new skill distribution curve

The white line that rises from left to right until it hits the middle and then falls off again... that's the skill curve for the game and represents the typical number of players at a given skill level. The line is low on the left, meaning there are relatively few completely unskilled players. It rises to a high point in the middle, the statistical average, where most players live. And then it falls off again to the right, representing a dwindling number of players who are higher-skilled. And cheaters.

The grey area represents the span of skill within this particular match. It's a team average, not individual skill. There will normally be individual players who fall outside the grey area, most commonly in "average" skill level matches, where also worth noting, the grey area is typically much wider than in the above example.

The red line represents the average skill of your squad. In this example it's a tight average because the entire lobby is tight. In more typical "average" skill matches things are much more all over the place. People seem to assume that the red line is their personal spot on the scale and are puzzled at why it moves so much from match to match. Again, it's an average, not an individual. If you want to know your individual place on the curve, your hidden mmr if you will, then just go into a no-fill trios match. The red line will represent only you and it will be in the same place every time. Basically, this tells you your rank without having to go through the grind and humiliation of playing ranked matches. Maybe that's not a selling point for you, maybe it is. You be the judge. I personally hate ranks, so for me it's a great short cut.

The most important thing to remember about the data they're showing you is that it all represents team averages, and again, that means that in a lobby of normal players (not the masters and predators in the above example) you'll see a wider grey area. This means a wider array of skills in the match, and many players who are both above and below the range of averages. Basically it's telling you that the matchmaking in the part of the skill range where most players live... is shockingly loose. Which explains why you will destroy some squads and turn around only to be instantly vaporized by another. It also reaffirms what all solo queue players have always known: the matchmaker "balances" a lobby of solos by putting together a squad out of one highly experienced player, one moderately experienced player, and one inexperienced player. Assuring that if there's any three stack in the lobby at all, even a stack of moderate skill, they will probably dominate the match. Unless the randoms mic up and have common match goals and play styles. Which they don't, don't, and don't.

Best of luck. You're gonna need it. We all will.