We updated it after season 1. I don't have a pretty graph handy, but the breakdown by percentage of players is...

Bronze: 8% Silver: 35% Gold: 35% Platinum: 15% Diamond: 8% Master: 1%

Yeah, I typo'd it the first time but fixed it when I added the edit a few minutes later. You read fast. ;)

Feels, basically.

We aren't aiming for a normal distribution, but rather one that makes sense and feels good for the majority of players. High ranks should feel exclusive, but not impossible to reach, while lower ranks should allow for movement while still containing the majority of players.

For bronze specifically, no one wants to be in the bottom tier, but someone has to be on the bottom. So, bronze exists, but is a relatively small number of players.

This is the rank distribution, not the MMR one. MMR distribution follows a normal curve.

It uses both. MMR is the primary match, but because players can't see MMR, it also tries to put players of similar rank together since rank is the only visible indication of skill currently.

It's a perception consideration. Players get upset when they see people of different rank in their games, even if they're the same MMR.

It's the primary argument for getting visible MMR in-game.

There are downsides to showing MMR.

MMR is just a measurement. Its simply a representation of skill that the system can use to put people of similar skill together in a game. In a perfect world, MMR only moves as a player's skill changes, which is to say, it doesn't change much for most players and when it does change, it does so pretty slowly. Getting better at the game takes practice and time.

When MMR is visible, though, it gets viewed as a reward system rather than a measurement. It becomes a focus for players to "increase their MMR" instead of working to increase their skill, despite the fact that increasing skill is how you increase MMR. That can then lead to frustration when MMR doesn't increase quickly and, worst case, it can lead to players trying to find ways to artificially increase MMR. Most of the time, that doesn't pan out, but even if they were to find a reliable way to boost their MMR, all they're doing is creating worse matches for themselves and people matched with them.

So, we show rank instead of MMR. Rank IS meant as a reward mechanism. It's linked to your MMR, but allows more movement than MMR so you can go on a win streak and spike your rank up a bit, which feels good without hurting matchmaking quality since your MMR isn't spiking in the same way.

This whole thing has led to many long, and often heated, discussions about whether showing MMR is a net positive or net negative, but overall we'd like to make it visible in a way that doesn't put a lot of focus on it. Then we can stop taking rank into account for matchmaking at all and do it purely on MMR. Doing so comes with potentially significant downsides, though, so it hasn't been a high priority item.

Happy to answer. I enjoy these conversations, just don't get an opportunity very often. :)

I should make clear that the rank consideration is secondary. MMR is the primary matching mechanism. The system first tries to find players of similar MMR and rank to make matches. If it can't, it first expands the range of ranks it will consider while still trying to make tight MMR matches.

So, if your rank and MMR differ significantly (which doesn't happen a lot due to the effect of PRA), the impact is primarily on increased queue times for that player instead of match quality.