SELECT "Player" FROM table_4720 WHERE "From" < '2012' AND "Position" = 'center' AND "Nationality" = 'united states'
Which player played center, is from the United States, and entered before 2012?
CREATE TABLE table_4720 (
    "Player" text,
    "Nationality" text,
    "Position" text,
    "From" real,
    "School/Country" text
)