How is Dota 2 MMR calculated after Role Rank is implemented?

As the title suggests, how does Dota 2 calculate the MMR (Matchmaking Rating) after the implementation of the role queue?

I noticed that it is not a simple +25 or -25 MMR. I tracked my MMR and found out that both of my roles' MMR (support & core) changed after the game (in a party of 2 with both members selecting core role).

1 Answer

So the main MMR change will be for the selected role. Lets say you selected core role, and win, you'll get around +25 for this win on your core MMR. But your support MMR will also adjust somewhat, although to a much lesser degree.

The aim of this is to prevent people with great support skills from having a much lower core MMR (or vice versa), when many skills are transferable.