Dota 2 may replace the ranking system
Valve, Dota 2 developer, may add to the game ranking system Gliko. The information came from a dataminer with the nickname DOTA_DM.
At the moment, Dota 2 uses the ELO system. It gives or takes away a fixed number of MMR points. Single players get 30 points for winning, and group players get 20 points.
The Gliko system works differently. It is based on coefficients of variation and deviation. The system also takes into account the regularity of matches, with wins after a long break bringing more points and losses less. The system was developed back in 1996. It was first used in chess championships and later added to Team Fortress 2 and CS:GO.