NC Bench
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Run: 2026-02-16-01KHK9G5F7Z8ST1581HA0YJNTG
Run Details
Model:
GPT-5.1
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
26.1s
Cost:
$0.013571
Provider:
OpenAI
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
Rain hammered the old station roof as Detective Mara Quinn stepped onto Platform Three, coat dripping, eyes already narrowing suspiciously. The overnight train from Norbridge waited shuddering, doors ajar, its windows glowing pale green against the bruised morning sky above. Somewhere along its twelve carriages, a conductor had found a man slumped alone in first class, unnaturally still and silent. Mara noted the clustered uniforms, their radios hissing nervously, passengers craning from doorways like gulls scenting blood on water below. She moved toward Carriage D, shoes squeaking on wet concrete, every step measured, building a rhythm against gathering whispers behind. Sergeant Lewis met her at the doorway, face grey, thumb worrying his notepad spiral until paper strands curled like shavings. He whispered that no one had entered or left the compartment since discovery, yet the window remained bolted from within. Inside, the carriage smelled of stale perfume and metal, and the dead man sat upright, smiling faintly at nothing nearby.
created_at
"2026-02-16T13:16:35.477939+00:00"
2/16/2026, 1:16:35 PM
model
"openai/gpt-5.1-20251113"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
5775
moderation_latency
(null)
generation_time
25870
tokens_prompt
46
tokens_completion
1055
native_tokens_prompt
41
native_tokens_completion
1352
native_tokens_completion_images
0
native_tokens_reasoning
1129
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
"completed"
usage
0.01357125
router
(null)
provider_responses
0
id
"resp_070e559a5b3a29c7016993189925648197b019a17ecb038a94"
status
200
is_byok
false
latency
145
endpoint_id
"764eb97f-8bab-4326-b29b-7a8799b00a70"
provider_name
"OpenAI"
model_permaslug
"openai/gpt-5.1-20251113"
api_type
"completions"
id
"gen-1771247769-b9iYOraAwPOAJjbSaD9G"
upstream_id
"resp_070e559a5b3a29c7016993189925648197b019a17ecb038a94"
total_cost
0.01357125
cache_discount
(null)
upstream_inference_cost
0
provider_name
"OpenAI"
Evaluation details
Result
Evaluator
Details
Meta Data
100.0000%
Matches word count
n/a
neededClean
false
sentences
8
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20
6
20
7
20