I'm looking at pulling a blog post together at least. To answer some of these quickly...

• Uncertainty doesn't exist in the same form in the new system. The core concept of something that limits how much MMR can adjust on a per-game basis is there, but the factors that go into it are different.

• The most important thing is still winning the game. That hasn't changed. Sometimes, that means sticking to heroes you know really well. Other times, that means having flexibility in your hero roster and playing the heroes that best fit the situation.

• Drafting matters in the same way as the above statement. Drafting is a skill and how well you draft affects your win rate.

• We have great insight into what parameters are used...but aren't going into that level of detail externally.

• We'll add more parameters as it makes sense.

• We have more than enough data on all existing heroes. For new heroes or major reworks, the performance-based adjustments will basically be disabled until enough data exists.

• It will apply to all game modes that have MMR.

We won't have visible MMR for this update, but I do still want to do it in the future.

For now, you'll mainly see the effects through rank points. We're planning to swap out personal rank adjustment for a more direct performance adjustment which will give better insight while filling a similar role of keeping rank close to MMR. I'm not sure right now whether that will be for this season or the next yet.

Quite right. For the "who determines which stats are important", its the players. We've chosen the stats to monitor, but which ones are important for that situation is something we are measuring, not determining ourselves.

Time is factored into the measurements. If you're dead for the last few seconds of a match, there wouldn't be any measurable impact relative to everything else that happened that game.

No. You'll only gain points on a win and lose them on a loss.

If you get full carried for a game, you won't lose points, but you also aren't going to gain very many either.

Very different system with very different goals.

It's about speed more than accuracy.

The current system, based entirely on wins vs loses, works, but because your skill is diluted in a team of 5, unless you are dramatically better (or worse) than the rest of the team, it can take a large number of games before the difference in skill translates to more wins (or loses) and moves your MMR to where it should be.

By factoring in individual skill to the equation, it can arrive at the proper MMR much faster which means the matchmaker can make better matches overall.

Spot on and part of why visible MMR hasn't been a big priority for us.

But, there are some advantages to it.

• Currently, rank is the only visible indicator of skill. This forces us to link rank to MMR so they don't diverge too much because players get upset when they see people of different rank in their games even if they are actually the same skill. That's not ideal and leads to oddities with matchmaking when rank and MMR do diverge.

• Even though we don't show MMR, players have created other sources to approximate their MMR. The information isn't very accurate, but being the only source of knowledge, it gets cited frequently when players feel there are issues with matchmaking. There's two issues here: first, it gives a false impression that matchmaking is poor for some players and second, it makes it harder to understand when there are actually issues with matchmaking since the real issues can get buried. Effectively, for players that really care about MMR, we already have most of the downsides associated with visible MMR without having the upsides of it being accurate information.

That's a tuning point we haven't settled on yet.