If you initialize your variables, the () makes a difference: context. 
use strict;
use warnings;

sub print_context {
    say wantarray ? 'list' : 'scalar';
}

my $x   = print_context;
my ($y) = print_context;
__END__
scalar
list

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Examples where this makes a difference: 

my  $time1  = localtime;
my ($time2) = localtime; 

my  $rev1   = reverse $some_string;
my ($rev2)  = reverse $some_string;

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Perl 6 - second systems done right

In reply to Re: Declaring my $var versus declaring my($var) by moritz
in thread Declaring my $var versus declaring my($var) by dh1760

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