NC Bench
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Run: 2026-02-20-01KHY944XE1DR4MQVCCYJSD9TS
Run Details
Model:
Grok 4 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
3.7s
Cost:
$0.000264
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
0.57%
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 thickly to the ancient cobblestone streets of Victorian London on that fateful autumn night. A single gas lamp flickered weakly outside the grand home of wealthy industrialist Sir Reginald Thorne. Inside the opulent drawing room, crystal glasses and fine cigars lay scattered across the polished oak table. Sir Reginald's loyal butler, Mr. Hargrove, discovered his master's lifeless body slumped in the velvet armchair. A pool of crimson blood spread slowly from a single stab wound piercing the old man's chest. The room's heavy curtains were drawn tight, blocking out the silvery glow of the full moon outside. No signs of forced entry marred the solid oak doors or the tall sash windows nearby. Footsteps echoed faintly in the upstairs hallway as family members stirred from their uneasy slumber. Detective Inspector Eliza Hawthorne arrived swiftly, her keen eyes scanning the scene for hidden clues. The air hung heavy with the metallic tang of blood mixed with expensive pipe tobacco's faint aroma.
created_at
"2026-02-20T19:41:14.039Z"
2/20/2026, 7:41:14 PM
model
"x-ai/grok-4-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
2091
moderation_latency
(null)
generation_time
3550
tokens_prompt
46
tokens_completion
266
native_tokens_prompt
191
native_tokens_completion
502
native_tokens_completion_images
0
native_tokens_reasoning
304
native_tokens_cached
166
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
0.0002643
router
(null)
provider_responses
0
endpoint_id
"c9586d9d-97ff-40ca-ae94-22504d6f9b7e"
id
"1d0a13d8-1857-86ae-c5b0-73f29fdf72ea"
is_byok
false
latency
78
model_permaslug
"x-ai/grok-4-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771616474-QvIQ8h9UXdPITC5gj39a"
upstream_id
"1d0a13d8-1857-86ae-c5b0-73f29fdf72ea"
total_cost
0.0002643
cache_discount
0.0000249
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
0.57%
Matches word count
n/a
neededClean
false
sentences
10
wordCounts
0
17
1
16
2
17
3
16
4
17
5
17
6
16
7
15
8
15
9
17