Model

Claude Opus 4.5

Test

N-Length Sentences

Scenario

Write sentences with 10 words each

Run ID

2026-02-08-01KGYZNWV0EJA8HAPWWZKSG7ZF

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

AI
The old mansion stood silent against the dark stormy sky. Detective Sarah Chen stepped out of her car into rain. 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 butler with hollow eyes gestured for her to enter. The body lay sprawled across the grand marble entrance hall. Blood pooled beneath the victim like a dark red mirror. Lord Ashworth had been stabbed precisely through his cold heart. His wife stood trembling on the ornate curved wooden staircase. Every member of the household had motives for this murder. Sarah pulled out her notebook and began her grim work.
created_at"2026-02-08T15:59:48.54808+00:00" Sunday, February 8th, 2026 at 3:59:48 PM GMT+00:00
model"anthropic/claude-4.5-opus-20251124" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency1435
moderation_latency(null)
generation_time5540
tokens_prompt35
tokens_completion139
native_tokens_prompt44
native_tokens_completion160
native_tokens_completion_images(null)
native_tokens_reasoning0
native_tokens_cached0
num_media_prompt(null)
num_input_audio_prompt(null)
num_media_completion0
num_search_results(null)
origin"https://ncbench.com/" 
is_byokfalse
finish_reason"stop" 
native_finish_reason"stop" 
usage0.00422
router(null)
provider_responses
0
id"msg_01623UobLTCuVBYUxYQbw8dM" 
status200
is_byokfalse
latency1435
endpoint_id"be883404-eb42-4b2d-b6e4-c7daa3aa8d62" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.5-opus-20251124" 
api_type"completions" 
id"gen-1770566382-6fiDB26KsnbhT7cBKJh2" 
upstream_id"msg_01623UobLTCuVBYUxYQbw8dM" 
total_cost0.00422
cache_discount(null)
upstream_inference_cost0
provider_name"Anthropic" 

Evaluation details

Result Evaluator Details Meta Data
100.0000% Matches word count n/a
neededCleanfalse
sentences12
wordCounts
010
110
210
310
410
510
610
710
810
910
1010
1110