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Run: 2026-04-24-01KQ0MR5YTN4GBY6NKC6DQK7YA
Run Details
Model:
GPT-5.5 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
16.5s
Cost:
$0.037165
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 grandfather clock stopped, and every guest in Blackthorn Hall turned toward the library doors in sudden silence. Behind them, rain hammered the windows, hiding the scrape of something heavy dragged across the marble floor outside the study. Inspector Vale arrived late, coat dripping, eyes fixed on the single bloody fingerprint staining the silver handle before anyone spoke. No one admitted hearing the shot, though Lord Blackthorn lay dead beside a pistol still warm on the carpet there. His daughter clutched a torn invitation, while the vicar whispered prayers that sounded suspiciously like apologies for old sins tonight. In the hearth, a charred letter curled inward, protecting one name from the flames as if alive and ashamed there. Vale noticed mud on the duchess's shoes, fresh grave soil, though she claimed never leaving dinner during the storm alone. Then the corpse's pocket watch chimed once, and someone hidden behind the curtains began to laugh very softly at last.
created_at
"2026-04-24T21:01:22.792Z"
4/24/2026, 9:01:22 PM
model
"openai/gpt-5.5-20260423"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
15233
moderation_latency
(null)
generation_time
16237
tokens_prompt
46
tokens_completion
550
native_tokens_prompt
41
native_tokens_completion
1232
native_tokens_completion_images
0
native_tokens_reasoning
1034
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
0.037165
router
(null)
provider_responses
0
endpoint_id
"58e5b336-423e-430b-a2ab-8bc353f0c51b"
id
"resp_0bcf7f663b0b0f5a0169ebda22e7b481958bcd148ec085d852"
is_byok
false
latency
258
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-1777064482-EyrQe68lZ0jHQvhQI8Py"
session_id
(null)
api_type
"completions"
id
"gen-1777064482-CMxcIB7Ii25MXtxscq5H"
upstream_id
"resp_0bcf7f663b0b0f5a0169ebda22e7b481958bcd148ec085d852"
total_cost
0.037165
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