it depends on the type of coat, which blade is best, if its fine downy hair you want to shift then the more blades the better, so a 20 blade, if its heavier then less blades. Willow has a very fine coat so I use a 26 blade coat king, but it would not shift Paddy's coat which is long, sleek and thick and don't get me started on Bilbo's 6 foot curls