Pro players, say goodbye to your 13,000 MMR.
New strings in the Dota 2 depository seems to indicate a switch to the Glicko rating system, according to Github user muk-as.
The defining characteristic of a Glicko-based system is the presence of ratings deviation (RD) — a confidence check on whether a player’s rating is currently accurate. This factor is largely influenced by how active a player is — a player whose last played game is a year ago will have a large RD, which means the system isn’t confident that their rating is accurate. This player could experience large swings in their rating, since the system is trying to quickly but accurately calibrate their skill level for balanced matchmaking.
Conversely, an active player who plays ten games a day will likely have a low RD, and thus will experience less drastic changes to their MMR.
You can read more about Glicko here.
How will Dota 2 change with a Glicko-based ranked system?
It remains to be seen how Valve will implement the system. Glicko and Glicko-2 are both in the public domain, which means that they could be wholesale transplanted into Dota 2 — or receive further modifications to suit the game’s unique, role-based nature.
Dota 2’s ranked system has undergone several changes over its lifespan to arrive at its present iteration.
The current system for Dota 2 sees every game featuring a static amount of MMR gain or loss — 30 for solo queue games, and 20 for party queue. While no system can be perfect, it’s no surprise that static gains have caused an ever-widening gulf for players at the top. A 13,000 MMR pro player would be Immortal — the same as a person at 6,000 MMR, with a difference that more than encapsulates the entire rank progression from Herald to the beginning of Immortal.
Several Valve games already use the Glicko rating system, including CS:GO, Team Fortress 2, and Dota Underlords.