NC Bench
Overview
About
Tests
Models
Model
Claude Haiku 4.5
Test
N-Length Sentences
Scenario
Write sentences with 20 words each
Run ID
2026-02-08-01KGYZKJCV0FMVB2R98CMDG6T6
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 grandfather clock struck midnight as Detective Sarah Chen entered the sprawling Victorian mansion on Blackthorn Hill. Lord Edmund Ashworth lay motionless on the Persian rug, a silver letter opener protruding grotesquely from between his shoulder blades. His wife Margaret stood trembling near the fireplace, her face drained of color, mascara streaking down her porcelain cheeks. The study door had been locked from the inside when the screaming began, which complicated everything considerably. Outside, rain hammered against the tall windows as thunder rumbled across the Yorkshire moors in the distance. Sarah knelt beside the body, noting the still-warm skin and the peculiar smell of bitter almonds lingering in the air. Four suspects waited nervously in the drawing room: his son, his secretary, his estranged brother, and the housemaid. Each one had motive, opportunity, and secrets they desperately wanted to keep hidden from police scrutiny. Sarah stood slowly, her mind already cataloging inconsistencies in the stories she would soon hear from the assembled guests. The game, as they say in detective novels, was now afoot, and Edmund Ashworth would receive no earthly justice.
created_at
"2026-02-08T15:58:31.427749+00:00"
Sunday, February 8th, 2026 at 3:58:31 PM GMT+00:00
model
"anthropic/claude-4.5-haiku-20251001"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1396
moderation_latency
(null)
generation_time
4403
tokens_prompt
35
tokens_completion
234
native_tokens_prompt
44
native_tokens_completion
266
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
0.001374
router
(null)
provider_responses
0
id
"msg_01Ve8PtBs3yvhMfURtBudw7J"
status
200
is_byok
false
latency
1396
endpoint_id
"41d2915a-92e6-4993-b537-210b4e10cba8"
provider_name
"Anthropic"
model_permaslug
"anthropic/claude-4.5-haiku-20251001"
api_type
"completions"
id
"gen-1770566306-P3M0qP9I2FSTAJgVrqgD"
upstream_id
"msg_01Ve8PtBs3yvhMfURtBudw7J"
total_cost
0.001374
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Anthropic"
Evaluation details
Result
Evaluator
Details
Meta Data
32.6829%
Matches word count
n/a
neededClean
false
sentences
11
wordCounts
0
6
1
17
2
20
3
19
4
17
5
17
6
21
7
18
8
16
9
19
10
19