Model

Claude Opus 4.5

Test

N-Length Sentences

Scenario

Write sentences with 10 words each

Run ID

2026-02-08-01KGYXWEHWS35YGYK6VWSKEKRF

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 Sarah Chen stepped out of her black sedan slowly. Rain poured down heavily, soaking her worn brown leather coat. She had seen many crime scenes throughout her long career. But something about this one felt different, almost eerily wrong. The butler waited nervously at the massive oak front door. His pale hands trembled as he gestured for her inside. A body lay crumpled at the bottom of the stairs. The victim was wealthy industrialist Marcus Webb, aged sixty two. Blood pooled beneath his head like a dark crimson halo. His eyes stared blankly at the crystal chandelier hanging above. No one had heard him fall during the dinner party. Twelve guests had been present when the lights went out. Now twelve suspects waited anxiously in the grand dining room. Sarah knelt beside the body and studied it very carefully. This was no accident, she realized with growing cold certainty. Someone in this house had committed a very calculated murder. She stood up slowly and turned to face the butler. The truth was hiding somewhere within these ancient elegant walls. Tonight, she would find it, no matter what the cost.
created_at"2026-02-08T15:28:28.746867+00:00" Sunday, February 8th, 2026 at 3:28:28 PM GMT+00:00
model"anthropic/claude-4.5-opus-20251124" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency1435
moderation_latency(null)
generation_time8075
tokens_prompt35
tokens_completion241
native_tokens_prompt44
native_tokens_completion269
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" 
usage0.006945
router(null)
provider_responses
0
id"msg_01MPRonSM4ucQL4vs7ozLotv" 
status200
is_byokfalse
latency1435
endpoint_id"be883404-eb42-4b2d-b6e4-c7daa3aa8d62" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.5-opus-20251124" 
api_type"completions" 
id"gen-1770564500-5Sl8uaLIm9uFMQBAnOln" 
upstream_id"msg_01MPRonSM4ucQL4vs7ozLotv" 
total_cost0.006945
cache_discount(null)
upstream_inference_cost0
provider_name"Anthropic" 

Evaluation details

Result Evaluator Details Meta Data
100.0000% Matches word count n/a
neededCleanfalse
sentences20
wordCounts
010
110
210
310
410
510
610
710
810
910
1010
1110
1210
1310
1410
1510
1610
1710
1810
1910