And not everyone even follows the 15 to 20 percent principle; I've given great service to people who thought 10 percent should cut the mustard.
It doesn't. Waitpeople make $2.13 an hour base pay. Some of them are good, some of them are bad--and some diners' perceptions of what is good and what is bad vary greatly. I never took kindly to people who treated me as their personal slave for the one and a half hours it took them to eat their meals. One customer once asked: "Honey, would you go buy me a pack of cigarettes and I'll pay you back in your tip?" (He didn't.) And waitpeople are often punished for kitchen mistakes. Kitchen staffers get their six bucks an hour whether or not they send the food out cold, in the process perhaps freezing the waiter out of a fair tip.
Out of empathy for their waitstaffs, some restaurateurs have tried to fix the problem. One notable example is Jimmy Schmidt, now back to try again with the Rattlesnake Grill. In a recent Rocky Mountain News interview, Schmidt said that one of his mistakes at his last Denver restaurant, the Rattlesnake Club, was putting a mandatory 18 percent gratuity charge on all checks, regardless of table size. Diners balked at the idea, and Schmidt credits their reluctance to pay the set charge as being one reason for the restaurant's downfall.
Frankly, I'm all for the way it's often done in Europe: Diners pay higher food prices, but the waitpeople are also paid decently. There, the act of tipping is what it was intended to be: a reward for exemplary service, nothing more or less.
Some people argue that this encourages bad service: If waitpeople don't have to work for their tip, they become lazy and indifferent. In response, I quote Rhodes and Hilliker: "Wouldn't it be great to pay for the parts being replaced in your sink, and then it was left up to you to judge the service of your plumber and pay for his labor, his tip!" With that as an analogy, I'd say that waitpeople would work harder if they knew they were already earning enough money to put food on their own tables and would earn even more if they put forth extra effort.
In the meantime, here's what I propose: If you get service above and beyond the call, tip 20 percent. If the waitperson delivers your wife's baby on the table, tip still more. If your service is average, but satisfactory, tip 15 percent. Between that, tip accordingly. And if your service is truly lousy, get the waitperson's name and call the manager. That's the only way to weed out terrible waitpeople--otherwise, your below-15-percent tip will be seen only by the bad server, which usually doesn't help the next diner.
One last thought: I always know when I'm dining with former waitpeople--they overtip.