NC Bench
Overview
About
Tests
Models
Vendors
Run: 2026-02-16-01KHKB2TF8S8HRZRNVYKE110Z9
Run Details
Model:
GPT-5.1
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
25.9s
Cost:
$0.019221
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 station roof as the last train wheezed away, abandoning Platform Three to flickering fluorescent ghosts that lingered. Detective Mara Iwasaki watched reflections jitter across puddles, counting footsteps behind her that stubbornly refused matching numbers in the dark. The call had mentioned a body on the tracks, but dispatch's voice carried something heavier than ordinary midnight tragedy tonight. Two uniformed officers waited near the edge, their breath steaming upward like offerings as trains howled unseen through neighboring tunnels. Floodlights bleached the gravel, revealing a man's body sprawled between rails, umbrella still folded neatly beside gloved, bloodless fingers there. No train was scheduled for hours, yet his crushed ribs suggested steel and speed, while immaculate shoes contradicted any desperation. Mara crouched, noticing tiny black crescents beneath his nails, each rimmed with glittering quartz dust that did not belong here. When she rolled him gently, the station clock chimed midnight, and everyone saw his throat was missing an apology entirely.
created_at
"2026-02-16T13:44:15.46626+00:00"
2/16/2026, 1:44:15 PM
model
"openai/gpt-5.1-20251113"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
12233
moderation_latency
(null)
generation_time
25753
tokens_prompt
46
tokens_completion
947
native_tokens_prompt
41
native_tokens_completion
1917
native_tokens_completion_images
0
native_tokens_reasoning
1699
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
0.01922125
router
(null)
provider_responses
0
id
"resp_04d58f781b53b4590169931f150b7c8197aa4c7b7cf77a3762"
status
200
is_byok
false
latency
146
endpoint_id
"764eb97f-8bab-4326-b29b-7a8799b00a70"
provider_name
"OpenAI"
model_permaslug
"openai/gpt-5.1-20251113"
api_type
"completions"
id
"gen-1771249428-nmOyR0XbWsewSLUZ9IV1"
upstream_id
"resp_04d58f781b53b4590169931f150b7c8197aa4c7b7cf77a3762"
total_cost
0.01922125
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