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_42173 ( "Position" real, "Team" text, "Points" real, "Played" real, "Drawn" real, "Lost" real, "Against" real, "Difference" text )

### Question ###
Team Estudantes Paulista with a position less than 4 has what average against?

### Accurate SQL ###

SELECT AVG("Against") FROM table_42173 WHERE "Team" = 'estudantes paulista' AND "Position" < '4'