Model

Claude Opus 4.6

Test

N-Length Sentences

Scenario

Write sentences with 5 words each

Run ID

2026-02-08-01KGYXA3N4TXB8REJ8FFGCPVHQ

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 body lay perfectly still. Detective Morgan arrived at dawn. Blood stained the white carpet. Nobody heard a single scream. The window was wide open. Cold wind filled the room. Morgan knelt beside the victim. A young woman, eyes closed. Her silk dress was torn. No weapon could be found. The neighbors claimed total ignorance. Something felt deeply, terribly wrong. Morgan studied the crime scene. A broken glass caught light. Red lipstick marked its rim. Two plates sat on table. Dinner for two, it seemed. The candles had burned down. Wax pooled on dark wood. She had known her killer. Morgan pulled out his notebook. This case would prove difficult. The clock read five fifteen. Dawn crept through the curtains. Murder never waits for morning.
created_at"2026-02-08T15:18:27.317824+00:00" Sunday, February 8th, 2026 at 3:18:27 PM GMT+00:00
model"anthropic/claude-4.6-opus-20260205" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency1973
moderation_latency(null)
generation_time7470
tokens_prompt35
tokens_completion155
native_tokens_prompt44
native_tokens_completion171
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" 
usage0.004495
router(null)
provider_responses
0
id"msg_01VhHuK6LetWEkBqdPj6TEwc" 
status200
is_byokfalse
latency1973
endpoint_id"c926c048-563e-44b0-8434-95965bee924c" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.6-opus-20260205" 
api_type"completions" 
id"gen-1770563899-YIyfFtedM8Q3YHwcHPiC" 
upstream_id"msg_01VhHuK6LetWEkBqdPj6TEwc" 
total_cost0.004495
cache_discount(null)
upstream_inference_cost0
provider_name"Anthropic" 

Evaluation details

Result Evaluator Details Meta Data
100.0000% Matches word count n/a
neededCleanfalse
sentences25
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