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Run: 2026-02-08-01KGYZWSANBJW6APEYJHXBJ0B7
Run Details
Model:
Claude Opus 4.5
Test:
N-Length Sentences
Scenario:
Write sentences with 10 words each
Duration:
8.3s
Cost:
$0.007020
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 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 stood silent against the dark stormy night. Detective Sarah Chen stepped out of her car very slowly. Rain pounded the gravel driveway like a thousand tiny drums. She had seen many crime scenes throughout her long career. But something about this one felt different from the others. The front door creaked open before she could even knock. A pale butler gestured for her to come inside now. "The body is in the study," he whispered to her. Sarah followed him down a long and shadowy marble hallway. Portraits of stern ancestors seemed to watch her every move. The study door was open just a crack for her. She pushed it wider and saw the horrible gruesome scene. Lord Harrison Blackwood lay slumped over his massive oak desk. A silver letter opener protruded from his back quite deeply. Blood had pooled beneath him and stained the Persian rug. "Who found the body first?" Sarah asked the nervous butler. "The maid discovered him when she brought his evening tea." Sarah knelt beside the corpse and examined it very carefully. The murder had happened recently, perhaps only two hours ago. Everyone in this house tonight was now a possible suspect.
created_at
"2026-02-08T16:03:36.967434+00:00"
2/8/2026, 4:03:36 PM
model
"anthropic/claude-4.5-opus-20251124"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1620
moderation_latency
(null)
generation_time
8207
tokens_prompt
35
tokens_completion
238
native_tokens_prompt
44
native_tokens_completion
272
native_tokens_completion_images
(null)
native_tokens_reasoning
0
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
0.00702
router
(null)
provider_responses
0
id
"msg_015dii7ZJfFpY8y7KLTbL8VU"
status
200
is_byok
false
latency
1620
endpoint_id
"be883404-eb42-4b2d-b6e4-c7daa3aa8d62"
provider_name
"Anthropic"
model_permaslug
"anthropic/claude-4.5-opus-20251124"
api_type
"completions"
id
"gen-1770566608-E9QOCnlCBD25J8K2m30M"
upstream_id
"msg_015dii7ZJfFpY8y7KLTbL8VU"
total_cost
0.00702
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
20
wordCounts
0
10
1
10
2
10
3
10
4
10
5
10
6
10
7
10
8
10
9
10
10
10
11
10
12
10
13
10
14
10
15
10
16
10
17
10
18
10
19
10