Composing for Grub Steet, alan Sytsma:

Dormant, just waiting for the online Outrage Machine to find it.
This week, it had been discovered, and yet another tipping debate — if
that is what you would like to call it — exploded. As you would expect the whole thing was exactly as idiotic. Tipping is simple, but for
anyone who still doesn’t get it, this FAQ that is helpful has been constructed by Grub Street.

This is how I’ve tipped my life: 20 percent tax, over the invoice included. That’s it. For service that is outstanding, or if you receive dishes or drinks, you hint on top of that. Don’t give me some Mr. Pink shit — this is how the machine operates, and if you tip less than 20% on your closing charge you’re stiffing your server.
Yes.

 ★ 

This entire thing is U.S.-centric, needless to say, but let me add that while I know how odd U.S. tipping culture has to seem to somebody from a different nation, it’s not complex, and in my experience, average support in U.S. restaurants is far better than in other nations. I think that the simple idea works as it incentivizes exceptional service.

It is not. If you drink and eat in café or pub or a restaurant or
whatever, where tips are accepted by servers, you’ll leave a tip, and
that suggestion will probably be 20 percent of their invoice, including tax and
whatever you’ve spent on alcohol.

For 14 months, this CNBC story on tipping has been lying
Do I Must tip?

It’s so complicated.