#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11124600
use warnings;

my $line;
my @teams;

while ( $line = <DATA> )
  {
  chomp $line;
  if ($line =~ /^#/ || $line =~ /^\s*$/) 
    {
    next;
    }
  $line =~ s/^[^=]*\=//;

  push @teams, map [ split /,/ ], "$line," =~ /((?:.*?,){1,3})/gx;

  }
use Data::Dump 'dd'; dd \@teams;

__DATA__
Teams=PATRIOTS,BILLS,DOLPHINS,JETS,COWBOYS,GIANTS,EAGLES,REDSKINS,BENG
+ALS,OILERS,STEELERS,BROWNS,SEAHAWKS,RAMS,49ERS,RAIDERS
[download]

Outputs:

[
  ["PATRIOTS", "BILLS", "DOLPHINS"],
  ["JETS", "COWBOYS", "GIANTS"],
  ["EAGLES", "REDSKINS", "BENGALS"],
  ["OILERS", "STEELERS", "BROWNS"],
  ["SEAHAWKS", "RAMS", "49ERS"],
  ["RAIDERS"],
]
[download]