Re: shuffling algorithm

From: Bill Unruh (unruh_at_string.physics.ubc.ca)
Date: 11/22/04 

Date: 22 Nov 2004 18:39:48 GMT

Phil Carmody <thefatphil_demunged@yahoo.co.uk> writes:

]Joe Soap <me@privacy.net> writes:

]> In response to what Paul Tomkins <tomkinsp@iinet.net.au> posted in
]> news:41a0a186$0$25785$5a62ac22@per-qv1-newsreader-01.iinet.net.au:
]>
]> > There are three methods of shuffling cards that I can think of. When
]> > done on a computer, they are all based on numbers generated by a
]> > random or pseudo random number generator.
]>
]> You missed the easiest one:
]>
]> For i = 1 to 52, swap card #i with a randomly chosen card [of 52].

]That's not a fair shuffle. Some permutations are favoured over others.
](You have 52^52 outcomes, but there are only 52! permutations, and
]52! does not divide 52^52.)

???? There are NOT 52^52 outcomes. There are 52! outcomes. There would be
52^52 only if you could have a deck after shuffling with all Ace of hearts.
Ie only if repeated cards were allowed. They are not.

Whether or not the suggestion is a good shuffle is a valid question, but
your answer is not valid.

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