NC Bench
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Run: 2026-02-20-01KHY9PPYM4A0FZVK74QXRJZDH
Run Details
Model:
Grok 4 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
2.1s
Cost:
$0.000228
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
16.42%
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
The fog clung to the cobblestone streets like a shroud on that moonless autumn night in Victorian London. Inspector Hargrove stepped from his carriage, his boots splashing in puddles that mirrored gaslight flames flickering nearby. He had been summoned urgently by a frantic telegram from the reclusive widow at Elmwood Manor. The wrought-iron gates creaked open, revealing a path lined with skeletal trees whispering secrets in the wind. As he approached the grand oak door, a butler appeared, his face pale and etched with unspoken dread. "Inspector, the master of the house lies dead in the library, foul play is evident," the butler stammered quickly. Hargrove nodded gravely, pushing past into the dimly lit foyer where shadows danced like accusing specters. The air was thick with the scent of cigar smoke and something metallic, sharp, and disturbingly familiar. He entered the library, where bookshelves towered like silent witnesses to the unfolding tragedy within. There, slumped over his desk, was Lord Harrington, a crimson pool spreading from a fatal wound in his chest.
created_at
"2026-02-20T19:51:22.334Z"
2/20/2026, 7:51:22 PM
model
"x-ai/grok-4-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1075
moderation_latency
(null)
generation_time
1939
tokens_prompt
46
tokens_completion
282
native_tokens_prompt
191
native_tokens_completion
437
native_tokens_completion_images
0
native_tokens_reasoning
215
native_tokens_cached
190
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
0.0002282
router
(null)
provider_responses
0
endpoint_id
"c9586d9d-97ff-40ca-ae94-22504d6f9b7e"
id
"6acb43c3-eeaf-257e-94f1-59d5ad86a632"
is_byok
false
latency
101
model_permaslug
"x-ai/grok-4-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771617082-qrrX3w52uJ2cYt7L27YO"
upstream_id
"6acb43c3-eeaf-257e-94f1-59d5ad86a632"
total_cost
0.0002282
cache_discount
0.0000285
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
16.42%
Matches word count
n/a
neededClean
false
sentences
10
wordCounts
0
18
1
17
2
16
3
18
4
18
5
19
6
16
7
17
8
15
9
19