NC Bench
Overview
About
Tests
Categories
Models
Vendors
Compare
Run: 2026-07-25-01KYCRN3WNENPE6PZJMGGZDNGW
Run Details
Model:
Claude Opus 5 (Reasoning, Low)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
39.4s
Cost:
$0.098300
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 Ashcombe Hall since midnight, and by dawn the gravel drive resembled a shallow river. Mrs. Pemberton found the library door locked at seven, which had never once happened during her thirty years of service. She knocked twice, called the colonel's name, and pressed her ear against the cold oak until her patience finally failed. The spare key hung in the pantry, beneath a faded chart of tides nobody had consulted in nearly forty years. Her hands shook so badly that she dropped it twice before the lock surrendered with a small, reluctant metallic click. Colonel Ashcombe sat in his usual chair beside the fire, facing the window, his broad back turned toward the door. The fire had gone out hours ago, and the room held the stillness of a breath being held too long. One of his shoes lay overturned on the hearthrug, and his teacup lay shattered across the pale marble fender below. Mrs. Pemberton did not scream, because screaming had never once solved a single problem in the course of her life. Instead she noticed that the window latch stood open, though the colonel had feared draughts more than he feared death. She noticed too the wet footprints crossing the carpet, coming inward, and not one of them going back out again. Then she turned, very slowly, toward the tall bookcase where the shadows did not seem to be standing entirely still.
created_at
"2026-07-25T13:50:22.621Z"
7/25/2026, 1:50:22 PM
model
"anthropic/claude-opus-5-20260723"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
4381
moderation_latency
(null)
generation_time
39308
tokens_prompt
46
tokens_completion
928
native_tokens_prompt
60
native_tokens_completion
3920
native_tokens_completion_images
(null)
native_tokens_reasoning
583
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
0.0983
router
(null)
provider_responses
0
endpoint_id
"76cb4608-f48c-483d-8da8-9957fb44244e"
id
"msg_011CdNtCX6kc6G8aKLDvCX8A"
is_byok
false
latency
1647
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-1784987422-09lGoE7QtxRvEdNMg8aZ"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1784987422-B4NN9wk46tJZkRY4ZkBy"
upstream_id
"msg_011CdNtCX6kc6G8aKLDvCX8A"
total_cost
0.0983
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
12
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