Model

Claude Haiku 4.5

Test

N-Length Sentences

Scenario

Write sentences with 20 words each

Run ID

2026-02-08-01KGYXP6YFRXV4Z0D9EB7F8XVE

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 sun filtered through the tall windows of Ashworth Manor, casting long shadows. Detective Sarah Chen stepped out of her unmarked car, noting the grand estate's isolation. Mrs. Eleanor Hartwell lay sprawled across the Persian rug, quite obviously very dead. Blood had pooled beneath her head, suggesting a violent blow from some heavy object. The butler discovered the body at seven o'clock this morning while preparing breakfast. Sarah's keen eyes swept across the room, cataloging every detail with practiced professional attention. Three people had been sleeping in the house throughout the entire previous night. Eleanor's husband Richard stood in the doorway, his face pale with shock and grief. The gardener claimed he saw nothing unusual during his early morning routine outside today. Sarah knew that one of these people had committed this terrible, calculated, premeditated murder.
created_at"2026-02-08T15:24:58.808584+00:00" Sunday, February 8th, 2026 at 3:24:58 PM GMT+00:00
model"anthropic/claude-4.5-haiku-20251001" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency411
moderation_latency(null)
generation_time2609
tokens_prompt35
tokens_completion175
native_tokens_prompt44
native_tokens_completion184
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" 
usage0.000964
router(null)
provider_responses
0
id"msg_016PK78FHxqFvu4VQ77J66kH" 
status200
is_byokfalse
latency411
endpoint_id"41d2915a-92e6-4993-b537-210b4e10cba8" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.5-haiku-20251001" 
api_type"completions" 
id"gen-1770564295-WqOKesR5GFSBK0afkwOw" 
upstream_id"msg_016PK78FHxqFvu4VQ77J66kH" 
total_cost0.000964
cache_discount(null)
upstream_inference_cost0
provider_name"Anthropic" 

Evaluation details

Result Evaluator Details Meta Data
0.0000% Matches word count n/a
neededCleanfalse
sentences11
wordCounts
06
114
214
313
414
513
614
713
814
914
1014