Not another ranking system post...But kind of?

I would like to see something that would track a players improvement.

Such as:
When I started reach I’d be getting my -Yoink- kicked because I stopped playing video games for oh so long. Now however I am getting much better and going 20 and 10 and such … However my BPR is only 54/100 and that is because all my bad games from the past, are being averaged with all of my better games from the present. I would like a monthly KD ratio or a monthly BPR on top of the total ones. Something along those lines