"...unique tracking label for every card in the deck"<p>I'd like more details on how this was accomplished on a practical level. Got me thinking about how to embed trackers thin enough to go into a playing card that would operate like a mesh network then the deck could self report once it's properly randomized making a green light go off indicating play may begin.
Anecdotally, I find that certain card games are more enjoyable with the imperfections of human shuffling: when clumps naturally arise after playing, packing, and unpacking the game several times. An element of organic personality arises when you see a sequence of cards from a previous game. That human element is lost when a computer perfectly shuffles a deck into a never-before-seen orientation.
Shouldn't a perfect shuffle just reorder the cards without adding entropy?<p>You would need sloppy ones to introduce randomness.
A "perfect shuffle" according to the article:<p>>The riffle shuffle has to follow a realistic but strict model where cards are randomly interleaved from the left or right pile one by one. (Each card gets dropped from either the left or the right pile with a probability that’s proportional to the number of cards remaining in that pile. This means that the cards don’t simply alternate between left and right, which would result in a predictable structure; instead, the order might go “left, right, right, left, right, left, left.”)
You misunderstood because the title is ambiguous.<p>This talks about seven consecutive <i>riffle shuffles</i> ("cut the deck and interleave the piles"): Those are not a "perfect shuffle" (i.e. same probability for every permutation) by themselves, only after doing them several times consecutively (which is kinda suprising by itself).
It's modelled with randomness, each card is taken from left or right with a probability, it's not a deterministic model.
shouldn't a perfect hackernews rtfa?
I don’t know on perfect shuffles but for the sloppy shuffles, the deck is cut at a random location between each shuffle.
See the paragraph beginning "Yet terms and conditions also apply."
Upper limit of 14. I’m curious then - when playing cards with friends we start with a semi -random, but definitely clumped, deck. It gets shuffled a couple times.<p>How random is that deck? How many “cold spots” does it have? Just how not random of decks are people playing with, and ultimately does that even matter if players lack the knowledge or skill to change their play because of that knowledge?
And 8 perfect shuffles resets it back to starting order (perfect being cards interlaced 1 by 1)
Quite the assumption here: "cards are randomly interleaved from the left or right pile one by one. (Each card gets dropped from either the left or the right pile with a probability that’s proportional to the number of cards remaining in that pile."<p>... Why would it be proportional to the number of cards in each pile? (Edit: I suppose the person doing the shuffling might adjust the rate of cards coming from each hand ... But not perfectly and continuously)
The paper: <a href="https://arxiv.org/abs/2510.22783" rel="nofollow">https://arxiv.org/abs/2510.22783</a>
TL;DR "roughly 14"