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The biggest problem with shuffling algorithms (not just
Fisher-Yates) is the imperfectness of the RNG. The sequence
of numbers it returns is determined by the seed, and only
by the seed. And if from the seed only 32 bits are being
used, there will be at most 2**32 different sequences.
Which means that for a deck of more than 2 cards, Fisher-Yates
cannot be 'fair', as N! won't be a divisor of any
power of 2. Furthermore, 13! > 2**32, so even if
you shuffle a deck of 13 cards, some permutations will
*never* be selected, no matter how many times you perform
the shuffle.
This was pointed out by R. Salfi: COMPSTAT 1974, Vienna: 1974, pp 28 - 35. See also the documentation of the Shuffle module on CPAN. Abigail In reply to Re: Fisher-Yates theory
by Abigail-II
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