At the close of work one day, you head for a neighborhood saloon where you've agreed to meet a friend at 5:30. You arrive on time, but there's no sign of your friend. You sit idly, and somewhat bored, on a stool at the bar awaiting the friend's delayed arrival.
As you glance down the bar, you make eye contact with someone sitting a few seats away. He looks vaguely familiar. After a few seconds, he walks over and sits down beside you, asking, "Have we met before?" After a few false starts, the two of you agree that you must have met at a charity affair a few years ago. The fellow mentions that he, too, is awaiting an associate's arrival. An awkward silence ensues.
The man pipes up, "To help pass the time, would you like to play a game?" You reply, "Sure, but nothing that requires much concentration. It's been a long day." "Fine," he says, "How about a simple gambling game? We'll see who is luckier. I'll flip a coin: Heads, I give you five dollars; tails, you pay me five."
This sounds simple enough to you, and you agree to play.