Seven riffles suffice
Riffle — Seven shuffles
to forget
the order.
Fifty-two cards, dealt in perfect sequence, then cut and interleaved the way a dealer's thumbs do it. Watch the order come apart — and the count of rising runs climbs, one shuffle at a time, to the flat line of pure chance.
Sortedness readoutshuffle 3 / 7
8
Rising sequences
31%
Randomness
How to read it. A rising sequence is a run of cards still in ascending order. A sorted deck has one; a random deck has about twenty-six. Each riffle roughly doubles the count — until, near the seventh, it saturates and the deck is, for all practical purposes, forgotten.