Less than 10% of accounts are calibrated in Dota 2
The Esports data analytics company Stratz shared information about the total number of registered Dota 2 accounts and how many of them are calibrated for ranked matchmaking. As it turned out, after the rating was reset in September 2019, only 9% of all users were calibrated.
According to the portal, about 6.5 million accounts have been calibrated now. The largest number of the users play at Archon and Crusader ranks, which is about 3 million accounts. About 68,000 players compete at the highest level — Immortal. It is worth noting that most professional players started their careers with the World Leaderboards based on their MMR score.
Of course, this doesn't mean that at the moment, only 6.5 million active users play Dota 2 because some players don't play ranked matchmaking at all.