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Last Two — mated pairs

Cut as often as you like. Spell a phrase. The last two cards match.

Take pairs of mated cards and lay them out twice in the same order: say Q♥ 7♠ 3♥ then Q♦ 7♣ 3♦. Cut the packet as often as you like, split it in half, and reverse one half: turn it face up, or deal it out face down. Then spell a phrase over the two piles, choosing a pile for every letter. After each word, set aside the top card of each pile. The two cards left at the end match — and so does every pair you set aside on the way.

1

The pairs and the phrase

Playing cards by default.

One word per round, and a round for every pile size from n down to 2. With m cards in each pile, a word's length must be one less than a multiple of m. Only letters are counted.

Taking words from the audience

The words do not have to make a phrase, or make sense together. Each round's word can be called out by the audience, on whatever theme your presentation is using. All you need to know is how many cards are in each pile, and so how many letters the word can have. If a word does not fit that round, ask for another. Type the words above in the order they are used to try them out.

2

The deck, and the cuts

cards

Why the cuts have to come before the reversal

Before the reversal the packet holds the same run twice, here with five pairs: A B C D E a b c d e. A cut only turns that ring, so mates stay five cards apart, and when it is split each half holds one card of every pair. Reversing one half then sets up the mirror between the piles, whatever the cuts were.

Stack the piles back together after the reversal and that is lost. The ring is now A B C D E e d c b a, and mates are no longer five cards apart. Cut off two cards and split, and you get C D E e d and c b a A B. D and d are in the same pile, so they can never come up as a pair.

Cutting the separate piles does not work either. Moving cards from the top of a pile to the bottom is exactly what spelling a letter does, so a cut adds to the length of the word. It only cancels out if the cuts on the two piles add up to the size of the pile, such as two cards from one pile and three from the other, and that is not a free choice to offer anyone.

3

Split, and reverse one half

Either way the piles are mirror images.

4

Spell the phrase

Each letter moves the top card of a pile to the bottom. Use the button beside a pile to choose it yourself, or press Play to have the piles chosen for you. After each word the two ringed top cards are set aside, and they turn out to be mates, however the letters were shared out.

A ring marks the top card of each pile. The card being moved has a heavy ring. A pair set aside gets a green ring once both its cards can be seen, or a red one if they do not match. Stepping back and picking again replaces the rest of the run.

5

Why it works