what's the average grid that has a time/retired piston and laps smaller than 15?
CREATE TABLE table_name_81 (grid INTEGER, time_retired VARCHAR, laps VARCHAR)
SELECT AVG(grid) FROM table_name_81 WHERE time_retired = "piston" AND laps < 15
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_name_81 (grid INTEGER, time_retired VARCHAR, laps VARCHAR) Question: what's the average grid that has a time/retired piston and laps smaller than 15? [/INST] SELECT AVG(grid) FROM table_name_81 WHERE time_retired = "piston" AND laps < 15 </s>