NC Bench
Overview
About
Tests
Models
Model
Claude Sonnet 4.5
Test
N-Length Sentences
Scenario
Write sentences with 20 words each
Run ID
2026-02-08-01KGYZNTBV9TBENM659W92TW8H
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 Thornwood Affair The morning fog clung to Thornwood Manor like a shroud, obscuring the gardens where Lord Pemberton lay quite dead. Detective Sarah Chen arrived at precisely eight o'clock, her coat damp from the mist that refused to lift properly. The butler, Harrison, stood rigid by the entrance hall, his face pale as the marble columns flanking the doorway. "I discovered him at dawn, Detective," Harrison said, his voice trembling with emotion he struggled to carefully contain within. Lord Pemberton's body rested face-down in the rose garden, his evening clothes soaked through with morning dew and blood. A single champagne flute lay shattered nearby, its crystal fragments catching what little light penetrated the oppressive grey morning. The household staff gathered in nervous clusters, whispering anxiously about the events of last night's dinner party gone wrong. Lady Pemberton remained upstairs in her chambers, sedated by the family physician after her hysterical screaming woke the servants. Chen knelt beside the body, noting the distinctive bruising around the neck and the odd angle of the head. "Who was the last person to see Lord Pemberton alive?" she asked, surveying the faces of the assembled staff. Three people stepped forward simultaneously: the secretary, the gardener, and Lord Pemberton's own estranged daughter, Victoria, newly arrived from abroad.
created_at
"2026-02-08T15:59:48.134553+00:00"
Sunday, February 8th, 2026 at 3:59:48 PM GMT+00:00
model
"anthropic/claude-4.5-sonnet-20250929"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1569
moderation_latency
146
generation_time
7519
tokens_prompt
35
tokens_completion
278
native_tokens_prompt
44
native_tokens_completion
314
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
0.004842
router
(null)
provider_responses
0
id
"32a09c30-c556-42c5-ae65-ac184fb416d0"
status
200
is_byok
false
latency
1562
endpoint_id
"d8bee848-f020-454a-b2be-4a7ce868f99f"
provider_name
"Amazon Bedrock"
model_permaslug
"anthropic/claude-4.5-sonnet-20250929"
api_type
"completions"
id
"gen-1770566379-n0aRrAtqiqA2SC6dZ227"
upstream_id
"32a09c30-c556-42c5-ae65-ac184fb416d0"
total_cost
0.004842
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Amazon Bedrock"
Evaluation details
Result
Evaluator
Details
Meta Data
62.1565%
Matches word count
n/a
neededClean
false
sentences
12
wordCounts
0
4
1
19
2
19
3
19
4
19
5
20
6
19
7
19
8
19
9
19
10
19
11
20