#! perl -slw
use strict;
use Data::Dump qw[ pp ]; $Data::Dump::WIDTH = 1000;
use List::Util qw[ shuffle ];

my @data = 'a'..'d';

my %once; ++$once{ join'',shuffle @data } for 1 .. 1e6;
pp \%once;

my %twice; ++$twice{ join'',shuffle shuffle @data } for 1 .. 1e6;
pp \%twice;

my %ten; ++$ten{ join'',shuffle shuffle shuffle shuffle shuffle shuffle shuffle shuffle shuffle shuffle @data } for 1 .. 1e6;
pp \%ten ;

__END__
C:\test>shuffleStats.pl
{ abcd => 41717, abdc => 41646, acbd => 41468, acdb => 41646, adbc => 41673, adcb => 42050, bacd => 41883, badc => 41624, bcad => 41523, bcda => 41667, bdac => 41775, bdca => 41282, cabd => 41674, cadb => 41598, cbad => 41587, cbda => 41892, cdab => 41650, cdba => 41706, dabc => 41452, dacb => 41859, dbac => 41638, dbca => 41895, dcab => 41600, dcba => 41495 }

{ abcd => 41481, abdc => 41541, acbd => 41422, acdb => 41699, adbc => 41601, adcb => 41502, bacd => 41610, badc => 42086, bcad => 41860, bcda => 41864, bdac => 41537, bdca => 41770, cabd => 41669, cadb => 42034, cbad => 41649, cbda => 41568, cdab => 41802, cdba => 41802, dabc => 41745, dacb => 41742, dbac => 41405, dbca => 41441, dcab => 41628, dcba => 41542 }

{ abcd => 41723, abdc => 41512, acbd => 41613, acdb => 41633, adbc => 41587, adcb => 41547, bacd => 42015, badc => 41615, bcad => 41706, bcda => 41752, bdac => 41903, bdca => 41539, cabd => 41306, cadb => 42037, cbad => 41673, cbda => 41579, cdab => 41767, cdba => 41582, dabc => 42219, dacb => 41463, dbac => 41228, dbca => 41659, dcab => 41892, dcba => 41450 }