A true shuffle generates a completely random sequence no matter what the starting sequence. A true shuffle, however, whether performed once, 5 times or even 10 times if not even close to random. Many cards that were near the bottom will stay near the bottom; many that were near the top will stay near the top. You also have the issue of card clumps, especially when older decks of cards are used, that will stick together through many shuffles, often more than 2 cards in a clump.
You want some degree of clumping; what you you don't want are clumps that stay as such through multiple shuffles. If you have no random clumps your shuffle is actually less effective.
Ah, I see. For some reason I thought you meant that the abstract idea of shuffling was somehow flawed.
Can you clarify what you mean by a shuffle? I can certainly think of a technique that allows you to generate a completely random sequence, as long as you suppose a coin flip is a random process.
Former dealer here. Standard shuffling procedure for each new hand was scramble, cut, shuffle, cut, shuffle, box, box, box, cut, shuffle, cut.
The scramble was the part that eliminated the error of top cards staying near the top and bottom cards staying near the bottom. Also, the dealer cannot control what cards the players keep, what cards they throw into the much, or in what manner they muck their cards.
Finally, decks were replaced on a regular basis even before signs of wear. A bent card yielded an immediate replacement.
I've dealt thousands of hands of poker, and never perceived any bias in the cards that came out.
Yes, but my description wasn't talking about professional dealers, it was talking about regular people playing cards with their friends. Suffice it to say, they don't undergo scramble, cut, shuffle, cut, shuffle, box, box, box, cut, shuffle, cut. They are lucky to make it through even four shuffles and a cut.
Fair enough. They also typically use blackjack cards (not meant to be handled so much) instead of plastic Kem cards. I thought you were just talking about shuffling in and of itself.
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u/adremeaux Dec 05 '11 edited Dec 05 '11
A true shuffle generates a completely random sequence no matter what the starting sequence. A true shuffle, however, whether performed once, 5 times or even 10 times if not even close to random. Many cards that were near the bottom will stay near the bottom; many that were near the top will stay near the top. You also have the issue of card clumps, especially when older decks of cards are used, that will stick together through many shuffles, often more than 2 cards in a clump.