Mathematical Blackjacks by Henry Christ

Effect

The Mathematical Blackjacks trick uses two specially designed Black Jacks from a deck of cards. The magician explains the unique history and mathematical significance of these Jacks. The deck is shuffled, and the Jacks appear lost in the middle. Two spectators pick numbers, and after some counting and dealing, the magician reveals that the difference between their numbers leads directly to the positions of the two Black Jacks. The trick ends with both Jacks appearing exactly where the math predicted.

Full details

The trick relies on two Black Jacks (Jack of Spades and Jack of Clubs) from the Theory 11 Silver Art deck. These Jacks have symbolic imagery—an hourglass and a measuring stick—which the magician ties to a mathematical principle. The magician controls the position of the Jacks using shuffling techniques like a thumb jog or a slip cut.

Two spectators choose numbers (one between 1-10, the other between 10-20). The magician deals cards based on these numbers, but the Jacks do not appear immediately. Instead, the difference between the two numbers is calculated, and counting to that number reveals the Jacks in their predicted positions.

Who should consider the trick

This trick is ideal for beginners because it requires minimal sleight of hand. However, experienced magicians can enhance it with advanced shuffles and storytelling. Performers who enjoy interactive magic will appreciate the spectator involvement. Those who like mathematical or self-working tricks will find this particularly appealing.

Information on how difficult it is to perform

The trick is beginner-friendly, with most of the work relying on setup rather than complex moves. Basic shuffling techniques like the thumb jog or slip cut are used to control the Jacks. The hardest part is maintaining a smooth presentation while guiding spectators through the counting process.

What magicians say

CardMechanic describes it as "very basic beginner level" but emphasizes that strong storytelling makes it more impactful. He recommends involving spectators in the dealing process to increase engagement. He also notes that the shiny backs of the Theory 11 Silver Art deck add visual appeal.

In his performance, he highlights the importance of explaining the mathematical principle behind the trick, saying, "The difference between the two selected numbers reveals the position of the Black Jacks." He also suggests false shuffles and cuts to reinforce the illusion that the Jacks are fairly lost in the deck.

Overall, reviewers agree that Mathematical Blackjacks is a simple yet deceptive trick that works well with minimal practice but can be elevated with strong presentation.