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Run: 2026-04-24-01KQ0P2MECVWBMXA2RA5C0K767
Run Details
Model:
GPT-5.5 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
18.6s
Cost:
$0.034285
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
Rain stitched silver threads across Blackthorn Manor as Inspector Vale arrived, finding every window blazing except the library's darkened one. Inside, a grandfather clock hammered midnight while servants whispered beside portraits whose painted eyes seemed freshly frightened by something unseen. Lord Ashbury lay sprawled over scattered telegrams, one gloved hand clutching a chess knight carved from ivory and stained scarlet. No blood marked his dinner jacket, yet the air smelled sharply of almonds, smoke, and extinguished candles after desperate prayer. Lady Ashbury stood motionless near the mantel, her pearls broken, her smile too careful for newly widowed grief tonight alone. When Vale asked who discovered him, three guests answered together, then stared at each other in sudden terror and silence. On the desk, beneath Ashbury's cold cheek, someone had written tomorrow's date in ink still glistening wet beside his name. Vale removed his hat slowly, because the locked door had been bolted from the inside with ceremonial precision and purpose.
created_at
"2026-04-24T21:24:33.874Z"
4/24/2026, 9:24:33 PM
model
"openai/gpt-5.5-20260423"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
17976
moderation_latency
(null)
generation_time
18349
tokens_prompt
46
tokens_completion
674
native_tokens_prompt
41
native_tokens_completion
1136
native_tokens_completion_images
0
native_tokens_reasoning
930
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
0.034285
router
(null)
provider_responses
0
endpoint_id
"58e5b336-423e-430b-a2ab-8bc353f0c51b"
id
"resp_0a6ea25039ca046c0169ebdf925bf481949dbcaf73fb88e90d"
is_byok
false
latency
997
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-1777065873-wtCUkKR6PKfEswJXHw2c"
session_id
(null)
api_type
"completions"
id
"gen-1777065873-rDnfxUo6vYEa3VWsteuF"
upstream_id
"resp_0a6ea25039ca046c0169ebdf925bf481949dbcaf73fb88e90d"
total_cost
0.034285
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