NC Bench
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Run: 2026-02-20-01KHY9GN146VZCRXM7M6VJ4FT4
Run Details
Model:
Grok 4 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
4.3s
Cost:
$0.000284
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
0.23%
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 cobblestone streets of Victorian London on that fateful autumn evening. A lone gas lamp flickered weakly, casting eerie shadows on the alley's damp and uneven walls. Inspector Hargrove hurried along, his coat whipping in the chill wind that howled through the narrow pass. He'd received a urgent telegram about a grisly discovery in the heart of Whitechapel district now. Pushing open the creaking gate, he entered the modest townhouse where screams had echoed earlier tonight. Inside the parlor, candlelight revealed a scene of chaos with overturned furniture and shattered porcelain dolls. The victim, a prominent banker named Elias Thorne, lay sprawled across the Persian rug in silence. A single stab wound pierced his chest, blood staining the silk cravat he wore so proudly. Hargrove knelt beside the body, noting the absence of struggle marks or signs of forced entry here. Footsteps echoed from the hallway as the maid appeared, her face pale with unbridled terror. She whispered that she'd found him moments after the clock struck midnight in the empty house.
created_at
"2026-02-20T19:48:03.758Z"
2/20/2026, 7:48:03 PM
model
"x-ai/grok-4-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
2324
moderation_latency
(null)
generation_time
4069
tokens_prompt
46
tokens_completion
287
native_tokens_prompt
191
native_tokens_completion
548
native_tokens_completion_images
0
native_tokens_reasoning
321
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
0.0002837
router
(null)
provider_responses
0
endpoint_id
"c9586d9d-97ff-40ca-ae94-22504d6f9b7e"
id
"4890b64e-e6ac-c605-0cd5-ff258629e9a6"
is_byok
false
latency
427
model_permaslug
"x-ai/grok-4-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771616883-5U7cDlMrK4NpKKklrmw2"
upstream_id
"4890b64e-e6ac-c605-0cd5-ff258629e9a6"
total_cost
0.0002837
cache_discount
0.0000285
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
0.23%
Matches word count
n/a
neededClean
false
sentences
11
wordCounts
0
16
1
16
2
17
3
16
4
16
5
16
6
16
7
16
8
17
9
15
10
16