NC Bench
Overview
About
Tests
Models
Model
Claude Opus 4.6
Test
N-Length Sentences
Scenario
Write sentences with 20 words each
Run ID
2026-02-08-01KGYX7SK0PX8HEX3N8Q55KBJS
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 mansion stood silently at the end of Blackwood Lane, its windows dark like the eyes of a skull. Detective Sarah Chen arrived at precisely eleven fifteen that evening, her boots crunching against the gravel of the long winding driveway ahead. A single light flickered behind the curtain on the second floor, casting strange and eerie shadows that danced across the lawn. The front door hung open just a few inches, revealing nothing but an impenetrable darkness that seemed almost alive and breathing. She pushed it wider with her gloved hand, and the smell of copper and roses hit her like a freight train. On the marble floor of the grand foyer lay the body of billionaire Marcus Webb, his silk robe soaked completely in blood. His eyes were open wide, frozen in an expression of pure terror, as though he had seen something truly beyond comprehension. A shattered crystal glass rested near his outstretched fingers, and deep red wine had pooled and mixed with the thickening blood. Sarah knelt beside the body and noticed something unusual clutched tightly in his other hand, a small torn piece of paper. Written on it in his own trembling handwriting were just three words that would change the entire course of this investigation.
created_at
"2026-02-08T15:17:10.565855+00:00"
Sunday, February 8th, 2026 at 3:17:10 PM GMT+00:00
model
"anthropic/claude-4.6-opus-20260205"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1132
moderation_latency
144
generation_time
6941
tokens_prompt
35
tokens_completion
243
native_tokens_prompt
44
native_tokens_completion
268
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
0.00692
router
(null)
provider_responses
0
id
"c96d2b51-11f8-4d4f-8ed5-e236665b75e9"
status
200
is_byok
false
latency
1132
endpoint_id
"a8708fb9-08ea-43bb-a3b1-165c87ef09df"
provider_name
"Amazon Bedrock"
model_permaslug
"anthropic/claude-4.6-opus-20260205"
api_type
"completions"
id
"gen-1770563823-BOot2PumgifJmBQOwMyQ"
upstream_id
"c96d2b51-11f8-4d4f-8ed5-e236665b75e9"
total_cost
0.00692
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Amazon Bedrock"
Evaluation details
Result
Evaluator
Details
Meta Data
55.1639%
Matches word count
n/a
neededClean
false
sentences
10
wordCounts
0
20
1
22
2
21
3
21
4
21
5
22
6
21
7
21
8
21
9
21