A few years ago I worked for and traveled with a guy who had interesting tipping habits. He left reasonable (~20%) tips on food, but always tipped a fixed amount on beverages. As I recall it was $5 or 10 for a bottle of wine and $1 or 2 for a drink.
His take on it was that there is no difference between serving a $25 bottle of wine and serving one that cost $200, and that a server's efforts have nothing to do with the grade of liquor poured into a glass. But frankly, we didn't drink many $25 bottles of wine or much booze from the well.
Once I figured this out, my solution was to sneak money to the servers to make up for what I perceived as his under-tipping. I was eating and drinking well at somebody else's expense, and didn't mind hiding a few bucks under the dessert plate when my boss wasn't looking.
As years have gone by, though, I've occasionally wondered whether my ex-boss's tipping theories were a merely product of his demented mind, or whether there is wider acceptance of those habits. Can anybody fill me in?