NC Bench
Overview
About
Tests
Models
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
Messages
Meta
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_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
382
moderation_latency
(null)
generation_time
3447
tokens_prompt
35
tokens_completion
225
native_tokens_prompt
44
native_tokens_completion
248
native_tokens_completion_images
(null)
native_tokens_reasoning
0
native_tokens_cached
0
num_media_prompt
(null)
num_input_audio_prompt
(null)
num_media_completion
0
num_search_results
(null)
origin
"https://ncbench.com/"
is_byok
false
finish_reason
"stop"
native_finish_reason
"stop"
usage
0.001284
router
(null)
provider_responses
0
id
"msg_01HfBMGifBq9TVVSgD14RWMt"
status
200
is_byok
false
latency
382
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_cost
0.001284
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Anthropic"
Evaluation details
Result
Evaluator
Details
Meta Data
10.0445%
Matches word count
n/a
neededClean
false
sentences
11
wordCounts
0
6
1
17
2
18
3
18
4
18
5
18
6
18
7
18
8
18
9
18
10
17