Magicians have been performing magic tricks for thousands of years. If I asked you to guess how many tricks have been created — in all of recorded history — you’d likely say hundreds of thousands or millions. And you could make a case for such lofty numbers.

But in a very real sense, the number of tricks created, now and forever, is capped at 19. Why a figure so small?

In 1944, a semi-professional magician — who also happened to be an engineer — named Dariel Fitzkee published a book called “The Trick Brain.” In it, he condensed every conceivable magic trick down to 19 basic plots. Plot #1. An object could appear. Plot #2. An object could disappear. Plot #3. An object could change places with a second object. And so forth. Up to 19.

If you look through the eyes of Fitzkee the engineer, magically producing a coin falls in the same category as magically producing a 700-pound tiger. They’re both appearances or materializations. To create a new materialization trick, all you’d have to do is materialize an object of a different type.

And magicians have. Through the years they’ve magically produced billiard balls, blocks of ice, bricks, cockroaches, doves, fighter jets, helicopters, macaws, playing cards, rabbits, sand, snowflakes, streamers, water, whiskey, and umbrellas. They’ve produced a lone human as well as a crowd.

So how does a magician decide what to magically produce?

If the magician is smart, they base their choice on meaning. And I’m not talking about what’s most meaningful to the magician. I’m talking about what’s meaningful to the audience. The magician needs to see through the audience’s eyes.

A 20th Century performer, Henning Nelms, calls this idea “The Ham Sandwich Theory.” He says if a magician magically produces a ham sandwich from your previously empty jacket pocket, at first you’ll be amazed but that amazement will die out fast, because the trick has no point. A sandwich? What’s that got to do with anything?

But imagine that same sandwich materializing in your pocket after you told the magician you’re starving. What would your reaction be then? Oh my gosh, a miracle! You’ll eat the sandwich, your hunger will fade, you’ll tell everyone you know, and you’ll remember the moment for the rest of your life.

All because the trick had a point. All because it had meaning — from the audience’s perspective.

Basing a trick on what the audience finds meaningful is such a powerful strategy that famed magician, David Blaine, used a version of the sandwich idea to close his first TV special.

On a Manhattan sidewalk sat a destitute man holding a takeaway cup of coffee. Blaine bent down, whispered a few magic words, and the coffee inside the cup seemed to bubble and transform. Into what? An overflow of silver coins. The man on the sidewalk, overwhelmed by his good fortune, began singing and praising the lord.

The trick was mystifying, for sure, but in the end its power came from having a point. It was ABOUT something.

Blaine could have chosen to magically fill the man’s cup with a thousand different things: acorns, feathers, gyroscopes, marbles, push pins, soil. But the sudden appearance of any of those objects would have constituted mere spectacle. What the impoverished man could really use was a cup spilling over with money. And that’s what he got.

The illusion was predicated on deep wish fulfillment.