I think averaging out all the numbers and reporting service doesn't matter may be missing those rare occasions when the restaurant really does screw up and you

I think averaging out all the numbers and reporting service doesn't matter may be missing those rare occasions when the restaurant really does screw up and you want to punish them with no tip. I want the waiter to go work hard and get me the right thing, etc., after a screw up or to know not to ignore my table for an hour. I don't have that option with an enforced service charge.