## How much shuffling is enough?

For most games, four to seven riffle shuffles are sufficient: for unsuited games such as blackjack, four riffle shuffles are sufficient, while for suited games, seven riffle shuffles are necessary. There are some games, however, for which even seven riffle shuffles are insufficient.

**Can you shuffle too much?**

There’s no such thing as “over-shuffling” the cards. Either you haven’t shuffled enough for a fair game, or you have. Shuffling only two or three times produces less-than-random hands.

### What is the perfect shuffle?

A perfect shuffle can refer to: A shuffling technique perfectly executed, most often meaning “divide cards into two equal piles of 26 cards each, and exactly interleave”.

**How long would it take to shuffle every order in a pack of cards?**

As you say, there are approximately 8*1067 possible combinations of cards that can make up a deck. Shuffling 100 times a second, assuming you could never have repeats, gives you 8E65 seconds, or 3E58 years.

## How many times should you shuffle cards?

Jim Reeds at Bell Laboratories and showed that a deck is perfectly mixed if it is shuffled between 5 and 20 times. Next, Dr. Diaconis worked with Dr. Aldous and showed that it takes 5 to 12 shuffles to perfectly mix a deck.

**How large is 52 factorial?**

52! is approximately 8.0658e67. For an exact representation, view a factorial table or try a “new-school” calculator, one that understands long integers.

### How many times should I shuffle?

Dr. Diaconis said he almost never sees a dealer shuffle seven times. He said his research also shows that when dealers shuffle several decks at once, they need to shuffle more. Two decks should be shuffled nine times, he said, and six decks should be shuffled 12 times, which is unheard of in the casinos.

**How often do you shuffle a deck of cards?**

Let’s go nuts and assume that every person who has ever lived shuffled a deck of cards once per second for their entire lives, even in their sleep. That’s 108 billion people times 25,915 days times 86,400 seconds in a day, giving us 241,818,048,000,000,000,000 shuffles. Our new odds: That is, one in 333 quattuordecillion.

## Is it true that No 52 cards have ever been shuffled?

What if I told you that each time you shuffle a deck of cards thoroughly, it is a near certainty that no 52 cards have ever been arranged in that order at any time in history? Hard to believe? It’s true, and it is fairly easy to demonstrate. Let’s start with the number of ways that a deck of cards can be arranged.

**What are the different types of deck shuffles?**

Two popular kinds of shuffles are the random riffle shuffle and the overhand shuffle. The random riffle shuffle is modeled by cutting the deck binomially and dropping cards one-by-one from either half of the deck with probability proportional to the current sizes of the deck halves.

### How is the random riffle shuffle is modeled?

The random riffle shuffle is modeled by cutting the deck binomially and dropping cards one-by-one from either half of the deck with probability proportional to the current sizes of the deck halves.