# SWITCH! Magic Trick Tutorial

From the desk of David Britland

There is a genre of mathematical tricks in which you appear to control and predict the actions of a spectator. For example, the spectator mixes around three cups. Under one is a banknote. Even though you cannot see the cups, you always know which cup hides the banknote. The method is simple and sure-fire. What makes the system worth knowing is its versatility. You can use it impromptu, with props, or create a routine for a special situation. In this example, one spectator becomes a would-be assassin. Unfortunately, their attempts to poison their victim, you, end with the spectator poisoning themselves.

**THE SYSTEM**

Magician Bob Hummer published a long-guarded secret in 1951. He called it **Mathematical 3 Card Monte**. Three years later, Jack Yates devised **Match Miracle**, a simplified version of the Hummer trick. Imagine there are three cards on the table; a Queen is at the centre position. You are asked to switch the Queen with one of its neighbours. Now the Queen is in a different position. If the performer has their back to you, they can have no idea where the Queen now lies.

To further confuse the performer, you switch the Queen again, and again, and again, always with a neighbouring card. It would appear impossible to know where the Queen would end up. Except it isn’t impossible. Yates realised that if the Queen starts in an odd position and you switch the cards an even number of times, the Queen ends back in the centre. And that you could use the system with more than three objects. It became the foundation for many mind-reading effects you could perform face to face or remotely. In the routine described here, we’ll use five glass tumblers, some imaginary poison, and give one spectator a chance to kill you.

**PRESENTATION**

You are at a house party with a group of spectators and have gathered some props together for a demonstration. On the table are five paper coasters and on the coasters five glasses. Two are mouth down, three are mouth up. Let's mentally number the positions from 1 to 5 for this explanation (1).