Model

Claude Haiku 4.5

Test

N-Length Sentences

Scenario

Write sentences with 20 words each

Run ID

2026-02-08-01KGYZ01HRVJVT71EBTNWXF1TH

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 Discovery The body lay sprawled across the mahogany desk, its lifeless eyes staring blankly at the ornate ceiling above. Detective Sarah Mitchell stepped into the study, her shoes clicking softly against the polished hardwood floor of the mansion. A pool of crimson blood had begun to congeal around the victim's head, suggesting death occurred hours before discovery. The victim was identified as Victor Ashford, a wealthy businessman known for his ruthless corporate dealings and numerous enemies. His right hand still clutched a fountain pen, as if he had been signing documents when the fatal blow struck. The window behind the desk stood open, cold December air flowing freely into the room and disturbing scattered papers everywhere. Sarah surveyed the scene methodically, noting that nothing appeared stolen or disturbed except for the overturned chair beneath the body. "Who discovered the body?" she asked the uniformed officer standing silently in the doorway, waiting for answers to emerge slowly.
created_at"2026-02-08T15:47:49.907071+00:00" Sunday, February 8th, 2026 at 3:47:49 PM GMT+00:00
model"anthropic/claude-4.5-haiku-20251001" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency435
moderation_latency(null)
generation_time2702
tokens_prompt35
tokens_completion190
native_tokens_prompt44
native_tokens_completion214
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" 
usage0.001114
router(null)
provider_responses
0
id"msg_01L4CQAHjwTkEzBWfhE62Bgj" 
status200
is_byokfalse
latency435
endpoint_id"41d2915a-92e6-4993-b537-210b4e10cba8" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.5-haiku-20251001" 
api_type"completions" 
id"gen-1770565666-eVmXLk7bPlFT0ZPJqFfx" 
upstream_id"msg_01L4CQAHjwTkEzBWfhE62Bgj" 
total_cost0.001114
cache_discount(null)
upstream_inference_cost0
provider_name"Anthropic" 

Evaluation details

Result Evaluator Details Meta Data
66.1659% Matches word count n/a
neededCleanfalse
sentences9
wordCounts
03
118
219
319
419
520
620
720
820