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Run: 2026-02-24-01KJ8VH6KK6W6N5Q1M3PEBNAS3
Run Details
Model:
Claude Sonnet 4.6 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
1m 54s
Cost:
$0.181998
Provider:
Anthropic
Evaluation summary
Score
Evaluator
Details Link
100.00%
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 old lighthouse keeper found the body at dawn, just as the thick grey fog had swallowed everything around him. She lay face down on the cold, wet rocks, her pale outstretched hand reaching desperately toward the dark churning water. Her deep red evening dress had fanned out around her like a wound, and the keeper knew this was murder. He stumbled backward in shock and knocked over his old lantern, casting wild and dancing shadows across the wet stones. He had seen death before in his long years alone, but never anything this deliberate, this precise, this utterly cold. Detective Mara Quinn received the call at three in the morning, pulling her gray coat tight against the coastal wind. She drove the winding cliff road entirely alone, her headlights cutting through the thick fog like a pale uncertain blade. When she finally arrived, the old keeper sat on a rock, staring blankly down at his trembling and weathered hands. He looked up at Quinn with hollow eyes and said only one thing: she did not belong to the sea. Quinn knelt beside the dead woman and noticed immediately that her elegant shoes were entirely free of sand or mud. Someone had carried her here and then placed her perfectly, like a painting intended for someone very specific to find. The cold wind picked up then, scattering Quinn's dark hair across her face as the lighthouse beam swept past again. In that brief flash of light, she noticed something no one else had thought to find: a folded white note. It had been carefully placed beneath the woman's right hand, as though the killer had wanted it to be found. Quinn pulled on her gloves and unfolded the note with steady hands, though her heart was beating very fast now. Three words had been written inside in a small, deliberate script, and each one felt like a very personal threat. The note read simply, Welcome back, Quinn, and in that moment she felt the cold blood drain from her face.
created_at
"2026-02-24T22:15:20.441Z"
2/24/2026, 10:15:20 PM
model
"anthropic/claude-4.6-sonnet-20260217"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
641
moderation_latency
(null)
generation_time
113797
tokens_prompt
46
tokens_completion
2669
native_tokens_prompt
61
native_tokens_completion
12121
native_tokens_completion_images
(null)
native_tokens_reasoning
2181
native_tokens_cached
0
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
"stop"
usage
0.181998
router
(null)
provider_responses
0
endpoint_id
"6d408764-7dd7-4626-bb87-a6cc1589bc86"
id
"msg_016jCQnkUd5Gd7eY8nDyhNej"
is_byok
false
latency
621
model_permaslug
"anthropic/claude-4.6-sonnet-20260217"
provider_name
"Anthropic"
status
200
api_type
"completions"
id
"gen-1771971320-odqUVlnab6aeFISEcuhC"
upstream_id
"msg_016jCQnkUd5Gd7eY8nDyhNej"
total_cost
0.181998
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Anthropic"
Evaluation details
Result
Evaluator
Details
Meta Data
100.00%
Matches word count
n/a
neededClean
false
sentences
17
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20
6
20
7
20
8
20
9
20
10
20
11
20
12
20
13
20
14
20
15
20
16
20