Editor’s note: Now that we don’t have a schedule, I can do important things like schedule posts for the 7th day of the month.

There’s a long history in magic of using a deck of cards to force a number by adding up the values of cards. A significant portion of this history is devoted to the 14/15 stack. I think it was the most popular primarily because it was the first.

Today, I’m taking a stand for the 13/14 stack.¹ And I’m adding plenty of footnotes just for you footnote fetishists.²

To be clear, a 13/14 stack is one in which every pair of adjacent cards sums to 13 or 14. I think a 13/14 stack originates with P. Howard Lyons’ “Northern Force”. He explains how to set it up from new deck order with a Klondike shuffle. Sure, great, but who has the time for a Klondike shuffle? And besides which, that only works in a “new deck order” where all the suits are arranged Ace to King, and decks aren’t usually arranged that way today. That’s actually good news, since the modern new deck order permits setting up a 13/14 stack with a single perfect faro.

Fast stack from NDO

1. Open a new deck and toss the ad cards. Turn it face up. Move the colored Joker to the face so the deck is sandwiched between the Jokers.
2. Spread through face-up and cut the block of diamonds to the back of the deck. (Move only the diamonds.) The deck should now be in this order from back to face: KD-AD, Joker, AH-KH, AC-KC, KS-AS, Joker.
3. Split the deck in half (between the KH and AC) and do one perfect out-faro (so that the Joker remains on the face).

That’s it. Congratulations. Now, you have a 13/14 stack. This particular fast stack has some nice properties as well, which I’ll now detail.

This 13/14 Stack’s Properties

• It includes the Jokers (and the fundamental summation property are retained by assigning it a value of zero).
• Except where the Jokers are, the pair sums alternate between 13 and 14.
• Consequently, every run of 3 cards sums to 27 minus the value of the middle card.³
• The major suits are in the bottom half of the deck, alternating in color. The minor suits are in the top half. In other words, aside from the Kings, every Hearts is between two Spades and vice versa, and every Club is between two Diamonds and vice versa. (Each pair of same-colored Kings sandwiches a Joker.⁴)
• Clubs and Hearts are in increasing order from top to bottom, while Spades and Diamonds are in decreasing order. (That is, the first two versus the last two suits of CHaSeD.)
• It’s also reasonably unsuspicious looking when the faces are flashed. You don’t want to leave them spread face-up and examined thanks to the color alternation and suit separation, but it’ll pass a cursory inspection, same as a Stebbins stack.

What’s It Good For?

Well, your most common use case is going to be to force a number by having someone cut to a random spot, take the top two cards, and add them together. You still need to figure out or ask whether they got 13 or 14, or depend on a procedure that has two outs. For example, it works just fine for the page force in Annemann’s Premier Book Test. Likewise, you could force the 14th card in a second deck a la Kaplan’s Medium’s Card Test.

But you can also use it for other stacky kinds of things in a pinch. For example, have a participant pull two adjacent cards from the middle of the deck,⁵ and then box the rest. She keeps one and discards or gives you the other.⁶ You look at the rejected card, and you already have their card narrowed down to two cards using the properties described above. For example, if they hand you a 7D, you know they have the 7C or 6C. If they hand you a KS, you know they have an AH or Joker. If you saw whether it was above or below the card they kept, you can use the fact that only Clubs and Hearts are in increasing order to infer which of the two it was, but even if you lost track, you can just guess⁷. At worst, you’ll nail the suit and be off by only one on the value.⁸ No other kind of stack makes that guarantee.

But that third property up there is very interesting, and it lets you do the following trick. This feels like the kind of thing that would make John Bannon drool a bit just from the novelty and mathematical beauty of it, even if he doesn’t really like to depend on whole deck stacks.

A Card, A Number, Another Stop Trick

After stacking the deck and giving it a few false shuffles, briefly flash some faces as you scan for the centralized Joker. As soon as you see it, cut behind it. Take all the cards behind it as a block and turn them face-down on the table.

“I’m not going to spread through those. I don’t want to know which cards they are or what order they’re in, so I’ll look away for the moment. Please pick up the pile.

“Now, wherever feels right for you, cut the pile. You can cut a few or a lot. But go ahead and complete the cut. Done that? Nice, now turn over the top card so it’s face up on the pile. And when you’ve done that, go ahead and cut it back into the middle again. I’ll spread these out to see which one you picked. Aha, the Five of Diamonds. Do me a favor and pull it out along with the cards on either side of it. Gather up the rest and put them aside somewhere out of sight.”

“Now, so far, the two of us only know where one card is—that one red five. Neither of us knows what those two face-down cards next to it are, for example, nor where the other red five is. So let’s each get a secret from one another. Go ahead and look at those two face-down cards, but don’t let me see them.”

Spread the cards you’re holding toward your face, smile, and say, “Alright, I’ve got a secret. I know where the other red five is. As for your secret, I want you to add together the values of those two cards. Remember Jacks are worth 11, etc. Double-check your addition with your neighbor there. It wouldn’t do to have the wrong secret.”

Of course, you know exactly what sum they have. You’ve already calculated it by subtracting the visible card from 27 twice. Or, equivalently, by subtracting it from 13, doubling the result, and adding 1. In the case of 5, you get 27-2*5=17. Similarly, for a Queen=12, you get (13-12)*2+1=3. Generally, speaking the former method is probably faster for small numbers, while the latter is faster for larger numbers like face cards.⁹

“Great, now I’m just going to deal cards from my pile one at a time. I’ll count as I deal. Don’t count with me. Don’t say anything at any point. But, in your mind only, when I get to your secret number, I want you to mentally shout ‘Stop!’ Don’t move a muscle, don’t change your expression, don’t give anything away. Just shout ‘Stop!’ in your mind only. Got it?”

Begin dealing and counting cards now. If the face-up card is red, deal from the bottom of your pile.¹⁰ Otherwise, deal from the top. Don’t look at the cards in your hands or at the ones on the table. Just look at your participant. After you say the predetermined number, stop dealing.

(quizzically) “And I’m… going to stop dealing… right there. Wait…, did you just shout ‘stop’ in your mind? Really? 17 was really your secret number? I honestly didn’t feel a thing, psychically. I guess that’s why you never got an invite to Xavier’s School for Gifted Youngsters, huh? Actually, I only stopped because, like I said, I know where the other red five is.”

Deal the next card face-up.¹¹

Yep, it’s really that easy. It’s all self-working, thanks to this 13/14 stack. The position of the matching card is always the same distance from one end of your pile as the sum of the two cards on either side of the card in the other pile. Convenient, right? I may not have invented the 13/14 stack, but can’t I at least claim that this post has contributed the most to its use in the last 50 years?

(Inspiration for this presentation comes from John Bannon’s effects (with very different methods than above) Dead Reckoning and Second Reckoning.)

1. Everything described herein can also be done with a 14/15 stack with only minor differences. However, a 14/15 stack requires either omitting two aces or saying that Jokers are worth 14. I find it feels less arbitrary in practice to say Jokers are worthless, hence the focus on this 13/14 stack. ↩︎
2. I would force everyone to read them by using headnotes instead, but I think Jerry is the only one who enjoys it when I give headnotes. ↩︎
3. Unless the middle card is a Joker, which means the sum is 26. ↩︎
4. If you followed the instructions, the colored Joker will be between the red Kings and the black Joker will be between the black Kings. ↩︎
5. I recommend spreading the deck on the table with the cards tight and even, then having the participant drop a finger on it somewhere. Wherever her finger lands, place your own in front of it but touching two cards and slide both forward. “Okay, looks like you touched both of those, so I’ll let you choose. Go ahead and take a look before you decide.” Also see Meeting of the Masterminds. ↩︎
6. One nice way to get the participant to show you a card without verbally asking for it or noticeably picking it up to look might be to open the box so the cards inside are face up, slide them out halfway, open a big break in the middle, and ask her to insert the card she doesn’t want. Because the deck is seen to be face up, the implicit message is to insert the reject card face up (and facing you!) as well. ↩︎
7. If you’re given a King, always go with a funny look, followed by “you didn’t pick a Joker, did you?” You want it to seem like you knew they were being intentionally cheeky if they did, and if they didn’t, like Jokers weren’t even supposed to be allowed as a choice. ↩︎
8. Except if you’re given a Joker, whereupon you’ll definitely nail the value and color, but might miss on the suit. Even better. ↩︎
9. You don’t have to worry about the place in the participant’s pile that has two adjacent Kings. There is no way she could have cut to that position if she followed your directions. ↩︎
10. If you think dealing from the bottom looks weird, then when you see a red card, you can do an overhand shuffle before you start dealing, but make sure you start running cards singly around the position where the card is. That is, if your computed number is in the twenties or high teens, run a bunch of cards singly before shuffling off. If it’s a single digit, run the last ten cards singly. If it’s in the middle, shuffle a few blocks, run a bunch in the middle singly, then shuffle off. This will move the card from the correct position from the bottom to the correct position from the top. ↩︎
11. If you’d rather the matching card be AT the secret number than immediately AFTER it, that’s possible too. At the very beginning, move the face Joker to the back, spread through face up to the central Joker and cut BEFORE it, giving the Joker and everything behind it to the participant. Now you have 26 cards, she has 28, and the selected card will be dealt at the same time as you count the secret number. ↩︎