Six: 10 wallclock secs ( 4.82 usr +  5.18 sys = 10.00 CPU) @ 437.30/s (n=4373)
       One: 13 wallclock secs (12.92 usr +  0.01 sys = 12.93 CPU) @  4.87/s (n=63)
      Five: 13 wallclock secs (13.39 usr +  0.00 sys = 13.39 CPU) @  5.15/s (n=69)
      Four: 10 wallclock secs ( 4.74 usr +  5.56 sys = 10.30 CPU) @ 443.69/s (n=4570)

##</code><code>##

#!/usr/bin/perl -w
use strict;
use Benchmark;
my $testlarge = "a " x 100000;
my $testsmall = "a b c d e f";
timethese(-10,{
        One   => sub { my ($y) = (split(/\s+/,$testlarge))[0]; },
        Two   => sub { my ($y) = (split(/\s+/,$testsmall))[0]; },
        Three => sub { $testsmall =~ /([^\s]*)\s+/; my $y = $1; },
        Four  => sub { $testlarge =~ /([^\s]*)\s+/; my $y = $1; },
        Five  => sub { my  $y  =  split(/\s+/,$testlarge)      },
        Six   => sub { my ($y) =  split(/\s+/,$testlarge,1)    }
              });