As far I know the ranking list only counts saved points. 20 kills without to save your points means nothing in your progress to level up and also in the rankings it makes no different.

How to save your points you can see here.

But you can save the way. Zuperman changed the point system recently, so is no need to save points. Now is a kill a kill and will be a part of your rank and a step of your way to MoRAF. And if you kill a Marshal you'll get much more points than killing a wing commander. So always watch out for zebras.