NC Bench
Overview
About
Tests
Models
Model
Claude Opus 4.5
Test
N-Length Sentences
Scenario
Write sentences with 10 words each
Run ID
2026-02-08-01KGYXWEHWS35YGYK6VWSKEKRF
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 black sedan slowly. Rain poured down heavily, soaking her worn brown leather coat. She had seen many crime scenes throughout her long career. But something about this one felt different, almost eerily wrong. The butler waited nervously at the massive oak front door. His pale hands trembled as he gestured for her inside. A body lay crumpled at the bottom of the stairs. The victim was wealthy industrialist Marcus Webb, aged sixty two. Blood pooled beneath his head like a dark crimson halo. His eyes stared blankly at the crystal chandelier hanging above. No one had heard him fall during the dinner party. Twelve guests had been present when the lights went out. Now twelve suspects waited anxiously in the grand dining room. Sarah knelt beside the body and studied it very carefully. This was no accident, she realized with growing cold certainty. Someone in this house had committed a very calculated murder. She stood up slowly and turned to face the butler. The truth was hiding somewhere within these ancient elegant walls. Tonight, she would find it, no matter what the cost.
created_at
"2026-02-08T15:28:28.746867+00:00"
Sunday, February 8th, 2026 at 3:28:28 PM GMT+00:00
model
"anthropic/claude-4.5-opus-20251124"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1435
moderation_latency
(null)
generation_time
8075
tokens_prompt
35
tokens_completion
241
native_tokens_prompt
44
native_tokens_completion
269
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
0.006945
router
(null)
provider_responses
0
id
"msg_01MPRonSM4ucQL4vs7ozLotv"
status
200
is_byok
false
latency
1435
endpoint_id
"be883404-eb42-4b2d-b6e4-c7daa3aa8d62"
provider_name
"Anthropic"
model_permaslug
"anthropic/claude-4.5-opus-20251124"
api_type
"completions"
id
"gen-1770564500-5Sl8uaLIm9uFMQBAnOln"
upstream_id
"msg_01MPRonSM4ucQL4vs7ozLotv"
total_cost
0.006945
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Anthropic"
Evaluation details
Result
Evaluator
Details
Meta Data
100.0000%
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