NC Bench
Overview
About
Tests
Categories
Models
Vendors
Compare
Run: 2026-07-25-01KYCRMBD1FYS9TW11V73TDXCW
Run Details
Model:
Claude Opus 5 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
25.7s
Cost:
$0.062075
Provider:
Amazon Bedrock
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 rain had been falling on Ravenscourt House since midnight, and by dawn the gravel drive resembled a shallow river. Mrs. Halloway found the library door locked at seven, which had never happened in her thirty years of service here. She knocked twice, listened, then set her tray down and pressed one ear flat against the cold dark oak panel. Inside, something ticked steadily, and beneath that ticking she heard nothing at all, no breath, no chair, no turning page. The master of the house had a rule about the library, absolute and unbending: nobody entered it before nine o'clock. Mrs. Halloway broke that rule at eight minutes past seven, using the spare key hidden inside the tall hall clock. Sir Edmund Vane sat in his chair facing the window, and the back of his silver head was terribly wrong. The tray fell, the china shattered, and forty years of careful silence left her throat in one long thin scream. Outside, the rain kept falling, erasing whatever footprints the killer had left across the drive before the dawn had come. By eight, three cars had come, and every person inside Ravenscourt House was already quietly deciding exactly what to conceal.
created_at
"2026-07-25T13:49:57.568Z"
7/25/2026, 1:49:57 PM
model
"anthropic/claude-opus-5-20260723"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
4052
moderation_latency
(null)
generation_time
25534
tokens_prompt
46
tokens_completion
567
native_tokens_prompt
60
native_tokens_completion
2471
native_tokens_completion_images
(null)
native_tokens_reasoning
275
native_tokens_cached
0
num_media_prompt
(null)
num_input_audio_prompt
(null)
num_media_completion
0
num_search_results
(null)
num_fetches
(null)
web_search_engine
(null)
origin
"https://ncbench.com/"
is_byok
false
finish_reason
"stop"
native_finish_reason
"end_turn"
service_tier
"default"
usage
0.062075
router
(null)
provider_responses
0
endpoint_id
"76cb4608-f48c-483d-8da8-9957fb44244e"
id
"msg_011CdNtAfkqu6ibFrMz9pGfB"
is_byok
false
latency
1512
model_permaslug
"anthropic/claude-opus-5-20260723"
provider_name
"Amazon Bedrock"
status
200
user_agent
"langchainjs-openai/1.0.0 ((node/v24.18.0; linux; x64))"
http_referer
(null)
request_id
"req-1784987397-GgramPzPWq1Jw71D7LjB"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1784987397-MuaYL4FFAUZXK27E25d5"
upstream_id
"msg_011CdNtAfkqu6ibFrMz9pGfB"
total_cost
0.062075
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Amazon Bedrock"
response_cache_source_id
(null)
data_region
"global"
Evaluation details
Result
Evaluator
Details
Meta Data
100.00%
Matches word count
n/a
neededClean
false
sentences
10
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20
6
20
7
20
8
20
9
20