NC Bench
Overview
About
Tests
Models
Model
Claude Haiku 4.5
Test
N-Length Sentences
Scenario
Write sentences with 20 words each
Run ID
2026-02-08-01KGYYQVF8FYEMPHKPBWF3P3G3
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, casting dark shadows everywhere. Inspector Ashford arrived at the grand mansion just as the church bells struck midnight. Lady Pemberton's body lay motionless across the mahogany desk in the dusty old library. Her silk evening gown was stained with blood; a pearl-handled revolver rested near her hand. The butler stood nervously in the doorway, wringing his hands and avoiding the inspector's piercing gaze. "Who discovered the body, and when exactly did you find the poor woman?" Ashford demanded. The servant's voice trembled as he explained that he heard the gunshot around eleven o'clock. Three other people were in the mansion that night, all of them with secrets to hide. The inspector surveyed the room carefully, noting a broken window and muddy footprints on the floor. This case would prove far more complicated than anyone had initially anticipated or wanted to believe.
created_at
"2026-02-08T15:43:21.9894+00:00"
Sunday, February 8th, 2026 at 3:43:21 PM GMT+00:00
model
"anthropic/claude-4.5-haiku-20251001"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
661
moderation_latency
(null)
generation_time
3253
tokens_prompt
35
tokens_completion
197
native_tokens_prompt
44
native_tokens_completion
215
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
0.001119
router
(null)
provider_responses
0
id
"msg_01EZjtX6yBx67Jv5eebud9Vz"
status
200
is_byok
false
latency
661
endpoint_id
"41d2915a-92e6-4993-b537-210b4e10cba8"
provider_name
"Anthropic"
model_permaslug
"anthropic/claude-4.5-haiku-20251001"
api_type
"completions"
id
"gen-1770565398-dhwlQlZExD4oXmv5LozI"
upstream_id
"msg_01EZjtX6yBx67Jv5eebud9Vz"
total_cost
0.001119
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Anthropic"
Evaluation details
Result
Evaluator
Details
Meta Data
0.0154%
Matches word count
n/a
neededClean
false
sentences
11
wordCounts
0
6
1
15
2
14
3
14
4
16
5
16
6
15
7
15
8
16
9
16
10
16