NC Bench
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Run: 2026-02-18-01KHQ9280B2C5W3YJ3Z1VA8HFR
Run Details
Model:
Claude Sonnet 4.6
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
6.0s
Cost:
$0.003477
Provider:
Amazon Bedrock
Evaluation summary
Score
Evaluator
Details Link
77.28%
Matches word count
(details)
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 old lighthouse stood alone at the edge of town, its broken light casting shadows across the wet sand. Detective Sara Voss arrived at the scene just before midnight, her boots sinking slowly into the cold mud. A body had been found face down near the rocks, one pale hand reaching toward the churning black water. She pulled out her flashlight and swept the beam across the ground, searching carefully for anything the killer left behind. The victim was a man, well dressed, perhaps fifty years old, with no wallet and no identification on him. Her partner, Grady, knelt beside the body and shook his head slowly, whispering that this felt deeply personal to him. The rain began falling harder now, threatening to wash away every last trace of evidence scattered along the shoreline tonight. Sara looked up at the lighthouse and noticed a single candle burning in the highest window, flickering against the glass. Someone had been watching, she was certain of it, and somewhere in this dark town they were still watching now.
created_at
"2026-02-18T02:25:37.140182+00:00"
2/18/2026, 2:25:37 AM
model
"anthropic/claude-4.6-sonnet-20260217"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
599
moderation_latency
164
generation_time
5763
tokens_prompt
46
tokens_completion
271
native_tokens_prompt
44
native_tokens_completion
223
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
0.003477
router
(null)
provider_responses
0
id
"425b2428-420d-4ae6-ac12-2059e4765dbe"
status
200
is_byok
false
latency
599
endpoint_id
"83d802cb-44f2-45a0-a9d5-cb9bf79777c8"
provider_name
"Amazon Bedrock"
model_permaslug
"anthropic/claude-4.6-sonnet-20260217"
api_type
"completions"
id
"gen-1771381530-315OjKk6nGwPytvUQTxS"
upstream_id
"425b2428-420d-4ae6-ac12-2059e4765dbe"
total_cost
0.003477
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Amazon Bedrock"
Evaluation details
Result
Evaluator
Details
Meta Data
77.28%
Matches word count
n/a
neededClean
false
sentences
9
wordCounts
0
19
1
18
2
19
3
20
4
19
5
20
6
20
7
20
8
20