With the exception of Showdown matches, you will notice that there's always a Star Player selected at the end of every match.
This rewards the most vital player of the match for their efforts in battle. A Star Player is chosen based on:
Game mode objectives
Kills
Damage dealt
Damage received
Healing done
At the end of the day, winning relies on teamwork, which is why being a team player is the best way to be crowned Star Player!
Star Players are rewarded with extra Mastery Points for their Brawler!