NC Bench
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Run: 2026-02-20-01KHY9B5FY7XR0CRYSAB1SRZX4
Run Details
Model:
Grok 4 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
5.0s
Cost:
$0.000327
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
7.76%
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
In the quiet village of Eldridge, the old mansion stood silently under the full moon's eerie glow, windows dark. Detective Harlan Graves pulled up to the wrought-iron gates precisely at midnight, his tires crunching on gravel. He stepped out into thick fog that swirled around ancient oaks, flashlight piercing the night's heavy veil. A servant rushed forward from the shadowed porch, face pale and twisted in obvious terror and despair. "Sir, it's the master of the house; he's been found dead in his locked study upstairs now." Graves nodded grimly and followed the trembling man inside, coat brushing against creaking wooden floors below. The air hung heavy with scent of aged books mixed with something metallic and sharply disturbing. Up the grand staircase they climbed, portraits of stern ancestors watching their every hurried footstep. At the study door, sealed tight with yellow tape, two officers stood guard in silent vigil. Graves examined the keyhole closely, noting scratches that suggested forced entry despite claims otherwise.
created_at
"2026-02-20T19:45:04.01Z"
2/20/2026, 7:45:04 PM
model
"x-ai/grok-4-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
2832
moderation_latency
(null)
generation_time
4908
tokens_prompt
46
tokens_completion
277
native_tokens_prompt
191
native_tokens_completion
635
native_tokens_completion_images
0
native_tokens_reasoning
437
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
0.0003272
router
(null)
provider_responses
0
endpoint_id
"c9586d9d-97ff-40ca-ae94-22504d6f9b7e"
id
"8b4051df-bce5-d4fa-a054-a3cded516486"
is_byok
false
latency
102
model_permaslug
"x-ai/grok-4-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771616704-awm7GkIEnMZtKOkZiZMd"
upstream_id
"8b4051df-bce5-d4fa-a054-a3cded516486"
total_cost
0.0003272
cache_discount
0.0000285
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
7.76%
Matches word count
n/a
neededClean
false
sentences
10
wordCounts
0
19
1
18
2
17
3
17
4
17
5
16
6
16
7
15
8
16
9
14