The Rants of Mister P

Too much free time

It's true: If you shuffle a fresh deck of cards perfectly, after 8 shuffles the cards will be back in their original order:

Fresh deck:
A234567890JQKA234567890JQKA234567890JQKA234567890JQK

Shuffle 1:
AA223344556677889900JJQQKKAA223344556677889900JJQQKK

Shuffle 2:
AAAA222233334444555566667777888899990000JJJJQQQQKKKK

Shuffle 3:
A7A7A8A8282829293939303040404J4J5J5J5Q5Q6Q6Q6K6K7K7K

Shuffle 4:
A470A47JA48JA58J258J258Q259Q269Q369Q369K360K370K470K

Shuffle 5:
A94Q7206A94Q73J6A94Q83J6A95K83J6205K83J7205K84Q7205K

Shuffle 6:
A59K48Q37J260260A59K48Q37J37J260A59K48Q48Q37J260A59K

Shuffle 7:
A3579JK24680QA3579JK24680Q24680QA3579JK24680QA3579JK

Shuffle 8:
A234567890JQKA234567890JQKA234567890JQKA234567890JQK