Run: 2026-09-23-01M37PTTBDPS3G9NCA0DQ44XEC

Run Details

Duration:
22.4s
Cost:
$0.046968
Provider:
Claude Platform on AWS

Evaluation summary

Score Evaluator
Details Link
100.00% Matches word count (details)

Model input

User/Human
Please write the opening scene of a murder mystery where each sentence has exactly 20 words. Please make sure that each sentence has the same length. Only return the opening itself.

Model response

AI
The winter storm had been battering Blackwood Manor for three hours when the lights flickered once and then died completely. In the sudden darkness, eleven guests froze around the dining table, their silverware suspended above plates of cooling roast duck. Somewhere upstairs, a door slammed with such force that the crystal chandelier above them trembled and chimed like nervous laughter. Margaret Ashford, the elderly hostess, was the first to speak, and her voice carried a sharpness nobody had heard before. "Nobody move," she said, striking a match that briefly illuminated her pale face and the empty velvet chair beside her. That chair belonged to her nephew Julian, who had excused himself ten minutes earlier to fetch another bottle of wine. Doctor Harwell pushed back his seat, muttering about fuses, but Margaret seized his wrist with surprising strength for her age. Then came the scream, long and ragged, spilling down the grand staircase and echoing through every corridor of the house. By the time they reached the library, candles trembling in their hands, the maid was kneeling beside Julian's motionless body. A silver letter opener protruded from his chest, and clutched in his hand was a torn page from Margaret's diary. Every frightened face turned slowly toward their hostess, who stared at the page as though she had seen a ghost.
created_at"2026-09-23T18:00:49.278Z" 9/23/2026, 6:00:49 PM
model"anthropic/claude-opus-5.5-20260921"
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency4457
moderation_latency(null)
generation_time22379
tokens_prompt46
tokens_completion567
native_tokens_prompt62
native_tokens_completion2336
native_tokens_completion_images(null)
native_tokens_reasoning1900
native_tokens_cached0
num_media_prompt(null)
num_input_audio_prompt(null)
num_media_completion0
num_search_results(null)
num_fetches(null)
web_search_engine(null)
origin"https://ncbench.com/"
is_byokfalse
finish_reason"stop"
native_finish_reason"end_turn"
service_tier"default"
usage0.046968
router(null)
user_agent"langchainjs-openai/1.0.0 ((node/v24.20.0; linux; x64))"
http_referer(null)
request_id"req-1790186449-QNkpHXIjyIa5BcqWpwA9"
session_id(null)
preset_id(null)
api_type"completions"
id"gen-1790186449-EPQUZVMGPbRrBC3wsb9R"
upstream_id"msg_011CfLoq9TPK2cN4LronG517"
provider_responses
0
endpoint_id"3a2388bc-3740-4e64-a1f5-4e301726b6b9"
id"msg_011CfLoq9TPK2cN4LronG517"
is_byokfalse
latency1389
model_permaslug"anthropic/claude-opus-5.5-20260921"
provider_name"Claude Platform on AWS"
status200
total_cost0.046968
cache_discount(null)
upstream_inference_cost0
provider_name"Claude Platform on AWS"
response_cache_source_id(null)
data_region"global"
workspace_id"97e315e5-d303-487d-83c1-83180e8a13d4"

Evaluation details

Result Evaluator Details Meta Data
100.00% Matches word count n/a
neededCleanfalse
sentences11
wordCounts
020
120
220
320
420
520
620
720
820
920
1020