How are you supposed to tip when you have a tab?
Tip every round or wait 'til the end?
I have never had a tab before, usually someone else is paying, so I am not sure of the rules. The other night a friend and I went to play some pool and we opened a tab. I didn't tip the waitress 'til the very end, but then realized the reason why she really didn't come back around much while we had an open tab was probably because we weren't tipping her.