new skill distribution curve

They will never openly state how they assess skill because players would use that information to manipulate their match quality (at least in theory they would - the truth is that the matchmaking in this game is too loose to allow for much active manipulation, and is even worse now with seemingly everyone playing on a secondary).

But it really isn't too hard to reverse engineer their formula by simply playing the game and observing the effects of your performance on your match quality. It was a lot easier to do this early on in the game before all the secondaries took over. Now it's harder. And the dev changes the secret sauce every now and then just to mix things up even more.

But essentially it's all the things you would expect it to be plus one that you wouldn't. The obvious: k/d, win rate, maybe accuracy, and I'm pretty sure also your quit rate. The unexpected data that I'm pretty sure they use is your average match length.

And when all is said and done, the game doesn't have a picture of you that says, "Okay this guy's good at cqc, bad at midrange, doesn't know how to drop, but does know how to rotate, etc." It simply averages all the data and assigns you a number. Then that number has a stickiness to it where it will change if it thinks you're improving, but will change more slowly if it thinks you're deteriorating. Because players don't typically get worse over time. They sandbag to try and convince the matchmaker that they're less good than they really are, but it mostly won't work unless you are seriously tenacious. And quit a lot. And fire your weapons randomly into the air for no reason. And then if you have one single god-like match then you'll snap right back to the mmr you had before you put weeks into lowering it.

Anyone please add if I've forgot anything, or tell me I'm full of it if this doesn't describe your experience.