CREATE TABLE table_name_16 (points NUMBER, year VARCHAR2, entrant VARCHAR2, chassis VARCHAR2)

What are the average points of Scuderia Scribante with a Brabham bt11 chassis before 1968?
SELECT AVG(points) FROM table_name_16 WHERE entrant = "scuderia scribante" AND chassis = "brabham bt11" AND year < 1968
SELECT AVG("points") FROM "table_name_16" WHERE "brabham bt11" = "chassis" AND "entrant" = "scuderia scribante" AND "year" < 1968