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

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")