NC Bench
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Run: 2026-02-20-01KHYB9W2WVTWTVWD8CMZYTD22
Run Details
Model:
Grok 4 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
7.4s
Cost:
$0.000604
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
22.67%
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 dim library light, Sir Reginald's body lay sprawled lifelessly on the antique Persian rug near the fireplace. Blood pooled slowly from the deep gash across his throat, staining the wool fibers a dark crimson red. The annual family gala had ended just hours before, with guests retiring to their rooms in the old mansion. Now whispers echoed through the shadowed halls as footsteps hurried toward the discovery in growing alarm. Inspector Harlan Graves arrived swiftly, his rain-soaked coat dripping water onto the polished oak floorboards. Who among the heirs could have wielded the knife under cover of the stormy midnight darkness outside?
created_at
"2026-02-20T20:19:18.759Z"
2/20/2026, 8:19:18 PM
model
"x-ai/grok-4-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
4623
moderation_latency
(null)
generation_time
7208
tokens_prompt
46
tokens_completion
169
native_tokens_prompt
191
native_tokens_completion
1176
native_tokens_completion_images
0
native_tokens_reasoning
1049
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
0.00060355
router
(null)
provider_responses
0
endpoint_id
"c9586d9d-97ff-40ca-ae94-22504d6f9b7e"
id
"83ef7041-9d5e-04a3-6c32-ac0a260759d2"
is_byok
false
latency
194
model_permaslug
"x-ai/grok-4-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771618758-BpYMJKrDZ5CIiawaYxrO"
upstream_id
"83ef7041-9d5e-04a3-6c32-ac0a260759d2"
total_cost
0.00060355
cache_discount
0.00002265
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
22.67%
Matches word count
n/a
neededClean
false
sentences
6
wordCounts
0
19
1
18
2
19
3
16
4
16
5
17