Elmer Wyatt has been driving a cab here for 43 years. Shortly after dawn on Tuesday, he picked up a man who emerged from the Madison Hotel and asked to be taken to the 400 block of Brandywine Street SE.

When Elmer reached that destination, his passenger grabbed Elmer's neck with one hand and pressed a knife against it with the other. "Lemme have it," the passenger said, punctuating the command by pressing a little harder with the knife.

Elmer handed over $110. "Now beat it," the man said. "Get lost."

The man stood still and watched nonchalantly as Elmer drove away. Meanwhile Elmer picked up his two-way radio and asked that police be dispatched on the scene. When they arrived a couple of minutes later, the man was gone, but the police told Elmer that his description of the "passenger" was a good fit for a man who was already wanted in several similar robberies.

Elmer went back to work. He brooded all morning about what an unlucky date April 21 had been for him. A few hours later, he stopped in a nearby Maryland store that sells lottery tickets and made a bet on the date: 421.

The ticket seller asked him if he wanted to "box" it. "No," Elmer said, "Just straight up 421."

The number came out 124.

And that night Elmer's two-way radio was stolen from his cab.

When I heard about his misadventures, I said: "Maybe there's something to the old superstition that bad luck runs in sets of threes."

"At first, I thought so, too," Elmer said. "But the little hole in my neck where the guy pressed his knife tells me that April 21 was really one of the luckiest days I have ever had. The last time my name was in the paper was like 34 years ago when I changed a tire for a lady and she sent you my license number and you tracked me down and wrote about me. On April 21, I came real close to having my name in the paper again -- in an obituary. I think it was a lucky day."

What a great hunch for a numbers game bet. Figure out the number of days it has been since Elmer's name was in this column 34 years ago, multiply by your age, add your street address, subtract 172,000 (for the $172,000 in taxes Spiro Agnew paid on "unreported income" he says he didn't take), and then throw away all your calculations and play the first number that pops into your mind. Remember, ya gotta play to lose.