The Truth is that the only decent hardcourt or clay tournament tennis balls are Dunlop Grand Prix, Penn Pro and Prince Tour. Penn and Wilson Championship and recently even the Wilson US Open tennis balls are ofter bald or the outer cover worn smooth after only one set or sometimes even in the 5 minute warm up period prior to a match. While they are decent tennis balls, they just always seem to get bald way too quick. I play 3 or 4 times a week on different courts thru out NorCal and I know from experience that Dunlop Champion tennis balls are very decent, the cover or nap lasts longer and bounce is more consistant than the above mentioned balls. Again, for $ .19 cents a can more, get the best tennis balls made, Dunlop Grand Pris, extra duty or Penn Pro extra duty.