Magic & Math with Cards

Lecture 32 · Performance

Four suits survive the shuffle

Video in production

This lecture is still face down. Its script is written; filming and animation are under way.

Meanwhile, play the trick

What you will learn

Perform a four-suit Gilbreath effect and explain aligned-block suit inventories.

The trick in this lecture Four Suits Survive Cut, deal some, riffle once. Every group of four taken from the top still holds one card of each suit. Play the trick

Before this lecture

In this lecture

An outline of the lecture, scene by scene, with the statements that appear on screen. It follows the draft script, so details may change in production.

  1. Prepare the four-suit effect

    At the table
    • One shuffle; groups of four

  2. Predict hidden suits

    At the table
    • Three visible suits determine the fourth

  3. Reveal full group structure

    At the table
    • Each aligned group: C H S D

  4. Connect the cycle to source frontiers

    • Cycle labels, distinct card identities

  5. Inspect aligned and shifted groups

    • Aligned: S D C H | H S C D
    • Shifted: D C H H

  6. Prove by cumulative inventories

    • Prefix 4: one of each
    • Prefix 8: two of each
    • Next block = difference

  7. Locate the allowed freedoms

    • One interleave; original source order

  8. Play and retrieve

    • Inventory survives; exact order may change

Companion interactive

Choose every legal shuffle decision and predict one hidden suit in each aligned group.

The trick page is this lecture’s companion: be the spectator, lift the curtain to step through why it works, try the challenge, then learn the handling.

Open Four Suits Survive

Sources

How these sources were used
  • Persi Diaconis and Ron Graham, Magical Mathematics: Four-suit illustration of the general Gilbreath principle. Sixteen-card presentation and explicit group handling adapted here.