Model

Claude Opus 4.5

Test

N-Length Sentences

Scenario

Write sentences with 5 words each

Run ID

2026-02-08-01KGZ0BE4M717DA8V0XZSD7478

Model input

User/Human
Please write the opening scene of a murder mystery where each sentence has exactly 5 words. Please make sure that each sentence has the same length. Only return the opening itself.

Model response

AI
The mansion stood eerily silent. Detective Morgan approached the door. Rain pelted her worn coat. She knocked three sharp times. No answer came from within. The door creaked slowly open. Darkness swallowed the grand foyer. Her flashlight cut through shadows. A chandelier hung above, shattered. Glass crunched beneath her boots. The smell hit her hard. Death had visited this place. She found him near stairs. Lord Ashworth lay quite still. Blood pooled on marble floors. His eyes stared at nothing. A knife protruded from chest. Someone wanted him very dead. Morgan knelt beside the body. This was no simple robbery. The victim's watch remained intact. Diamond cufflinks still adorned sleeves. She noticed something clutched tight. His fist held torn fabric. Red silk, expensive and rare. The killer left evidence behind. Morgan smiled ever so slightly. This case would prove interesting.
created_at"2026-02-08T16:11:36.198422+00:00" Sunday, February 8th, 2026 at 4:11:36 PM GMT+00:00
model"anthropic/claude-4.5-opus-20251124" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency1638
moderation_latency(null)
generation_time7390
tokens_prompt35
tokens_completion182
native_tokens_prompt44
native_tokens_completion199
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" 
usage0.005195
router(null)
provider_responses
0
id"msg_01Tt8TYdpiWa5xQLvb9AX2QF" 
status200
is_byokfalse
latency1638
endpoint_id"be883404-eb42-4b2d-b6e4-c7daa3aa8d62" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.5-opus-20251124" 
api_type"completions" 
id"gen-1770567088-HSiQxzIihF0PyEKIjpAd" 
upstream_id"msg_01Tt8TYdpiWa5xQLvb9AX2QF" 
total_cost0.005195
cache_discount(null)
upstream_inference_cost0
provider_name"Anthropic" 

Evaluation details

Result Evaluator Details Meta Data
100.0000% Matches word count n/a
neededCleanfalse
sentences28
wordCounts
05
15
25
35
45
55
65
75
85
95
105
115
125
135
145
155
165
175
185
195
205
215
225
235
245
255
265
275