NC Bench
Overview
About
Tests
Models
Model
Claude Haiku 4.5
Test
N-Length Sentences
Scenario
Write sentences with 10 words each
Run ID
2026-02-08-01KGYYXCJJ3RP8AMZCVF7P3N62
Model input
User/Human
Please write the opening scene of a murder mystery where each sentence has exactly 10 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 hard against the Victorian mansion's windows. Detective Sarah Chen stepped out of her unmarked sedan. The grand house loomed dark except for upstairs lights. A uniformed officer met her at the iron gates. "The victim is Margaret Ashford, age seventy-two," he said. Her body was discovered this morning by the maid. The scene is preserved upstairs in the east wing. Sarah climbed the spiral staircase with practiced, careful steps. The bedroom door stood open, revealing an unsettling, quiet scene. Margaret lay motionless upon her four-poster mahogany bed frame. Her silk nightgown was stained deep crimson with blood. An empty teacup sat on the nightstand beside her. The window behind her was open to the rain. Sarah's eyes narrowed as she surveyed the silent room. Something about this murder didn't feel quite right somehow. She turned to the officer waiting nervously in doorway. "Tell me everything you know about Margaret Ashford's life."
created_at
"2026-02-08T15:46:23.534108+00:00"
Sunday, February 8th, 2026 at 3:46:23 PM GMT+00:00
model
"anthropic/claude-4.5-haiku-20251001"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
395
moderation_latency
(null)
generation_time
3154
tokens_prompt
35
tokens_completion
205
native_tokens_prompt
44
native_tokens_completion
227
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
0.001179
router
(null)
provider_responses
0
id
"msg_01NPJLVEUJykecfkbxLgZvGb"
status
200
is_byok
false
latency
395
endpoint_id
"41d2915a-92e6-4993-b537-210b4e10cba8"
provider_name
"Anthropic"
model_permaslug
"anthropic/claude-4.5-haiku-20251001"
api_type
"completions"
id
"gen-1770565579-Bk4xmz9FpgTmo1CdjdNj"
upstream_id
"msg_01NPJLVEUJykecfkbxLgZvGb"
total_cost
0.001179
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Anthropic"
Evaluation details
Result
Evaluator
Details
Meta Data
74.3316%
Matches word count
n/a
neededClean
false
sentences
18
wordCounts
0
6
1
9
2
9
3
9
4
9
5
10
6
9
7
9
8
9
9
10
10
10
11
9
12
9
13
9
14
9
15
9
16
9
17
9