NC Bench
Overview
About
Tests
Models
Vendors
Run: 2026-02-20-01KHY8VPK6G56K4MJ4FEM9TR46
Run Details
Model:
Grok 4 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
2.5s
Cost:
$0.000262
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
0.01%
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
The detective arrived at the fog-shrouded mansion just as the clock struck midnight in silence. A maid's frantic scream shattered the quiet night air filled with tension and dread. She led him to the library where the body lay sprawled on the Persian rug. Blood pooled beneath the victim's head from a single, precise blow with a heavy candlestick. Bookshelves loomed like silent witnesses around the scene of this brutal, unexpected crime. No signs of forced entry appeared on the heavy oak doors or the tall windows nearby. The victim's eyes stared blankly at the chandelier above in frozen, eternal surprise and fear. Footprints in dust trailed toward the French doors leading out into the misty garden path. Whispers of family secrets hung heavy in the room like the scent of aged leather. Who among the guests had motive strong enough to end this life so ruthlessly now?
created_at
"2026-02-20T19:36:37.233Z"
2/20/2026, 7:36:37 PM
model
"x-ai/grok-4-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1528
moderation_latency
(null)
generation_time
2313
tokens_prompt
46
tokens_completion
230
native_tokens_prompt
191
native_tokens_completion
504
native_tokens_completion_images
0
native_tokens_reasoning
322
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
0.0002617
router
(null)
provider_responses
0
endpoint_id
"c9586d9d-97ff-40ca-ae94-22504d6f9b7e"
id
"21b804a4-bdf3-b1ad-987f-d4867e8a283f"
is_byok
false
latency
131
model_permaslug
"x-ai/grok-4-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771616197-348OpiY0KfjCPiI6zlJW"
upstream_id
"21b804a4-bdf3-b1ad-987f-d4867e8a283f"
total_cost
0.0002617
cache_discount
0.0000285
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
0.01%
Matches word count
n/a
neededClean
false
sentences
10
wordCounts
0
16
1
14
2
15
3
15
4
13
5
16
6
15
7
15
8
15
9
15