tl;dr We limit the information exposed across teams prior to a match because it can influence match outcomes and make games less fun.

Information exposed to players before a game begins anchors their perception about how the match will play out and can change how they play. The most obvious example of this is with ranked status. Playing against someone who has a higher skill from the previous season, even if you’re currently equal in skill, can be intimidating in a way that influences the end result of a lane. Given that, we default to not exposing skill information across teams.

In the case of champion mastery, while we don’t think the effect would be as pronounced as with ranked borders, it would likely have a similar negative impact in some games. For example, knowing it’s your first game on a champ and facing up against a mastery 7 Yasuo isn’t a great experience. When we weigh the negative impact of surfacing this every match-up against the pretty minimal benefits that come from the opposing team knowing exactly how big your emote is, it doesn’t seem worth the trade.

There is some gray area around this. Some of you might be thinking: dropping the emote in game when you go to lane seems like it could anchor players in a similar way, so why allow that? We debated this when we first launched emotes and even created an emergency switch we could flip to make it only appear for your team if things got out of hand. Ultimately the decision to leave it cross team came down to two things. 1. For the most part, people don’t drop their emote right when they get to lane. Usually by the time an emote gets dropped much of the game has already unfolded, so any impact to match outcome is minimal in aggregate. 2. Some of the most interesting and memorable moments across teams are highlighted emote drops. Preserving those moments felt important.

Along these same lines, we know many players scout one another via third party sites to determine opponents rank before games. This is a natural result of ranked game stats being public information and some players looking for any way to get a competitive edge. In spite of this, we wouldn’t change the pregame to give this information more visibility. Though some players want this information, we don’t believe forcing more players to absorb it would ultimately make the game more fun.