Model

Claude Opus 4.5

Test

N-Length Sentences

Scenario

Write sentences with 5 words each

Run ID

2026-02-08-01KGYZN3JZ4P872A5VZMA9RHKB

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 arrived at dawn. Blood stained the marble floor. A body lay face down. The victim was Lord Ashworth. His wife screamed upstairs loudly. Servants gathered in the hallway. No one had heard anything. The study window was open. Cold wind filled the room. A letter opener was missing. Morgan examined the fresh wound. Someone wanted Lord Ashworth dead. The butler seemed unusually nervous. Lady Ashworth stopped her crying. She pointed at the gardener. He had motive and opportunity. But something felt terribly wrong. Morgan noticed muddy footprints everywhere. This case would prove difficult.
created_at"2026-02-08T15:59:22.80382+00:00" Sunday, February 8th, 2026 at 3:59:22 PM GMT+00:00
model"anthropic/claude-4.5-opus-20251124" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency1569
moderation_latency(null)
generation_time5659
tokens_prompt35
tokens_completion126
native_tokens_prompt44
native_tokens_completion143
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" 
usage0.003795
router(null)
provider_responses
0
id"msg_01HtFwBPHqqzGqbS1ma1uMHi" 
status200
is_byokfalse
latency1569
endpoint_id"be883404-eb42-4b2d-b6e4-c7daa3aa8d62" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.5-opus-20251124" 
api_type"completions" 
id"gen-1770566356-pVRuGBwxtVHEyxjoC95u" 
upstream_id"msg_01HtFwBPHqqzGqbS1ma1uMHi" 
total_cost0.003795
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
05
15
25
35
45
55
65
75
85
95
105
115
125
135
145
155
165
175
185
195