Look again!

Update: Maybe this will clarify things a little?

#! perl -sw
use strict;

sub shuffl (\@) {
    my $r=pop;
    for (0..$#{$r}) {
        my $size = scalar @{$r};
        my $choices = $size - $_;
        printf 'iteration: %2d Size: %2d     rand(%2d) range: %2d .. %
+2d             %s',
                           $_,       $size,   $choices,       $_, $cho
+ices + $_,     $/;
        $a = $_ + rand @{$r} - $_;
        @$r[$_, $a] = @$r[$a, $_];
    }
}

my @array = (1 ..15);

shuffl @array;

__END__
C:\test>210557
iteration:  0 Size: 15     rand(15) range:  0 .. 15
iteration:  1 Size: 15     rand(14) range:  1 .. 15
iteration:  2 Size: 15     rand(13) range:  2 .. 15
iteration:  3 Size: 15     rand(12) range:  3 .. 15
iteration:  4 Size: 15     rand(11) range:  4 .. 15
iteration:  5 Size: 15     rand(10) range:  5 .. 15
iteration:  6 Size: 15     rand( 9) range:  6 .. 15
iteration:  7 Size: 15     rand( 8) range:  7 .. 15
iteration:  8 Size: 15     rand( 7) range:  8 .. 15
iteration:  9 Size: 15     rand( 6) range:  9 .. 15
iteration: 10 Size: 15     rand( 5) range: 10 .. 15
iteration: 11 Size: 15     rand( 4) range: 11 .. 15
iteration: 12 Size: 15     rand( 3) range: 12 .. 15
iteration: 13 Size: 15     rand( 2) range: 13 .. 15
iteration: 14 Size: 15     rand( 1) range: 14 .. 15

C:\test>
[download]