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_16 (points INTEGER, year VARCHAR, entrant VARCHAR, chassis VARCHAR)

### Question ###
What are the average points of Scuderia Scribante with a Brabham bt11 chassis before 1968?

### Accurate SQL ###

SELECT AVG(points) FROM table_name_16 WHERE entrant = "scuderia scribante" AND chassis = "brabham bt11" AND year < 1968