NC Bench
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Run: 2026-02-20-01KHY9GM8BN8TJ5RWVEC0TWZJP
Run Details
Model:
Grok 4.1 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
13.5s
Cost:
$0.000819
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
85.24%
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
Thick dense fog enveloped the secluded old English manor house where wealthy industrialist Victor Langford hosted his annual gala tonight. Guests mingled happily in the opulent ballroom laughing and dancing to orchestra's lively tunes with champagne flutes in their hands. Suddenly a piercing scream echoed through the grand marble halls from the library where Victor had retired alone just before. Panicked guests rushed toward the awful sound pushing past ornate furniture and servants in the dimly lit corridor ahead. They burst into the library and froze at the horrific sight of Victor slumped over his desk in death. A jeweled dagger protruded from his back amid scattered papers and an overturned glass of cognac on the oak floor. Inspector Eliza Thorne arrived swiftly at the scene alerted by constable who had summoned her from nearby town station. Her sharp eyes scanned the room noting the French windows ajar and faint muddy footprints leading toward the garden outside.
created_at
"2026-02-20T19:48:02.964Z"
2/20/2026, 7:48:02 PM
model
"x-ai/grok-4.1-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
539
moderation_latency
(null)
generation_time
13363
tokens_prompt
46
tokens_completion
382
native_tokens_prompt
191
native_tokens_completion
1606
native_tokens_completion_images
0
native_tokens_reasoning
1429
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
0.00081855
router
(null)
provider_responses
0
endpoint_id
"9821aa0e-dce3-4c27-9716-161359123d0b"
id
"8b11cb56-74ec-6a78-00cc-07c78a91317a"
is_byok
false
latency
399
model_permaslug
"x-ai/grok-4.1-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771616882-qZflZPLp2lcqJhh8n4CB"
upstream_id
"8b11cb56-74ec-6a78-00cc-07c78a91317a"
total_cost
0.00081855
cache_discount
0.00002265
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
85.24%
Matches word count
n/a
neededClean
false
sentences
8
wordCounts
0
20
1
20
2
20
3
19
4
19
5
20
6
19
7
20