Card Tricks...

I love card tricks that rely completely on the math to work. For example, the card trick Michael shows in his video with the 3 piles of 7.

I then found this trick on youtube: http://www.youtube.com/watch?v=HAsaVZi5XLs&feature=g-vrec&context=G2aefaaeRVAAAAAAAABQ

This is another trick that relies completely on the math. My goal is to figure out why it works.

That URL didn't work for me. It is always helpful to make them into links.

Quote: Wizard

That URL didn't work for me. It is always helpful to make them into links.

Worked for me :-)

Okay, here you go: link.

Let's simplify the trick. Create three piles of cards as they do in the video. And turn over the top card in two of them.

There are 52 cards in the deck. Subtract 2 for the two you just turned over and there are 50 left. (13-c1)+(13-c2) are underneath those two cards, leaving

50-(13-c1)-(13-c2)=24+c1+c2.

Burn off 10+c1+c2, like they do in the trick. That will leave 24+c1+c2-(10+c1+c2)=14.

Let's subtract one for the mystery card revealed at the end, leaving 13.

We know there are 13-x under the mystery card, where x is the mystery card. (the one turned over at the end of the trick).

That must mean there are 13-(13-x)=x cards left after the burn.

So the mystery card must be x.

Ever see Ricky Jay do card tricks? Its unbelievable. He
practices for hours a day, since he was a kid. At red
lights, waiting in line at the bank, he's always practicing.

Quote: EvenBob

Ever see Ricky Jay do card tricks? Its unbelievable. He
practices for hours a day, since he was a kid. At red
lights, waiting in line at the bank, he's always practicing.

I met him, long ago; Summer of '71. He was friends with someone in my dormitory, and he visited. He gave an impromptu show for about an hour, doing a lot of basic sleight of hand, showing how to do a "reveal" (card behind the hand, held with forefinger and pinkie; move the hand up and down quickly, pivoting the card to the front with the ring and index fingers), and throwing cards around the room and hitting things and sticking them into fruit etc.

I tried and tried, and never could do the reveal. It takes practice, but talent helps. A lot.

He wrote a great book, long out of print: Learned Pigs and Fireproof Women, about sideshow oddities throughout history. Highly recommended, if you ever come across it.

I think Ricky Jay is in the Guiness Book for throwing cards
the longest distance or sticking them in a target or something.
He was on Mythbusters and he's lethal sticking cards in stuff.
I believe him and Penn Gillette aren't allowed to play any card
games in casinos. Ricky Jay admits its a really bad idea for them
to let him play.

Quote: EvenBob

Ever see Ricky Jay do card tricks? Its unbelievable. He
practices for hours a day, since he was a kid. At red
lights, waiting in line at the bank, he's always practicing.

Also a pretty good actor, in most of David Mamet's movies and notably, "Magnolia." He usually does some sort of magic trick or con.

Quote: Wizard

Let's simplify the trick. Create three piles of cards as they do in the video. And turn over the top card in two of them.

There are 52 cards in the deck. Subtract 2 for the two you just turned over and there are 50 left. (13-c1)+(13-c2) are underneath those two cards, leaving

50-(13-c1)-(13-c2)=24+c1+c2.

Burn off 10+c1+c2, like they do in the trick. That will leave 24+c1+c2-(10+c1+c2)=14.

Let's subtract one for the mystery card revealed at the end, leaving 13.

We know there are 13-x under the mystery card, where x is the mystery card. (the one turned over at the end of the trick).

That must mean there are 13-(13-x)=x cards left after the burn.

So the mystery card must be x.

My math was similiar, except I was using 52 (not accounting for the cards you turn over), and instead doing 14-c1 and c2...However my answers were off at the end.

It was bothering the hell out of me...

Here is another self-working trick that I learned over a decade ago, that I never see performed or explained elsewhere. Get a deck of cards, and follow these instructions.

• Shuffle a deck of cards; 52, no jokers.
• Choose any 3 cards from the deck. You may look through the deck and find "favorite" or easy to remember cards. When performing, one volunteer can take three, or three volunteers may each choose one. Keep hidden/face down.
• Create 4 piles of cards, left to right, all face down. The number of cards in each pile is 14, 15, 15, and 5, respectively.
• Place the first volunteer's card face down on pile 1. Then, cut any number of cards from pile 2: Zero, 1, some, or all. Place those cards on top of pile 1, to hide the mystery card.
• Place the second volunteer's card face down on pile 2. If pile 2 is gone because the first volunteer cut all the cards, then place the card in the empty space, on top of a pile of zero cards. Again, cut any number of cards from pile 3, and place them on top of pile 2, hiding the second volunteer card.
• Place the third volunteer's card on top of pile 3.
• Place all of pile 4 on top of pile 3. Place all of pile 3 on top of pile 2. Place all of pile 2 on top of pile 1, forming the deck once again, with 3 mystery cards hidden randomly within.
• Do not shuffle or otherwise reorder the cards, except for what these steps instruct.
• When performing, you can say, "We will now deal the card -up and down-. If you see one of your mystery cards, let me know when I stop dealing all the cards up."
• Begin dealing the cards into two stacks: a face-up stack, and a face-down stack. Deal from the top of the deck, one card at a time. Deal one card face-up, the next card face-down. Face-up, face-down, until the deck is exhausted.
• Although while performing you instructed your audience to tell you when they see a mystery card, they WILL NOT see it. Usually, they will confuse suits. Just patter that you needed to know what face-up stack their card is in, and move on.
• Pick up the face-down pile, leaving the face-up pile where it is.
• Repeat the "up and down" process again, but create a brand new face-up pile next to the existing one. Start by dealing the top card of your deck face-up, and the next face-down, into two piles.
• When you finish this step, there should be 3 stacks on the table, from left-to-right: Face-up, face-up, face-down.
• Pick up the face-down pile, and deal them "up and down" once more. When finished, there will be three face-up piles, and one face-down.
• Pick up the face-down pile, which will have 6 cards in it by this point. No one should have seen their cards by now.
• For the last "up and down", deal the top card face-up onto pile 1, then then next face-down on top of pile 1. Next card face-up on pile 2, and the next face-down onto pile 2. Next, face-up on pile 3, and final card face-down on pile 3.
• Turn the card on pile 1 face up. This will be the card Volunteer 1 picked. Pile 2's card will belong to Volunteer 2, and pile 3 belongs to Volunteer 3.
-Dween!

It works beacause the cuts when placing the cards back are misdirection. The selected cards set to be at fixed places in the deck.