NC Bench
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Run: 2026-02-20-01KHY843K98Y2E6TK4MHTDBSSB
Run Details
Model:
Grok 4.1 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
6.2s
Cost:
$0.000374
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
14.76%
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
Fog shrouded Blackwood Manor on the stormy moor where ten guests gathered for a lavish dinner party tonight. Lightning flashed across the sky as thunder rumbled, casting eerie shadows through the tall mullioned windows inside. Host Edgar Blackwood raised his glass to toast the group's success in their secretive business ventures together. Suddenly, a piercing scream echoed from the library, shattering the tense atmosphere of polite conversation and clinking glasses. Guests rushed toward the heavy oak door, hearts pounding with dread at the unknown horror awaiting them there. Pushing it open, they found Edgar sprawled lifeless on the Persian rug, blood pooling beneath his head. A sharp letter opener lay clutched in his stiff hand, but the wound gaped wide from behind his skull. Constable Hale arrived swiftly through the gale, his raincoat dripping as he surveyed the gruesome scene before him.
created_at
"2026-02-20T19:23:44.115Z"
2/20/2026, 7:23:44 PM
model
"x-ai/grok-4.1-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
268
moderation_latency
(null)
generation_time
6116
tokens_prompt
46
tokens_completion
317
native_tokens_prompt
191
native_tokens_completion
716
native_tokens_completion_images
0
native_tokens_reasoning
541
native_tokens_cached
151
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
0.00037355
router
(null)
provider_responses
0
endpoint_id
"9821aa0e-dce3-4c27-9716-161359123d0b"
id
"a62ceee2-d6bd-d7e9-f436-009bc4275050"
is_byok
false
latency
73
model_permaslug
"x-ai/grok-4.1-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771615424-5pzt2fJ6O0Tq3ZAqa4DY"
upstream_id
"a62ceee2-d6bd-d7e9-f436-009bc4275050"
total_cost
0.00037355
cache_discount
0.00002265
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
14.76%
Matches word count
n/a
neededClean
false
sentences
8
wordCounts
0
18
1
17
2
17
3
18
4
18
5
17
6
19
7
18