Table schema:
CREATE TABLE table_name_70 (school_club_team VARCHAR, years_for_grizzlies VARCHAR, nationality VARCHAR, position VARCHAR)

Question: What team is from the United States and plays a guard position for the Grizzlies in 2012?
SQL: SELECT school_club_team FROM table_name_70 WHERE nationality = "united states" AND position = "guard" AND years_for_grizzlies = "2012"