CREATE TABLE table_203_577 (id DECIMAL, "tenure" TEXT, "coach" TEXT, "years" DECIMAL, "record" TEXT, "pct." DECIMAL)

which coach had the most years as a coach ?
SELECT "coach" FROM table_203_577 ORDER BY "years" DESC LIMIT 1
SELECT "coach" FROM "table_203_577" ORDER BY "years" DESC NULLS LAST LIMIT 1