I remember playing in a 6 v 6 tournament a few years (okay almost a decade) ago and the championship game did that. If it was tied each team removed a player after every 15 minutes (or 10 or something). I think it could get down to 3 v 3. Of course this was using the smaller goals and not regulation ones, but it was very interesting. You had to completely rethink the way you played.
