CREATE TABLE table_name_8 (tries_against INTEGER, tries_for VARCHAR(255), points_against VARCHAR(255), points_for VARCHAR(255))
Which Tries against has Points against larger than 156, and Points for of 127, and Tries for larger than 17?
    
SQL: SELECT AVG(tries_against) FROM table_name_8 WHERE points_against > 156 AND points_for = 127 AND tries_for > 17