Question: Which coach had the highest winning rates in the 2009 season? What's coach's nickname.
SQL: SELECT T2.coachID, T1.nameNick FROM Master AS T1 INNER JOIN Coaches AS T2 ON T1.coachID = T2.coachID WHERE T2.year = 2009 ORDER BY CAST(T2.W AS REAL) / (T2.W + T2.L) DESC LIMIT 1