NC Bench
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Run: 2026-02-20-01KHYAJ35S3B5926Z8DX67VV6R
Run Details
Model:
Grok 4.1 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 10 words each
Duration:
13.5s
Cost:
$0.000452
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
94.82%
Matches word count
(details)
Model input
User/Human
Please write the opening scene of a murder mystery where each sentence has exactly 10 words. Please make sure that each sentence has the same length. Only return the opening itself.
Model response
Messages
Meta
AI
The fog enveloped the mansion atop the lonely, windswept hill. Sir Reginald's body sprawled lifelessly across the study's Persian rug. A crimson pool spread slowly from the single fatal stab wound. Detective Harlan Black arrived swiftly at the chaotic crime scene. The butler trembled nearby, his face pale with obvious terror. Guests huddled fearfully in the drawing room down the hall. Lady Eleanor swooned dramatically upon the shocking, gruesome news report. A gleaming candlestick rested oddly on the mantelpiece by the fire. Footprints trailed suspiciously toward the rain-lashed French doors outside. Who plunged the blade into the heart of the host?
created_at
"2026-02-20T20:06:19.585Z"
2/20/2026, 8:06:19 PM
model
"x-ai/grok-4.1-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
266
moderation_latency
(null)
generation_time
13408
tokens_prompt
46
tokens_completion
226
native_tokens_prompt
191
native_tokens_completion
872
native_tokens_completion_images
0
native_tokens_reasoning
736
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
0.00045155
router
(null)
provider_responses
0
endpoint_id
"9821aa0e-dce3-4c27-9716-161359123d0b"
id
"c00663cf-97b7-853c-abe5-486ef698bcc9"
is_byok
false
latency
47
model_permaslug
"x-ai/grok-4.1-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771617979-ux9Exx4S4sRw6YYkgoRa"
upstream_id
"c00663cf-97b7-853c-abe5-486ef698bcc9"
total_cost
0.00045155
cache_discount
0.00002265
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
94.82%
Matches word count
n/a
neededClean
false
sentences
10
wordCounts
0
10
1
10
2
11
3
10
4
10
5
10
6
10
7
11
8
10
9
10