The Upside-Down Glass: Science Fiction

He finished his drink, wiped his mouth, and set the glass upside-down on the bar with some decisiveness. Then he turned around, leaned his elbows on the bar, and waited for the first taker. A low mumble went up around the bar as they noted his challenge, and some of the closer men picked up their drinks and moved over to a place where they were less likely to be disturbed by flying fists and bodies. He waited, a little impatiently, a little nervously. It might not have worked, after all. There was always a 70% chance that a processing improvement wouldn't take, and a 10% chance that it would--

Inspiration: My survival day calendar - in Australia, turning a glass upside-down and placing it on the bar may signal that you believe you can win a fight with anyone.
Story Potential: Low.
Notes: Cute scene, no story. On the other hand, that would be an awesome name for a pub.