Model

Claude Haiku 4.5

Test

N-Length Sentences

Scenario

Write sentences with 20 words each

Run ID

2026-02-08-01KGYWZCTT2JDEPFDG2KD3BJ0A

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 Body in the Library The rain fell heavily on the cobblestone streets of Victorian London as midnight approached with ominous inevitability. Detective Inspector Blackwood arrived at the sprawling Ashworth Manor to find chaos and fear everywhere throughout the house. The butler, trembling and pale, pointed toward the library where the body lay motionless upon the Persian rug. Lord Ashworth's lifeless form was still warm, suggesting the murder had occurred mere moments before anyone discovered him. A crystal glass of poisoned brandy sat nearby on the mahogany table, half empty and deadly in appearance. Inspector Blackwood surveyed the room carefully, noting that the locked library door had been forced open just recently. Three suspects remained in the manor that fateful night: the ambitious nephew, the angry wife, and the gardener. Each one had motive, opportunity, and secrets that they desperately wanted to keep hidden from law enforcement officials. Blackwood lit his pipe thoughtfully while examining the crime scene with the practiced eye of a seasoned investigator. The game, as they say, was afoot, and the truth would soon be revealed through careful deduction.
created_at"2026-02-08T15:12:32.015921+00:00" Sunday, February 8th, 2026 at 3:12:32 PM GMT+00:00
model"anthropic/claude-4.5-haiku-20251001" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency382
moderation_latency(null)
generation_time3447
tokens_prompt35
tokens_completion225
native_tokens_prompt44
native_tokens_completion248
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" 
usage0.001284
router(null)
provider_responses
0
id"msg_01HfBMGifBq9TVVSgD14RWMt" 
status200
is_byokfalse
latency382
endpoint_id"41d2915a-92e6-4993-b537-210b4e10cba8" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.5-haiku-20251001" 
api_type"completions" 
id"gen-1770563548-c0JFl2IMnShFvbdehX1Z" 
upstream_id"msg_01HfBMGifBq9TVVSgD14RWMt" 
total_cost0.001284
cache_discount(null)
upstream_inference_cost0
provider_name"Anthropic" 

Evaluation details

Result Evaluator Details Meta Data
10.0445% Matches word count n/a
neededCleanfalse
sentences11
wordCounts
06
117
218
318
418
518
618
718
818
918
1017