Model

Claude Opus 4.6

Test

N-Length Sentences

Scenario

Write sentences with 10 words each

Run ID

2026-02-08-01KGZ050VMGXY31HRSW4VQW653

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

AI
The old mansion stood silent against the dark stormy night. Detective Morgan arrived at the scene just after midnight struck. Rain poured down heavily as she walked up the path. The front door was already open, creaking in the wind. A butler stood waiting, his face pale with visible shock. "The master is dead," he whispered with a trembling voice. She stepped inside and noticed muddy footprints across the floor. The grand hallway smelled of copper, smoke, and dying roses. A broken vase lay scattered near the winding spiral staircase. Upstairs, the body of Lord Ashworth waited in his study. He was slumped over his desk, a knife protruding deeply. The window behind him was shattered from an outside impact. Morgan pulled on her gloves and surveyed the gruesome scene. Three guests had been staying at the manor that weekend. Each one of them had a reason to want revenge. She turned to the butler and asked her first question. "Tell me exactly who was here when the screaming started." The investigation had begun, and the truth would soon emerge.
created_at"2026-02-08T16:08:06.966824+00:00" Sunday, February 8th, 2026 at 4:08:06 PM GMT+00:00
model"anthropic/claude-4.6-opus-20260205" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency1727
moderation_latency(null)
generation_time8204
tokens_prompt35
tokens_completion217
native_tokens_prompt44
native_tokens_completion255
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" 
usage0.006595
router(null)
provider_responses
0
id"msg_01HqSNWNRa28HgeezvvFdk7N" 
status200
is_byokfalse
latency1725
endpoint_id"c926c048-563e-44b0-8434-95965bee924c" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.6-opus-20260205" 
api_type"completions" 
id"gen-1770566878-gwEncq8cFuqxTtFRII67" 
upstream_id"msg_01HqSNWNRa28HgeezvvFdk7N" 
total_cost0.006595
cache_discount(null)
upstream_inference_cost0
provider_name"Anthropic" 

Evaluation details

Result Evaluator Details Meta Data
100.0000% Matches word count n/a
neededCleanfalse
sentences18
wordCounts
010
110
210
310
410
510
610
710
810
910
1010
1110
1210
1310
1410
1510
1610
1710