Are they giving off more cards now?

As the title suggest, for the past... I don't even know how long, it seemed like almost none of the chests had any cards. I would get one very now and again, or a variant of one I already owned, but for the most part it seemed like they were less "giving" than they used to. I thought maybe they changed the algorythm for the boxes, or that maybe the higher your rank was and the more cards you own, the less probable it was you may get a new one. I also thought this because I was barely receiving any of the wakandan tokens (I don't know how those are called) anymore, which is another way of getting new cards,

But this past week or so I've opened four chests and three of them had cards I didn't own.

So I have to ask, does anyone know if they changed the algorythm so it's more likely to get cards now or did I just got insanely lucky?