Model

Claude Sonnet 4.5

Test

N-Length Sentences

Scenario

Write sentences with 20 words each

Run ID

2026-02-08-01KGZ01YYBQCY1E24EJK8CKK4H

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

AI
# The Clockmaker's Final Hour The body of Edmund Hargrove lay sprawled across his workshop floor, surrounded by hundreds of ticking clocks on every wall. Detective Sarah Chen stepped carefully over scattered gears and springs, her keen eyes absorbing every detail of the macabre scene before her. Blood pooled beneath the victim's head, mixing with oil from an overturned lamp that had somehow failed to ignite the wooden building. "Time of death approximately midnight," announced the medical examiner, snapping his black bag shut with an air of grim professional efficiency and certainty. Sarah noticed the victim's pocket watch clutched in his right hand, its glass face shattered, the hands frozen at eleven forty-seven. Every clock in the workshop had stopped at that exact moment, as if the whole room had died along with its master. "Could be coincidence," muttered her partner, Detective James Morrison, though his furrowed brow suggested he didn't believe his own casual dismissive words. Sarah knelt beside a workbench where an unfinished clock mechanism lay partially assembled, tiny tools arranged in suspiciously perfect order and precision. A teacup sat on the windowsill, still half full of cold liquid, a faint residue of something chemical coating its porcelain rim. "Get that tested immediately," Sarah instructed a nearby officer, pointing at the cup with her pen while avoiding any direct physical contact. The workshop door had been locked from inside, all windows sealed shut, presenting the impossible puzzle of a completely sealed room murder. Three keys existed for that door: one with the victim, one with his estranged daughter, one with his former business partner and rival. Sarah stood, surveying the frozen moment of violence preserved in this chamber, knowing someone had orchestrated an elaborate and deadly theatrical performance.
created_at"2026-02-08T16:06:28.018686+00:00" Sunday, February 8th, 2026 at 4:06:28 PM GMT+00:00
model"anthropic/claude-4.5-sonnet-20250929" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency1426
moderation_latency170
generation_time9405
tokens_prompt35
tokens_completion355
native_tokens_prompt44
native_tokens_completion399
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" 
usage0.006117
router(null)
provider_responses
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id"71b8d05e-3075-4cb9-85f9-44f6e5f64a4a" 
status200
is_byokfalse
latency1426
endpoint_id"d8bee848-f020-454a-b2be-4a7ce868f99f" 
provider_name"Amazon Bedrock" 
model_permaslug"anthropic/claude-4.5-sonnet-20250929" 
api_type"completions" 
id"gen-1770566777-IUSzJsY3Z1GddlEEnuGF" 
upstream_id"71b8d05e-3075-4cb9-85f9-44f6e5f64a4a" 
total_cost0.006117
cache_discount(null)
upstream_inference_cost0
provider_name"Amazon Bedrock" 

Evaluation details

Result Evaluator Details Meta Data
16.9684% Matches word count n/a
neededCleanfalse
sentences14
wordCounts
05
120
222
322
423
522
622
722
822
922
1022
1122
1223
1322