Perfect Shuffles: Faro shuffles are a specialized type of shuffle where the cards are inter-weaved together exactly one card at a time. If you do eight perfect faro out-shuffles, the deck will return exactly to its original order! You can see someone accomplish this impressive feat in a video clip here .
Possible Shuffles: The number of different ways to arrange a single deck of 52 cards is staggering - it's a number greater than the number of atoms on earth! Just how many exactly? 52! (52 factorial = 52x51x50x49 ... x2x1). That's an 8 with around 67 zeroes! Or to be exact: 80658175170943878571660636856403766975289505440883277824000000000000
This means that even if you shuffled a new arrangement every single second, it would still take millions of years to cover every combination. So next time you shuffle a deck of cards, think about how unique that arrangement and that moment really is. Each time you pick up a shuffled deck, it's almost certain that the exact order of the cards in your hands has never existed before, and will likely never exist!