For how many times has SC Ganguly played as team captain in a match?
SC Ganguly refers to Player_Name = 'SC Ganguly'; team captain refers to Role_Desc = 'Captain'
SELECT SUM(CASE WHEN T3.Role_Desc = 'Captain' THEN 1 ELSE 0 END) FROM Player AS T1 INNER JOIN Player_Match AS T2 ON T1.Player_Id = T2.Player_Id INNER JOIN Rolee AS T3 ON T2.Role_Id = T3.Role_Id WHERE T1.Player_Name = 'SC Ganguly'