Table: formula1_results
Columns: year
entrant
chassis
engine
points

Question: What is the average points that Centro Asegurador earned with the McLaren M23 chassis?
SQL: SELECT AVG("points") FROM formula1_results WHERE "chassis" = 'mclaren m23' AND "entrant" = 'centro asegurador'

Question: What was the chassis of Emilio de Villota in 1981?
SQL: SELECT "chassis" FROM formula1_results WHERE "year" > 1981