IF YOU WANT TO KNOW what real pressure is, just try using a Barbie doll to set underwear on fire on national television. I did this on December 21, on "The Late Show With David Letterman." Technically, I was on this show to promote a book, but unless you're an extremely deep thinker such as Madonna, the Letterman people don't like you to just sit there and talk. They want you to have what is known in the TV business as a Strong Visual Element, to keep things moving along. To give you an idea of what I mean, here's how the Letterman show would rate two hypothetical guest spots:

WEAK GUEST SPOT : Nobel Prize-winning research scientist explains revolutionary new and easy way to prevent cancer.

STRONG GUEST SPOT : Nobel Prize-winning research scientist plays badminton against a cow.

So when a Letterman show producer named Dan Kellison called me up to find out if I had any visual elements, I told him about my Rollerblade Barbie experiment. Rollerblade Barbie is a type of Barbie doll -- no longer available in stores, for reasons that will soon become apparent -- that comes with little booties equipped with cigarette-lighter-type flint wheels; when you roll Rollerblade Barbie along a flat surface, her booties shoot out sparks. A while back, after reading a newspaper account of an accident involving a Rollerblade Barbie and some kids who were playing "beauty shop," I conducted a scientific experiment in my driveway. This experiment proved that if you spray hair spray on a set of underwear, then roll Barbie across it, the underwear will burst into flames.

Dan instantly realized that this experiment would have great visual potential as a way to educate the Letterman audience. But he wanted to make sure it would work, so on the day of my scheduled TV appearance, I went to the theater several hours early for a rehearsal.

Backstage, besides Dan, were maybe a dozen Letterman show personnel, as well as a representative of the New York City Fire Department. The ambiance was a lot less casual than it had been in my driveway. Everybody was concerned about the fire danger; everybody was also VERY concerned about how Letterman would react. One guy kept saying things like, "Is this okay with Dave? Is Dave going to be comfortable with this? How close is Dave gonna be? Did we run this by Dave? Maybe we should run this by Dave again."

Many eyes were watching me closely as I spread a pair of men's cotton briefs on a table, then sprayed them with hair spray. Then I picked up a Rollerblade Barbie, put her on the briefs and scooted her forward, sparks flying, and suddenly . . .

. . . And suddenly nothing happened.

"Ha ha!" I said, to add levity to the moment. But it was not a light moment. It was a moment only hours before the taping of a hit national show that was supposed to feature flaming underpants, and here we had a set of what is known in the TV business as Stone Cold Briefs.

So I sprayed more hair spray and tried again. Nothing. I tried a different kind of hair spray. Nothing. I tried a different set of briefs. Nothing. I tried a Rollerblade Ken (which we had on hand as a backup). Nothing.

Pretty soon all the observers had changed from being-concerned-about-too-much-fire mode to being-concerned-that-there-would-not-be-any-fire mode. As I furiously swiped Barbie and Ken across various sets of underwear, people crowded around, offering suggestions, including: "Maybe we should PREHEAT the underwear." At one point, the Fire Department representative, on hand to ensure the public safety, said to me (I swear): "You should use Ken. You're getting more sparks with Ken."

Finally, just as we were about to give up, we got it to work (the secret, discovered by Dan, was to use an ENORMOUS amount of hair spray). As the blue flames flickered on the underwear, Dan and I gave each other triumphant high-fives. I was elated, until suddenly the thought hit me: What if it didn't work on the show?

So I was a nervous wreck when, two hours later, I found myself in front of TV cameras and a live studio audience, placing underwear on David Letterman's desk, spraying it with hair spray and picking up Rollerblade Barbie. In my entire life, except for during a couple of crucial free throws in the 1983 NBA playoffs, I have never asked for the help of a Higher Power, but I was definitely thinking in those terms as, with Letterman watching me closely, I positioned Barbie on the briefs, and rolled her forward, and . . .

. . . And once again nothing happened.

Fortunately, this turned out to be just a little Higher Power prank, because when I quickly rolled Barbie a second time, the briefs burst into flames. I don't remember much after that. Letterman picked up a fire extinguisher and blasted the briefs, then the camera person, then the audience, which was thrilled. So it turned out to be a highly educational guest spot after all, and I'm sure that you, the viewing public, learned a lot.

You don't have to thank me. I'm just trying to avoid getting a real job.