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Run: 2026-04-24-01KQ0MV6GDJADNZ6SMGMA8GHJH
Run Details
Model:
GPT-5.5 (Reasoning, Low)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
17.6s
Cost:
$0.028855
Provider:
OpenAI
Evaluation summary
Score
Evaluator
Details Link
100.00%
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
At midnight, the bell above Blackthorn Manor's library door rang once, though everyone swore the house was empty that night. Inspector Vale found Lord Ashcombe seated beside the cold hearth, a silver letter opener buried beneath his ribs at dawn. Rain crawled down the tall windows, blurring the gardens where fresh footprints vanished into the yew maze before sunrise entirely. On the desk lay five teacups, four still warm, and one stained dark with bitter almond poison around its rim. His widow stood in the doorway without tears, twisting a pearl necklace until the clasp snapped open in her hands. Behind her, the nephew laughed too loudly, while the governess watched him with a face like thin paper in candlelight. Vale noticed mud on the Persian rug, smelling faintly of river silt and crushed greenhouse lilies near the corpse alone. Then the dead man's pocket watch chimed thirteen times, and someone upstairs began to scream his name again and again.
created_at
"2026-04-24T21:03:01.654Z"
4/24/2026, 9:03:01 PM
model
"openai/gpt-5.5-20260423"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
16189
moderation_latency
(null)
generation_time
17509
tokens_prompt
46
tokens_completion
253
native_tokens_prompt
41
native_tokens_completion
955
native_tokens_completion_images
0
native_tokens_reasoning
756
native_tokens_cached
0
num_media_prompt
(null)
num_input_audio_prompt
(null)
num_media_completion
0
num_search_results
(null)
num_fetches
(null)
web_search_engine
(null)
origin
"https://ncbench.com/"
is_byok
false
finish_reason
"stop"
native_finish_reason
"completed"
usage
0.028855
router
(null)
provider_responses
0
endpoint_id
"58e5b336-423e-430b-a2ab-8bc353f0c51b"
id
"resp_0508d58ff1d7e14a0169ebda85baf88196861d1893bea263be"
is_byok
false
latency
313
model_permaslug
"openai/gpt-5.5-20260423"
provider_name
"OpenAI"
status
200
user_agent
"langchainjs-openai/1.0.0 ((node/v24.14.1; linux; x64))"
http_referer
(null)
request_id
"req-1777064581-xTa9gz2SwJKdSHSDudHj"
session_id
(null)
api_type
"completions"
id
"gen-1777064581-NtouPYpICCQK2AMIxRxy"
upstream_id
"resp_0508d58ff1d7e14a0169ebda85baf88196861d1893bea263be"
total_cost
0.028855
cache_discount
(null)
upstream_inference_cost
0
provider_name
"OpenAI"
response_cache_source_id
(null)
Evaluation details
Result
Evaluator
Details
Meta Data
100.00%
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