10
9
11
14
12
31
13
6
14
2
15
17
16
1
17
3
18
27
19
17
20
21
21
20
22
4
23
2
24
7
25
6
26
21
27
9
28
8
29
6
30
21
31
9
32
11
33
12
34
9
35
15
36
8
37
17
38
14
39
21
40
2
41
14
42
31
43
2
44
2
45
23
46
15
47
6
48
33
49
14
47.9798%
Sentence opener variety
Target: ≥60% unique sentence openers
consecutiveRepeats
15
diversityRatio
0.3560606060606061
totalSentences
132
uniqueOpeners
47
91.6667%
Dialogue tag variety (said vs. fancy)
Target: ≤30% fancy dialogue tags
totalTags
3
fancyCount
1
fancyTags
0
"shouted (shout)"
94.4191%