For the team had the biggest power play percentage in 2011, who was their coach that season? Give the full name.
the biggest power play percentage = max(divide(PPG, PPC))
SELECT T1.coachID FROM Coaches AS T1 INNER JOIN Teams AS T2 ON T1.tmID = T2.tmID WHERE T2.year = 2011 ORDER BY CAST(T2.PPG AS REAL) / T2.PPC DESC LIMIT 1