NC Bench
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Run: 2026-02-20-01KHY8XAW5SH81FBFPZXH13H0W
Run Details
Model:
Grok 4.1 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
37.4s
Cost:
$0.003504
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
90.16%
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
Shadows danced eerily on the walls of Blackwood Manor as thunder crashed and lightning illuminated the dark stormy night sky. Elegant Lord Harrington warmly greeted his ten invited guests in the grand foyer beneath the sparkling crystal chandelier above. Among those present were renowned Inspector Graves, the beautiful but scorned lover Elena, ruthless businessman Victor Slade, an enigmatic widow. The assembled guests conversed politely in the drawing room while sipping fine brandy amid flickering candlelight and the dancing shadows. The group raced up the grand staircase following the blood-curdling scream that had come from Lady Harrington's upstairs private suite. They burst into her bedroom to discover her body sprawled lifeless on the floor in her own pool of blood. Her throat bore a deep gash from a jeweled dagger now lying beside her on the rich bloodstained carpet below. Guests stared in shock at the locked door to her bedroom, with no visible key and no escape route available.
created_at
"2026-02-20T19:37:30.768Z"
2/20/2026, 7:37:30 PM
model
"x-ai/grok-4.1-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
227
moderation_latency
(null)
generation_time
37192
tokens_prompt
46
tokens_completion
939
native_tokens_prompt
191
native_tokens_completion
6989
native_tokens_completion_images
0
native_tokens_reasoning
6795
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
0.0035042
router
(null)
provider_responses
0
endpoint_id
"9821aa0e-dce3-4c27-9716-161359123d0b"
id
"47c1603b-bcf0-2031-e45c-0b33efa99890"
is_byok
false
latency
76
model_permaslug
"x-ai/grok-4.1-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771616250-xUYoOKKQhJSHY8IpJPsi"
upstream_id
"47c1603b-bcf0-2031-e45c-0b33efa99890"
total_cost
0.0035042
cache_discount
0.0000285
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
90.16%
Matches word count
n/a
neededClean
false
sentences
8
wordCounts
0
20
1
19
2
20
3
20
4
21
5
20
6
20
7
20