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Run: 2026-02-20-01KHY815Y9XPYV2KK9HDA2JQAH
Run Details
Model:
Grok 4 Fast
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
3.0s
Cost:
$0.000259
Provider:
xAI
Evaluation summary
Score
Evaluator
Details Link
0.16%
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 fog clung to the cobblestone streets of Victorian London like a shroud on All Hallows' Eve. Inspector Hargrove stepped from his hansom cab, his lantern cutting through the misty veil ahead. Gaslights flickered weakly along the alley, casting long shadows that danced with unseen threats nearby. A scream pierced the night from the old manor house, sharp and filled with raw terror. Hargrove quickened his pace, boots echoing against the damp stones as urgency gripped him tightly. He reached the wrought-iron gate, its creak announcing his arrival to the silent estate within. Pushing open the heavy oak door, he entered the dimly lit foyer where candles burned low. The air was thick with the scent of pipe smoke and something metallic, disturbingly familiar now. Footsteps hurried from the parlor, revealing the butler's pale face twisted in abject fear. "Sir, it's the master," the man gasped, leading Hargrove to the study's crimson-stained threshold. There, slumped in his leather armchair, lay Lord Ashford with a dagger plunged deep into his chest. Blood pooled on the Persian rug, staining it dark as the inspector surveyed the gruesome scene. Bookshelves loomed like silent witnesses, their volumes undisturbed except for one fallen volume nearby. No signs of forced entry appeared, suggesting the killer was someone trusted in this household. Hargrove's mind raced with questions as the first clues began to weave their tangled web.
created_at
"2026-02-20T19:22:08.21Z"
2/20/2026, 7:22:08 PM
model
"x-ai/grok-4-fast"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1141
moderation_latency
(null)
generation_time
2790
tokens_prompt
46
tokens_completion
379
native_tokens_prompt
191
native_tokens_completion
499
native_tokens_completion_images
0
native_tokens_reasoning
200
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
0.0002592
router
(null)
provider_responses
0
endpoint_id
"c9586d9d-97ff-40ca-ae94-22504d6f9b7e"
id
"43bbf833-acdc-9c0d-23e6-8d953a107e54"
is_byok
false
latency
83
model_permaslug
"x-ai/grok-4-fast"
provider_name
"xAI"
status
200
api_type
"completions"
id
"gen-1771615328-knCwYlfH3trtfSiivQZp"
upstream_id
"43bbf833-acdc-9c0d-23e6-8d953a107e54"
total_cost
0.0002592
cache_discount
0.0000285
upstream_inference_cost
0
provider_name
"xAI"
Evaluation details
Result
Evaluator
Details
Meta Data
0.16%
Matches word count
n/a
neededClean
false
sentences
15
wordCounts
0
17
1
15
2
15
3
16
4
15
5
16
6
16
7
16
8
14
9
15
10
17
11
16
12
14
13
15
14
15