SWITCH! Magic Trick Tutorial

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).

Give one spectator a chance to play the role of an assassin and hand them a slip of paper, on the outside of which is drawn a skull and crossbones or a big ‘X’ depending on your artistic ability or preference. (2).

‘Imagine this is poison. And you are the assassin,’ you say to the assisting spectator. ‘There are three glasses mouth upwards. I want you to drop the poison into one of the glasses. Not yet. Wait until I turn around. I don’t want to see anything.’

You turn away from the spectator, who now drops the paper into one of the three upturned glasses. At this point, it doesn’t seem like you have much information, but because of the way you arranged the glasses, you know the poison is at an odd-numbered position i.e. 1, 3 or 5.

‘Now, if you were trying to poison me, I’d want to guess where you placed that poison. But let’s make it more difficult. There are two glasses mouth down. Turn them over. Now we have five glasses to play with.’ (3).

The spectator does as instructed, and you give the first of several directions that will change the positions of the glasses.

Switch 1

‘I want you to switch the poisoned glass with one of the glasses next to it. Could be the one to its left or the one to its right. You decide.’

The spectator switches the poison glass with one of its neighbours.

This brings the poison glass from an odd position to an even position.

Switch 2

‘And now do it again. Switch the poison glass with a glass that is next to it. Sometimes you’ll have two choices. Sometimes only one. Make the switch now.’

Mention of ‘choices’ refers to the fact that the poison glass might be at the end of the row so only one switch is possible.

The glass moves back to an odd position.

Switch 3

‘You’re probably thinking that although I can’t see what you’re doing, I can hear what you’re doing. Switch the glass again, but this time do it quietly. Do it now.’

The spectator switches the poison glass with one next to it.‘Have you done it? That’s how quiet it was. I had to ask.’The poison glass is in one of the even positions, 2 or 4.‘In fact, I heard nothing from your left. So, take the glass on the left end of the row away.’

The spectator takes glass 1 away, a glass at an odd position. This leaves four glasses on the table (4).

You don’t know whether the poison is in position 2 or 4, but you can narrow down the possibilities.

‘The poison is still on the table, yes?’‘Great. Tell you what. Take away the glass on the right. That glass is empty.’ (5)

The glass at the right end of the row is removed, leaving three on the table. The poison is still in position 2 or 4.

Switch 4.

‘I want you to make another switch. Switch the poison glass for the one next to it.’

The spectator follows the instruction. The poison will now be in position 3. Even though you did not know the starting position of the poison, you have successfully manoeuvred it to a known position.

‘You have three glasses on the table. Let me think a moment. Take away the right-hand glass.’

The spectator does, and there are now two glasses on the table. The poison is in the right-hand glass.

Revelation 1

‘There are two glasses on the table. One glass for you. And one glass for me. Unfortunately, one of those glasses is poisoned. You poisoned it. And I am your intended victim. But if we were together at the bar, do you know what I would do? I'd take the glass on your left. Which means you get the glass on your right.’

Be very clear in your statement before you turn around and pick up the glass on the spectator’s left. This is the empty glass.

‘Cheers.’

Revelation 2

‘When we started, I said you could play the role of the assassin. And I'd be the victim. But there were other people in the room.’

You point to the others around the table.

‘If we’d all been playing the game, maybe someone else would have got the poison. Maybe the poisoned glass would have landed here, or here, or...’

You turn the paper coasters over. Each of them has a name of one of the spectators written on the underside. People are surprised to see their names there.

Ask the assassin to take the poison paper from the glass, unfold it and read out the contents. It says, ‘You poisoned yourself!’

Revelation 3

Lift the assassin’s glass from the table and turn over its coaster. On the other side is written the assassin’s name.

Let me explain how.

REVELATIONS EXPLAINED

To set up the finale, you need to know the names of some people around the table. Write five on them on the coasters. Make sure your assassin’s name is on the middle coaster (position 3) because that is where the glass will end up at the finish.

You can do this preparation ahead of time or even at the table. The spectators do not know what you’re writing so it will still be a surprise when it’s revealed.

The assassin can make more than one switch at a time. For example, at Switch 4, instead of asking the assassin to move the poison once, have them move it three times. The poison is at an even number, so any odd number will put the glass in the middle of the row of three i.e., the only odd number available.

Similarly, instead of asking the spectator to make one switch or three, you can ask them to keep switching glasses but call out every time they have made a switch. When the spectator has made an odd number of switches, you ask them to stop. You can then proceed with the next step in the routine. This is very effective when there are just two glasses on the table.

NOTES

The strength of this trick lies in the system. You can apply it in many ways, use different items, and dress it up with any plot. Jack Yates used four matches lying on the table. The spectator turns one end for end so that it points in a different direction to the rest. This match is switched with matches either side. Mel Stover suggested that, instead of switching glasses, the spectator can pour an ice cube from one adjacent glass to another. You can borrow items from the spectators and predict which will be left at the end of the switching game, asking each owner to remove their item as you discard it from the table.

You don’t have to call out instructions, you can record them in an audio or video file on your phone. As a demonstration of telepathy, you can call a friend and have them give out the instructions over the phone even though they can’t see what is happening in the room.

Although this system has been in existence for 70 years, it still seems full of untapped possibilities. One of these is to perform the trick with two different spectators at the same time. Giving each of them slightly different instructions. That would look very impressive indeed.