When a player joins the server, assuming mp_force_assign_teams is set to 0, the player has to pick a team and if they don't, they get a randomly assigned team in like 15 seconds.
I wanted to change this behavior somehow to assign players that are not choosing a team into the spectator team, but couldn't find any cvar or a sourcemod plugin at least for that. So, is this possible without creating a new plugin from scratch?