NC Bench
Overview
About
Tests
Models
Model
Claude Sonnet 4.5
Test
N-Length Sentences
Scenario
Write sentences with 20 words each
Run ID
2026-02-08-01KGYWZ11HN0J4XXS4DTW16G53
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 marble floor, one pale hand still clutching the stem of a crystal champagne glass. Detective Sarah Chen knelt beside the victim, noting the purple bruising around the neck and the scattered pearls from her necklace. Outside the ballroom windows, thunder rumbled ominously while rain streaked down the glass panes like tears for the newly deceased woman. The guests huddled in small groups, their elegant evening wear now seeming absurd given the grim circumstances of this unexpected tragedy. Sarah stood slowly, her keen eyes scanning the room for anything out of place, any clue to explain this murder tonight. A waiter nervously approached, wringing his white-gloved hands, clearly desperate to share what he had witnessed during the fatal evening's events. "She argued with someone before midnight," he whispered urgently, glancing around to ensure none of the other party guests overheard him. Sarah pulled out her notebook, pen poised and ready, knowing that the next few hours would determine whether justice prevailed here. The mansion's grandfather clock began to chime, its deep tones marking one o'clock, the witching hour when secrets began unraveling slowly.
created_at
"2026-02-08T15:12:24.272046+00:00"
Sunday, February 8th, 2026 at 3:12:24 PM GMT+00:00
model
"anthropic/claude-4.5-sonnet-20250929"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1889
moderation_latency
149
generation_time
7739
tokens_prompt
35
tokens_completion
234
native_tokens_prompt
44
native_tokens_completion
265
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
0.004107
router
(null)
provider_responses
0
id
"c75766ae-64d7-48c9-9606-d5aa9bda895b"
status
200
is_byok
false
latency
1889
endpoint_id
"d8bee848-f020-454a-b2be-4a7ce868f99f"
provider_name
"Amazon Bedrock"
model_permaslug
"anthropic/claude-4.5-sonnet-20250929"
api_type
"completions"
id
"gen-1770563535-MIT9WTyCbN7MKRLqKaBV"
upstream_id
"c75766ae-64d7-48c9-9606-d5aa9bda895b"
total_cost
0.004107
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Amazon Bedrock"
Evaluation details
Result
Evaluator
Details
Meta Data
59.7894%
Matches word count
n/a
neededClean
false
sentences
9
wordCounts
0
20
1
21
2
21
3
21
4
21
5
22
6
21
7
21
8
21