Back in the days when times were hard and good drinks were hard (and illegal) to come by, there were always places to go to find good food and good drink, but one had to know how to get in. A soft knock or a light tap meant that whoever was out there did not really need a drink or were not really hungry. Or it might mean Johnny Law was looking for someone to arrest.
A good stout knock meant I'm here, I'm hungry, and I'm thirsty! Let me in!!! So to this day, The Hard Knock Grill is the place to go for good food, good drink and a fun time!