Liar's Clock
by Werner Miller

Werner Miller is a retired teacher of mathematics, whose hobbies are recreational mathematics and magic. A magical inventor and writer, Werner has produced a prolific volume of work, mostly what he calls “semi-automatic” card tricks based on mathematical principles. He is the author of "Fast von selbst", "Alles Miller oder was", "Ratatouille", more than 300 trick contributions to various magazines and web sites and more than 30 related computer programs. In addition, Werner is also a staff member of the German magazine "Magische Welt", a columnist for the British magazine "The Magician", and regular contributor here at Visions. Werner's first English-language book, Ear-Marked, is available here.

Got hooked on the "Josephus Problem"? Dealing with playing cards, it's an obvious challenge to have a chosen card revealed also via continuously spelling its suit: C-L-U-B (4 letters), H-E-A-R-T (5 letters), S-P-A-D-E (5 letters), D-I-A-M-O-N-D (7 letters). Is it possible to end up with the same object, no matter whether every fourth or every fifth or every seventh object drops out? Definitely not within a reasonable number of objects.

But it's promising to test the number twelve: When every fourth or every fifth object drops out, you will end up with the first object, i.e. the one you originally started at. When every seventh object drops out, the last object remains.
Here's a way to use this peculiarity:

The spectator shuffles the deck and deals off two 6-card packets; the rest of the deck is discarded. He decides on either 6-card packet, shuffles it again, notes and remembers the bottom (face) card, and drops the packet on top of the other one.
You take the combined packet, false cut it and mix it by doing a Klondyke (Milk) Shuffle, thus bringing the noted card to the top.

Deal the cards singly into a circle, starting at 1 o'clock and proceeding clockwise (see figure).

Then place a pencil or ball pen between 12 o'clock and 1 o'clock to mark the top.

Ask the spectator if his noted card is a Club card, a Heart card, a Spade card or a Diamond card, but stress that the spectator is free to answer truthfully or to tell a lie.

Whatever the spectator replies, use the named suit to locate openly the noted card:

If the answer is Club, Heart or Spade, spell it continuously, with each letter tapping with the pencil the back of every card starting at the first card (1 o'clock) proceeding clockwise; the card indicated by the last letter of each spell drops out. You will automatically end up with the spectator's card.

If the answer is Diamond, do the same but starting at the last card (12 o'clock) proceeding counterclockwise; after eleven spells all cards but the noted one are eliminated.

Turn the remaining card face up. Seeing its suit, you know now whether the spectator has told the truth or not, and you can make a suitable remark.

Werner Miller