Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_55 ( year INTEGER, sets VARCHAR, aces VARCHAR, opponent VARCHAR )

### Question ###
what's the most recent year that samantha stosur was the opponent with 20 aces and having played more than 2 sets?

### Accurate SQL ###

SELECT MAX(year) FROM table_name_55 WHERE aces = 20 AND opponent = "samantha stosur" AND sets > 2