Model

Claude Opus 4.5

Test

N-Length Sentences

Scenario

Write sentences with 5 words each

Run ID

2026-02-08-01KGYXAFVP2CPQ26N1NMA9J24X

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 loomed above her. Rain pelted the stone steps. Detective Morgan checked her watch. Midnight had just struck twice. Something felt wrong inside here. She pushed the heavy door. It creaked open very slowly. Darkness swallowed the grand foyer. Her flashlight cut through shadows. A chandelier hung above, shattered. Glass crunched beneath her shoes. The smell hit her hard. Copper and roses mixed together. She followed the terrible scent. It led to the study. A body lay face down. Blood pooled on expensive carpet. The victim wore silk pajamas. His hand clutched a letter. Morgan knelt beside the corpse. She recognized him right away. Theodore Blake, the famous billionaire. Someone wanted him dead tonight. The killer was still nearby. Morgan could feel their presence. A floorboard creaked somewhere upstairs. She drew her service weapon. The hunt had finally begun.
created_at"2026-02-08T15:18:39.014155+00:00" Sunday, February 8th, 2026 at 3:18:39 PM GMT+00:00
model"anthropic/claude-4.5-opus-20251124" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency1337
moderation_latency(null)
generation_time7123
tokens_prompt35
tokens_completion180
native_tokens_prompt44
native_tokens_completion203
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" 
usage0.005295
router(null)
provider_responses
0
id"msg_01MkUUzyiF5rJn7aLSwAqH51" 
status200
is_byokfalse
latency1337
endpoint_id"be883404-eb42-4b2d-b6e4-c7daa3aa8d62" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.5-opus-20251124" 
api_type"completions" 
id"gen-1770563911-y2x53HbiOdhf7Crlobq9" 
upstream_id"msg_01MkUUzyiF5rJn7aLSwAqH51" 
total_cost0.005295
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