Run: 2026-05-01-01KQHQEZKSDAFJKP66CAZHGMS5

Run Details

Model:
Grok 4.20 (Reasoning)
Test:
Data extraction
Scenario:
What instrument does Lucy play?
Duration:
8.7s
Cost:
$0.002049
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, trumpet) and three players: John (drums), Mary (flute), Pete (trumpet). This leaves bass as the only unassigned instrument. The statement that Lucy does not play a wind instrument eliminates flute and trumpet (the two wind instruments in the list), which are already assigned, confirming that she must play the remaining non-wind instrument: bass.
created_at"2026-05-01T12:15:52.449Z" 5/1/2026, 12:15:52 PM
model"x-ai/grok-4.20-20260309"
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency7341
moderation_latency(null)
generation_time8635
tokens_prompt75
tokens_completion238
native_tokens_prompt185
native_tokens_completion781
native_tokens_completion_images(null)
native_tokens_reasoning692
native_tokens_cached128
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"
usage0.00204935
router(null)
provider_responses
0
endpoint_id"3ecee37f-b217-4093-87fb-aaf0afe307af"
id"1452c2bd-10a9-986c-9d2c-f08073f9b226"
is_byokfalse
latency133
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-1777637752-4dcBH7l50zKVodsHY4rn"
session_id(null)
api_type"completions"
id"gen-1777637752-VBWSW1VUQR4df4NdYZJQ"
upstream_id"1452c2bd-10a9-986c-9d2c-f08073f9b226"
total_cost0.00204935
cache_discount0.0001344
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