Run: 2026-05-01-01KQHR2XDW5X5YCQ1997R4RWM8

Run Details

Model:
Grok 4.20 (Reasoning)
Test:
Data extraction
Scenario:
What instrument does Lucy play?
Duration:
7.0s
Cost:
$0.001617
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 explicitly assigns three of them (John: drums; Mary: flute; Pete: trumpet), leaving only bass unassigned. The additional clause that Lucy does not play a wind instrument is consistent with bass (a non-wind instrument) and rules out any ambiguity with the wind instruments already taken by Mary and Pete. No other instrument satisfies both the assignment logic and the non-wind constraint.
created_at"2026-05-01T12:26:45.57Z" 5/1/2026, 12:26:45 PM
model"x-ai/grok-4.20-20260309"
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency6023
moderation_latency(null)
generation_time6909
tokens_prompt75
tokens_completion213
native_tokens_prompt185
native_tokens_completion608
native_tokens_completion_images(null)
native_tokens_reasoning513
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"
usage0.00161685
router(null)
provider_responses
0
endpoint_id"3ecee37f-b217-4093-87fb-aaf0afe307af"
id"1699a190-d9dc-9e37-a4ef-b7da2bba7d38"
is_byokfalse
latency100
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-1777638405-VlL1095mco4X6gRwPBop"
session_id(null)
api_type"completions"
id"gen-1777638405-u933U2otzza3CNbOlFuH"
upstream_id"1699a190-d9dc-9e37-a4ef-b7da2bba7d38"
total_cost0.00161685
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