Hmm, seems illogical. If we start with a new deck of cards, right out of the box (52, jokers excluded). Assuming the cards are ordered A-K is individual suits from top to bottom, the first perfect shuffle will create paurs of cards. AA, KK on the top and bottom half of the deck. The second shuffle will group all cards AAAA-KKKK. Since 26 isn’t divisible by four the group of card 7 should diverge for all subsequent shuffles indefinitely with one 7 remaining on top and one 7 remaining on bottom indefinitely. Or is my logic flawed?