NC Bench
Overview
About
Tests
Models
Model
Claude Sonnet 4.5
Test
N-Length Sentences
Scenario
Write sentences with 20 words each
Run ID
2026-02-08-01KGYZK9XWSPEJWFNN1KNB8SS0
Model input
User/Human
Please write the opening scene of a murder mystery where each sentence has exactly 20 words. Please make sure that each sentence has the same length. Only return the opening itself.
Model response
Messages
Meta
AI
The body lay sprawled across the mahogany desk, blood pooling beneath the chairman's silver hair in the moonlight shining through windows. Detective Sarah Chen arrived at precisely midnight, her badge glinting as she stepped over the yellow tape into the crime scene. "Victim is Robert Ashford, aged sixty-three, founder of Ashford Industries," Officer Martinez reported, consulting his notes with a grim expression on his face. The murder weapon, an ornate letter opener, rested nearby on the Persian rug, its blade still glistening with fresh crimson blood. "No signs of forced entry," Sarah observed, studying the locked windows and sealed doors with her practiced eye, noting every detail carefully. Three champagne glasses sat on the sideboard, two empty and one half-full, suggesting the victim had entertained guests before his death. The office safe stood open behind a painting, its contents apparently undisturbed despite the violence that had occurred just feet away tonight. "His secretary found him an hour ago when she returned for forgotten files," Martinez added, flipping through pages of notes. Sarah knelt beside the body, noticing defensive wounds on Ashford's hands and a peculiar expression frozen on his dying face forever. "Get me a list of everyone with building access tonight," she commanded, her mind already racing through possible suspects and motives.
created_at
"2026-02-08T15:58:25.079672+00:00"
Sunday, February 8th, 2026 at 3:58:25 PM GMT+00:00
model
"anthropic/claude-4.5-sonnet-20250929"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1531
moderation_latency
150
generation_time
7036
tokens_prompt
35
tokens_completion
266
native_tokens_prompt
44
native_tokens_completion
297
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
0.004587
router
(null)
provider_responses
0
id
"3574c60d-6bff-4601-bfd0-fbb1286a1021"
status
200
is_byok
false
latency
1526
endpoint_id
"d8bee848-f020-454a-b2be-4a7ce868f99f"
provider_name
"Amazon Bedrock"
model_permaslug
"anthropic/claude-4.5-sonnet-20250929"
api_type
"completions"
id
"gen-1770566297-N6tSJhc26EjcJsH1qexa"
upstream_id
"3574c60d-6bff-4601-bfd0-fbb1286a1021"
total_cost
0.004587
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Amazon Bedrock"
Evaluation details
Result
Evaluator
Details
Meta Data
44.3899%
Matches word count
n/a
neededClean
false
sentences
10
wordCounts
0
21
1
21
2
24
3
21
4
22
5
22
6
22
7
20
8
21
9
21