Run: 2026-05-01-01KQHSE56CKTRT0Q0BRVM447XK

Run Details

Model:
Grok 4.20 (Reasoning)
Test:
Data extraction
Scenario:
What instrument does Lucy play?
Duration:
7.5s
Cost:
$0.001852
Provider:
xAI

Evaluation summary

Score Evaluator
Details Link
Fail Matches text (details)
Pass Matches Regex (details)
no eval Overall

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
bass The text lists four instruments: drums, bass, flute, and trumpet (noting "trumped" as a clear typo). It assigns John to drums, Mary to flute, and Pete to trumpet, leaving bass as the only unassigned instrument. The additional detail that Lucy does not play a wind instrument (flute and trumpet qualify as wind instruments, while drums and bass do not) eliminates any possibility of her playing the already-assigned wind options and confirms she must play the remaining non-wind instrument, bass. This assignment satisfies all constraints without contradiction.
created_at"2026-05-01T12:50:22.546Z" 5/1/2026, 12:50:22 PM
model"x-ai/grok-4.20-20260309"
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency6243
moderation_latency(null)
generation_time7455
tokens_prompt75
tokens_completion234
native_tokens_prompt185
native_tokens_completion675
native_tokens_completion_images(null)
native_tokens_reasoning561
native_tokens_cached64
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"completed"
usage0.00185155
router(null)
provider_responses
0
endpoint_id"3ecee37f-b217-4093-87fb-aaf0afe307af"
id"49ee6dc7-007d-09e9-e788-aa4a41a596f9"
is_byokfalse
latency66
model_permaslug"x-ai/grok-4.20-20260309"
provider_name"xAI"
status200
user_agent"langchainjs-openai/1.0.0 ((node/v24.14.1; linux; x64))"
http_referer(null)
request_id"req-1777639822-bikmEA9F4y8lw2fPVgB4"
session_id(null)
api_type"completions"
id"gen-1777639822-cEYlfvPhpPdl5HkFa4o4"
upstream_id"49ee6dc7-007d-09e9-e788-aa4a41a596f9"
total_cost0.00185155
cache_discount0.0000672
upstream_inference_cost0
provider_name"xAI"
response_cache_source_id(null)

Evaluation details

Result Evaluator Details Meta Data
Fail Matches text
Case insensitive: bass
 n/a
Pass Matches Regex
/\bbass\b/i
 n/a
no eval