Model

Claude Haiku 4.5

Test

N-Length Sentences

Scenario

Write sentences with 20 words each

Run ID

2026-02-08-01KGYX8485ZTNMEAFXQW67MYCF

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 upon the Victorian mansion, casting dark shadows across every corner of the sprawling estate grounds. Detective Sarah Mitchell stepped out of her car, examining the wet pavement with careful attention to every possible detail. Inside the grand library, beneath towering shelves of leather-bound books, lay the body of renowned philanthropist Marcus Ashford, cold. The victim's face was frozen in an expression of pure terror, his eyes still wide open in final shock and fear. A ornate letter opener protruded from between his shoulder blades, the handle decorated with intricate silver patterns and expensive jewels. Inspector Davies stood near the body, his weathered face betraying no emotion despite decades spent investigating violent deaths and terrible crimes. "Nobody leaves this house until we've interviewed everyone here today," Detective Mitchell announced loudly to the assembled group of suspects. The gathered crowd of houseguests exchanged worried glances, each one wondering who among them could possibly be the ruthless murderer.
created_at"2026-02-08T15:17:17.993778+00:00" Sunday, February 8th, 2026 at 3:17:17 PM GMT+00:00
model"anthropic/claude-4.5-haiku-20251001" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency690
moderation_latency294
generation_time2762
tokens_prompt35
tokens_completion196
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"0e433e7b-2b0e-4744-ac76-5856440dd9ff" 
status200
is_byokfalse
latency689
endpoint_id"d000261c-5aeb-47d1-ac87-ad64dbe1cdb6" 
provider_name"Amazon Bedrock" 
model_permaslug"anthropic/claude-4.5-haiku-20251001" 
api_type"completions" 
id"gen-1770563834-N08Hjs5CEJOSL6Zn5x6w" 
upstream_id"0e433e7b-2b0e-4744-ac76-5856440dd9ff" 
total_cost0.001114
cache_discount(null)
upstream_inference_cost0
provider_name"Amazon Bedrock" 

Evaluation details

Result Evaluator Details Meta Data
71.4014% Matches word count n/a
neededCleanfalse
sentences9
wordCounts
06
119
219
320
421
520
621
720
820