Was more interested interested post '95 if everyone started on equal points.  No idea how the original rankings were created.

The issue I have the rankings is team can be pretty much dominant for a short period of time and not be reflected in the overall result.  If England/Ireland were to win every game this year and beat NZ in the final they'd probably still only be ranked 2nd.  In fact in all likelihood they'd still be ranked 2nd is they completed a grand slam (please note I'm guessing with NZ's 8 point cushion they have on those two teams) next 6 nations only really be allowed to wrestle for  it in the following summer internationals.  Even then one loss during those internationals would probably leave NZ top.

The problem with a rankings system is whilst they work extremely well if teams are evenly matched but if a team build up a cushion it takes forever to topple them.  Australia did it with Cricket.  Between 2009-2011 England lost zero tests series (unless you include WIdies debarcle 2008/9) however despite this they were only made 1st in rankings at the end of that period and because they didn't build a cushion lost it pretty quickly.

The rankings work to some degree but will reward NZ for a long time even after this period of total dominance ends (which it will), there's where I have a problem with them.  It's less now when it shows that NZ have been a dominant team for an extended period of time but 2 years from now and they still top ranked despite other teams having a better win %age than them and against them.