Model

Claude Opus 4.6

Test

Data extraction

Scenario

What instrument does Lucy play?

Run ID

2026-02-08-01KGYYZC4JP9PC0YKTHMXTTJVV

Model input

User/Human
What instrument does Lucy play based on the following text? Only return the instrument, nothing else. In the school band, there are four instruments: drums, bass, flute, trumped. John plays the drums, Mary plays the flute, and Pete plays the trumpet. Lucy doesn't play a wind instrument.

Model response

AI
Drums Wait, let me reconsider. John already plays the drums. Bass
created_at"2026-02-08T15:47:28.060662+00:00" Sunday, February 8th, 2026 at 3:47:28 PM GMT+00:00
model"anthropic/claude-4.6-opus-20260205" 
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency2218
moderation_latency(null)
generation_time2798
tokens_prompt62
tokens_completion16
native_tokens_prompt73
native_tokens_completion22
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" 
usage0.000915
router(null)
provider_responses
0
id"msg_01GBHnkh2qs5yswW2HYxSAYu" 
status200
is_byokfalse
latency2218
endpoint_id"c926c048-563e-44b0-8434-95965bee924c" 
provider_name"Anthropic" 
model_permaslug"anthropic/claude-4.6-opus-20260205" 
api_type"completions" 
id"gen-1770565644-wq242nMXeVZxRfgs972x" 
upstream_id"msg_01GBHnkh2qs5yswW2HYxSAYu" 
total_cost0.000915
cache_discount(null)
upstream_inference_cost0
provider_name"Anthropic" 

Evaluation details

Result Evaluator Details Meta Data
Fail Matches text
Case insensitive: bass
 n/a
Pass Matches Regex
/\bbass\b/i
 n/a
50.0000%