Overwatch's 21st competitive season began on March 5th, and with it came the introduction of hero pools. Each week, one tank, one support, and two DPS heroes will be removed entirely from competitive play. Kicking off the new season and system, the first ever banned heroes are Orisa, Baptise, Hanzo, and Mei.
The Overwatch League, which also recently implemented a hero pool system, revealed its first banned heroes at the end of the fourth week of the season's Houston homestand. Heroes eligible to be removed from competition were first narrowed down to those with a total playtime of 10% or more. From that pool, the league's first bans — Reinhardt, Moira, Widowmaker and McCree — were selected.
Hero bans in the general Overwatch client's competitive mode are chosen differently from the method utilized by the Overwatch League. In lieu of introducing a random element, the development team hand-picks the heroes that will be disallowed each week. That said, no hero can be banned for more than two weeks in a row, so players struggling with a specific meta emergent from one week's hero bans can expect their comfort hero to return within two weeks at maximum.
Orisa and Baptise were likely chosen due to their synergy in a bunker composition, in which a stationary, turret-form Bastion is a team's primary source of damage. Though Orisa's shield has been nerfed multiple times across a few recent game patches, effectively removing bunker compositions from frequent use, the combination of her shield and Baptiste's immortality field is nonetheless a strong one that will now see no playtime during the new competitive season's first week.
In both the Overwatch League and general Overwatch play, Mei has recently become a must-pick in many scenarios due to the wide-ranging utility. While she has her fair share of fans, an equal if not larger numbers of players find her freezing-based abilities particularly frustrating to play against. All of those players can now partake in the first ever period of time in which competitive mode is Mei-free.
Season 21 is now live across all platforms. Hero pools only effect competitive play, which means that all other game modes remain the same.
Source: Reddit