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_21489362_2 (rr3_pts INTEGER, rr4_pts VARCHAR)

### Question ###
When 20 is the rr4 points what is the lowest rr3 points?

### Accurate SQL ###

SELECT MIN(rr3_pts) FROM table_21489362_2 WHERE rr4_pts = "20"