The Twelve Card Problem (and Similar Mentally-Selected Card Divinations)

The Twelve Card Problem
(and Similar Mentally-Selected Card Divinations)
by Scott Baird
 
After explaining his effect 3H in his Ebook
More Plots and Methods (2021, p.25), Michal Kociołek writes:
 
Twelve-card problem
Here’s a little dare. I invite you, the reader, to solve this little card “problem”:
Perform this trick, but just with twelve cards. Once you have a method, please reach out to me as I’m very curious about your approach (unless you’re reading this in 2077, then I’m definitely dead so don’t bother).
 
This ebook contains my solutions to his challenge. The routines range from impromptu to stacked, though the majority of the effects can be done with a borrowed deck of cards and no preparation. Those who are familiar with The Three Hours or the mis-named Princess Card Trick should appreciate the impromptu nature of the effects, as these routines often rely on a memorized deck.
 
Contents:
 
Seriate Twelve - An impromptu three-selection mindreading effect.
 
Seriate In Sync - A variation of Seriate Twelve, giving the spectators more freedom of choice.
 
Seriate Simplified - A handling variation of Seriate Twelve, simplifying the shuffle and the final sequence.
 
Seriate Stack - A unique handling of Seriate Twelve that sacrifices a completely free choice in favour of an improved query phase.
 
Seriate 52 - A full deck approach to Seriate Stack.
 
Seriate In Mind - The approach to Seriate Stack is used in conjunction with the one-ahead principle and a full deck. A three-card revelation with no clocking!
 
Four Card Symphony - A four-spectator card revelation based on Simon Aronson’s Four Part Harmony. An easy to do, baffling four-card divination.
 
Indexed Possibilities - One card (or more) is remembered from a fan of twelve, and divined despite the spectator shuffling and cutting the deck themselves.
 
3 Hours or Less - The Three Hours, turned inside out and upside down. Uses twelve cards.
 
Stebbins Twelve - Seriate Twelve, but the performer never appears to see the face of a single card, and yet names all three selected cards—and the secret number!