Is the inequality of those within a free system different than "taken opportunity?" What I mean is, I think sometimes that on one level, all people have the same opportunity. As individuals, no, but as parts of our own lineages, we benefit from those who take advantage of opportunity. This opinion is more philisophical than technical, but I think that in a truly free system, all people have the same abilities.
On another note, I thought the 80/20 rule referred to "80% of the work done in 20% of the effort." Could be wrong on that one though.