The Dota 2 Competitive Hero Tier List for May 2018 includes data from 7.14 and 7.15, for a total of 253 games. All heroes are split in five groups.
The Dota 2 Competitive Hero Tier List for March 2018 includes data from 7.10 and 7.11, for a total of 587 games. All heroes are split in five groups.