Table schema:
CREATE TABLE table_name_8 (tries_against INTEGER, tries_for VARCHAR, points_against VARCHAR, points_for VARCHAR)

Question: 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