Model

Claude Haiku 4.5

Test

N-Length Sentences

Scenario

Write sentences with 20 words each

Run ID

2026-02-08-01KGYXQG360YE5AB5HYFB63B9S

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 morning fog clung to Blackwood Manor like a shroud as Detective Sarah Chen arrived. Lady Margaret's body lay motionless across the mahogany desk in her private study downstairs. Her silk nightgown was torn and blood stained the Persian rug beneath her still form. The butler had discovered her at half past seven while opening the curtains for daylight. Every window and door in the study had been locked from the inside when found. Sarah's eyes narrowed as she examined the room, counting five suspects in the drawing room. Someone in this house had committed murder, and the killer was undoubtedly still here somewhere. The storm last night had blocked the only road out, trapping everyone within these stone walls.
created_at"2026-02-08T15:25:41.113619+00:00" Sunday, February 8th, 2026 at 3:25:41 PM GMT+00:00
model"anthropic/claude-4.5-haiku-20251001" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency576
moderation_latency(null)
generation_time2581
tokens_prompt35
tokens_completion148
native_tokens_prompt44
native_tokens_completion163
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" 
usage0.000859
router(null)
provider_responses
0
id"msg_01Ef6DtmpphUi7cJPFNF6ZHa" 
status200
is_byokfalse
latency576
endpoint_id"41d2915a-92e6-4993-b537-210b4e10cba8" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.5-haiku-20251001" 
api_type"completions" 
id"gen-1770564337-p5ksZf0ZGSOg4VX7cDpI" 
upstream_id"msg_01Ef6DtmpphUi7cJPFNF6ZHa" 
total_cost0.000859
cache_discount(null)
upstream_inference_cost0
provider_name"Anthropic" 

Evaluation details

Result Evaluator Details Meta Data
0.0040% Matches word count n/a
neededCleanfalse
sentences9
wordCounts
06
115
214
315
415
515
615
715
816