Open Prediction (also known as "The Curry Unsolved Card Problem") is a classic Card Problem devised by Paul Curry in which a prediction is shown openly before the deal of the cards is started. A spectator deals cards face up onto the table until they choose to deal one card face down, then continues dealing the remainder of the pack face up. Everyone watches the deal, looking for the predicted card in the face up cards dealt. It does not appear. Spectator turns up the sole face down card. It is the card that was openly predicted at the start.
Curry's solution to the Open Prediction first appeared in Special Effects (1977).
51 Faces North
51 Faces North Conditions
- Borrowed cards may be used.
- The deck is ordinary, and might even have cards missing. You don't have to know which cards, or how many are missing. You only have to be sure that the card you predict is there.
- You do not need privacy with the cards to set something.
- The deck is never out of sight for a moment.
- No card or cards are stolen from or added to the deck.
- Borrowed writing materials may be used.
- It is described as a prediction at the time of writing. The prediction is the name of a card. It is known to all before the first card is dealt.
- Strictly impromtu. No set-up or special tools necessary.
- No alternative meanings or effect.
- Nothing but the borrowed articles used.
- When the spectator starts dealing, the performer does not know where the predicted card is. It would not help to know with this method. Nor does the performer know the location in the pack of any other card.
- The performer never knows when the spectator will leave a card face down until after they have done so.
- The spectator deals straight through from top to face, the only variation is when he leaves a card face down.
- It is not a once-in-a-while trick. If the instructions are followed, it cannot fail.
- The cards are never handled by the performer from first to last, at any time before, during or after the trick.
- The spectator himself checks that the face down card is the predicted one.
- The method could be used by someone for criminal purposes.
- It is not a well-known method for use with cards. It could be used for other than cards.
Stewart James' preferred solution to his own problem was never revealed. A solution found after his death, was published in the inaugural issue of The Penumbra (May-June 2002).
- Paul Curry's A Cur(r)i-ous Prediction (premiss) in More Card Manipulations No. 3 (1940). Premise because it's a closed prediction
- Gerald Kosky's A Sure-fire Card Prediction in The Phoenix, dec. 30th 1949, page 772. A letter with the "easy solution". (mentions others working on the problem as Dai Vernon, Paul Curry, Bill Simon, Martin Gardner).
- ANGLE ON MARLO (credited to Ed Marlo by Francis Haxton who didn't know Marlo got the idea from Curry via Oscar Weigle) in Pentagram (March 1953)
- Ed Marlo's Open Prediction in The Cardician (credited to Curry) (1953)
- THE CARDICIAN’S SECOND PROBLEM in Pentagram (May, 1954).
- Bill Simon's "The Vital Prediction" in Sleightly Sensational (1954)
- 25 variations by Stewart James and 11 more by Howard Lyons in Ibidem No. 3, August 1955
- Alex Elmsley's Open Intruder in The Pentagram, Vol. 10, no. 12, September 1956. Reprint in The Collected Works of Alex Elmsley, Vol. 2 (1994)
- Bruce Cervon's Open Prediction in Pallbearers Review, Vol. 3, No. 2, December, 1967, page 145.
- Robert Parrish’s On The Open Prediction Second Folio of the Pallbearers Review: Winter, 1968
- Paul Curry's Open Prediction in Special Effects (1977)
- Karl Fulves's "Cards #2 51 Faces North" (1978)
- Ed Marlo's The Re-Opened Prediction in Marlo's Magazine, Vol. 3 (1979)
- Ed Marlo's Olram's Open Prediction in Marlo Without Tears (1983)
- Ed Marlo's Application to Open Prediction in Marlo's Magazine, Vol. 5 (1984)
- Steve Rogers' Central Limit in Apocalypse Vol. 10, no. 8, august 1987.
- Bruce Cervon's Open Prediction in The Cervon File (1988)
- Tom Craven's Unclosed Prediction in Apocalypse, Vol. 12, no. 8, august 1989.
- Paul Cummins' Almost Open Prediction in From a Shuffled Deck in Use... Part Two (1996)
- Paul Curry & Bernard Bilis, The Open Prediction in Card College, Vol. 3 (1998)
- Thomas Baxter's Brrr! in Stewart James in Print (2000)
- David Regal's Open from the Bottom in Constant Fooling 1 (2002)
- David Regal's Roughly Identical in Constant Fooling 2 (2002)
- David Ben's Window To The Soul in Tricks (2003)
- Nick Trost's Open Prediction in Subtle Card Creations, Vol. 1 (2007)
- Thomas Baxter's 27 Below in The Open Prediction Project (2008)
- Thomas Baxter's book, The Open Prediction Project (2010)