CREATE TABLE table_203_593 (id NUMBER, "tenure" CLOB, "coach" CLOB, "years" NUMBER, "record" CLOB, "pct." NUMBER, "ncaa tournament" NUMBER)

which head coach had the top win percentage ?
SELECT "coach" FROM table_203_593 WHERE "pct." = (SELECT MAX("pct.") FROM table_203_593)
SELECT "coach" FROM "table_203_593" WHERE "pct." = (SELECT MAX("pct.") FROM "table_203_593")