NC Bench
Overview
About
Tests
Models
Model
Claude Sonnet 4.5
Test
N-Length Sentences
Scenario
Write sentences with 20 words each
Run ID
2026-02-08-01KGYZXK5NCAVDSSK9X3A03RJV
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 rain hammered against the library windows as Detective Sarah Chen studied the body sprawled across the Persian rug below. Lord Ashworth lay face down, a silver letter opener protruding from between his shoulder blades, blood pooling beneath him. The grandfather clock in the corner struck midnight, its chimes echoing through the room where death had visited tonight. Six dinner guests stood frozen in the doorway, their faces pale with shock, each one a potential suspect now. Sarah pulled on her latex gloves and knelt beside the victim, noting the expensive cologne still lingering in the air. "Nobody leaves this manor," she announced firmly, her voice cutting through the tension like the blade that killed him. The butler wrung his hands nervously, his starched collar now askew, sweat beading on his forehead despite the cold. Outside, lightning illuminated the estate grounds, revealing no escape routes through the storm that trapped them all here together. Sarah knew that somewhere among these frightened faces hid a killer, and she had until dawn to find them.
created_at
"2026-02-08T16:04:02.789641+00:00"
Sunday, February 8th, 2026 at 4:04:02 PM GMT+00:00
model
"anthropic/claude-4.5-sonnet-20250929"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
2621
moderation_latency
201
generation_time
7118
tokens_prompt
35
tokens_completion
209
native_tokens_prompt
44
native_tokens_completion
232
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
0.003612
router
(null)
provider_responses
0
id
"5937a442-d471-4b1f-b182-dfdad4a6c19c"
status
200
is_byok
false
latency
2620
endpoint_id
"d8bee848-f020-454a-b2be-4a7ce868f99f"
provider_name
"Amazon Bedrock"
model_permaslug
"anthropic/claude-4.5-sonnet-20250929"
api_type
"completions"
id
"gen-1770566634-qXdhtcp0NjKAyL0Ob1kS"
upstream_id
"5937a442-d471-4b1f-b182-dfdad4a6c19c"
total_cost
0.003612
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Amazon Bedrock"
Evaluation details
Result
Evaluator
Details
Meta Data
69.3968%
Matches word count
n/a
neededClean
false
sentences
9
wordCounts
0
20
1
19
2
19
3
19
4
20
5
19
6
19
7
19
8
19