NC Bench
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Run: 2026-02-20-01KHY8V158TA19KVDPC9BRQ8WN
Run Details
Model:
Grok 4 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 10 words each
Duration:
3.6s
Cost:
$0.000349
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
89.63%
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 old mansion loomed dark under the stormy midnight sky. Detective Harlan arrived quickly with his sharp-eyed assistant close. They entered the foyer where silence hung heavy and thick. A scream echoed suddenly from the library down the hall. Rushing inside, they found the body slumped over desk. Blood stained the oak wood and scattered papers everywhere. The victim's eyes stared blankly at the flickering candle flame. No weapon lay nearby in the dimly lit room. Harlan noted the broken window and missing family heirloom. Who could have entered and committed this brutal midnight crime?
created_at
"2026-02-20T19:36:15.287Z"
2/20/2026, 7:36:15 PM
model
"x-ai/grok-4-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
2765
moderation_latency
(null)
generation_time
3389
tokens_prompt
46
tokens_completion
160
native_tokens_prompt
191
native_tokens_completion
678
native_tokens_completion_images
0
native_tokens_reasoning
557
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
0.0003487
router
(null)
provider_responses
0
endpoint_id
"c9586d9d-97ff-40ca-ae94-22504d6f9b7e"
id
"436b5535-588d-263c-5e0f-af4ce26063b7"
is_byok
false
latency
481
model_permaslug
"x-ai/grok-4-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771616175-u4vhyaChOcIIoBWbC9yN"
upstream_id
"436b5535-588d-263c-5e0f-af4ce26063b7"
total_cost
0.0003487
cache_discount
0.0000285
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
89.63%
Matches word count
n/a
neededClean
false
sentences
10
wordCounts
0
10
1
10
2
10
3
10
4
9
5
9
6
10
7
9
8
9
9
10