CREATE TABLE table_name_5 (games INTEGER, debut_year VARCHAR(255), years_at_club VARCHAR(255), goals VARCHAR(255))
Which Games have Years at club of 1977, and Goals of 17, and a Debut year smaller than 1977?
    
SQL: SELECT AVG(games) FROM table_name_5 WHERE years_at_club = "1977" AND goals = 17 AND debut_year < 1977