Guild Wars 2

The Solo Arena in sPvP is absolutely littered with people who, while they may be excellent players in PvE and WvW, have clearly never played PvP before. They do not attempt to cap, cannot figure out how to coordinate attacks, do not respond when prompted or asked to cap something, or better yet respond with hostility to people trying to strategize for the good of the team.

As a solution to this, I would recommend:
1. Impose limitations on who can participate in Arena PvP. This would mean that a player looking at Arenas (Solo at the very least) would need some amount of time or score spent in hot-join before they were allowed into the higher-level. Other games, like SMITE or League of Legends do this; they do not allow new players into their ranked, high-level play.
2. Make it possible to report people who are toxic to the team or who leave early; those people who respond with hostility to team members or flat out refuse to do what the team needs done to win. Again, this system is in other PvP focused games.