#! perl; -slw
use strict;
use Data::Dump qw[ pp ];

my @a = (
    [ qw[ A BBL 0.2 ] ],
    [ qw[ B BBH 0.3 ] ],
    [ qw[ C BB 0.1  ] ],
);

my @ordered = sort{ $b->[ 2 ] <=> $a->[ 2 ] } @a;

pp \@ordered;

__END__
c:\test>junk.pl
[["B", "BBH", "0.3"], ["A", "BBL", "0.2"], ["C", "BB", "0.1"]]